Findings Published From MITRA-FR Study of Percutaneous Valve Repair for Secondary Mitral Regurgitation

August 27, 2018—In The New England Journal of Medicine (NEJM), Professor Jean-François Obadia, MD, et al published findings from the multicenter MITRA-FR study of percutaneous mitral valve repair with the MitraClip device (Abbott Structural Heart) in patients with severe secondary mitral regurgitation. The findings were published online simultaneous with their presentation by Prof. Obadia at the European Society of Cardiology Congress 2018 held August 25–29 in Munich, Germany.

The study sought to determine whether percutaneous mitral valve repair improves clinical outcomes in patients who have chronic heart failure with reduced left ventricular ejection fraction. Severe secondary mitral regurgitation is defined as an effective regurgitant orifice area of > 20 mm² or a regurgitant volume of > 30 mL per beat.

The investigators concluded that among patients with severe secondary mitral regurgitation, the rate of death or unplanned hospitalization for heart failure at 1 year did not significantly differ between patients who underwent percutaneous mitral valve repair in addition to receiving medical therapy and those who received medical therapy alone. The MITRA-FR study was funded by the French Ministry of Health and Research National Program and Abbott.

As summarized in NEJM, the study was composed of 304 patients who had severe secondary mitral regurgitation, left ventricular ejection fraction between 15% and 40%, and symptomatic heart failure. The patients were randomly assigned in a 1:1 ratio to undergo percutaneous mitral valve repair in addition to receiving medical therapy (intervention group, 152 patients) or to receive medical therapy alone (control group, 152 patients). The primary efficacy outcome was a composite of death from any cause or unplanned hospitalization for heart failure at 12 months.

At 12 months, the rate of the primary outcome was 54.6% in the intervention group and 51.3% in the control group (odds ratio, 1.16; 95% confidence interval [CI], 0.73–1.84; P = .53). The rate of death from any cause was 24.3% in the intervention group and 22.4% in the control group (hazard ratio, 1.11; 95% CI, 0.69–1.77). The rate of unplanned hospitalization for heart failure was 48.7% in the intervention group and 47.4% in the control group (hazard ratio, 1.13; 95% CI, 0.81–1.56), reported the investigators in NEJM.

In a press release from the European Society of Cardiology, Prof. Obadia, who is the study's principal investigator, commented, "We show for the first time that despite reducing secondary mitral regurgitation, percutaneous repair of the mitral valve does not improve survival or symptoms, or reduce heart failure hospitalizations compared to standard medical treatment alone. This strongly suggests that this procedure is futile in patients with heart failure and secondary mitral regurgitation." Prof. Obadia continued, "The reduction in mitral regurgitation that was achieved with the intervention did not translate into a clinical benefit in patients with heart failure. There is therefore no reason to perform this procedure in all patients with heart failure and secondary mitral regurgitation. Other randomized trials could examine whether there are subgroups that might be more suitable candidates."