Should patients with severe degenerative mitral regurgitation delay surgery until symptoms develop?

Area of Science:

• Cardiology
• Cardiac Surgery
• Heart Valve Disease

Background:

• Guidelines for severe degenerative mitral regurgitation (DMR) surgery in asymptomatic patients are debated.
• This study investigates the impact of symptom development on cardiac changes and outcomes in DMR patients.

Purpose of the Study:

• To determine if delaying surgery for severe DMR until symptoms appear leads to adverse cardiac remodeling.
• To assess the effect of symptom severity on surgical outcomes and long-term survival.

Main Methods:

• Analysis of 4,586 patients undergoing primary isolated mitral valve surgery for DMR between 1985-2008.
• Utilized multivariable analysis and propensity matching to correlate New York Heart Association (NYHA) class with cardiac structure, function, and outcomes.
• Preoperative NYHA class distribution: 30% Class I, 56% Class II, 13% Class III, 2% Class IV.

Main Results:

• Increasing NYHA class correlated with reduced left ventricular function, enlarged left atrium, and higher incidence of atrial fibrillation and tricuspid regurgitation.
• Adverse cardiac changes were observed even in NYHA Class II (mildly symptomatic) patients.
• Mitral valve repair rates decreased with increasing NYHA class (96% in Class I vs. 85% in Class IV).
• Hospital mortality was low overall (0.37%) but significantly higher in Class IV patients (5.1%).
• Long-term survival declined with worsening symptoms, primarily due to impaired left ventricular function and comorbidities.

Conclusions:

• Even mild symptoms at surgical referral indicate detrimental cardiac changes in severe DMR.
• High rates of successful mitral valve repair support early surgical intervention.
• Early surgery is justified for asymptomatic patients with severe degenerative mitral regurgitation to prevent adverse cardiac remodeling and improve outcomes.