Mixed and multiple valve disease

Article written and reviewed by Dr Luca Moretti

Mixed and multiple valve disease describes situations in which the heart is simultaneously exposed to more than one hemodynamic defect. In mixed disease, the same valve is both stenotic and regurgitant, whereas in multivalvular disease two or more valves have significant lesions; the two conditions may naturally overlap, as when mixed aortic valve disease coexists with mitral and tricuspid regurgitation. The resulting physiology is not simply the sum of the individual findings, because each lesion changes flow and pressures across the others.

Each lesion modifies the flow and pressures that determine measurements of the others. An upstream stenosis can reduce flow across a downstream valve and mask its gradient; regurgitation can increase forward volume and make a stenosis appear more severe; left-sided valve disease can generate pulmonary hypertension, right-heart remodeling and secondary tricuspid regurgitation. Correcting one valve therefore changes the hemodynamics of the entire system.

Mixed aortic valve disease combines stenosis and regurgitation, imposing both pressure and volume load on the left ventricle. In mixed mitral valve disease, obstruction to filling coexists with systolic backflow and common measurements of valve area or regurgitation are subject to specific interactions. Multiple valve disease additionally requires distinguishing organic lesions from potentially reversible functional consequences.

The evidence base is less robust than for isolated valve disease because many studies and trials exclude patients with other important lesions. Guidelines provide principles, but many decisions depend on clinical coherence, multimodality imaging and center expertise. The goal is not to normalize every jet or gradient, but to correct the dominant load, prevent irreversible damage and choose a sequence that minimizes overall risk and reintervention.

Definitions, causes and clinical combinations

The term mixed valve disease is reserved for the presence of both stenosis and regurgitation in the same valve. Each component is graded separately, but overall severity considers their combined consequences. One severe lesion makes the mixed disease severe; even two moderate components can produce high velocities, symptoms and prognostically adverse remodeling. Simply labeling them “moderate” can therefore underestimate total load.

Multiple valve disease involves at least two valves, but not every minimal echocardiographic regurgitant jet merits this label. At least moderate, organic or hemodynamically significant lesions are considered, with mechanism and causal relationship specified. A patient with aortic stenosis and degenerative mitral regurgitation has two primary diseases; if the regurgitation results from ventricular dilatation induced by the aortic lesion, the second lesion is functional and may change after replacement.

Rheumatic disease is the etiologic paradigm of multivalvular involvement: commissural fusion, thickening and retraction can affect the mitral, aortic and tricuspid valves with combinations of stenosis and regurgitation. Degenerative disease in older adults more often combines calcific aortic stenosis, mitral annular calcification and functional regurgitation. Endocarditis, mediastinal radiation, carcinoid disease, connective tissue disorders and fibrogenic drugs produce characteristic distributions.

Congenital heart disease and previous interventions create their own anatomies: dysplastic valves, conduits, prostheses, shunts and chambers with nonconventional morphology. A pulmonary valve lesion may coexist with tricuspid regurgitation, or a systemic atrioventricular valve may become regurgitant in a systemic right ventricle. Applying acquired-heart-disease algorithms without describing the anatomical connections leads to errors.

Among the most common multiple combinations are aortic stenosis with mitral regurgitation, mitral valve disease with tricuspid regurgitation and mitral stenosis with an aortic lesion. Pulmonary hypertension represents a pathophysiological bridge between the left and right heart. Atrial fibrillation dilates both atria and can produce atrial mitral and tricuspid regurgitation, whereas ischemia or cardiomyopathy generates bivalvular tethering.

The distinction between organic and secondary disease is therapeutic. A degenerative or rheumatic leaflet does not return to normal by removing the load imposed by another valve; functional regurgitation may decrease with normalization of pressure and geometry, but may also persist if the annulus, atrium or ventricle has crossed a remodeling threshold. The probability of reversibility, not an assumption, guides concomitant treatment decisions.

