Demographic characteristics, aortic valve intervention rates and all-cause mortality in 4 flow-gradient sub-types of severe aortic stenosis

Abstract

Abstract Introduction Severe aortic stenosis (AS), defined as aortic valve area (AVA) <1.0 cm2, can be divided into 4 categories based on flow status and mean gradient. Stroke volume index <35 ml/m2 has classically been used to define low flow, but recent data suggest that flow rate (FR) <200ml/sec may be a more accurate and robust marker of low flow. Methods We prospectively collected demographic, echocardiographic, aortic valve intervention (AVI) and all-cause mortality data on 1562 patients with symptomatic severe AS from 2010 to 2017 with a mean follow up period of 35±22 months. Patients were divided into 4 flow-gradient sub-groups based on a FR threshold of 200ml/s and mean pressure gradient of 40mmHg. Comparative analyses were performed among the 4 groups using analysis of variance. Results The prevalence of normal flow high gradient (NFHG) severe AS was 30%, NF low gradient (NFLG) 21%, low flow HG (LFHG) 18% and LFLG 31% (Table). Across these 4 sub-groups, there was a graded reduction in LVEF and FR, and an increase in age and all–cause mortality. Conclusions Classification of aortic stenosis based on flow-gradient patterns, shows important differences in the demographic profile and clinical outcome among the 4 groups. Classical NFHG AS was associated with the highest rate of AVI and lowest all-cause mortality compared to the 3 discordant flow-gradient subtypes. The LFLG group had the lowest AVI rates and worst outcome. Funding Acknowledgement Type of funding source: None