How Small Is Too Small? A Systematic Review of Center Volume and Outcome After Cardiac Transplantation

Abstract

Background-The aim of this study was to assess the relationship between the volume of cardiac transplantation procedures performed in a center and the outcome after cardiac transplantation. Methods and Results-PubMed, Embase, and the Cochrane library were searched for articles on the volume-outcome relationship in cardiac transplantation. Ten studies were identified, and all adopted a different approach to data analysis and varied in adjustment for baseline characteristics. The number of patients in each study ranged from 798 to 14 401, and observed 1-year mortality ranged from 12.6% to 34%. There was no association between the continuous variables of center volume and observed mortality. There was a weak association between the continuous variables of center volume and adjusted mortality up to 1 year and a stronger association at 5 years. When centers were grouped in volume categories, low-volume centers had the highest adjusted mortality, intermediate-volume centers had lower adjusted mortality, and high-volume centers had the lowest adjusted mortality but were not significantly better than intermediate-volume centers. Category limits were arbitrary and varied between studies. Conclusions-There is a relationship between center volume and mortality in heart transplantation. The existence of a minimum acceptable center volume or threshold is unproven. However, a level of 10 to 12 heart transplants per year corresponds to the upper limit of low-volume categories that may have relatively higher mortality. It is not known whether outcomes for patients treated in low-volume transplant centers would be improved by reorganizing centers to ensure volumes in excess of 10 to 12 heart transplants per year. (Circ Cardiovasc Qual Outcomes. 2012;5:783-790.)

Trends in the Use and Outcomes of Ventricular Assist Devices Among Medicare Beneficiaries, 2006 Through 2011

“…Previous observational studies have shown a volume-outcome relationship in which surgical procedures improve with clinical experience (34,35). This phenomenon has also been observed to a limited extent among clinical trial patients receiving pulsatile VADs who had improvements in 1-year mortality with increasing institutional experience (36).…”

Minimum Volume Standards in Surgery - Are We There Yet

“…Training of the surgeon and his/her experience level have a unique influence on the early results after renal transplantations [31]. There is also a definite relationship between center volume and mortality in heart transplants [32]. Heart transplants in Germany are not under the influence of Mm-R yet.…”

Institutional volume of heart transplantation with left ventricular assist device explantation influences graft survival

“…Most significant advances have occurred during the first year after transplantation, likely related to improvement in surgical technique (4), and immunosuppressive therapy (1). Our understanding of the expertise needed to treat these complex patients has dramatically changed, as a clear association between transplant center volume and graft survival after transplant has been demonstrated, especially among patients with high perioperative risk (5–7). Landmark reports have identified a relationship between LVAD center implantation volume and survival for both pulsatile and continuous flow LVAD populations (8, 9).…”