The Impact of Recipient Age on Outcomes of Simultaneous Heart-Lung Transplantation

Abstract

<h3>Purpose</h3> The shortage of donor organs underscores the importance of identifying risk factors for adverse outcomes in multiorgan transplantation. Heart-lung transplantation (HLTx) is relatively uncommon, and there is a paucity of literature to suggest at what recipient age threshold mortality risk increases. This analysis aimed to identify a threshold of age that predicts adverse post-HLTx outcomes. <h3>Methods</h3> The United Network of Organ Sharing (UNOS) registry was used to identify adult combined HLTx from 2005-2021. The primary outcome was one-year mortality. Threshold regression analysis was used to identify the threshold at which age impacts one-year post-HLTx mortality. Patients were stratified according to the age threshold. Kaplan-Meier analysis was used to model survival, and multivariable Cox proportional hazards regression was used for risk-adjustment. <h3>Results</h3> 453 patients underwent HLTx in the study period. Threshold analysis identified that age >58 years impacted one-year mortality. Using this threshold, 47 (10.38%) patients were included in the older cohort, and 406 patients (89.62%) were included in the younger cohort. Older recipients were more likely to be male, have diabetes, and have higher lung allocation scores compared to younger recipients. On Kaplan Meier analysis, one-year survival was significantly lower in patients >58 years (64.7% vs 82.0%, <i>p</i> = 0.007). On multivariable analysis, the adjusted hazard for one-year mortality in recipients older than 58 years was 2.27 (95% CI [1.21-4.28], <i>p</i> =0.011). Recipient creatinine, total bilirubin, temporary mechanical circulatory support, and non-ABO-identical matching were also independent predictors of one-year mortality. Patients >58 years more frequently required new onset dialysis after HLTx (19.2% vs 12.8%, <i>p</i> = 0.031) and had a higher incidence of postoperative stroke (13.0% vs 4.5%, <i>p</i> = 0.040). <h3>Conclusion</h3> The threshold of recipient age above which one-year mortality risk most increases in HLTx is 58 years. Although age >58 is a risk factor for one-year mortality with over 2-fold increased risk as compared to younger patients, the majority (65%) of older HLTx recipients do survive to 1-year. These data suggest that older age should be heavily considered in the patient selection process for HLTx but may not necessarily need to serve as an absolute contraindication, particularly in the absence of other risk factors.