Ischemic heart failure

Article written and reviewed by Dr Luca Moretti

Ischemic heart failure is the clinical syndrome in which atherosclerotic coronary artery disease, one or more myocardial infarctions, persistent or recurrent ischemia, and the consequences of post-ischemic remodeling contribute substantially to the heart's inability to maintain an output adequate for the body's needs without a pathological increase in filling pressures. It is one of the main points of convergence in the natural history of ischemic heart disease: a process initially confined to the coronary arteries progressively becomes a disease of the myocardium, ventricular geometry, mitral apparatus, electrophysiology, and ultimately the entire circulatory system.

The term must not be used automatically as a synonym for low ejection fraction. A patient with coronary artery disease may develop heart failure with a reduced, mildly reduced, or preserved ejection fraction, and the causal relationship between ischemia and heart failure must be reconstructed through history, ECG, imaging, coronary anatomy, and myocardial characteristics. The classic form is nevertheless post-infarction HFrEF, in which cardiomyocyte loss, scar, and dilation cause progressive systolic dysfunction.
It is also necessary to distinguish three frequently overlapping concepts: ischemic cardiomyopathy, which describes the structural phenotype of ventricular dysfunction attributable to coronary artery disease; ischemic heart failure, which describes the clinical syndrome; and dysfunctional but viable ischemic myocardium, in which contractility is reduced without complete irreversible necrosis. This distinction has diagnostic and therapeutic implications, particularly when assessing revascularization.

Coronary artery disease remains among the most frequent causes of heart failure in contemporary registries. Risk increases with the number of infarctions, extent of multivessel disease, involvement of the left main or left anterior descending artery, diabetes and kidney disease, delayed reperfusion, and persistent exposure to atherogenic factors. Prognosis is further influenced by age, frailty, right ventricular function, and the ability to implement disease-modifying therapy at effective doses.
The modern paradigm has moved beyond the idea that ischemic heart failure can be treated simply by 'reopening the coronary arteries.' Revascularization may be essential in defined anatomical and clinical settings, but ventricular disease simultaneously requires neurohormonal therapy, SGLT2 inhibition, congestion control, atherothrombotic prevention, devices when indicated, and rehabilitation. In patients with extensive scar, perfect revascularization does not recreate lost myocardium; conversely, in the presence of viable ischemic myocardium, it may improve perfusion, symptoms, and sometimes function.

The assessment must therefore answer different questions: how much heart failure is truly attributable to coronary artery disease; what proportion of dysfunction is irreversible; whether inducible ischemia or high-risk anatomy is present; whether the patient has a prognostic indication for CABG; whether an arrhythmic substrate requires an ICD or ablation; whether QRS duration and ventricular mechanics indicate CRT; whether secondary mitral regurgitation, ventricular thrombus, or pulmonary hypertension is present; and which comorbidities limit the use of therapies.

Etiology, pathogenesis, and pathophysiology

The fundamental event is the loss or dysfunction of contractile myocardium. During infarction, prolonged ischemia causes energy depletion, loss of ionic homeostasis, mitochondrial injury, and cardiomyocyte death. Replacement with scar tissue preserves the mechanical integrity of the wall but does not contribute to contraction. The ventricle must therefore generate the same output with reduced functional mass, increasing stress on the remaining regions.
The relationship between necrosis and function is not linear. Small infarctions in strategically important locations may substantially impair global performance, whereas larger scars may be partially compensated for years. Scar transmurality, distribution relative to the longitudinal axis, involvement of the septum and papillary muscles, and right ventricular function influence the final phenotype.

In the hours and days after infarction, an inflammatory response necessary to remove necrotic tissue is activated. Neutrophils, monocytes, and macrophages participate in phagocytosis and subsequent repair. Transition to a controlled reparative response allows collagen deposition and scar maturation; an excessive or persistent response may promote infarct expansion and adverse remodeling.
Remodeling includes changes in wall size, shape, thickness, and composition. The ventricle tends to become more dilated and spherical. According to the Laplace relationship, an increase in chamber radius increases wall stress at the same pressure, imposing further work on the remaining myocardium. A cycle in which dilation and dysfunction perpetuate one another is thereby established.

At the cellular level, noninfarcted myocardium develops hypertrophy, abnormalities of excitation-contraction coupling, mitochondrial dysfunction, and changes in energy metabolism. Ion channel expression, sarcoplasmic calcium handling, and beta-adrenergic sensitivity change. The progressive loss of mechanical efficiency is therefore the result of profound biological reorganization, not merely the sum of scarred segments.
Activation of the renin-angiotensin-aldosterone system and sympathetic nervous system initially supports pressure and perfusion, but over the long term it promotes vasoconstriction, sodium retention, increased afterload, fibrosis, hypertrophy, apoptosis, and arrhythmogenicity. The rationale for neurohormonal therapies derives precisely from the need to interrupt these chronically maladaptive compensatory responses.

Reduced output and increased venous pressures stimulate renal retention of sodium and water. Congestion is not solely a problem of absolute volume: rapid redistribution of blood toward the pulmonary circulation may cause edema even without a large increase in body weight. Elevated filling pressures also impair kidney and liver function and contribute to exercise intolerance.
The concept of stunning describes reversible contractile dysfunction that persists after restoration of blood flow in the absence of irreversible necrosis. Free radicals, calcium overload, and abnormalities of contractile proteins contribute to the phenomenon. It is particularly relevant after reperfusion of an infarction and may explain recovery of function that occurs over the following days or weeks.

Hibernating myocardium, by contrast, is a phenotype of chronic dysfunction associated with reduced perfusion or, more commonly, repeated ischemic episodes and reduced coronary reserve, in which the tissue remains viable but reduces its function to adapt to an energetically unfavorable environment. Hibernation may be associated with structural cellular changes and does not imply that recovery after revascularization will be immediate or guaranteed.
The microcirculation makes an important contribution. Even after an epicardial coronary artery has been reopened, microembolization, edema, endothelial injury, capillary obstruction, and intramyocardial hemorrhage may cause microvascular obstruction. The presence of MVO after STEMI, documented by magnetic resonance imaging, is associated with a larger infarction and adverse remodeling.

