The impact of centre volume on outcomes of orthotopic heart transplant in older recipients.

Abstract

The aim of this study was to evaluate the impact of overall and older-recipient-specific centre volumes on outcomes of orthotopic heart transplant (OHT) in older recipients. Patients aged ≥60 years undergoing OHT were identified in the United Network for Organ Sharing (UNOS) registry. The primary outcome was 1-year post-OHT mortality. Secondary outcomes included the incidence and impact on 1-year survival of postoperative complications including infection, renal failure requiring dialysis and stroke. Patients were divided into equal size tertiles based on overall and older-recipient-specific OHT centre volumes. A total of 5373 older recipients were identified. Mean overall and older-recipient-specific volumes were 27.5 ± 19.5 and 9.4 ± 7.3 OHT/year, respectively. Although overall and older-recipient-specific low-volume centres were at higher risk of mortality in separate multivariable analysis, only older-recipient-specific volume contributed significantly to post-OHT mortality in the combined multivariable analysis (P < 0.05). In the receiver operating characteristic analysis, an older-recipient-specific volume of 8 OHTs/year was identified as the most discriminative volume threshold for mortality (area under the receiver operating characteristic curve = 0.68). Although low older-recipient-specific volume centres did not have significantly higher incidences of postoperative complications, they had significantly worse 1-year survival rates compared to higher volume centres in patients with postoperative infection or dialysis (each P < 0.01). This large-cohort analysis demonstrates that older-recipient-specific centre volume contributes to post-OHT outcomes in the older recipients more significantly than overall volume. This may be a consequence of higher older-recipient-specific volume centres to better manage specific complications in this patient population.