Does recipient age impact functional outcomes of orthotopic heart transplantation?

Background This study evaluated changes in physical functional performance after orthotopic heart transplantation (OHT) with particular attention to the impact of recipient age on functional outcomes. Methods Retrospective review of all first-time, single-organ adult OHTs in the United States between 2005 and 2010. Patients were primarily stratified by age. The validated Karnofsky performance scale, which ranges from 0 (death) to 100 (fully independent with no evidence of disease and no complaints), was used to measure functional status. Results A total of 10,049 OHT recipients were identified, with 1,431 (14%) aged 65 years or greater. Mean Karnofsky score prior to OHT was comparable between cohorts (younger: 50.7 ± 25.2 versus older: 50.1 ± 25.0; p = 0.38). At a median follow-up of 2.1 years (interquartile range 0.7 to 3.3 years), 64% of OHT recipients had improved functional performance. The mean improvement in Karnofsky score was similar between younger and older patients (19.6 ± 42.0 vs 17.5 ± 41.8; p = 0.10). Twenty percent of younger patients were functionally independent prior to OHT, with 67% being functionally independent at last follow-up (p < 0.001). Similarly, in the older cohort, 20% were functionally independent prior to OHT, with 66% being functionally independent at last follow-up (p < 0.001). Multivariable analysis adjusting for potential confounders confirmed that age, both as a continuous and categoric variable, did not impact odds of functional improvement after OHT. Subanalysis using 70 years as the age cutoff produced similar results. Conclusions In the modern era, OHT is associated with improvements in functional performance in most recipients, and this beneficial effect is preserved across the age spectrum. These data provide a benchmark for functional outcomes after OHT and may have important implications in organ allocation.