Ischemic scar is also an electrical substrate. Islands of surviving myocardium among fibrotic areas form channels of slow and heterogeneous conduction capable of sustaining reentry circuits; for this reason, ischemic heart failure and the risk of monomorphic ventricular tachycardia are closely linked, especially when the scar is extensive and ejection fraction is reduced.
Remodeling alters the mitral apparatus. Annular dilation, displacement of the papillary muscles, and leaflet tethering may cause secondary ischemic mitral regurgitation even in the absence of a primary leaflet lesion. Regurgitation increases volume overload and may further accelerate ventricular dilation.

Right ventricular dysfunction may result from right ventricular infarction, postcapillary pulmonary hypertension, ventricular interdependence, or diffuse disease. When it develops, it generally identifies a more advanced phenotype and reduces tolerance of vasodilator drugs and changes in preload.
In patients with preserved ejection fraction, coronary artery disease may contribute to heart failure through subendocardial ischemia, ventricular stiffness, hypertrophy, and endothelial and microvascular dysfunction. In these cases, causal attribution is more complex because age, hypertension, obesity, diabetes, and atrial fibrillation share many of the same pathophysiological pathways.

Clinical manifestations

The cardinal symptom is dyspnea, initially during more strenuous exertion and subsequently during ordinary activities or at rest. Increased left ventricular filling pressures are transmitted to the pulmonary veins and reduce lung compliance. Orthopnea and paroxysmal nocturnal dyspnea suggest a more marked congestive component, but their absence does not exclude heart failure.
Fatigue and reduced functional capacity result from inadequate cardiac output during exercise, muscle deconditioning, peripheral abnormalities in oxygen utilization, anemia, and comorbidities. Symptom severity does not correlate perfectly with ejection fraction: patients with a very low LVEF may be relatively compensated, whereas others with moderately reduced values may be severely limited.

Systemic congestion causes elevated jugular venous pressure, dependent edema, hepatomegaly, ascites, and weight gain. Cardiac cachexia may develop in advanced stages. Examination must distinguish congestion from hypoperfusion because treatment of a 'wet and warm' patient differs from that of a 'cold' patient with low output.
Angina may coexist with heart failure, but its absence does not exclude ischemia or severe coronary artery disease. Patients with diabetic neuropathy, previous infarction, or reduced physical activity may not report pain. Dyspnea and exercise intolerance may be the only clinical expression of ischemia.

An exacerbation may be precipitated by a new acute coronary syndrome, rapid atrial fibrillation, infection, anemia, uncontrolled hypertension, poor adherence, excess sodium, drugs that promote sodium and water retention, kidney failure, or ventricular arrhythmias. Identifying the precipitating factor is as essential as treating congestion.
Physical examination assesses blood pressure, rate and rhythm, peripheral perfusion, crackles, jugular venous distention, hepatojugular reflux, edema, and signs of valvular disease. An apical holosystolic murmur may suggest secondary mitral regurgitation; a third heart sound identifies elevated filling pressures or systolic dysfunction but is not always present.

The history must reconstruct previous infarctions, revascularizations, known coronary anatomy, hospitalizations for heart failure, therapies, and adherence. Chronology is important: a reduced LVEF immediately after infarction may partially recover as stunning resolves, whereas dysfunction persisting after months of therapy suggests a more stable substrate.

Investigations, diagnosis, and definition of the ischemic substrate

A diagnosis of heart failure requires compatible symptoms or signs associated with objective evidence of cardiac dysfunction. BNP and NT-proBNP are particularly useful for ruling out heart failure when low, whereas elevated values support the diagnosis but are not specific. Age, atrial fibrillation, kidney failure, and other conditions may increase them; obesity may reduce them.
Transthoracic echocardiography is the fundamental initial examination. It measures ejection fraction, volumes, right ventricular function, estimated pulmonary pressures, valves, and filling patterns. Regional wall-motion abnormalities in coronary territories support an ischemic etiology, but advanced cardiomyopathy may become globally hypokinetic.

LVEF must be interpreted together with volumes and not as the sole indicator. A severely dilated ventricle with an LVEF of 30% differs from a minimally dilated ventricle with the same ejection fraction. Global longitudinal strain may identify subtler dysfunction and contribute to follow-up, although it does not replace validated criteria for ICD and CRT.
Cardiac magnetic resonance imaging with late gadolinium enhancement characterizes scar. A subendocardial or transmural pattern distributed according to coronary territories is typical of ischemic injury and helps distinguish other cardiomyopathies. LGE transmurality provides probabilistic information on the potential for contractile recovery after revascularization.

CMR also identifies edema, thrombi, aneurysms, MVO, and ventricular function with high reproducibility. Scar amount and heterogeneity have prognostic and arrhythmic value, but thresholds for ICD implantation remain based primarily on criteria derived from trials, not on a single LGE cutoff.
Documentation of coronary anatomy is necessary when the ischemic etiology is not already known or when revascularization might change management. CCTA may be useful in selected patients whose probability is not high and in whom good examination quality is expected; invasive coronary angiography is preferred when probability is high, symptoms are significant, or an intervention is anticipated.

Imaging of ischemia and viability may be performed with PET, SPECT, stress echocardiography, or stress CMR. FDG PET assesses glucose metabolism and may identify perfusion-metabolism mismatch; low-dose dobutamine assesses contractile reserve; LGE CMR estimates scar transmurality. The different methods interrogate different biological aspects.
The concept of viability must not be turned into a binary rule. In STICH, the presence of viability did not convincingly identify a subgroup with a different survival benefit from CABG; in REVIVED-BCIS2, patients with LVEF ≤35%, extensive coronary artery disease, and viability did not obtain a reduction in death or hospitalization for heart failure from PCI added to optimal therapy. The decision must therefore integrate anatomy, symptoms, risk, and revascularization strategy.

