A severity index study of long-term prognosis in patients with chronic heart failure

The present study describes the derivation and validation of the Chronic Heart Failure Severity Index (CHFSI).

The CHFSI was derived using data obtained from a single-center prospective cohort study (2000-2014) that enrolled 756 patients. Logistic regression was used to identify independent predictors of mortality and quality of life over a 15-year follow-up period.

The score was validated at the first 5-year (n = 644), second 5-year (n = 364), and third 5-year (n = 262). Independent predictors of mortality were older age (OR = 2.04, P < 0.001), etiology score (OR = 2.61, P < 0.001), faster heart rate (OR = 1.46, P = 0.027), higher systolic blood pressure (OR = 2.35, P < 0.001), and left ventricular ejection fraction ≤45% (OR = 1.97, P = 0.018). The derived CHFSI predicted the mortality, and the AUC for the logistic model was 0.78 (95% confidence interval = 0.74-0.81, P < 0.001). Based on the logistic model, an integer scoring system was derived. Patients were classified into three groups: low risk (0-7 points), intermediate risk (8-11 points) and high risk (≥12 points) groups. The cumulative mortality for 15 years was 45.5% (125/275), 84.0% (204/243), and 100% (99/99), respectively (P < 0.001). The 6-min walk test revealed a significant difference in quality of life among patients in the low, medium and high risk groups (all, P < 0.0001).

The CHFSI is a very useful clinical predictive tool that identifies patients at risk of future mortality and their quality of life across healthcare systems.