The interaction of age and time on durable left ventricular assist device and its effect on heart transplant outcomes

This study aims to assess the interaction between age and left ventricular assist device duration on heart transplant outcomes in the modern era.

All heart transplantation in adults with a fully magnetically levitated centrifugal flow left ventricular assist device between October 2018 and June 2025 were identified from the United Network for Organ Sharing database. Groups were stratified primarily by age less than 55 years and 55 years or more and secondarily by age less than 2 years and 2 years or more of left ventricular assist device support. The primary outcome was post-heart transplant survival.

A total of 1005 patients were aged less than 55 years, with 608 having a left ventricular assist device for less than 2 years and 397 having a left ventricular assist device for 2 years or more. There was no significant difference in post-heart transplant survival between left ventricular assist device duration groups at 90 days (95.3% vs 94.4%, P = .57), 1 year (93.7% vs 90.2%, P = .07), or 3 years (88.0% vs 83.9%, P = .061). A total of 1411 patients were aged 55 years or more, with 935 having a left ventricular assist device for less than 2 years and 476 having a left ventricular assist device for 2 years or more. Patients having a left ventricular assist device for less than 2 years exhibited improved survival at 90 days (92.4% vs 89.2%, P = .046), 1 year (87.8% vs 81.9%, P = .0051), and 3 years (81.4% vs 72.7%, P = .0011). Multivariable adjustment showed a significant impact of age 55 years or more on post-heart transplant mortality (hazard ratio, 1.96; 95% CI, 1.34-2.86; P < .001); however, having a left ventricular assist device for 2 years or more showed no significant impact (hazard ratio, 1.47; 95% CI, 0.91-2.36; P = .116). Formal testing revealed no significant interaction of age and left ventricular assist device duration (hazard ratio, 1.1; 95% CI, 0.63-1.91; P = .735).

Although there is a lower observed post-heart transplant survival in patients aged 55 years or more and supported by a left ventricular assist device for 2 years or more, formal testing reveals no significant interaction of these variables on mortality.