MitraClip survivors show substantial, lasting gains in quality of life

Although nearly a quarter of patients in a U.S. registry study died in the year following transcatheter mitral valve repair (TMVR), those who survived showed significant gains in health status.

The average Kansas City Cardiomyopathy Questionnaire (KCCQ) summary scores improved from 41.9 out of 100 points at baseline to 66.7 for the 4,226 patients who completed the requisite follow-up at 30 days. Those improvements persisted out to one year post-TMVR for survivors, without significant increases or decreases, reported lead author Suzanne V. Arnold, MD, MHA, and colleagues in JAMA Cardiology. The analysis used the Transcatheter Valve Therapy Registry to look at TMVR procedures performed from 2013 through 2017 at 217 U.S. hospitals.

When broken down by domains of the KCCQ, post-procedural improvements were largest in the quality-of-life category (average increase of 33.5 points) and smallest in the physical limitations category (mean increase of 18.1 points).

On the whole, 54.2 percent of patients were estimated to be “alive and well” one year after edge-to-edge TMVR with Abbott’s MitraClip device, which meant they survived with a KCCQ summary score of 60 or higher—roughly equivalent to New York Heart Association functional class I or II symptoms. Twenty-three percent of patients died by the one-year mark, while 21.9 percent had persistently poor health status and another 10.1 percent showed declining health status from baseline.

“The mortality rate after TMVR remains high, owing to the age and comorbidities of the patients selected for TMVR, and this is particularly true for patients with advanced kidney or lung disease and those with very poor health status prior to TMVR,” Arnold et al. wrote. “However, among patients who survive, the health status benefits of TMVR are fairly consistent across groups.”

The authors identified several predictors of lower 30-day KCCQ scores, including:

  • Atrial fibrillation: -2.2 points
  • Permanent pacemaker: -2.1 points
  • Severe lung disease: -3.9 points
  • Home oxygen use: -2.7 points
  • Lower starting KCCQ score: -3.9 points for each 10-point decrease
  • In-hospital renal failure: -7.3 points
  • Residual mitral regurgitation: -3.1 points for grade 2+; -7.9 points for grade 3+

“Using these data to help inform the decision process prior to TMVR may help improve patient selection as well as patient expectations for recovery, particularly if a number of risk factors for worse health status are present in an individual patient,” Arnold and coauthors wrote.

“For a procedure that is currently reserved for patients who are poor candidates for valve surgery, is mainly performed to improve quality of life, and has low periprocedural risk, however, the health status outcomes of surviving patients are encouraging and support the continued use of edge-to-edge TMVR in selected patients who are poor candidates for cardiac surgery.”

KCCQ data were missing in 30.7 percent of survivors at 30 days and 52.6 percent of survivors at one year. Although the researchers attempted to use analytic and statistical methods to adjust for the missing data, they acknowledged it was a significant limitation of the study.

“It will be important to develop strategies to improve collection of these data to improve the understanding of these critical outcomes,” the authors wrote. “Potential approaches could include linking reimbursement of TMVR to a minimum threshold of health status ascertainment or providing direct financial support for collection of these data.”