The ECG looks for Q waves, bundle branch blocks, QRS duration, atrial fibrillation, and signs of ischemia. QRS is essential for evaluating CRT; an extensive anterior scar and left bundle branch block may produce particularly important mechanical dyssynchrony.
Laboratory testing should include complete blood count, creatinine and electrolytes, liver function, blood glucose/HbA1c, lipid profile, ferritin, and transferrin saturation in patients with HF, as well as TSH when indicated. Potassium and kidney function are indispensable for titrating RAAS inhibitors and mineralocorticoid receptor antagonists.

Cardiopulmonary exercise testing quantifies functional capacity and the mechanisms of limitation. Peak VO2, the VE/VCO2 slope, and blood pressure response are particularly important in patients with advanced disease and in evaluation for transplantation or ventricular assist devices, but they must be interpreted in the clinical context.

Pharmacological treatment, revascularization, and devices

Treatment of ischemic HFrEF must begin early with the four foundational classes of disease-modifying therapy: an ARNI or ACE inhibitor/ARB, an evidence-based beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor. The contemporary strategy favors rapid introduction of the classes at tolerated starting doses followed by titration, instead of waiting months to complete a rigid sequence.
Sacubitril/valsartan reduces the risk of cardiovascular death and hospitalization for heart failure compared with enalapril in symptomatic HFrEF. In patients unable to take an ARNI, an ACE inhibitor or ARB remains an appropriate option. Blood pressure, kidney function, potassium, and a history of angioedema influence selection and titration.

Beta-blockers with prognostic evidence in HFrEF include carvedilol, bisoprolol, and extended-release metoprolol succinate. They should be started in clinically stable patients and not during shock or severe uncontrolled congestion. By reducing heart rate, oxygen consumption, and adrenergic activation, they have a particularly strong rationale in the ischemic phenotype.
Spironolactone or eplerenone reduces mortality and hospitalizations in appropriate patients with HFrEF. Eplerenone has specific evidence after infarction in patients with ventricular dysfunction and heart failure or diabetes. The principal risks are hyperkalemia and worsening kidney function, which require close monitoring.

Dapagliflozin and empagliflozin reduce heart failure events in HFrEF regardless of the presence of diabetes. The effect appears early and is associated with renal benefits. In the 2026 ESC guidelines, SGLT2 inhibitors are recommended for heart failure both with LVEF <50% (HFrEF) and with LVEF ≥50% (HFpEF); in HFpEF, the reduction in the composite endpoint is driven mainly by fewer hospitalizations for heart failure.
Loop diuretics control congestion but do not replace prognostic therapies. The dose must be adjusted according to weight, symptoms, perfusion, kidney function, and diuretic response. In diuretic resistance, sequential nephron blockade strategies may be used in selected patients with careful electrolyte monitoring.

Hydralazine combined with nitrates remains indicated in specific populations and when RAAS inhibition is not feasible. Ivabradine may reduce hospitalizations in selected patients in sinus rhythm with LVEF ≤35% and a persistently elevated heart rate despite maximally tolerated beta-blockade. Digoxin may reduce hospitalizations in some symptomatic patients but requires attention to kidney function, interactions, and toxicity.
Atherosclerotic prevention remains indispensable. A high-intensity statin and the addition of ezetimibe, a PCSK9 inhibitor, or other drugs when necessary must pursue the appropriate lipid targets. After infarction or in established coronary artery disease, antithrombotic therapy follows specific indications and bleeding risk; anticoagulation is not indicated simply because LVEF is low in sinus rhythm.

Intravenous iron is recommended or considered in patients with symptomatic HFrEF and iron deficiency according to guideline criteria, to improve symptoms and quality of life and reduce the risk of hospitalization. Correction with oral iron does not produce the same documented benefit in this setting.
Revascularization must be distinguished by strategy. In the extended follow-up of STICH/STICHES, CABG added to medical therapy in selected patients with LVEF ≤35% and coronary artery disease amenable to surgery reduced long-term mortality. The benefit emerges over time and must be balanced against perioperative risk.

REVIVED-BCIS2, by contrast, showed that in stable patients with severe ventricular dysfunction, extensive coronary artery disease, and documented viability, PCI added to medical therapy did not reduce death or hospitalization for heart failure and did not produce significant sustained recovery of LVEF compared with medical therapy; these data prevent automatic extrapolation of the CABG evidence to PCI.
PCI remains appropriate when an acute coronary syndrome, refractory angina, treatable anatomy with a symptomatic indication, or other clinical reasons are present. The point is that PCI must not be prescribed solely with the expectation of 'raising the ejection fraction' in every patient with viable myocardium.

An ICD is indicated for secondary prevention after VT/VF not due to a reversible cause and for primary prevention in selected patients with ischemic heart disease and persistently reduced LVEF despite optimal therapy, after the specified time intervals following infarction and revascularization. Implantation too early after infarction has not shown the survival benefit observed in the chronic phase.
CRT is particularly effective in patients with HFrEF, an appropriate rhythm, and left bundle branch block with a markedly prolonged QRS, when symptoms persist despite optimal therapy. Benefit is smaller and more selective with non-LBBB morphologies or narrower QRS complexes. The presence of a posterolateral scar may reduce response and influence lead placement.

Secondary mitral regurgitation first requires optimization of heart failure therapy and, when appropriate, CRT. In patients who remain severely symptomatic with significant regurgitation and favorable anatomy, transcatheter edge-to-edge treatment may reduce hospitalizations and mortality in populations similar to that of the COAPT trial. Selection is crucial, and not every case of secondary MR has the same relationship between regurgitation severity and ventricular disease.
Cardiac rehabilitation integrates exercise, therapeutic optimization, education, and risk factor control. Training improves functional capacity and quality of life and may reduce hospitalizations. In more frail patients, it must be started with individualized assessment and controlled progression.

