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

Objectives: We aimed to evaluate the incidence and midterm clinical outcomes of left ventricular obstruction (LVO) after transcatheter aortic valve implantation (TAVI). Backgrounds: LVO is occasionally unmasked following valve replacement for severe aortic stenosis. However, little is known about the prevalence and effects of LVO after TAVI. Methods: 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. Results: 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. Conclusion: 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.