A dysfunctional prosthesis can become part of multiple valve disease. Structural deterioration, paravalvular leak, mismatch and thrombosis alter flow and pressures across native valves. The temporal sequence is essential: new tricuspid regurgitation after left-sided surgery may reflect progression, atrial fibrillation, a lead or residual pulmonary hypertension. Retrieving preoperative studies avoids simplistic causal attribution.

Prevalence depends on the definition and population. In registries of patients with severe left-sided valve disease, a second moderate or severe lesion is common and is associated with greater cardiac damage. Right-sided disease is probably underestimated because load-dependent jets are graded under variable compensation. For both research and clinical care, grade, etiology and timing of measurement should therefore be reported rather than an undifferentiated label.

Hemodynamic interactions and global cardiac damage

In mixed valve disease, stenosis opposes forward flow, whereas regurgitation forces the chamber to eject or receive additional volume. At the aortic valve, regurgitation increases total stroke volume and may elevate velocity and gradient even when valve area is not severely reduced; at the same time the ventricle faces both pressure and volume load. The gradient becomes an indicator of the combined load, not only of the orifice.

In mixed mitral disease, the volume regurgitated during systole returns across the valve during diastole and increases transmitral flow. Gradient and pressure half-time may therefore overestimate the stenotic component, while low output or altered compliance can do the opposite. Anatomical planimetry and independent quantification of regurgitation gain greater value, although they have limitations with calcified or distorted leaflets.

In multiple valve disease, lesions in series strongly influence one another. Mitral stenosis reduces ventricular preload and can lower velocity and gradient across truly severe aortic stenosis. Treating the mitral valve increases output and unmasks the aortic lesion. Conversely, aortic stenosis raises ventricular pressure and can amplify mitral regurgitation, particularly functional regurgitation.

Regurgitant lesions also modify the flow used to calculate the severity of another valve. In severe mitral regurgitation, forward stroke volume into the aorta decreases and aortic stenosis may therefore present as low-flow, low-gradient disease; similarly, in aortic regurgitation the volume crossing the mitral valve in diastole does not equal net aortic flow. The continuity equation and volumetric methods are reliable only when the model accounts for any volume losses between the sites being compared.

The right heart progressively accumulates the effects of left-sided disease. Increased left atrial pressure and pulmonary vasoconstriction raise right ventricular afterload, and the ventricle progressively dilates and loses the ability to maintain tricuspid coaptation. Early correction of the left-sided lesion may reduce pressure and regurgitation, but in advanced stages annular dilatation, tethering and atrial fibrillation make tricuspid disease increasingly autonomous; ignoring it during left-sided surgery can therefore lead to a high-risk late reintervention.

Global severity is expressed by chamber damage: dilatation, systolic and diastolic function, strain, atrial size, pulmonary pressure, right ventricular involvement, rhythm and organ congestion. An apparently normal ejection fraction may be inappropriate in the presence of regurgitation; hypertrophy can mask subclinical dysfunction. Symptoms and biomarkers are attributed only after coronary disease, lung disease, anemia and frailty have been excluded.

Correction of one valve instantly changes preload and afterload. Eliminating mitral regurgitation increases effective ventricular afterload; treating aortic stenosis can reduce the pressure driving secondary regurgitation; closing a tricuspid valve exposes the right ventricle to the full pulmonary afterload. A safe strategy anticipates these transitions through hemodynamic simulation and assessment of ventricular reserve.

Interactions among valves can also mask clinical signs. Tricuspid stenosis limits output and may attenuate pulmonary congestion from mitral disease, whereas significant mitral regurgitation reduces forward flow and may lessen the murmur and gradient of aortic stenosis. After correction of the dominant lesion, the second valve may therefore suddenly appear more severe despite no anatomical change; explaining this possibility in advance prevents the new picture from being misinterpreted as an unexpected complication.

Integrated diagnosis and the role of imaging

Transthoracic echocardiography is the starting point, but in multivalvular disease it is not enough to assign a grade to each of the four valves. Morphology, Doppler findings and consequences must be interpreted together, documenting rhythm, pressure and loading conditions and trying to identify the dominant lesion, interactions and any discordance. An examination performed during tachycardia or congestion may change substantially after stabilization, and the report should make this explicit.