In refractory advanced heart failure, replacement or support therapies, including an LVAD and heart transplantation, must be considered at specialist centers. Age, comorbidities, right ventricular function, pulmonary hypertension, frailty, and social support influence eligibility. The presence of coronary artery disease does not itself exclude these strategies.

Complications, follow-up, and prognosis

Exacerbations are the most frequent complication and are associated with a period of vulnerability carrying a high risk of rehospitalization and death. After hospitalization, the modern strategy recommends optimization of therapy before discharge and early follow-up, with rapid titration of disease-modifying therapies when tolerated.
Cardiogenic shock may result from a new infarction, severe chronic dysfunction with a precipitating factor, an arrhythmia, or a mechanical complication. Treatment requires identification of the cause, urgent revascularization when indicated, hemodynamic management, and individualized selection of vasopressors, inotropes, and mechanical circulatory support.

Ventricular arrhythmias may cause sudden death or repeated ICD therapies. An electrical storm requires correction of ischemia and electrolyte abnormalities, sympathetic control, appropriate antiarrhythmics, and often substrate ablation; in refractory cases, deep sedation or neuromodulation may be necessary.
Atrial fibrillation worsens hemodynamics and prognosis through loss of atrial contraction and increased rate. Management includes anticoagulation according to thromboembolic risk, rate or rhythm control, and consideration of ablation in selected patients with HFrEF.

A dilated ventricle with apical akinesia may develop a left ventricular thrombus, especially after an extensive anterior infarction. Contrast echocardiography and CMR increase diagnostic sensitivity. Anticoagulation is used when thrombus is documented, with individualized duration and follow-up imaging.
Disease progression may lead to kidney failure, congestive hepatopathy, hyponatremia, sarcopenia, and cachexia; these manifestations are not merely comorbidities: they modify treatment tolerability, diuretic response, and prognosis and require multidisciplinary management.

Prognosis is determined by the interaction among scar burden, LVEF, right ventricular function, functional class, blood pressure, kidney function, natriuretic peptides, arrhythmias, and previous hospitalizations. Contemporary therapy can profoundly modify risk, so a prognostic assessment made before optimization must not be considered definitive.
The best strategy is to prevent the transition from infarction to heart failure: rapid reperfusion, intensive LDL reduction, blood pressure and metabolic control, smoking cessation, post-infarction therapy, and rehabilitation reduce the amount of myocardium lost and the likelihood of adverse remodeling. Once heart failure has developed, the same principles must continue to prevent new ischemic events.

Post-infarction remodeling, scar, and the interaction between ischemia and heart failure

Post-infarction remodeling is not a uniform event. In the first hours, infarct expansion may occur, meaning thinning and dilation of the necrotic area without new necrosis, particularly in extensive anterior infarctions. In the following days and weeks, global ventricular changes predominate, with dilation of noninfarcted regions, compensatory hypertrophy, and a progressive increase in sphericity. Early reperfusion limits both processes by reducing necrotic mass and preserving architecture.
Mature scar consists of collagen and extracellular matrix and has mechanical properties different from those of myocardium. If it is too thin and dilated, it may form an aneurysm; if it disrupts electromechanical continuity, it alters the distribution of stress across the remaining regions. Scar geometry is therefore as important as its total mass.

The peri-infarct border zone contains surviving cardiomyocytes exposed to mechanical, neurohormonal, and ischemic stress; these cells may develop hypertrophy, metabolic changes, and interstitial fibrosis. The border zone is important both mechanically and for arrhythmogenesis because it contains channels of slow conduction between fibrotic areas.
Late revascularization cannot transform a transmural scar into contractile myocardium; however, it may protect territories that remain viable, reduce ischemic episodes, improve angina, and prevent new infarctions. The benefit of a revascularization strategy in ischemic cardiomyopathy must therefore be assessed on the basis of clinical outcomes and anatomy, not solely on LVEF recovery.

Hibernating myocardium may show reduced contractility, reduced flow reserve, and adapted metabolism. At the cellular level, loss of myofibrils, increased glycogen, and mitochondrial changes have been described. Recovery after revascularization may require weeks or months and depends on the severity of structural remodeling already established.
Repeated sublethal ischemia may produce a sequence of cumulative stunning and adaptation. In patients with severe stenoses and limited symptoms, regional dysfunction may therefore reflect a combination of scar and reversibly depressed tissue. Multimodality imaging is often necessary to separate these components.

Neurohormonal activation also alters the extracellular matrix of noninfarcted myocardium. Angiotensin II and aldosterone promote interstitial fibrosis, which increases stiffness and creates electrical discontinuities. The benefit of renin-angiotensin system and mineralocorticoid receptor antagonists therefore includes effects extending beyond simple blood pressure reduction.
Diastolic dysfunction may become clinically dominant even in ischemic HFrEF. Fibrosis, subendocardial ischemia, hypertrophy, and impaired relaxation increase filling pressures; for this reason, a patient may develop pulmonary edema with relatively small changes in LVEF.

The dilated left ventricle alters right ventricular geometry through the septum and pericardium. Elevated pulmonary pressures increase right ventricular afterload, while septal dysfunction reduces its contribution to right ventricular contraction. The development of right-sided failure is therefore often the result of multiple simultaneous mechanisms.
The relationship between ischemia and mitral regurgitation may be dynamic. During exertion or increased afterload, tethering and dyssynchrony may worsen and produce much more severe regurgitation than on the resting examination. In patients with disproportionate dyspnea, stress echocardiography may therefore clarify the dynamic component.

Reverse remodeling is the opposite process: a reduction in volumes and improvement in geometry after effective therapy, CRT, or control of causal factors. It is not equivalent to complete recovery, but it is associated with a better prognosis. The extent of reverse remodeling varies with etiology, disease duration, scar, and treatment adherence.
In ischemic heart disease, the potential for reverse remodeling is generally lower than in nonischemic cardiomyopathies with little fibrosis because some tissue has been permanently replaced by scar; this does not reduce the importance of therapy: even without normalization of LVEF, therapies can reduce death and hospitalizations.

