Do age and functional dependence affect outcomes of simultaneous heart–kidney transplantation?

OBJECTIVE: This study assessed characteristics and outcomes of younger (18-65) versus older (>65) recipients of simultaneous heart–kidney (SHK) transplantation with varying functional dependence. METHODS: This study retrospectively analyzed 1398 patients from the United Network for Organ Sharing database who received SHK between 2010 and 2021. Patients who were <18 year old, underwent transplant of additional organs simultaneously, or had previous heart transplant were excluded. The primary end point was all-cause mortality, and secondary end points included adverse events and cause of death. Outcomes were also evaluated by propensity score–matched comparison. RESULTS: The number of annual SHK transplantation in the United States has significantly increased among both age groups over the past 2 decades (P < .0001). After propensity score matching of recipients aged 18 to 65 years (n = 1162) versus age >65 years (n = 236), baseline characteristics were similar and well-balanced between the 2 cohorts. Between matched cohorts, older recipients did not have increased posttransplant mortality compared with younger recipients (90-day survival, P = .85; 7-year survival, P = .61). Multivariable Cox regression analysis found that age (hazard ratio [HR], 1.039 [0.975-1.106], P = .2415) and pretransplant functional status with interaction term for age (some assistance, HR, 0.965 [0.902-1.033], P = .3079; total assistance, HR, 0.976 [0.914-1.041], P = .4610) were not significant risk factors for 7-year post-SHK transplantation mortality. CONCLUSIONS: Older and more functionally dependent recipients in this study did not have increased post-SHK transplantation mortality. These findings have important implications for organ allocation among elderly patients, as they support the need for thorough assessment of SHK candidates in terms of comorbidities, rather than exclusion solely based on age and functional dependence.