Implementation of Echocardiography Core Laboratory Best Practices: A Case Study of the PARTNER I Trial

Background Multicenter clinical trials use echocardiographic core laboratories to ensure expertise and consistency in the assessment of imaging eligibility criteria, as well as safety and efficacy end points. The aim of this study was to report the real-world implementation of guidelines for best practices in echocardiographic core laboratories, including their feasibility and quality results, in a large, international multicenter trial. Methods Processes and procedures were developed to optimize the acquisition and analysis of echocardiograms for the Placement of Aortic Transcatheter Valves (PARTNER) I trial of percutaneous aortic valve replacement for aortic stenosis. Comparison of baseline findings in the operative and nonoperative cohorts and reproducibility analyses were performed. Results Echocardiography was performed in 1,055 patients (mean age, 83 years; 54% men) The average peak and mean aortic valve gradients were 73 ± 24 and 43 ± 15 mm Hg, and the average aortic valve area was 0.64 ± 0.20 cm2 . The average ejection fraction was 52 ± 13% by visual estimation and 53 ± 14% by biplane planimetry. The mean left ventricular mass index was 151 ± 42 g/m2 . The inoperable cohort had lower left ventricular mass and mass indexes and tended to have more severe mitral regurgitation. Core lab reproducibility was excellent, with intraclass correlation coefficients ranging from 0.92 to 0.99 and κ statistics from 0.58 to 0.85 for key variables. The image acquisition quality improvement process brought measurability to >85%, which was maintained for the duration of the study. Conclusions This real-world echocardiographic core lab experience in the PARTNER I trial demonstrates that a high standard of measurability and reproducibility can result from extensive quality assurance efforts in both image acquisition and analysis. These results and the echocardiographic data reported here provide a reference for future studies of aortic stenosis patients and should encourage the wider use of echocardiography in clinical research.