Outcomes of Patients at Estimated Low, Intermediate, and High Risk Undergoing Transcatheter Aortic Valve Implantation for Aortic Stenosis

Abstract

Intermediate- or low-risk patients with severe aortic stenosis were excluded from earlier transcatheter aortic valve implantation (TAVI) clinical trials; however, they are already being treated by TAVI despite a lack of data regarding the safety and efficacy in these patients. We aimed to assess the safety and efficacy of TAVI in patients at intermediate or low risk. Patients undergoing TAVI during 2008 to 2014 were included into a shared database (n = 1,327). Procedural outcomes were adjudicated according to Valve Academic Research Consortium 2 definitions. Patients were stratified according to their Society of Thoracic Surgeons (STS) score into 3 groups: high (STS ≥8, n = 223, 17%), intermediate (STS 4 to 8; n = 496, 38%), or low risk (STS <4; n = 576, 45%). Low-risk patients were significantly younger and more likely to be men compared to intermediate- and high-risk patients. Baseline characteristics differed significantly between the groups with a gradual increase in the rates of previous bypass surgery, stroke, peripheral vascular disease, renal failure, lung disease, and frailty scores, from low to high risk groups. Compared with intermediate- and high-risk patients, low-risk patients were more likely to undergo TAVI through the transfemoral route (81% vs 88% vs 95%, p <0.001) and under conscious sedation (69% vs 72% vs 81%, <0.001). There were no significant differences in the rates of procedural complications apart from acute kidney injury (19% vs 17% vs 13%, p = 0.03) and stroke rates (4.5% vs 2% vs 2.3%, p = 0.1). Short- and long-term mortality rates were significantly higher for intermediate- (hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.2 to 2.9) and high-risk patients (HR 4.1, 95% CI 2.7 to 6.4) than low-risk patients also after multivariate adjustment (HR 1.6, 95% CI 1 to 2.6 and HR 2.7, 95% CI 1.7 to 4.5, respectively; all p <0.05). In conclusion, TAVI for intermediate- and low-risk patients is safe and associated with improved outcome compared with high-risk patients.