Learning curves for transfemoral transcatheter aortic valve replacement in the PARTNER-I trial: Success and safety.

OBJECTIVES: To identify number of cases needed to maximize device success and minimize adverse events after transfemoral transcatheter aortic valve replacement (TF-TAVR), and determine if adverse events were linked to the technical performance learning curve. BACKGROUND: TF-TAVR is a complex procedure with an incompletely characterized learning curve for clinical outcomes. METHODS: From 4/2007-2/2012, 1521 patients underwent TF-TAVR in the PARTNER-I trial. Outcomes learning curves were defined as number of cases needed to reach a plateau for device success, adverse events, and post-procedure length of stay. Institutional variation was accounted for by mixed-model non-linear techniques, which were also used to identify contribution of the procedure time learning curve to 30-day major adverse events and length of stay. RESULTS: Eighty percent device success was achieved after 22 cases; major vascular complications fell below 5% after 70 cases and major bleeding below 10% after 25 cases. It took an average of 28 cases to achieve a consistent low risk of 30-day major adverse events, but institutions entering in the middle of the trial achieved it after about 26. The most significant correlate of 30-day major adverse events and post-procedure length of stay was procedure time (P < 0.0001). However, this association was related to patient and unmeasured variables, not the procedure time learning curve (P = 0.6). CONCLUSIONS: By end of trial, a consistent low risk of adverse events was achieved after ∼26 cases. However, these improved results were due to change in patient risk profile; outcomes were not linked to the technical performance learning curve. © 2015 Wiley Periodicals, Inc.

Learning curves for transapical transcatheter aortic valve replacement in the PARTNER-I trial: Technical performance, success, and safety.

OBJECTIVES: Introduction of hybrid techniques, such as transapical transcatheter aortic valve replacement (TA-TAVR), requires skills that a heart team must master to achieve technical efficiency: the technical performance learning curve. To date, the learning curve for TA-TAVR remains unknown. We therefore evaluated the rate at which technical performance improved, assessed change in occurrence of adverse events in relation to technical performance, and determined whether adverse events after TA-TAVR were linked to acquiring technical performance efficiency (the learning curve). METHODS: From April 2007 to February 2012, 1100 patients, average age 85.0 ± 6.4 years, underwent TA-TAVR in the PARTNER-I trial. Learning curves were defined by institution-specific patient sequence number using nonlinear mixed modeling. RESULTS: Mean procedure time decreased from 131 to 116 minutes within 30 cases (P = .06) and device success increased to 90% by case 45 (P = .0007). Within 30 days, 354 patients experienced a major adverse event (stroke in 29, death in 96), with possibly decreased complications over time (P âˆ¼ .08). Although longer procedure time was associated with more adverse events (P < .0001), these events were associated with change in patient risk profile, not the technical performance learning curve (P = .8). CONCLUSIONS: The learning curve for TA-TAVR was 30 to 45 procedures performed, and technical efficiency was achieved without compromising patient safety. Although fewer patients are now undergoing TAVR via nontransfemoral access, understanding TA-TAVR learning curves and their relationship with outcomes is important as the field moves toward next-generation devices, such as those to replace the mitral valve, delivered via the left ventricular apex.