The Association of Echocardiographically Measured Donor Left Ventricular Mass and 1-Year Outcomes After Heart Transplantation

BACKGROUND Donor-recipient heart size matching is crucial in heart transplantation; however, the often-used predicted heart mass (PHM) ratio may be inaccurate in the setting of obesity. OBJECTIVES In this study, the authors sought to investigate the association between echocardiographically measured donor left ventricular mass (LVM) for heart size matching and the risk of the primary 1-year composite outcome of death or retransplantation. METHODS The Donor Heart Study was a prospective, multicenter, observational cohort study that collected echocardiograms from brain-dead donors. The measured LVM ratio (donor measured LVM/recipient predicted LVM) was defined as the exposure variable, and the association with the primary outcome was analyzed with Cox proportional hazard modeling. Secondary analyses evaluated the association of the PHM and predicted LVM (donor predicted LVM/recipient predicted LVM) ratios with the primary outcome. RESULTS In 2,015 heart transplants, the measured LVM ratio demonstrated that undersized matches (<0.80) had a 47% higher risk (adjusted HR [aHR]: 1.47; 95% CI: 1.01-2.15) and oversized (>1.20) matches had a 58% increased risk (aHR: 1.58; 95% CI: 1.05-2.37) of the 1-year composite outcome compared with ideally matched transplants. However, the PHM and predicted LVM ratios were not associated with the primary outcome. Nonlinear modeling demonstrated a U-shaped relationship between the measured LVM ratio and composite outcome. The measured LVM ratio had superior predictive power for poor post-transplantation outcomes in obese recipients. CONCLUSIONS Measuring donor LVM with the use of echocardiography may provide a more accurate method for donor-recipient heart size matching that could improve heart transplant outcomes, especially in obese recipients.