Original article
Adult cardiac
Should Patients With Severe Degenerative Mitral Regurgitation Delay Surgery Until Symptoms Develop?

Presented at the Forty-sixth Annual Meeting of The Society of Thoracic Surgeons, Fort Lauderdale, FL, Jan 25–27, 2010.
https://doi.org/10.1016/j.athoracsur.2010.03.101Get rights and content

Background

The American College of Cardiology/American Heart Association practice guidelines recommending surgery for asymptomatic patients with severe mitral regurgitation caused by degenerative disease remain controversial. This study examined whether delaying surgery until symptoms occur causes adverse cardiac changes and jeopardizes outcome.

Methods

From January 1985 to January 2008, 4,586 patients had primary isolated mitral valve surgery for degenerative mitral regurgitation; 4,253 (93%) underwent repair. Preoperatively, 30% were in New York Heart Association (NYHA) class I (asymptomatic), 56% in class II, 13% in class III, and 2% in class IV. Multivariable analysis and propensity matching were used to assess association of symptoms (NYHA class) with cardiac structure and function and postoperative outcomes.

Results

Increasing NYHA class was associated with progressive reduction in left ventricular function, left atrial enlargement, and development of atrial fibrillation and tricuspid regurgitation. These findings were evident even in class II patients (mild symptoms). Repair was accomplished in 96% of asymptomatic patients, and in progressively fewer as NYHA class increased (93%, 86%, and 85% in classes II to IV, respectively; p < 0.0001). Hospital mortality was 0.37%, but was particularly high in class IV (0.29%, 0.20%, 0.67%, and 5.1% for classes I to IV, respectively; p = 0.004). Although long-term survival progressively diminished with increasing NHYA class, these differences were largely related to differences in left ventricular function and increased comorbidity.

Conclusions

In patients with severe degenerative mitral regurgitation, the development of even mild symptoms by the time of surgical referral is associated with deleterious changes in cardiac structure and function. Therefore, particularly because successful repair is highly likely, early surgery is justified in asymptomatic patients with degenerative disease and severe mitral regurgitation.

Section snippets

Study Population

From January 1985 to January 2008, 4,586 patients underwent primary isolated surgery for MR caused by degenerative disease. Preoperative MR grade was assessed semiquantitatively by echocardiogram and was severe (grade 4) in 91% and moderately severe (grade 3) in 9%. Primary indication for surgery was MR in all patients; patients with coronary artery disease, aortic valve disease, hypertrophic cardiomyopathy, and ascending aortic aneurysm were excluded. Two hundred and fifty-seven patients

Preoperative Characteristics and NYHA Functional Class

Increasing functional class was associated with increasing age, female sex, greater comorbidity, and more structural and functional cardiac changes (Table 2). More symptomatic patients had more complex mitral valve pathology, with more valvar calcification and more anterior and bileaflet prolapse. Although left ventricular dimensions did not differ across functional classes (mean left ventricular end-systolic diameter was less than 40 mm in all groups), mean and median left ventricular ejection

Key Findings

Asymptomatic patients with severe degenerative MR can undergo surgery with low hospital mortality (0.3%) and a repair probability of 96%. These figures and long-term survival are similar in patients who have mild symptoms (NYHA functional class II). However, waiting until patients develop symptoms has a price. Development of even mild symptoms is associated with adverse changes in cardiac structure and function, including a slight decrease in left ventricular ejection fraction, left atrial

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