For each stenosis, valve area, velocity, gradients, dimensionless index and flow are integrated; for each regurgitant lesion, vena contracta, flow convergence, venous or arterial Doppler, volumes and chamber response are considered. In combinations, flow-dependent parameters are more vulnerable. Multiparametric quantification does not mean averaging incompatible results, but understanding which assumption is violated and choosing independent methods.

Transesophageal and three-dimensional echocardiography clarify anatomy, calcification, commissures, coaptation and repair feasibility. They are central to mitral and tricuspid procedures, but sedation and ventilation alter loading and regurgitation. A lower intraoperative grade does not prove that the lesion has regressed; comparison with the awake study and with valve geometry prevents incomplete correction.

Magnetic resonance measures biventricular volumes, fibrosis and flows without depending on acoustic windows. It is useful when multiple regurgitant lesions make echocardiographic volume balances inconsistent, but magnetic resonance also requires appropriate equations: mitral regurgitant volume derived from ventricular stroke volume minus aortic flow is altered by aortic regurgitation or shunts. Direct 4D-flow measurements are promising but depend on image quality and have not replaced validated methods.

CT quantifies aortic calcium, the mitral annulus, roots, coronary arteries, access routes and spatial relationships for multiple procedures. Aortic calcium can support the severity of low-flow stenosis, but it is not a universal surrogate of severity in mixed mitral or right-sided valve disease. When several devices are anticipated, CT assesses spatial interactions, risk of outflow obstruction and the feasibility of future access.

Exercise testing and stress echocardiography objectify symptoms and reserve, showing changes in gradients, pulmonary pressure and regurgitation. Dobutamine is used for specific low-flow aortic stenosis scenarios, not as a generic test for all lesions. Cardiopulmonary exercise testing distinguishes circulatory limitation and provides a serial reference before a complex intervention.

Catheterization is indicated when noninvasive data remain discordant and the answer would change the plan. Simultaneous pressures, output and resistances reconstruct the circuit, but sedation, nonsimultaneous waves and flow equations introduce error. Even invasively, one lesion alters the other; the added value lies in testing precise hypotheses, not in treating catheterization as infallible.

Extracardiac assessment includes coronary arteries, aorta, lungs, kidneys, liver, anemia, frailty and nutritional status. In rheumatic disease, activity and thromboembolic risk are assessed; in endocarditis, extension and infectious foci; in carcinoid disease, tumor control. The Heart Valve Centre integrates this information with repair probability, operative risk and access to transcatheter interventions.

Diagnostic quality also depends on terminology. The report should avoid vague formulas such as “double valve disease” without a mechanism and should specify which component is primary, which is secondary, which is severe and which is uncertain. A concluding hemodynamic synthesis, accompanied by a plan to resolve discordances, is more useful than a long list of measurements that the clinician must reconstruct without knowing which assumptions are violated.

Therapeutic strategy, priorities and sequencing

If one component of mixed disease is severe, management first follows the recommendations for that lesion while incorporating the contribution of the other. If stenosis and regurgitation are balanced and moderate, symptoms, velocity or gradient, remodeling and dysfunction may identify a globally severe load. Closer surveillance is appropriate because natural history may be worse than the individual labels suggest.

In multiple valve disease, the dominant lesion is identified and the behavior of the others after its correction is anticipated. A severe organic lesion is generally treated; a moderate secondary lesion may regress, but a dilated annulus, atrial fibrillation, pulmonary hypertension and advanced tethering reduce that probability. The cost of a concomitant procedure is weighed against that of a late reintervention.

Surgery offers simultaneous access to multiple valves, the aorta, coronary arteries and arrhythmias. Risk increases with cross-clamp duration, number of prostheses, age and organ damage; durable repair reduces prosthetic burden, but should not leave important residual lesions. The choice between mechanical and biological prostheses considers the overall anticoagulation strategy: a single mechanical prosthesis requires anticoagulation even if the others are biological.

