Recovery of left ventricular mechanics after transcatheter aortic valve implantation: effects of baseline ventricular function and postprocedural aortic regurgitation

Abstract

Background: Impaired left ventricular (LV) myocardial deformation is associated with adverse outcome in patients with severe aortic stenosis (AS). The aim of this retrospective study was to assess the impact of transcatheter aortic valve implantation (TAVI) on the recovery of myocardial mechanics and the influence of postprocedural aortic regurgitation (AR).

Methods: Speckle-tracking echocardiography was used to assess multidirectional myocardial deformation (longitudinal and circumferential strain) and rotational mechanics (apical rotation and twist) before and at midterm follow-up after TAVI. Predictors of myocardial recovery, defined as a ≥20% relative increase in the magnitude of global longitudinal strain compared with baseline, were examined.

Results: Sixty-four patients (median age, 83 years; interquartile range, 77-86 years) with severe AS and high surgical risk (mean European System for Cardiac Operative Risk Evaluation score, 20 ± 13%) were evaluated. Overall, LV longitudinal deformation was impaired at baseline compared with controls. At 5 ± 3 months after TAVI, LV longitudinal deformation had significantly improved only in the group of patients with baseline LV ejection fractions (LVEF) ≤ 55%: global longitudinal strain from -9.7 ± 3.7% to -11.8 ± 3.2% (P = .05), longitudinal strain rate from -0.44 ± 0.14 sec(-1) to -0.57 ± 0.16 sec(-1) (P = .001), and early diastolic strain rate from 0.38 ± 0.17 sec(-1) to 0.49 ± 0.18 sec(-1) (P = .01). In patients with normal LVEFs, LV twist was supraphysiologic at baseline and normalized after TAVI (from 16.1 ± 6.9° to 11.9 ± 6.2°, P = .004). In patients with baseline LVEFs ≤ 55%, circumferential deformation was impaired before TAVI and improved after TAVI. Baseline LVEF (odds ratio, 0.56 per 10% increment; P = .02) and global longitudinal strain (odds ratio, 0.65 per absolute 1% increment; P < .001) were significant predictors of myocardial recovery. LV mass, volumes, and longitudinal strain failed to favorably remodel in patients with post-TAVI important AR (defined as new mild post-TAVI AR or moderate or severe post-TAVI AR [either preexisting or new AR]).

Conclusions: TAVI restores LV function toward more physiologic myocardial mechanics in both normal- and depressed-LVEF groups. Patients with lower systolic function derive the most benefit in terms of longitudinal reverse remodeling. Postprocedural AR adversely affects LV structural and functional remodeling.

Keywords: Aortic stenosis; Myocardial mechanics; Paravalvular aortic regurgitation; Speckle-tracking echocardiography; Strain; Transcatheter aortic valve implantation.