Comparison of Early Outcomes in Patients at Estimated Low, Intermediate and High Risk Undergoing Transcatheter Aortic Valve Implantation: A Multicentre Australian Experience

Background Transcatheter aortic valve implantation (TAVI) has been shown to be a safe and effective alternative to surgical aortic valve replacement (SAVR) in high- and intermediate-risk patients with severe aortic stenosis. TAVI for patients at lower risk of periprocedural mortality has not been extensively investigated. We aimed to describe outcomes in low-, intermediate- and high-risk patients undergoing TAVI in a multicentre Australian study. Methods We evaluated data from 601 patients who underwent TAVI at two hospitals in Melbourne, from August 2008 to February 2018. Patients were stratified according to low risk (STS<4%), intermediate risk (Society for Thoracic Surgeons [STS] 4.0-7.9%) and high risk (STS>8%). Outcomes were reported according to Valve Academic Research Consortium-2 (VARC-2) criteria. Results Mean age was 8465 years and 49% were female. Two hundred and eighty-five (285) (47%) patients were low-risk, 243 (40%) were intermediate risk and 73 (12%) were high risk. Thirty-day (30-) mortality was low in all three groups (1.1%, 1.7% and 1.4%, respectively, p=0.8). Similarly, patients had a low risk of disabling stroke (0.4%, 1.3%, 0%, p=0.8). Rates of post-procedural permanent pacemaker were also similar (21%, 27%, 26%, p=0.5). At least moderate aortic regurgitation occurred in 9% of patients at discharge with no significant differences between groups. Conclusions In this large Australian multicentre cohort of TAVI patients, 30-day mortality, and post-procedural outcomes were excellent and similar across the patient-risk spectrum. Our study offers further support for the safety of TAVI in low-risk populations and demonstrates the limitations of the STS score.