Objectives: This study aimed to investigate the effect of diabetes and insulin use on survival in a large cohort of patients with advanced heart failure (HF) of multiple etiologies.
Background: Although diabetes is a well-known risk factor for both systolic and diastolic dysfunction, the impact of diabetes and insulin treatment on prognosis of patients with HF has not been well studied.
Methods: History of diabetes and insulin treatment was assessed in 554 consecutive patients with advanced systolic HF who presented to a single center for HF management and/or transplant evaluation (mean age 52.0 +/- 13.1 years, ejection fraction 24.6 +/- 7.4). Patients were stratified into 3 groups based on presence or absence of diabetes and insulin use. Differences in patient characteristics and survival were evaluated.
Results: There were 132 patients (23.8%) with diabetes; 43 patients (7.8%) were insulin treated and 89 patients (16.1%) were non-insulin-treated patients with diabetes. The groups were similar in sex, smoking history, medication profile, ejection fraction, body mass index, and serum sodium. Survival at 1 year was 89.7% for nondiabetic patients, 85.8% for non-insulin-treated diabetic patients, and 62.1% for insulin-treated diabetic patients (P < .000 01). After Cox multivariate analysis, insulin-treated diabetes was found to be an independent predictor of mortality (hazard ratio 4.30, 95% CI 1.69-10.94) whereas non-insulin-treated diabetes was not (hazard ratio 0.95, 95% CI 0.31-2.93). Similar findings were seen in clinically relevant subgroups.
Conclusions: Insulin-treated diabetes is associated with a significantly worse prognosis in patients with advanced HF. Further investigations into mechanisms for the association of insulin treatment and mortality in patients with HF are warranted.