- In the Cardiothoracic Surgical Trials Network (CTSN) severe ischemic mitral regurgitation (SIMR) randomized trial of mitral valve (MV) replacement vs. repair for patients with severe ischemic mitral regurgitation, echocardiography showed that women had more disproportionate MR in relation to left ventricular (LV) volume
- During the two years after surgery, women were at greater risk of death and major adverse cardiac/cerebrovascular events compared with men
- Functional status and quality of life improved in both sexes after MV surgery, but two years after surgery, women had worse health-related and heart failure-related quality of life scores than men did
- Change in LV end-systolic volume index, a surrogate for LV reverse remodeling, improved similarly in both sexes over the two years after MV surgery
Women with primary mitral regurgitation (MR) are less likely than men to undergo mitral valve (MV) surgery, according to data from registry studies. Even if they do have surgery, women are at greater risk of postoperative heart failure.
It wasn't known whether there are other sex-based differences after surgery for severe ischemic MR (SIMR) because women have been underrepresented in randomized trials in cardiology. Judy Hung, MD, director of the Echocardiography Lab in the Division of Cardiology at Massachusetts General Hospital, led a team of researchers on the first secondary analysis of a trial that provides some answers. Their report is published in JACC: Heart Failure.
The CTSN SIMR Trial
The Cardiothoracic Surgical Trials Network (CTSN) severe ischemic mitral regurgitation (SIMR) study was a multicenter, prospective, randomized trial sponsored by the National Institutes of Health. It compared chordal-sparing MV replacement with MV repair in patients with primary SIMR and coronary artery disease who were eligible for either procedure, with or without concomitant coronary artery bypass graft surgery. The principal findings, as published in The New England Journal of Medicine, were that at two years after surgery, there were no significant differences between strategies with respect to reverse left ventricular (LV) remodeling. However, MV replacement was associated with significantly lower rates of rehospitalization and recurrence of moderate or greater MR.
Of 251 patients enrolled in the trial, 96 were women (38%). Dr. Hung and colleagues found that women had smaller LV volumes (after accounting for body surface area), as well as smaller effective regurgitant orifice areas (EROA) and tethering areas.
However, the ratio of EROA to LV end-diastolic volume (EROA/LVEDV) was greater in women, suggesting more disproportionate MR in relation to LV volume. EROA/LVEDV has been proposed to better characterize the hemodynamic severity of SIMR.
Two years after MV surgery, after adjustment for key covariates associated with each outcome of interest, women showed:
- An 85% higher risk of death than men (27% vs. 17%; HR, 1.85; 95% CI, 1.05–3.26; P = .03)
- A 58% higher risk of the composite of death, stroke, MV reoperation, hospitalization for heart failure or increase in New York Heart Association (NYHA) functional class ≥I (49% vs. 38%; HR, 1.58; 95% CI, 1.06–2.37; P = .02)
- A slight trend toward a higher risk of treatment failure and MR recurrence than men
Quality of Life and Function
After MV surgery, quality of life scores improved in both men and women. However, at two years, women had worse average scores than men on the European QOL-5 questionnaire, the Minnesota Living with Heart Failure questionnaire and the Duke Activity Status Index.
NYHA functional class improved in both women and men over two years, but there was a slight trend toward a higher prevalence of NYHA functional class III or IV in women.
Left Ventricular Reverse Remodeling
Two years after surgery, the LV end-systolic volume index had improved similarly in both women and men. A smaller EROA/LVEDV ratio was associated with less reverse remodeling.
Recommendations for Physicians
The recently completed COAPT trial of transcatheter MV repair similarly found that correction of secondary severe MR, compared with no correction, reduced the risk of death or heart failure-related rehospitalization in both men and women.
The findings from both trials emphasize the need for earlier diagnosis of SIMR in women, more timely referral to MV surgery or transcatheter therapies and more aggressive treatment of comorbidities prior to surgery to reduce disparities between the sexes in outcomes.
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