QRS duration is a risk indicator of adverse outcomes after MitraClip

Background: While QRS duration is a known marker of left ventricular (LV) function, little is known about its utility for predicting clinical prognosis after transcatheter mitral valve repair (TMVR). We investigated the association between QRS duration and one-year adverse events after TMVR with the MitraClip system.

Methods: From January 2011 through April 2019, we identified consecutive patients who underwent TMVR. Patients who had prior cardiac resynchronization therapy or a ventricular pacing rhythm were excluded. The patients were divided into two groups according to their QRS duration (<120 or ≥ 120 ms). Cox proportional hazard model was applied to determine the association between QRS duration and the composite outcome (all-cause mortality and re-hospitalization due to heart failure) within 1 year.

Results: A total of 348 patients were analyzed. Prolonged QRS duration (≥120 ms) was associated with an increased risk of the composite outcome (adjusted-HR 2.35, 95%CI 1.30-4.24, p = .005). There was a linear relationship between prolonged QRS duration and the increased risk of the composite outcomes. The observed association was consistent both in patients with left ventricular ejection fraction ≤35% and those with >35%. Furthermore, a QRS duration ≥120 ms was associated with lower improvement of LVEF at follow-up (adjusted-β coefficient - 5.31%, 95%CI -8.17 to -2.46, p < .001).

Conclusions: Prolonged QRS duration was associated with an increased risk of mortality and re-hospitalization and less improvement of LVEF following TMVR. QRS duration could be a useful marker to predict adverse outcomes and LV function after TMVR.