Ischemic mitral regurgitation (IMR) – or the leakage of blood backward through the valve and into the heart – affects more than 2 million Americans, and can increase a patient’s risk for adverse cardiovascular events and even death. While there is no definitive treatment for IMR, patients may be treated with mitral valve repair or valve replacement. In a study presented today at the American Heart Association Scientific Sessions 2015, and published in this week’s issue of the New England Journal of Medicine, a team of researchers from the Cardiothoracic Surgical Trials Network (CTSN) found that recipients of a mitral valve replacement for IMR experienced a lower rate of heart failure and fewer cardiovascular-related hospital readmissions in the two years following surgery.

“We evaluated clinical outcomes as well as echocardiographic data to compile the results of the trial,” said Daniel Goldstein, M.D., professor and vice chairman of the Department of Cardiothoracic Surgery at Montefiore Einstein Center for Heart and Vascular Care and Albert Einstein College of Medicine, and first author of the study. “It is clear from these findings that after a two-year post-surgery period, there is no difference in left ventricular reverse remodeling or survival between patients who received mitral valve repair and those who received valve replacement. There was more recurrence of the leaking of the valve, however, in the repair group, which led to more heart failure adverse events and more cardiovascular readmissions.”

The Cardiothoracic Surgical Trials Network, which includes Montefiore Einstein Center for Heart and Vascular Care, the Icahn School of Medicine at Mount Sinai and the Perelman School of Medicine at the University of Pennsylvania, among others, followed 251 patients over a two-year postoperative period, and compared mitral valve repair to valve replacement for treating IMR. At 22 clinical centers, researchers assessed the degree of a patient’s left ventricular reverse remodeling – the improved function of the left ventricle – by monitoring left ventricular end systolic volume index – the amount of blood left in the ventricle following a heartbeat. At the end of the two-year period, patients were also evaluated for the occurrence of stroke, subsequent mitral valve surgery, heart failure, re-hospitalization, recurrent regurgitation, quality of life and mortality.

“Expert opinion favors surgical correction of severe ischemic mitral regurgitation, but the optimal surgical strategy remains controversial, leading to practice pattern variations.  The results of this trial should better inform therapeutic decisions for the care of these complex patients,” said Annetine C. Gelijns, Ph.D., the Edmond A. Guggenheim professor and chair of the Department Population Health Science and Policy at Icahn School of Medicine at Mount Sinai, and the principal investigator for the Data Coordinating Center based at Mount Sinai.

At the American Heart Association Scientific Sessions 2014, one-year postoperative results were presented, concluding that there was no difference in left ventricular end systolic volume index for mitral valve repair or replacement. However it was also reported that patients with a mitral valve repair experienced significantly more recurrent regurgitation than those with a mitral replacement.  “From a patient’s perspective, the observed differences in MR recurrence are reflected in higher rates of heart failure and hospitalizations, and these have a measurable effect on formal measures of quality of life” said Alan J. Moskowitz, M.D.,  professor and vice-chair of Population Health Science and Policy at the Icahn School of Medicine.

“Building on the one-year clinical data reported in 2014, we concluded that while there was no difference in the rate of survival for valve replacement or repair, mitral valve replacement did prove to be a more durable option for the treatment of severe ischemic regurgitation,” said Michael A. Acker, M.D., chief of the division of Cardiovascular Surgery and the William Maul Measey, professor of Surgery in the Perelman School of Medicine at the University of Pennsylvania, and senior author of the study. “Recurrence of MR led to increased cardiovascular readmissions and more heart failure adverse events when compared to replacement. Until we can reliably predict the patients who will recur after repair, replacement is a more reliable treatment for patients with severe ischemic mitral regurgitation. Additional research is needed to better predict the patients who can be repaired without recurrence.”

The study was presented as the Late-Breaking Clinical Trial (Abstract 23690): Two-Year Outcomes following Mitral Valve Repair or Replacement for Severe Ischemic Mitral Regurgitation.

http://www.nejm.org/doi/full/10.1056/NEJMoa1512913?query=featured_home