Comparison of outcomes of balloon-expandable versus self-expandable trans-catheter heart valves for severe aortic stenosis

Trans-catheter aortic valve implantation (TAVI) is the treatment of choice for inoperable and high risk patients with severe aortic stenosis. Our objectives were to elucidate potential differences in clinical outcomes and safety between balloon-expandable versus self-expandable trans-catheter heart valves (THV). We performed a retrospective cohort study of all trans-femoral TAVI procedures in Ontario, Canada from 2007-2013. Patients were categorized into either balloon-expandable or self-expandable THV groups. The primary outcomes were 30-day and 1-year death, with secondary outcomes of all-cause readmission. Safety outcomes included bleeding, permanent pacemaker implantation, need for a 2nd THV device, post-procedural para-valvular aortic regurgitation, stroke, vascular access complication and intensive care unit (ICU) length of stay. Inverse probability of treatment weighted regression analyses using a propensity score were used to account for differences in baseline confounders. Our cohort consisted of 714 patients, of whom 397 received a self-expandable THV while 317 had a balloon-expandable THV system. There were no differences in death or all-cause readmission. In terms of safety, the self-expandable group was associated with significantly higher rates of in-hospital stroke (p-value <0.05), need for a 2nd THV device (5.3% vs 2.7%; p-value 0.013) and permanent pacemaker (22.6% vs 8.9%; p-value <0.001), while the balloon-expandable group had more vascular access site complications (23.1% vs 16.7%; p-value 0.002). Thus, we found similar clinical outcomes of death or readmission for patients undergoing trans-femoral TAVI with either balloon-expandable or self-expandable THV systems. However, there were important differences in their safety profiles.