In patients with severe mitral regurgitation (MR) secondary to heart failure, transcatheter mitral valve repair with a MitraClip might serve as a bridge to heart transplant or, in some cases, help their condition to improve enough to no longer require a transplant, according to study results presented Friday at the TCT Connect virtual conference.
Cosmo Godino, MD, of San Raffaele Hospital, Milan, presented the results of the MitraBridge study, which were simultaneously published online in The Journal of Heart and Lung Transplantation.
There has been an increased prevalence of patients with advanced or end-stage heart failure and concomitant severe MR, constituting an estimated 1% to 10% of the overall heart failure population.
There is also a marked imbalance between the demand for heart transplant and the supply of available donor hears. This has resulted in expanded waiting lists and prolonged waiting times, sometimes exceeding 12 months. It is difficult to manage patients waiting for a transplant, as this population has a 1-year mortality rate of 15%.
The MitraBridge study investigators say that MitraClip (Abbott) to treat their severe MR could be a possible solution, providing a bridge to transplant while transplant candidates wait for a donor heart.
The study was a multicenter, a case-by-case retrospective review of case records. Patients with chronic advanced or end-stage heart failure and concomitant MR grade 3+ or 4+. It was started in June 2018 without any external funding and included 17 centers in Europe and Canada.
A total of 119 patients were included, and they comprised three groups: patients on an active heart transplant list with a low likelihood to receive a donation soon (dubbed “pure bridge” to transplant), patients waiting for a clinical decision (“bridge to decision”) and patients not listed for heart transplant, with potentially reversible contraindications to transplant (“bridge to candidacy”). Their 1-year outcomes were evaluated.
The primary composite endpoint was a composite of adverse events at 1 year: all-cause death, urgent heart transplant or left ventricular assist device implantation, or first rehospitalization for heart failure.
At baseline, the patients had a mean age of 58 years (range: 51-63 years), 91% were men, and their mean left ventricular ejection fraction was 26% (range: 20% to 32%). Before MitraClip implantation, 95% of patients had New York Heart Association (NYHA) class III or IV heart failure despite guideline-optimized medical and electrical therapy.
Procedural success was achieved in 87.5% of cases; 30-day mortality was 0%. At time of latest available follow-up (median 519 days), elective heart transplant was successfully performed in 16% of patients, 24% no longer needed a transplant because of significant clinical improvements, 8% remained on the transplant list, and another 7% were added to the transplant list. Of those who no longer needed a transplant, none had NYHA class IV heart failure, and 89% improved by at least one class.
At 1 year, Kaplan-Meier estimate of freedom from the composite adverse events was 65%. Postprocedural MR grade >2, hospitalization for heart failure within 6 months before the procedure, and a baseline Interagency Registry of Mechanically Assisted Circulatory Support (INTERMACS) score of 3 or 4 were independent predictors of the composite adverse-event outcome.
Godino emphasized during a press conference that these results should be considered “exploratory” and hypothesis-generating.