Cardiac Damage Staging Classification Predicts Prognosis in All the Major Subtypes of Severe Aortic Stenosis: Insights from the National Echo Database Australia.

Abstract

INTRODUCTION\nThere are currently no established prognostic models for low-gradient severe aortic stenosis (AS); including those with low-flow, low-gradient (LFLG) or normal-flow, low-gradient (NFLG) severe AS. The Cardiac Damage Staging Classification has been validated as a clinically useful prognostic tool in high-gradient severe AS, but not yet in these other common subtypes of severe AS, LFLG or NFLG.\n\n\nMETHODS\nWe analyzed data from the National Echocardiography Database of Australia, a large national multicenter registry with individual data linkage to mortality. Of 192,060 adults (aged 62.8±17.8 years) with comprehensive ultrasound profiling of the native aortic valve studied between 2000-2019, 12,013 (6.3%) had severe AS. Based on standard echocardiographic parameters, we identified 5,601 high-gradient, 611 classical and 959 paradoxical LFLG and 911 NFLG severe AS patients. Mean follow-up was 88±45 months. All-cause and cardiovascular-related mortality were assessed for each group on an adjusted basis (age and sex) and analyzed by cardiac damage stage.\n\n\nRESULTS\nLFLG patients had greater associated cardiac damage at diagnosis (Stages 3-4 in 34% Classical LFLG, 22.5% paradoxical LFLG, 15.5% NFLG and 14% high-gradient AS, p<0.001). In all 4 major subtypes of severe AS, there was a progressive increase in 1- and 5-year mortality with increasing cardiac damage score. For example, in paradoxical LFLG, compared with stage 0 patients, adjusted 1-year all-cause mortality was 22% higher in Stage 1 patients, 55% higher in stage 2 (p=0.095) and 155% higher in stages 3-4 patients (p<0.001). In classical LFLG patients, compared with stage 1 patients, adjusted 1-year all-cause mortality was 55% higher in Stage 2 patients (p=0.018) and 100% higher in stages 3-4 patients (p<0.001).\n\n\nCONCLUSION\nRegardless of severe AS subtype, increasing severity denoted by the cardiac damage staging classification is strongly associated with increasing mortality risk.