Advanced imaging, viability, ischemia, and revascularization planning

Imaging must answer a specific clinical question. If the objective is to identify the presence of coronary artery disease, CCTA or coronary angiography may be appropriate; if scar must be distinguished from recoverable myocardium, CMR, PET, or stress imaging provides different information. The choice must not be guided by the center's customary practice but by the decision that the result can change.
With late gadolinium enhancement, CMR identifies the ischemic pattern beginning in the subendocardium. The likelihood of recovery of contractility after revascularization decreases as scar transmurality increases. Segments without LGE or with limited scar have greater recovery potential, but the functional outcome also depends on loading conditions, timing, and dyssynchrony.

LGE does not directly measure inducible ischemia. A segment may be viable but adequately perfused at rest and not contribute to symptoms; conversely, a region with partial scar may contain viable ischemic tissue. Stress perfusion and tissue characterization must therefore be interpreted together.
PET may document a mismatch between reduced perfusion and preserved FDG metabolism, the classic sign of hibernating myocardium. A matched pattern of reduced perfusion and metabolism suggests scar; however, metabolic preparation is complex, and diabetes or insulin resistance may reduce examination quality.

SPECT is more widely available but has lower resolution. Perfusion tracers may identify reversible and fixed defects; viability assessment with reinjection or nitrates is possible but less precise than CMR or PET in some scenarios.
Echocardiography with low-dose dobutamine assesses contractile reserve: a dysfunctional segment that improves at low doses contains viable myocardium. A biphasic response, with improvement at low doses and deterioration at higher doses, suggests viability associated with inducible ischemia.

The choice of revascularization must not be entrusted to an isolated viability test. STICH and its follow-up studies have shown that surgical selection primarily requires anatomy amenable to CABG, operative risk, life expectancy, and the clinical picture. Viability may contribute to understanding but is not an absolute gatekeeper.
In REVIVED-BCIS2, viability was required for enrollment, but PCI did not reduce the endpoint of death or hospitalization for heart failure. Subsequent analyses have reinforced the concept that scar extent predicts prognosis more strongly than the simple number of viable segments and that viability does not automatically identify a prognostic benefit from PCI.

Coronary angiography defines stenoses and technical targets, but the complexity of ischemic heart disease requires assessment of completeness of revascularization. Chronic occlusions, small vessels, diffuse disease, and calcification may make complete revascularization with PCI impossible and favor CABG or medical therapy.
With CABG, prognostic benefit derives in part from the ability to bypass diseased proximal segments and provide blood flow to distal territories, also protecting against future progression of proximal plaques; this mechanism differs from focal PCI and helps explain why outcomes cannot be directly extrapolated between the two strategies.

Heart Team discussion is particularly important when reduced LVEF, diabetes, multivessel disease, left main disease, comorbidities, and high surgical risk coexist. The cardiac surgeon, interventional cardiologist, heart failure specialist, and imaging specialist must integrate prognosis, feasibility, and the patient's preferences.
Preoperative assessment must consider right ventricular function, mitral regurgitation, carotid or peripheral disease, frailty, kidney function, and lung function. A potential benefit at ten years may be irrelevant in a patient with a very limited life expectancy because of noncardiac comorbidities.

Acute ischemic heart failure and management of unstable phases

An episode of acute heart failure in a patient with ischemic disease requires immediate exclusion of an acute coronary syndrome. New pain, ECG changes, or a dynamic troponin pattern may indicate an event requiring urgent revascularization. A moderately elevated troponin may, however, also reflect injury secondary to heart failure without a primary myocardial infarction.
Bedside hemodynamic classification distinguishes congestion from hypoperfusion. A congested but well-perfused patient is treated primarily with diuretics and vasodilators when blood pressure permits; a patient with hypoperfusion and hypotension requires more complex assessment for shock and may need vasopressors or mechanical support.

Nitroprusside or intravenous nitrates may be useful in hypertensive pulmonary edema and a severe increase in afterload, whereas they are inappropriate in hypotension. The choice must be guided by hemodynamic physiology and not by a standard prescription for every case of heart failure.
Diuretics must achieve effective decongestion. A modest increase in creatinine during diuresis does not automatically imply structural kidney injury and should not prompt premature discontinuation of decongestion if the patient remains congested. Its significance depends on the hemodynamic context and clinical response.

Acetazolamide added to a loop diuretic improved decongestion in the ADVOR trial in patients with acute heart failure and volume overload; this does not mean that it should be used universally, but it expands sequential nephron blockade strategies.
In cardiogenic shock, norepinephrine is frequently preferred as a vasopressor when blood pressure support is required. Inotropes such as dobutamine or milrinone may increase output but also oxygen consumption and arrhythmic risk. They must be used as temporary support in selected patients, not as routine chronic therapy.

Mechanical support devices include IABP, microaxial pumps, and VA-ECMO, with different indications and nonuniform evidence. Benefit depends on selection, timing, shock phenotype, and the center's capabilities; simply increasing output does not guarantee a reduction in mortality.
Revascularization in infarct-related shock should initially focus on the culprit lesion in many situations, avoiding indiscriminate multivessel PCI in the acute phase when it increases procedural risk. Subsequent strategies may complete revascularization after stabilization.

After the acute phase, prognostic therapies must be reintroduced or started as soon as blood pressure, kidney function, and perfusion permit. Discharge without a titration plan exposes the patient to a high risk of therapeutic inertia.
Follow-up during the first six weeks after hospitalization is particularly important. Updated ESC guidelines recommend an intensive strategy of initiation and rapid titration before discharge and at early visits, based on the results of STRONG-HF and other evidence.

Devices, arrhythmias, valves, and advanced therapy

The indication for an ICD for primary prevention requires persistently reduced LVEF despite optimal therapy and a sufficient waiting period after infarction and revascularization to allow recovery. Immediate implantation after infarction does not reduce total mortality because the reduction in arrhythmic death may be offset by other causes of death.
An ICD does not treat the progression of heart failure. A patient with a device must continue an ARNI/RAAS inhibitor, beta-blocker, MRA, SGLT2 inhibitor, and coronary prevention. Conversely, good pharmacological therapy may reduce the number of appropriate shocks by preventing arrhythmias and progression.

