Is center specific implantation volume a predictor of clinical outcomes with mechanical circulatory support?

This study examined the relationship between implant center volumes and survival rate for implantation of mechanical circulatory support (MCS) devices. Using the Novacor left ventricular assist system (LVAS) Registry, the study cohort consisted of 1,348 patients with established outcomes from 97 centers stratified by the implant center volume: 1-10 implants (n = 199, 65 centers), 11-25 implants (n = 189, 12 centers), 26-50 implants (n = 445, 13 centers), and more than 51 implants (n = 515, 7 centers). Regression and correlation analyses were performed. Regression analysis found a negative impact on survival for centers performing 1-10 implants, with an odds ratio of 1.73 (95% confidence interval, 1.28-2.34; p < 0.001). Composite results from the first 10 implants of each larger volume center were then compared with the group with 1-10 implants, demonstrating that centers with larger volumes had superior results, even in the early patient experience (61% versus 46% transplanted/weaned, p < 0.001). However, when annualized outcomes (i.e., outcomes by calendar year) were determined for each center, no significant correlation was found between the outcomes and annualized frequency of implantation (R2 = 0.003, n = 422). Although the total number of implants performed at a specific center appeared to impact clinical outcomes, no correlation was found between annualized frequency of implant and clinical outcome.