Should We Operate on Asymptomatic Patients With Severe Mitral Regurgitation?

Timing of surgery in valvular heart disease: prophylactic surgery vs watchful waiting in the asymptomatic patient

In the absence of randomized controlled trial data, the management of patients with severe valvular heart disease without symptoms, ventricular dysfunction, or other identified triggers for surgery is controversial. In this review, we frame the debate between prophylactic surgery vs close follow-up until triggers occur (watchful waiting) for severe aortic stenosis and degenerative mitral regurgitation (MR), the 2 conditions for which the pros and cons of these approaches are best articulated. Classic high-gradient severe aortic stenosis is generally accurately diagnosed. In asymptomatic patients, stress testing can be used to confirm asymptomatic status and identify high-risk features including reduced exercise tolerance, exercise-induced symptoms, and absolute or relative hypotension. Resting echocardiographic predictors of disease progression and/or adverse events include very high gradients, rapid progression, and extensive calcification. Surgical risk calculators can help estimate perioperative morbidity/mortality with the ultimate choice of a medical vs a prophylactic surgical approach to be made after discussion with the patient. With degenerative MR, severity can be inaccurately estimated. Stress testing might clarify whether the patient is truly asymptomatic and identify features associated with worse prognosis and symptom onset. Selecting patients with high probability of repair can be challenging. Perioperative risk and postoperative risks including those of unanticipated valve replacement and recurrent MR after repair are also considerations. In aggregate, management of patients with valvular disease who are asymptomatic and who have no clear trigger for surgery is complex, requires individualization, and should be carried out by or in collaboration with a heart valve centre of excellence.

Practice variation among cardiovascular physicians in management of patients with mitral regurgitation

Severe mitral regurgitation (MR), whether isolated or with coronary disease, was associated with adverse clinical outcomes. However, clinician practice is characterized by different thresholds for treatment. No data exist that described current practice patterns, factors that affected these patterns, or whether physicians followed American College of Cardiology/American Heart Association guidelines in clinical practice for patients with MR. Cardiovascular specialists were surveyed using e-mail, and 1,076 physicians completed the survey (71% response rate), including adult cardiologists (94%) and cardiac surgeons (5%) who practiced in the United States (78%), Canada (5%), and other nations (17%). Wide variations were noted regarding rates of referral of asymptomatic patients with severe MR for mitral valve repair. There was geographic and specialty-dependent heterogeneity in practice. Most physicians (65%) used medications to delay the progression of MR in the absence of guideline recommendations. A minority (28%) of respondents routinely quantitated MR by calculating the effective regurgitant orifice area. In patients undergoing percutaneous coronary intervention, MR severity was not assessed before the procedure by 1 in 4 providers, and the presence of MR frequently did not affect clinical care decisions. In conclusion, considerable variability existed in the clinical management of MR, particularly regarding referral of asymptomatic patients for mitral valve reparative surgery. Medications were frequently used to treat asymptomatic patients with MR in the absence of evidence of pharmacologic efficacy. MR was frequently not considered a relevant factor before treatment of patients with coexistent coronary artery disease.