Modern ICD programming uses rate zones, detection times, and antitachycardia pacing to reduce unnecessary shocks. In patients with ischemic disease and monomorphic VT, ATP can terminate many episodes without a shock. Programming must be personalized according to arrhythmia type.
CRT corrects electrical dyssynchrony, but benefit requires a sufficient amount of recruitable myocardium. Extensive scar in the posterolateral wall may limit the response to the left ventricular lead. Imaging and venous anatomy may help optimize the pacing site.

Conduction system pacing, including left bundle branch area pacing, is rapidly evolving as an alternative or complement to biventricular CRT in selected scenarios. Indications continue to evolve and must be distinguished from established standards derived from large CRT trials.
Recurrent scar-related VT despite an ICD requires a strategy that includes beta-blockade, amiodarone or sotalol in selected patients, and ablation. Ablation modifies scar conduction channels and may reduce recurrences and shocks, although it does not eliminate the risk of heart failure progression.

Secondary mitral regurgitation must be quantified using an integrated approach. EROA and regurgitant volume depend on loading conditions and may vary. Before a transcatheter intervention, it is essential to demonstrate that heart failure therapy has genuinely been optimized.
In the COAPT trial, transcatheter repair with edge-to-edge therapy added to maximal therapy reduced hospitalizations and mortality in highly selected patients with significant secondary MR. MITRA-FR did not show the same benefit, highlighting the importance of selection, ventricular disease severity, and the proportionality of regurgitation.

In patients with a ventricular thrombus, the choice of anticoagulant is individualized. Warfarin has the longest historical tradition; DOACs are increasingly used on the basis of observational data and emerging studies, but the post-infarction setting requires attention to combination with antiplatelet agents and bleeding risk.
Advanced therapy with an LVAD may serve as a bridge to transplantation or as destination therapy. In advanced ischemic heart disease, previous CABG, aortic calcification, and peripheral disease may increase surgical complexity. Early assessment is preferable to referral during irreversible multiorgan shock.

Transplantation offers the most complete replacement of cardiac function in selected patients, but organ availability and comorbidities limit access. Severe systemic vascular disease, active malignancy, or fixed pulmonary hypertension may represent contraindications.
Palliative care and shared planning are not alternatives to advanced cardiology but part of the management of patients with terminal disease. Discussion of the ICD, hospitalizations, symptoms, and preferences must take place before stages of irreversible deterioration.

Clinical phenotypes, comorbidities, and prognostic stratification

Ischemic heart failure is not a single phenotype. A patient with a large anterior infarction and apical aneurysm, one with multiple small infarctions and diffuse multivessel disease, and one with HFpEF associated with microvascular ischemia share a coronary etiology but have different mechanisms, risks, and strategies. Phenotyping must precede decisions about revascularization and devices.
Diabetes accelerates atherosclerosis, promotes microangiopathy, and increases interstitial fibrosis. In patients with ischemic disease and HF, diabetes is associated with more hospitalizations and a worse prognosis. SGLT2 inhibitors are particularly important because they reduce heart failure events and kidney disease progression, including through mechanisms independent of glucose lowering.

Chronic kidney disease creates a cardiorenal cycle in which venous congestion, reduced perfusion pressure, RAAS activation, and drugs influence kidney function. Mild worsening of creatinine during effective decongestion or titration of RAAS inhibition must not automatically be interpreted as a reason to discontinue prognostic therapies.
Anemia reduces arterial oxygen content and increases cardiac demand. It must be distinguished from iron deficiency, which may be present even with normal hemoglobin and worsen functional capacity. Correction of iron deficiency with appropriate intravenous formulations improves symptoms and reduces hospitalizations in selected populations.

Obstructive sleep apnea, atrial fibrillation, and obesity are common. Treating sleep apnea improves symptoms and blood pressure in some patients but does not replace HF therapy. Weight loss may improve capacity and metabolic risk, while management of atrial fibrillation requires anticoagulation and an individualized rhythm/rate strategy.
Blood pressure has a U-shaped relationship with prognosis in advanced heart failure: high values increase afterload and ischemia, but very low pressures may reflect low output and limit titration. The objective is not to achieve an abstract number but to maximize tolerated therapy while preserving perfusion.

The risk of sudden death is not fully explained by LVEF. Scar burden, a history of VT, syncope, QRS, genetics, and autonomic activity contribute; however, the use of more sophisticated markers has not yet replaced LVEF thresholds and validated clinical criteria for primary prevention with an ICD.
BNP and NT-proBNP contribute to prognosis but are influenced by age, kidney function, atrial fibrillation, and obesity. Trends may help assess response, but therapy must not be titrated solely to normalize the biomarker.

Functional capacity, assessed with peak VO2 and the VE/VCO2 slope, becomes particularly important in patients with advanced disease. A very low peak VO2 is not an isolated criterion for transplantation but contributes alongside age, organ function, frailty, and estimated risk.
Scores such as MAGGIC and the Seattle Heart Failure Model may support prognosis, but they were derived from specific populations and do not fully incorporate all modern therapies. They must be used as a complement to clinical assessment and not as automatic algorithms for limiting treatment.

The presence of polyvascular disease, peripheral artery disease, or stroke identifies a systemic atherosclerotic burden and increases the risk of non-HF events. Secondary prevention must therefore include strategies that reduce infarction and stroke in addition to drugs specifically for heart failure.
In older, frail patients, the priority may shift from maximizing every target dose to combining multiple classes at tolerated doses, reducing hospitalizations, and preserving independence. Frailty is potentially modifiable through nutrition, exercise, and reduction of unnecessary polypharmacy.

