HOT OFF THE PRESS!
Originally published as an update to Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine, 11th Edition
Debra L. Beck and Eugene Braunwald, MD
Date Published: September 21, 2018
The optimal timing of mitral valve surgery in asymptomatic patients with primary mitral regurgitation (MR) remains controversial. Zilberszac et al sought to assess the 20-year outcome of an active surveillance strategy in a large population of patients with severe primary MR managed in a dedicated heart valve clinic.
A total of 280 patients (mean age at baseline, 58 years; 31% female) with severe asymptomatic primary MR (prolapse of flail leaflet) were assessed between 1997 and 2015 and enrolled in a long-term follow-up program. All were prospectively followed every 6 months with clinical and echocardiographic examinations until surgical criteria were reached, at which time they were immediately referred to surgery. The researchers measured event-free survival and overall survival as compared with an age- and gender-matched general population.
During follow-up (a median potential of 93.4 months), 161 patients developed an indication for surgery and 13 patients died. Event-free survival rates at 2, 6, 10, and 15 years were 78.0%, 52.2%, 35.5%, and 18.7%, respectively. Event-free survival did not differ significantly between patients with mitral prolapse and flail leaflet.
Overall survival (including perioperative survival and late deaths after surgery) at 2, 6, 10, and 15 years was 99.6%, 94.6%, 85.6%, and 74.5%, respectively. Overall survival also did not differ between patients with mitral prolapse and flail leaflet and were comparable with the expected cumulative survival in the general population. Early survival rates were actually better in the study population compared to that expected in an age- and gender-matched general population (standardized mortality ratio: 0.667; p = 0.013).
The investigators concluded that many patients with severe asymptomatic primary MR may remain free of indications for surgery for long periods of time and can be actively monitored by experienced practitioners. In such patients, “active surveillance was associated with a favorable prognosis, resulting in timely referral to surgery, excellent long-term survival, and good surgical outcomes.” A randomized trial comparing active surveillance and early elective surgery is warranted.
Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine features a unique update program by Dr. Braunwald, creating a “living textbook” by featuring weekly Hot off the Press, periodic Late-Breaking Clinical Trials (including links to authors’ presentation slides), and monthly Focused Reviews.
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