Incidence, predictors, and midterm clinical outcomes of left ventricular obstruction after transcatheter aortic valve implantation.

Abstract

We aimed to evaluate the incidence and midterm clinical outcomes of left ventricular obstruction (LVO) after transcatheter aortic valve implantation (TAVI). LVO is occasionally unmasked following valve replacement for severe aortic stenosis. However, little is known about the prevalence and effects of LVO after TAVI. A total of 158 patients who underwent TAVI in our center between October 2013 and November 2015 received echocardiographic evaluations at baseline; before hospital discharge; and at 3, 6, and 12 months after TAVI. LVO was defined as a peak pressure gradient >30 mm Hg. Over 1 year of follow-up after TAVI, 21 patients (13.3%) demonstrated postprocedural LVO. The incidence was highest at 3-months follow-up and decreased at 6 months or later. Of the 21 patients with LVO, 20 (95.2%) demonstrated midventricular obstruction (MVO), whereas only 1 (4.8%) showed obstruction of the outflow tract (LVOT) with systolic anterior motion (SAM) of the mitral leaflet. In a multivariate analysis, the LVOT diameter (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.30-0.67; P < 0.001), transvalvular velocity (OR, 2.44; 95% CI, 1.13-5.26; P = 0.023), and the presence of accelerated intraventricular flow at baseline (OR, 6.13; 95% CI, 1.49-25.2; P = 0.012) were associated with the occurrence of LVO. Postprocedural LVO was not associated with midterm all-cause death or heart failure events. In patients who underwent TAVI, MVO occurred more often than LVOT obstruction. However, the occurrence of postprocedural LVO was not associated with worsened clinical outcomes in these patients.