Prognosis changes over time. A patient who achieves reverse remodeling and is not hospitalized for years has a different risk than at diagnosis; conversely, two recent hospitalizations and worsening kidney function identify a phase of vulnerability. Stratification must be dynamic.
Follow-up must monitor weight, congestion, blood pressure, heart rate, kidney function, potassium, symptoms, and adherence. Telemonitoring may be useful in selected programs, but simply transmitting data without a clinical system capable of responding does not automatically improve outcomes.

Optimal management requires coordination among ischemic cardiology, heart failure, electrophysiology, cardiac surgery, and rehabilitation. Fragmentation, with independent decisions about stents, ICDs, and drugs, may produce treatments that are technically correct but strategically inconsistent.

Longitudinal monitoring and therapeutic goals

After therapy is initiated, ejection fraction is generally reassessed after a sufficient treatment period and, when relevant, after revascularization. The objective is not only to document recovery but to make decisions regarding ICD, CRT, and prognosis. Imaging performed too early may classify dysfunction that is still reversible as permanent.
Serial echocardiography must be performed using comparable methods. Changes of a few percentage points in LVEF may fall within measurement variability; changes in volumes, MR, and symptoms provide a more robust picture of reverse remodeling.

Drug titration requires close monitoring of creatinine, eGFR, and potassium after RAAS inhibitors or MRAs. A moderate increase in creatinine may be acceptable if it stabilizes and the patient gains hemodynamic benefit, whereas significant hyperkalemia requires specific corrective measures.
Home blood pressure measurement helps distinguish true persistent hypotension from isolated office measurements. In patients with orthostatic symptoms, reviewing diuretics, nitrates, and other nonprognostic drugs may make it possible to preserve disease-modifying classes.

Daily weight is useful for recognizing fluid retention but is not perfect: changes in diet, body mass, and bowel function may confound it. Patients must learn to integrate weight with edema, dyspnea, and exercise tolerance.
Heart rate is another physiological target. In sinus rhythm, a persistently high rate despite beta-blockade may reflect an insufficient dose, anemia, hyperthyroidism, or congestion. The cause must be identified before adding drugs.

Jugular venous pressure and signs of congestion remain important clinical tools even in the era of biomarkers. Follow-up must not be reduced to laboratory tests: the trajectory of symptoms and physical examination findings often precedes hospitalization.
Patients and family members must know an action plan for rapid worsening of dyspnea, syncope, chest pain, or an ICD shock. Early management reduces delays in assessing potentially fatal ischemia or arrhythmias.

Therapy is maintained even after LVEF recovers, unless there are specific reasons otherwise. The HF with improved EF phenotype does not equate to definitive recovery, and discontinuing therapies may promote recurrence of dysfunction.
Therapeutic success must be defined in terms of survival, freedom from hospitalization, functional capacity, and quality of life. Normalization of a single parameter, such as LVEF or BNP, does not replace these clinical outcomes.

Hemodynamics, ventricular-arterial interaction, and coronary reserve in ischemic heart failure

In ischemic heart failure, reduced pump function depends not only on the amount of myocardium replaced by scar. The remodeled ventricle operates under conditions of increased wall stress, altered ventricular-arterial coupling, and reduced contractile reserve. Increased end-systolic and end-diastolic volumes increase wall tension according to the Laplace relationship and raise the energy cost required to generate pressure; this results in a cycle in which dilation, initially compensatory, progressively reduces mechanical efficiency and increases vulnerability to ischemia during even modest increases in demand.

Subendocardial perfusion is particularly vulnerable because it occurs predominantly during diastole and is compressed by elevated intraventricular pressure. Tachycardia, increased end-diastolic pressure, systemic hypotension, and epicardial stenoses may therefore converge to reduce the coronary perfusion gradient. In a patient with advanced heart failure, an episode of tachyarrhythmia or a drop in blood pressure that would be tolerated by a normal heart may cause subendocardial ischemia, worsening function, and increased filling pressures.
Chronic sympathetic activation initially supports rate and contractility, but it increases oxygen consumption, afterload, and arrhythmic risk. Activation of the renin-angiotensin-aldosterone system promotes vasoconstriction, sodium retention, fibrosis, and remodeling. Effective neurohormonal therapy interrupts these pathways and may produce reverse remodeling, reducing ventricular volumes even when the ischemic scar remains anatomically present. Functional recovery therefore derives from modification of the remaining myocardium and hemodynamic load, not from regeneration of the necrotic area.

The ischemic ventricle frequently has regional dyssynchrony even in the absence of complete bundle branch block. Scarred segments, hibernating regions, and relatively preserved myocardium contract with different timing and amplitude, reducing systolic efficiency. When a wide QRS with an appropriate morphology coexists, resynchronization therapy may improve global coordination, but scar extent, especially posterolaterally, may attenuate the response if it involves the territory in which the left ventricle is paced.
Right ventricular dysfunction profoundly alters prognosis. It may result from right ventricular infarction, postcapillary pulmonary hypertension, ventricular interdependence, or biventricular progression of heart failure. Increased right-sided pressure reduces the renal perfusion gradient and promotes systemic venous congestion, liver dysfunction, and worsening kidney function. In a congested patient, creatinine may therefore reflect not only low output but also elevated venous pressure.

Functional capacity depends on integrated oxygen transport. Anemia, iron deficiency, muscle deconditioning, and peripheral endothelial dysfunction may cause dyspnea and reduced exercise tolerance even when ejection fraction remains stable. Cardiopulmonary exercise testing integrates cardiac, ventilatory, and peripheral responses and is particularly valuable in patients whose symptoms and echocardiographic parameters are discordant.
A reduced peak oxygen consumption does not identify the mechanism by itself, but it contributes to prognostic assessment in patients with advanced disease and selection for replacement therapies. The VE/VCO2 slope, blood pressure response, onset of oscillatory ventilation, and ability to increase oxygen pulse provide additional information; these data must be interpreted in the context of contemporary treatment because beta-blockers and devices modify chronotropic response and the relationship between heart rate and performance.

