COAPT shines light on transcatheter valve repair for secondary mitral regurgitation
The risk of hospitalization due to heart failure was almost halved in patients with secondary mitral regurgitation who underwent transcatheter mitral valve repair plus medical therapy compared with those who underwent medical therapy alone, according to findings of the COAPT* trial.
“At 2 years, transcatheter mitral valve repair … was found to be safe and effective. It substantially reduced the rate of hospitalizations and mortality, while improving quality-of-life [QoL] and functional capacity,” said study lead author Professor Gregg Stone from the Columbia University Medical Center, New York, US, who presented the findings at the recent Transcatheter Cardiovascular Therapeutics symposium (TCT 2018).
A total of 614 patients (mean age 72.2 years, 36 percent female) with heart failure and symptomatic moderate-to-severe or severe secondary mitral regurgitation despite maximum medical treatment were recruited from 78 sites in the US and Canada. They were randomized to receive either guideline-directed medical therapy alone (n=312) or in addition to undergoing transcatheter mitral valve repair with the MitraClip device within 14 days of randomization (n=302). Median follow-up was 22.7 and 16.5 months among patients in the device plus medical therapy and medical therapy alone groups, respectively.
The annualized rate of hospitalization for heart failure over 24 months was significantly reduced among patients who underwent transcatheter mitral valve repair in addition to medical therapy compared with patients who received medical therapy only (35.8 percent vs 67.9 percent per patient-year, hazard ratio [HR], 0.53, 95 percent confidence interval [CI], 0.40–0.70; p<0.001). [TCT 2018, Late-Breaking Trials 3; N Engl J Med 2018;doi:10.1056/NEJMoa1806640]
All-cause mortality at 24 months was also lower among patients who underwent transcatheter mitral valve repair plus medical therapy compared with medical therapy only (29.1 percent vs 46.1 percent, HR, 0.62, 95 percent CI, 0.46–0.82; p<0.001).
Device-related complication rate at 12 months was low, with a majority of patients (96.6 percent) not experiencing complications (p<0.001 compared with prespecified performance goal of 88.0 percent).
Fewer patients who underwent transcatheter mitral valve repair required left ventricular assist device implantation or heart transplantation during the follow-up period compared with those who received medical therapy only (4.4 percent vs 9.5 percent; p=0.01).
Compared with patients who received medical therapy only, more patients who underwent transcatheter mitral valve repair also had less severe mitral regurgitation (≤grade 2+; 94.8 percent vs 46.9 percent; p<0.001) and improved QoL at 12 months (NYHA** functional class I or II; 72.2 percent vs 49.6 percent; p<0.001). They also experienced a smaller decrease in functional capacity, as determined by change in 6-minute walk distance from baseline to 12 months, compared with patients who received medical therapy only (-2.2 vs -60.2; p<0.001).
The proposed mechanism behind the efficacy of transcatheter mitral valve repair in improving prognosis, QoL, and functional capacity is “transcatheter mitral leaflet approximation [leading] to a decrease in the severity of secondary mitral regurgitation”, said Stone and co-authors.
“The prognosis for heart failure patients who develop severe secondary mitral regurgitation is poor with limited treatment options,” said Stone. “This procedure gives cardiologists an important option for high-risk heart failure patients with secondary mitral regurgitation who remain symptomatic despite optimal medical therapy.”
The authors highlighted the need for data on long-term safety and efficacy of the device which will be available once the planned 5-year follow up is complete. The generalizability of these findings to patients with less severe mitral regurgitation and the effect of using other surgical procedures for this condition remains to be seen, they said.