Impact of Preprocedural Mitral Regurgitation Upon Mortality After Transcatheter Aortic Valve Implantation (TAVI) for Severe Aortic Stenosis

Objective: To identify the effects of preprocedural significant mitral regurgitation (MR) and change in MR severity upon mortality after transcatheter aortic valve implantation (TAVI) using the Edwards SAPIEN system.

Methods: A retrospective analysis of 316 consecutive patients undergoing TAVI for aortic stenosis at a single centre in the UK between March 2008 and January 2013. Patients were stratified into two groups according to severity of MR: ≥grade 3 were classed as significant and ≤grade 2 were non-significant. Change in MR severity was assessed by comparison of baseline and 30-day echocardiograms.

Results: 60 patients had significant MR prior to TAVI (19.0%). These patients were of higher perioperative risk (logistic EuroScore 28.7±16.6% vs 20.3±10.7%, p=0.004) and were more dyspnoeic (New York Heart Association class IV 20.0% vs 7.4%, p=0.014). Patients with significant preprocedural MR displayed greater 12-month and cumulative mortality (28.3% vs 20.2%, log-rank p=0.024). Significant MR was independently associated with mortality (HR 4.94 (95% CI 2.07 to 11.8), p<0.001). Of the 60 patients with significant MR only 47.1% had grade 3-4 MR at 30 days (p<0.001). Patients in whom MR improved had lower mortality than those in whom it deteriorated (log-rank p=0.05).

Conclusions: Significant MR is frequently seen in patients undergoing TAVI and is independently associated with increased all-cause mortality. Yet almost half also exhibit significant improvements in MR severity. Those who improve have better outcomes, and future work could focus upon identifying factors independently associated with such an improvement.