Ischemic mitral regurgitation, pulmonary hypertension, and interaction with revascularization

Secondary ischemic mitral regurgitation originates primarily from ventricular disease rather than leaflet disease. Dilation and regional remodeling displace the papillary muscles, increase leaflet tethering, and reduce closing forces. An inferoposterior infarction may produce asymmetric deformation, whereas diffuse ischemic cardiomyopathy tends to cause annular dilation and more global tethering. The extent of regurgitation is dynamic and may increase during exercise, hypertension, or ischemia.
Quantification requires integration of vena contracta, effective regurgitant orifice area, regurgitant volume, chamber dimensions, and Doppler patterns. In secondary MR, quantitative methods may be influenced by the noncircular shape of the orifice and variability during the cardiac cycle. A single measurement must therefore not be interpreted in isolation, especially when the decision concerns a transcatheter or surgical intervention.

Initial therapy consists of optimizing heart failure treatment and, when indicated, resynchronization. Reduced volumes and improved coordination of the papillary muscles may decrease regurgitation. Revascularization may improve regional function if reversibly dysfunctional myocardium is present, but it does not guarantee regression of MR when geometric remodeling is advanced. In patients undergoing CABG, the decision to add a mitral procedure depends on severity and anatomy.
In selected patients with persistent severe secondary MR, symptoms despite optimized therapy, and compatible anatomical features, transcatheter edge-to-edge repair may reduce hospitalizations and improve outcomes. The COAPT results emphasize that benefit depends on rigorous selection and already optimized heart failure therapy. Not all patients with severe MR obtain the same advantage, particularly when ventricular disease is extremely advanced.

Pulmonary hypertension in ischemic cardiomyopathy is initially postcapillary, as a consequence of increased left atrial pressure. Over time, a reactive precapillary component with remodeling of the pulmonary arterioles may develop. Differentiation by right heart catheterization is important in advanced cases, especially before transplantation or ventricular support, because elevated pulmonary vascular resistance may increase the risk of right ventricular failure after the procedures.
Right heart catheterization is not necessary in every stable patient but becomes useful when congestion is refractory, hemodynamics are uncertain, clinical signs and imaging are discordant, or advanced therapies are being considered. Wedge pressure, output, cardiac index, and vascular resistance help distinguish predominantly congestive from low-output states and avoid empirical escalation of diuretics or vasodilators in an inappropriate phenotype.

Comorbidities, frailty, advanced therapy, and end-of-care decisions

Chronic kidney disease is common and amplifies risk through diffuse atherosclerosis, calcification, anemia, and reduced tolerance of hemodynamic changes. The presence of CKD must not automatically lead to discontinuation of prognostic therapies. ARNIs, ACE inhibitors, ARBs, MRAs, and SGLT2 inhibitors require monitoring and adjustment, but renal risk must be balanced against cardiovascular benefit. A transient reduction in eGFR after effective decongestion may have a different significance from progressive kidney failure associated with hypoperfusion.
Iron deficiency may reduce functional capacity even without overt anemia. Ferritin and transferrin saturation are used to identify it because hemoglobin alone does not describe iron availability. In symptomatic patients with HFrEF or after hospitalization for heart failure, intravenous iron in selected individuals may improve symptoms and reduce the risk of new hospitalizations, according to contemporary recommendations. Oral iron has limited efficacy in many patients with advanced heart failure.

Atrial fibrillation may be both a cause and a consequence of heart failure. Loss of atrial contraction, a rapid ventricular response, and irregularity may reduce output; conversely, atrial dilation and elevated pressures promote AF. The rate- or rhythm-control strategy must be individualized, and anticoagulation depends on thromboembolic risk. In selected patients with HFrEF, AF ablation may improve symptoms and, in some studies, clinical outcomes.
Ventricular arrhythmias require an assessment that separates reversible triggers, such as acute ischemia, hypokalemia, and congestion, from the permanent scar substrate. An ICD prevents arrhythmic death but does not prevent heart failure progression and may deliver repeated shocks in the presence of recurrent VT. Antiarrhythmic drugs, ablation, and hemodynamic optimization must be integrated to reduce arrhythmic burden and device therapies.

Frailty is not the same as chronological age. Reduced walking speed, sarcopenia, weight loss, cognitive deficits, and functional dependence may alter the benefit-risk balance of CABG, devices, or advanced therapies. Multidimensional geriatric assessment makes it possible to distinguish potentially reversible frailty, due in part to congestion and deconditioning, from less modifiable structural vulnerability.
In patients with advanced heart failure, signs of progression must be recognized early: repeated hospitalizations, increasing diuretic requirements, hypotension limiting therapy, kidney deterioration, hyponatremia, recurrent arrhythmias, and inability to maintain daily activities. Late referral to an advanced heart failure center may preclude transplantation or ventricular support because multiorgan failure becomes irreversible.

Left ventricular support may be used as a bridge to transplantation or as destination therapy in selected patients. In ischemic cardiomyopathy, assessment must include residual coronary artery disease, right ventricular function, valvular regurgitation, arrhythmias, and peripheral vascular status. Potential benefit must be weighed against the risk of bleeding, thrombosis, infection, stroke, and long-term care burden.
Palliative care is not reserved for the final hours of life. It may be integrated throughout the course to control dyspnea, pain, and anxiety and to support prognostic communication and advance care planning. In patients with an ICD, discussion of future deactivation of antitachycardia therapies must take place before the terminal phase, while preserving the pacing function when appropriate. An informed choice prevents painful shocks during the dying process.

Individual prognosis remains dynamic. A patient with a very low LVEF may improve substantially after appropriate therapy and revascularization, whereas a patient with moderately reduced LVEF but advanced CKD, severe MR, and repeated hospitalizations may be at higher risk; stratification must therefore integrate clinical trajectory, imaging, biomarkers, functional capacity, arrhythmias, and comorbidities, avoiding reduction of ischemic cardiomyopathy to a single ejection fraction percentage.