Women fare worse than men after mitral-valve surgery


NEW YORK (Reuters Health) - Women have worse outcomes than men after mitral-valve surgery for severe ischemic mitral regurgitation (SMR), according to findings from the Cardiothoracic Surgical Trials Network (CTSN).

"Our study underscores the importance of timely and appropriate correction of severe ischemic MR in both men and women, alongside guideline-directed medical therapy, revascularization, or cardiac resynchronization therapy as appropriate," said Dr. Anuradha Lala from Icahn School of Medicine at Mount Sinai, in New York City.

"I believe that our current analysis supports the need to pay more attention to the earlier diagnosis of ischemic MR in women, more timely referral to mitral-valve surgery or transcatheter therapies, and more aggressive treatment of co-morbidities prior to surgery to reduce the observed outcome disparities between sexes," she told Reuters Health by email.

The findings were published online March 15 in JACC Heart Failure to coincide with a presentation at the American College of Cardiology annual meeting in New Orleans.

Current guidelines recommend consideration of surgical correction of severe ischemic MR in patients with persistent New York Heart Association class 3 and 4 symptoms despite optimal therapy. Registry data suggests that women are less likely to undergo mitral-valve surgery and have worse long-term outcomes compared with men, but whether outcomes after surgery differ between men and women remains unclear.

To investigate, Dr. Lala and colleagues examined outcomes after surgery for severe ischemic MR in a secondary analysis of data from the CTSN SMR trial, which found that mitral-valve replacement was associated with significantly lower rates of rehospitalization and recurrent moderate or greater MR, compared with mitral-valve repair.

Women accounted for 38.2% (96/251) of the patients enrolled in the trial. At baseline, they had worse Minnesota Living with Heart Failure (MLHF) scores; smaller left ventricular volumes, diameters, and mass; and smaller mitral-valve effective regurgitant orifice area, annulus area, and tethering area compared with men.

At two years, women had significantly higher risks of mortality (27.1% vs. 17.4% among men) and major adverse cardiac or cerebrovascular events (MACCE) (49.0% vs. 38.1% among men). There was no significant difference in the rate of rehospitalization.

Women tended to have a higher risk of treatment failure and MR recurrence, but these differences fell short of statistical significance. In both men and women, mitral-valve repair was associated with higher absolute rates of MR recurrence than was replacement.

After mitral-valve surgery, both groups experienced improvements in quality of life scores, but women continued to have worse mean MLHF scores than men at two years. There was also a trend for higher prevalence of NHYA class 3 or 4 symptoms in women at two years.

Men and women experienced similar improvements in left ventricular end-systolic volume index (LVESVI) at two years.

"It should be noted that these findings apply primarily to a population with ischemic mitral regurgitation treated with mitral valve surgery with or without concomitant coronary-artery bypass grafting," Dr. Lala said. "Whether these findings are applicable to patients undergoing transcatheter mitral-valve repair warrants further investigation."

First author Dr. Gennaro Giustino, also from Mount Sinai, told Reuters Health by email, "The role of treating secondary (or functional) MR in patients with heart failure has been recently the focus of much attention, given the impactful results of the COAPT trial, in which correction of secondary severe MR with transcatheter mitral-valve repair compared with no correction reduced the risk of death or heart-failure-related rehospitalizations. However, the rates of all-cause mortality in these patients at 2 years remain high. Further research is needed to further improve outcomes in this sick patient population."

Dr. Maurice E. Sarano from Mayo College of Medicine, in Rochester, Minnesota, who studies mitral regurgitation, told Reuters Health by email, "The excess mortality and MACE post mitral surgery is most interesting. The cause cannot be inferred from the data, i.e., is it a worse treatment or a worse presentation or a worse selection process. The result is more hypothesis generating than explaining what we should do next."

"Women with MR have been proven to have more adverse outcome because they are referred later to treatment due to the fact that their hearts are smaller and less 'impressive,'" explained Dr. Sarano, who was not involved in the study. "It is crucial that the cardiology community understands the involuntary biases that may affect our referral process and our selection of treatments, particularly the issue of smaller body size for women."

"We need a study of functional MR in men and women," Dr. Sarano added.

Dr. Eike Philipp Tigges of University Heart Center, in Hamburg, Germany, has researched gender-specific outcomes after transcatheter mitral-valve repair in high-risk patients. He told Reuters Health by email, "The real question is whether gender is the real driver behind the results or rather treatment approaches. It would have been interesting to see NT-proBNP values as surrogates for wall stress performed in gender and treatment subgroups."

"These very interesting findings should definitely lead to further in-depth investigation of equally distributed subgroups of treatment strategy and gender with results leading towards tailored strategies," said Dr. Tigges, who also was not involved in the new work.

JACC Heart Fail 2019.