Impact of cardiac staging classification in transcatheter aortic valve implantation for major subtypes of severe aortic stenosis

Abstract Background Staging classification to quantify the extent of extra-aortic valve cardiac damage is recognized as a useful prognostic tool in patients undergoing transcatheter aortic implantation (TAVI) for aortic stenosis (AS). However, this classification has not been validated in each AS subtype. Objectives The present study aimed to investigate the prognostic impact of staging classification in patients with four major AS subtypes. Methods In a prospective TAVI registry, patients were classified into high gradient AS (HG-AS), classical low flow low gradient AS (LFLG-AS), paradoxical LFLG-AS, and normal flow low gradient AS (NFLG-AS). Five-year mortality was compared between early stage (stage 0, 1, or 2) and advanced stage (stage 3 or 4). Results Among 1,507 patients undergoing TAVI, 812 patients had HG-AS, 186 patients had classical LFLG-AS, 277 patients had paradoxical LFLG-AS, and 232 patients had NFLG-AS. There were much difference in the distribution of cardiac stage among AS subtypes; advanced stage accounting for 54.3% in HG-AS, 58.6% in NFLG-AS, 62.5% in paradoxical LFLG-AS, and 80.6% in classical LFLG-AS. Patients with advanced stage had higher all-cause mortality compared with early stage in HG-AS and paradoxical LFLG-AS (HRadjusted 2.00; 95% CI 1.44-2.78 and HRadjusted 2.15; 95% CI 1.43-3.21), but not in classical LFLG-AS and NFLG-AS (HRadjusted 1.17; 95% CI 0.70-1.95 and HRadjusted 1.43; 95% CI 0.90-2.27). Conclusions Early stage was associated with a reduced risk for five-year mortality in patients with HG-AS and paradoxical LFLG-AS, while there was comparable mortality between early and advanced stages in patients with classical LFLG-AS and NFLG-AS.