Heart Transplant Survival Based on Recipient and Donor Risk Scoring: A UNOS Database Analysis.

Abstract

Unlike the lung allocation score, currently, there is no quantitative scoring system available for patients on heart transplant waiting list. By using United Network for Organ Sharing (UNOS) data, we aim to generate a scoring system based on the recipient and donor risk factors to predict posttransplant survival. Available UNOS data were queried between 2005 and 2013 for heart transplant recipients aged ≥18 years to create separate cox-proportional hazard models for recipient and donor risk scoring. On the basis of risk scores, recipients were divided into five groups and donors into three groups. Kaplan-Meier curves were used for survival. Total 17,131 patients had heart transplant within specified time period. Major factors within high-risk groups were body mass index > 30 kg/m (46%), mean pulmonary artery pressure >30 mmHg (65%), creatinine > 1.5 mg% (63%), bilirubin > 1.5 mg% (54%), noncontinuous-flow left ventricular assist devices (45%) for recipients and gender mismatch (81%) and ischemia time >4 hours (88%) for donors. Survival in recipient groups 1, 2, 3, 4, and 5 at 5 years was 81, 80, 77, 74, and 62%, respectively, and in donor groups 1, 2, and 3 at 5 years was 79, 77, and 70%, respectively (p < 0.001). Combining donor and recipient groups based on scoring showed acceptable survival in low-risk recipients with high-risk donor (75% at 5 years). A higher recipient and donor risk score are associated with worse long-term survival. A low-risk recipient transplanted with high-risk donor has acceptable survival at 5 years, but high-risk recipient combined with a high-risk donor has marginal results. Using an objective scoring system could help get the best results when utilizing high-risk donors.