A Frailty Screening Tool for Patients undergoing Orthotopic Heart Transplant.

BACKGROUND

Although frailty has been previously shown to negatively influence post-operative outcomes, frailty measurements remain undefined and underutilized for patients undergoing orthotopic heart transplantation (OHT). This study aims to derive and validate an OHT frailty screening tool.

METHODS

The UNOS database was queried for adults undergoing OHT between 2000 and 2018. The total population was randomly divided into derivation (80%) and validation (20%) cohorts. The primary outcome was mortality. Secondary outcomes included rates of major morbidities and hospital length of stay (LOS). Variables that were constructs within pre-existing frailty tools and that were predictive of a composite frailty outcome within the derivation cohort were incorporated into a multivariable regression model (exploratory, p<0.2). Independent predictors of frailty were included in the OHT frailty screening tool.

RESULTS

36,790 OHT recipients met criteria for inclusion. Twelve variables were identified as independent predictors of frailty and included as OHT frailty screening tool constructs. Recipients in the validation cohort were stratified as non-frail (72.9%, n=5,363), pre-frail (24.4%, n=1,795), and frail (2.7%, n=200). Frail patients had significantly higher rates of post-transplant stroke, renal failure, and mortality at all time intervals as well as longer LOS (all p<0.001). The risk model's predictive rates of mortality strongly correlated with the observed rates of mortality (r2=0.97, p<0.001). The c-index of the OHT frailty score was 0.74.

CONCLUSIONS

The OHT frailty screening tool is highly predictive of adverse post-transplant outcomes. This screening tool may provide a framework to improve enhance existing risk stratification tools and improve overall resource utilization.