Predicting changes in flow category in patients with severe aortic stenosis and preserved left ventricular ejection fraction on medical therapy

Abstract

Background/Objectives: Controversy surrounds the prognosis and management of patients with paradoxical low-flow severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF). It was not certain if patients in a particular flow category remained in the same category as disease progressed. We investigated whether there were switches in categories and if so, their predictors. Methods: Consecutive subjects (n = 203) with isolated severe AS and paired echocardiography (>180 days apart) were studied. They were divided into 4 groups, based on their flow categories and if they progressed on subsequent echocardiography to switch or remain in the same flow category. Univariate analyses of clinical and echocardiographic parameters identified predictors of these changes in flow category. Results: One hundred eighteen were normal flow (SVI ≥ 35 mL/m2), while 85 were low flow on index echocardiography. In the patients with normal flow, 33% switched to low flow. This was associated with higher valvuloarterial impedance (Zva, P 4.77 mm Hg/mL/m2, AUC = 0.81 [95% CI:0.75–0.87, P