MitraClip does not significantly improve outcomes in secondary mitral regurgitation: the MITRA-FR trial

1. Among patients with heart failure with reduced ejection fraction (HFrEF) and severe secondary mitral regurgitation on medical therapy, percutaneous mitral valve repair did not significantly reduce 12-month rates of death or hospitalization due to heart failure when compared to medical therapy alone.

2. Percutaneous mitral valve repair was associated with increased rates of stroke, need for renal-replacement therapy, and severe hemorrhage.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Among patients with HFrEF, secondary mitral regurgitation is associated with poor clinical outcomes; however, it is unknown whether the regurgitation impacts prognosis and if intervention is warranted. The aim of this trial was to determine if percutaneous mitral valve repair improved outcomes when added to medical therapy among patients with HFrEF and severe mitral regurgitation. The primary outcome, death or hospitalization due to heart failure, was not significantly different between interventional and control groups. There was also no significant difference in key secondary outcomes, including the individual components of the primary outcome, death from cardiovascular causes, and survival free from major adverse cardiovascular events (MACEs). Additionally, percutaneous intervention demonstrated a higher incidence of stroke, renal-replacement therapy, and severe hemorrhage. The results of this study conflict with other recent evidence supporting valve repair in this population; thus, more data is required before definitive conclusions are drawn.

This was a multicenter, randomized trial that used the standard MitraClip device, allowing comparison with similar studies. Furthermore, the results of the trial were consistent across all subgroups analyzed. Limitations include a high percentage of technical failure in the intervention group, periprocedural complications, and a substantial amount of missing follow-up data regarding echocardiography, functional status, and quality of life. Additionally, the results were discordant with the larger COAPT trial that evaluated percutaneous mitral valve repair in the same population, raising concern on the reproducibility of either study.

Click to read the study in NEJM

Click to read an accompanying editorial in NEJM

Relevant Reading: Transcatheter mitral-valve repair in patients with heart failure

In-Depth [randomized controlled trial]: This was a multicenter, parallel trial that randomized 304 patients with HFrEF (left ventricular ejection fraction 15-40% and symptoms of chronic heart failure) and severe mitral regurgitation to percutaneous mitral valve repair and medical therapy (n=152) or medical therapy alone (n=152). The MitraClip device was used for all percutaneous repairs. The primary outcome was a composite of death from any cause or unplanned hospitalization for heart failure at 12 months after randomization. Key secondary outcomes included the individual components of the primary outcome at 12 months, death from cardiovascular causes, and survival free from MACEs. Prespecified serious adverse events included ischemic or hemorrhagic stroke, myocardial infarction, need for renal-replacement therapy, periprocedural complications, and bleeding events at 12 months after randomization.

The primary outcome occurred in 83 patients in the intervention group versus 78 patients in the control group (odds ratio [OR], 1.16; 95% CI, 0.73 to 1.84; P=0.53). Among secondary outcomes, there were 37 versus 34 total deaths at 12 months (hazard ratio [HR] in the intervention group, 1.11; 95% CI, 0.69 to 1.77), 74 versus 72 unplanned hospitalizations for heart failure (HR, 1.13; 95% CI, 0.81 to 1.56), and 86 versus 78 MACEs (HR, 1.22; 95% CI, 0.89 to 1.66) in the intervention and control groups, respectively. Regarding serious adverse events, there was a higher rate of ischemic or hemorrhagic stroke, renal-replacement therapy, and severe hemorrhage in the intervention group.

Image: PD

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