Effectiveness of the frailty index in predicting short-term and long-term mortality risk in patients with chronic heart failure

Objective

This study explored the effectiveness of a newly constructed frailty index (FI) for predicting short-term and long-term mortality in patients with chronic heart failure (HF).

Materials and methods

This retrospective study included inpatients aged ≥60 years diagnosed with chronic HF at a teaching hospital in western China. General data on the patients were collected from the electronic medical record system between January 1, 2017, and July 7, 2022, and death information was obtained from follow-up calls made from July 31, 2022, to August 1, 2022. Receiver operating characteristic (ROC) curves were used to analyze the accuracy of the FI in predicting death in patients with chronic HF. Logistic regression (during hospitalization and within 30 days after discharge) and Cox regression (within 180 days after discharge and one year after discharge) analyses were used to assess associations between frailty and mortality risk in elderly patients with chronic HF.

Results

A total of 432 patients with chronic HF were included in the study. The non-frail group had FI values <0.3, while the FI values in the frail group were ≥0.3. Overall, 130 patients (30.09 %) were diagnosed with frailty, 66 (15.28 %) died during hospitalization or within 30 days after discharge, 55 (12.73 %) died within 180 days after discharge, and 68 (15.74 %) died within one year after discharge. The in-hospital and 30-day mortality rates, the 180-day mortality rates, and the 1-year mortality rates were higher in frail patients than in non-frail patients (in-hospital and 30-day mortality rates, 37.69 % vs. 5.63 %, P < 0.001; within 180 days, 30.61 % vs. 8.45 %, P < 0.001; within 1 year, 34.69 % vs. 11.49 %, P < 0.001). The area under the curve (AUC) values of FI for predicting in-hospital and 30-day mortality after discharge were 0.804, with values of 0.721 for 180-day mortality after discharge and 0.720 for 1-year mortality after discharge. Logistic regression analysis with adjustment for potential confounders indicated that frail HF patients had a higher risk of death during hospitalization and within 30 days than non-frail patients (odds ratio [OR] = 4.98, 95 % confidence interval [CI]: 2.46–10.09). Cox regression analysis with adjustment for potential confounders showed that frail HF patients had a higher risk of death within 180 days (hazard ratio [HR] = 2.63, 95 %CI: 1.47–4.72) and within 1 year (HR = 2.01, 95 %CI: 1.19–3.38).

Conclusion

The results of this study showed that the new FI constructed according to the established construction rules could predict the in-hospital mortality and the risk of death within 30 days after discharge, 180 days after discharge, and 1 year after discharge in patients with chronic HF.