Effect of Availability of Transcatheter Aortic-Valve Implantation on Survival For All Patients with Severe Aortic Stenosis.

Clinical outcomes for the overall severe aortic stenosis (AS) patient population are not well described because those medically managed are not included in procedural registries, and AS severity is not identifiable from administrative data. We aim to assess whether transcatheter aortic valve implantation (TAVI) availability has been associated with overall changes in survival for the whole AS patient population. This is important because patients with AS in real-world practice may differ from those included in randomized controlled trials, potentially attenuating the purported treatment efficacy estimated in trials. Classic severe AS patients (mean gradient ≥40 mmHg) were identified from an echocardiography database. Survival was defined as time since severe AS diagnosis until death. We first compared survival among all patients before and after TAVI availability in 2008. To further understand mechanism, we then assessed whether any survival changes were attributable to TAVI with extended Cox regression models comparing survival among TAVI, surgical aortic valve replacement (SAVR), and medically managed patients. 3663 classic severe AS patients were included in the study. Median survival years for all patients were greater during the TAVI-era than Pre-TAVI-era (>11.5 vs. 6.8, 5-year-HR=0.8, time-varying effect p 11.5 vs. 9.5, 5-year-HR=0.7, time-varying effect p=0.045). TAVI patients age 65-74 had the lowest risk of death compared to medically managed patients (HR=0.2, 95% CI=[0.1, 0.3], p<0.0001). In conclusion, in the TAVI-era, overall survival for patients with severe AS has doubled. This improvement is most marked for patients 65-74 years of age.