Procedural Experience for Transcatheter Aortic Valve Replacement and Relation to Outcomes

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has been introduced into U.S. clinical practice with efforts to optimize outcomes and minimize the learning curve. OBJECTIVES: The goal of this study was to assess the degree to which increasing experience during the introduction of this procedure, separated from other outcome determinants including patient and procedural characteristics, is associated with outcomes. METHODS: The authors evaluated the association of hospital TAVR volume and patient outcomes for TAVR by using data from 42,988 commercial procedures conducted at 395 hospitals submitting to the Transcatheter Valve Therapy Registry from 2011 through 2015. Outcomes assessed included adjusted and unadjusted in-hospital major adverse events. RESULTS: Increasing site volume was associated with lower in-hospital risk-adjusted outcomes, including mortality (p < 0.02), vascular complications (p < 0.003), and bleeding (p < 0.001) but was not associated with stroke (p = 0.14). From the first case to the 400th case in the volume-outcome model, risk-adjusted adverse outcomes declined, including mortality (3.57% to 2.15%), bleeding (9.56% to 5.08%), vascular complications (6.11% to 4.20%), and stroke (2.03% to 1.66%). Vascular and bleeding volume-outcome associations were nonlinear with a higher risk of adverse outcomes in the first 100 cases. An association of procedure volume with risk-adjusted outcomes was also seen in the subgroup having transfemoral access. CONCLUSIONS: The initial adoption of TAVR into practice in the United States showed that increasing experience was associated with better outcomes. This association, whether deemed a prolonged learning curve or a manifestation of a volume-outcome relationship, suggested that concentrating experience in higher volume heart valve centers might be a means of improving outcomes. (STS/ACC Transcatheter Valve Therapy Registry TVT Registry; NCT01737528).