Comparison of transcatheter aortic valve implantation outcomes between normal flow low gradient severe aortic stenosis and normal flow high gradient severe aortic stenosis.

Abstract Background Normal flow low gradient severe aortic stenosis (NFLG-AS) with preserved ejection fraction is the most prevalent form of low gradient severe aortic stenosis. Despite the increased prevalence, the clinical outcomes and management strategy of NFLG-AS remain controversial. Therefore, our study aimed to evaluate transcatheter aortic valve implantation (TAVI) outcomes of patients with NFLG-AS compared with normal flow high gradient severe aortic stenosis (NFHG-AS). Methods We performed a retrospective analysis of 394 patients who underwent TAVI between January 2011 to September 2020. Among 394 patients, 232 patients had NFLG-AS, and 162 patients had NFHG-AS. The primary outcomes included all-cause mortality and cardiovascular mortality. In addition, multiple secondary outcomes were evaluated, including stroke, myocardial infarction, duration of hospital stay, new-onset atrial fibrillation, temporary or permanent pacemaker requirement, major bleeding, blood transfusion, vascular complications, acute kidney injury, hemodialysis requirement, symptom improvement, and repeat hospitalizations due to any cardiac disease. Results The cumulative six months incidence of all-cause mortality and cardiovascular mortality were similar between and NFLG-AS and NFHG-AS (4.32% vs. 5.17%, P = 0.71 and 2.47% vs. 2.59%, P = 0.94 respectively). There was no difference in the rates of stroke, myocardial infarction, duration of hospital stay, new-onset atrial fibrillation, temporary or permanent pacemaker requirement, major bleeding, blood transfusion, vascular complications, acute kidney injury, hemodialysis requirement, and symptom improvement between the two groups. However, patients with NFLG-AS compared to NFHG-AS had more frequent cardiac-related repeat hospitalizations (19.14% vs. 11.64%, P = 0.04%). Conclusion There was no significant difference in all-cause mortality and cardiovascular mortality between NFLG-AS and NGHG-AS six months post-TAVI. However, patients undergoing TAVI with NFLG-AS had significantly higher rates of cardiac-related repeat hospitalizations.