Physicians tend to favor mitral valve repair over replacement for patients with severe ischemic mitral regurgitation, but a study published online Nov. 15 in the New England Journal of Medicine found no significant difference between treatment options. The results were presented simultaneously at the American Heart Association’s scientific session in Dallas.

Michael Acker, MD, of the University of Pennsylvania Perelman School of Medicine in Philadelphia, and members of the Cardiothoracic Surgical Trials Network (CTSN) conducted the randomized controlled clinical trial to compare the two approaches. “Practice guidelines recommend repairing or replacing mitral valves in severe cases, but there has been a lack of conclusive evidence that one approach is better than the other,” he said in a release.

They enrolled 251 patients with severe ischemic mitral regurgitation and coronary artery disease between 2009 and 2011 and randomized them to ether receive mitral valve repair (126 patients) or chordal sparing replacement (125 patients). The primary endpoint was left ventricular reverse modeling assessed by left ventricular end-systolic volume index (LVESVI) measured at 12 months.

Secondary endpoints included the composite of major adverse cardiac or cerebrovascular events, serious adverse events, recurrent mitral regurgitation, quality of life and rehospitalization measured at 30 days and six, 12 and 24 months.

The participants had similar baseline characteristics; 96 percent had severe mitral regurgitation confirmed by echocardiography and the remainder had moderate mitral regurgitation.

At 12 months, LVESVI was 54.6 ml per square meter in the repair group vs. 60.7 ml per square meter in the replacement group, for a mean change from baseline of -6.6 and -6.8 ml per square meter, respectively. The morality rate was 14.3 percent in the repair group vs. 17.6 in the replacement group.

The repair group showed a higher rate of recurrence of moderate or severe regurgitation at 12 months (32.6 percent vs. 2.3 percent).  There were no significant differences between the groups in the rate of a composite of major adverse cardiac or cerebrovascular events, functional status or quality of life at 12 months.

“Current practice tends to focus on valve repair (annuloplasty) instead of replacement. Our study did not show that repair is the most effective treatment,” Louis P. Perrault, MD, Canadian lead investigator and chief of the cardiac surgery department at the Montreal Heart Institute, said in a release. “Our findings therefore have major clinical repercussions in the field of heart surgery.” 

The CTSN researchers acknowledged that their findings contradict other published results. They added that patients treated with mitral valve replacement tend to be older and sicker and that adjustments in nonrandomized studies may not be adequate if risk factors are unmeasured or unknown.

Results from the 24-month follow-up, which is ongoing, may shed light on predictors of recurrence of mitral regurgitation and help physicians in patient selection, they wrote.