Transcatheter procedures permit staged strategies. Treating aortic stenosis first can reduce functional mitral regurgitation and pulmonary pressure, allowing reassessment; severe primary mitral disease is less likely to regress. The opposite sequence may be necessary if hemodynamics or anatomy require it. Each device should preserve space and access for the next.

A hybrid strategy combines surgery and catheter intervention during the same hospitalization or at separate times. It may limit operative extent in frail patients, but adds vascular, antithrombotic and contrast-related risks. Fragmentation has no intrinsic advantage: the strategy must have a hemodynamic rationale, a defined order and criteria for stopping if the second lesion improves.

Medical therapy treats congestion, hypertension, atrial fibrillation, ischemia and heart failure, but does not modify a severe mechanical obstruction. Diuresis can reduce functional regurgitation and flow-related gradients, so elective assessment is performed under compensated conditions. In acute patients, vasodilators or mechanical support have different effects according to coexisting stenotic and regurgitant lesions and require expert monitoring.

The plan should specify goals, the risk of leaving lesions untreated, antithrombotic therapy and follow-up. In younger patients, the sequence of prostheses over decades is considered; in frail older adults, quality of life may favor a procedure limited to the dominant lesion. Informed consent includes uncertainty about secondary lesions and the possibility that a planned two-stage strategy may end after the first intervention.

Before an irreversible decision, the probability of ventricular recovery is also discussed. Dysfunction mainly caused by loading may improve, whereas scar, infiltration or advanced organ damage reduce benefit and increase risk. Futility is not inferred from age or ejection fraction alone: it integrates frailty, life expectancy, independence, right- and left-sided reserve and the technical possibility of achieving a durable hemodynamic result.

Follow-up and outcome assessment

During conservative surveillance, the follow-up interval is determined by the combination of lesions and especially by the one with the most dynamic trajectory. Symptoms, functional class, rhythm, blood pressure, biomarkers and imaging of all four valves and chambers should be compared over time because small concordant changes in several parameters may carry more meaning than a single change in grade. Exercise testing is particularly useful when a patient reduces activity without recognizing it.

After treatment of the first valve, a new baseline is acquired once hemodynamics and volume status have stabilized. Comparison describes output, pulmonary pressure, function and the grade of residual lesions. Functional regurgitation may decrease over weeks or months through reverse remodeling; waiting is reasonable if the patient is stable, but not if a severe lesion persists with progressive damage.

After an intervention, the hemodynamic circuit changes and even familiar numbers take on a different meaning. Increased output may unmask the gradient of a second stenosis that was previously hidden, whereas correction of a regurgitant lesion changes stroke volumes and valve-area calculations. The postprocedural report should therefore explain the new equilibrium rather than compare values out of context and, when an echocardiographic result remains unexpected, magnetic resonance or catheterization can provide independent verification.

Prosthetic follow-up considers all valves and the overall antithrombotic regimen. Thrombosis, degeneration, endocarditis and prosthesis-patient mismatch can reactivate secondary regurgitation. Unexplained fever or new heart failure requires prompt assessment. Dental procedures, pregnancy and noncardiac surgery are planned according to the prosthesis at highest risk and the overall hemodynamic reserve.

Relevant outcomes include survival, hospitalizations, exercise capacity, quality of life, remodeling, repair durability and freedom from reintervention. Technical success on one valve does not compensate for leaving a second lesion severe; on the other hand, moderate residual regurgitation may be acceptable if it regresses and an additional correction would carry disproportionate risk. Assessment must remain centered on the patient and the trajectory.

The complexity of multivalvular disease does not justify a vague conclusion. Rigorous management describes each lesion, makes interactions explicit, selects the most reliable measurement methods and builds a therapeutic sequence that can be verified over time. After each change in loading, follow-up reassesses previous assumptions: in this way, mixed or multiple valve disease is treated as one hemodynamic system rather than a collection of independent diagnoses.