Mitral Valve Surgery in Women

Sex differences in outcomes have been noted in many areas of cardiovascular medicine. In mitral valve surgery, this topic is particularly important because in appropriately selected patients, mitral valve repair restores normal life expectancy, which cannot be said for other cardiac surgical operations. Current literature is replete with evidence supporting continued sex inequality in the detection and treatment of mitral valve disease. Women, although just as likely to have significant MR, are less likely to receive surgery than men, and when they do, they have worse observed outcomes after their operation. When women are referred for surgery, they typically present with more comorbidities and later in the disease process and have a lower likelihood of receiving mitral repair, the superiority of which over replacement has been firmly established for degenerative disease. There is no established medical therapy for degenerative mitral regurgitation (MR), and surgery remains the gold standard for severe MR associated with symptoms and ventricular dysfunction. Longstanding MR leads to many untoward consequences, including ventricular dysfunction, left atrial enlargement, development of secondary atrial fibrillation, pulmonary hypertension, and tricuspid regurgitation, and if left untreated, it inevitably leads to decompensated heart failure. Late referral to surgery does not always reverse these negative sequela. It is, therefore, important that this condition is detected early to prevent these untoward consequences and provide patients with the full benefit of their operation. Significant differences are noted in the baseline characteristics of women versus men presenting for mitral valve surgery. Women present at an older age, with excess comorbidity burden, including higher incidence of preoperative transient ischemic attack/stroke, atrial fibrillation, heart failure, respiratory failure, anemia, and others, and are more likely than men to have an urgent operation. At the time of mitral valve surgery, women are also more likely to undergo concomitant surgery for atrial fibrillation and tricuspid intervention, presumably reflecting higher incidence of atrial fibrillation and tricuspid regurgitation—factors known to reflect more advanced disease. The higher comorbid burden at presentation offers an explanation of the higher mortality in women undergoing mitral valve surgery compared with men. Data from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS ACSD) demonstrated that in patients aged between 40 and 59 years, women had 2.5 times higher riskadjusted mortality compared with men for isolated mitral valve operations. The survival disadvantage seemed to diminish with age. In a study of 47 602 Medicare beneficiaries with isolated mitral valve surgery, we demonstrated higher operative mortality for women compared with men (7.7% versus 6.1%; P<0.0001), and this was true both for the subset undergoing repair (4.2% versus 3.5%; P=0.0112) and replacement (9.3% versus 8.2%; P=0.0018). After adjustment for differences in baseline characteristics, operative mortality for mitral repair seemed similar between women and men, suggesting that this sex disparity might be largely because of worse preoperative profiles of women compared with men. Longterm survival differences after mitral valve surgery based on sex have also been reported. A study by Seeburger et al of 3761 patients undergoing minimally invasive mitral surgery reported 10-year survival of 58% for women compared with 72% for men. In the Medicare fee-for-service population, we found that in the subset of patients who underwent isolated mitral repair, long-term survival was worse for women, but this difference disappeared after risk adjustment. When taking sex into account, mitral repair seemed to restore normal life expectancy for men but not for women, and this might help explain the higher observed long-term mortality. Lower mitral repair rates for women have been documented across multiple data sources, including the Nationwide Inpatient Sample database, the Medicare database, and the STS ACSD. Considering the established superiority of mitral repair over replacement, addressing the lower likelihood of women to receive mitral repair compared with men represents an important opportunity in quality of care initiatives aimed at eradicating healthcare disparities. Compared with replacement, mitral repair is associated with improved survival, better preservation of ventricular function, lower risk of reoperation, and endocarditis, among others. In appropriately selected patients, mitral repair restores normal life expectancy to that of the ageand sex-matched US population. As a result, mitral valve repair rates have been proposed as a key indicator of quality in mitral valve surgery. Sex differences in mitral valve morphology and disease lesion have been documented and may partly explain the lower repair rates in women. Higher