Conclusions
In this analysis of patients undergoing primary OHT, we found FtoM recipients to have the lowest unadjusted one-year posttransplant survival, and both FtoF and FtoM donation to be associated with increased hazards of mortality after risk adjustment. When looking at proportions of undersizing in these donor-to-recipient sex matching cohorts, FtoM had the lowest rates of undersizing using weight and BMI sizing metrics. However, when looking at distributions of sizing using the pHM metric, FtoM recipients were actually most frequently undersized, accounting for nearly half of the population. In this cohort, increasing degree of undersizing is associated with increased hazards of mortality using all sizing metrics. However, in large degrees of undersizing, pHM had the largest associations with increased mortality. It appears that donor-to-recipient sizing using weight and BMI may be misleading in this FtoM cohort, and pHM may be the best sizing metric to use for these higher-risk patient subset.