Prolonged total isovolumic time is related to reduced long-axis functional recovery following valve replacement surgery for severe aortic stenosis

BackgroundThe left ventricular (LV) long axis (Lax) function is very sensitive in documenting myocardial abnormalities in aortic stenosis (AS). We hypothesized that Lax recovery after aortic valve replacement (AVR) is related to the extent of cavity dyssynchrony measured by total isovolumic time (t-IVT).MethodsA consecutive 107 patients (aged 70 ± 7 years, 70 male) with severe AS and Lax impairment were studied. T-IVT was measured before and after AVR. Reduced Lax function and its post-operative recovery were defined as mitral annular plane systolic excursion (MAPSE) ≦ 10 mm and an increase of MAPSE > 10%, respectively.ResultsLV function improved (EF: 43 ± 8 to 48 ± 10%; MAPSE: 7.9 ± 1.0 to 11.0 ± 2.4 mm) and t-IVT shortened (9.7 ± 3.7 to 7.0 ± 2.8 s/min, p < 0.01 for all) after AVR. Sixty-five (61%) patients had Lax recovery after a median of 32-month follow-up. Univariate predictors were LV size, LA dimensions, the presence of restrictive LV filling and prolonged t-IVT. Only LV end-systolic dimension, restrictive filling and t-IVT (OR 0.61, 95% CI 0.47–0.79, p < 0.01) were independent predictors. A pre-operative t-IVT ≦ 9.3 s/min was 81% sensitive and 63% specific in predicting Lax recovery (AUC 0.81, p < 0.001). The prevalence of CAD or concomitant CABG were similar in 2 patient groups with different t-IVT.ConclusionsLax recovery was evident in the majority of AS patients after AVR. The lower prevalence of Lax recovery seen in patients with prolonged t-IVT suggests that dyssynchrony may play an important role in the process of adverse LV remodeling.