The Edmonton Frail Scale Improves the Prediction of 30-Day Mortality in Elderly Patients Undergoing Cardiac Surgery: A Prospective Observational Study

Abstract

Objectives: To investigate whether the Edmonton Frail Scale (EFS), a multidimensional frailty assessment tool, improves the prediction of 30-day or in-hospital mortality over the use of the European System for Cardiac Outcome Risk Evaluation (EuroSCORE) II alone.

Design: Single-center prospective observational study.

Setting: University hospital.

Participants: Patients aged 75 years or older undergoing cardiac surgery between February 2014 and May 2017.

Intervention: No intervention was performed. The EFS was administered the day before surgery.

Measurements and main results: The primary endpoint was 30-day or in-hospital mortality. Secondary endpoints were times to discharge from the intensive care unit (ICU) and from the hospital, discharge to a health care facility, and ability to return home by postoperative day 30. The EFS had a good discriminative ability for 30-day mortality (area under the receiver operating characteristic curve = 0.69; 95% confidence interval [CI], 0.56-0.82). Adding frailty, defined by an EFS ≥8, to the EuroSCORE II significantly improved the prediction of 30-day (p = 0.04) mortality. The integrated discrimination index was 0.03 (95% CI, 0.01-0.06, p = 0.01), meaning that the difference in predicted risk between patients who died and those who survived increased by 3% due to the addition of frailty determined by the EFS to the EuroSCORE II. Frailty also was associated significantly with a decreased cumulative probability of discharge from the ICU (p = 0.02) and an increased incidence of discharge to a health care facility (p = 0.01).

Conclusion: The EFS has a good predictive ability for 30-day mortality after cardiac surgery in elderly patients and improves the prediction of 30-day mortality over the use of the EuroSCORE II.

Keywords: Edmonton Frail Scale; EuroSCORE II; cardiac surgery; elderly; frailty.