Diastolic mitral regurgitation following transcatheter aortic valve replacement: Incidence, predictors, and association with clinical outcomes.

BACKGROUND: Diastolic mitral regurgitation (DMR) results from atrioventricular conduction disturbances, acute aortic regurgitation, and/or marked elevation of left ventricular filling pressure. Generally benign, in some clinical circumstances DMR has presumed to result in hemodynamic decompensation. The aforementioned causes of DMR are frequently encountered in patients treated by transcatheter aortic valve replacement (TAVR) but its clinical significance in this setting has not been studied. We sought to investigate the incidence of DMR and its prognostic implications following TAVR.

METHODS: Baseline clinical and echocardiographic variables from a prospective TAVR registry were analyzed to determine the correlates of post-procedural DMR and its impact on late outcomes (all-cause mortality and the composite of mortality and readmission due to heart failure).

RESULTS: Of 267 patients undergoing TAVR, post-procedural DMR was present in 25 (9.3%). Independent predictors of DMR included pacemaker implantation [OR=2.7 (95%CI 1.03-6.50)], post-procedural systolic MR and aortic regurgitation [OR=3.7 (1.20-10.80) and OR=4.1 (1.50-10.60), respectively], and use of self-expanding bioprostheses [OR=4.9 (1.60-21.0)]. The incidence of the combined endpoint of death and/or readmission for heart failure was higher in patients with versus those without DMR (25% vs. 41%, respectively, p=0.08), although this association did not attain statistical significance on multivariable analyses. Interaction term analysis indicated a trend toward a heightened risk for the composite endpoint among patients with post-procedural aortic regurgitation (≥moderate) in whom DMR occurred (χ2 2.94, p=0.09).

CONCLUSIONS: Although DMR following TAVR is common (occurring in approximately 1 of 10 patients), it is not independently associated with an increased risk of death and/or readmission for heart failure. Therefore, DMR post TAVR is more likely a marker of cardiac dysfunction than a causative factor.