Study Cohort
Of the 33,657 patients included in the study, 3,728 (11%) experienced
the primary outcome of death within one year (Figure 1 ). The
majority of study participants were male (75%) with an average age of
52.8 ±12.4 years. Balancing by primary outcome, patients were randomly
split into 80% training cohort and 20% validation cohort. Patient
characteristics were similar between cohorts, including age, sex,
etiology of heart failure, end-organ function, pre-transplant mechanical
circulatory support, and days spent on waiting list (Table 1 ).