Background: Narrow fragmented QRS (fQRS) has recently been recognized as a significant predictor of prognosis in various cardiovascular diseases.

Hypothesis: We hypothesized that the presence of narrow fQRS on admission electrocardiogram (ECG) in patients with decompensated systolic heart failure (HF) of any cause would be associated with long-term prognosis.

Methods: Patients hospitalized for decompensated HF due to ischemic or nonischemic dilated cardiomyopathy (left ventricular ejection fraction <35%) were retrospectively analyzed. The primary clinical end points were cardiovascular mortality, sudden cardiac death, and rehospitalization for HF.

Results: The mean duration of follow-up was 3.73 ± 1.41 years. Patients were classified as fQRS(+) group (n = 114; mean age, 63.49 ± 12.04 years) and fQRS(-) group (n = 113 patients; mean age, 65.04 ± 11.95 years). fQRS on ECG was significantly correlated with New York Heart Association (NYHA) functional class (P = 0.001). In multivariate Cox proportional hazard analysis, narrow fQRS (odds ratio [OR]: 3.130, 95% confidence interval [CI]: 1.560-2.848, P = 0.001), chronic renal failure (OR: 2.455, 95% CI: 1.120-5.381, P = 0.025), NYHA class (OR: 8.305, 95% CI: 2.568-26.855, P < 0.0001), and hypoalbuminemia (OR: 2.099, 95% CI: 1.122-3.926, P = 0.020) were independent predictors of cardiovascular mortality. In Kaplan-Meier survival analysis, narrow fQRS on admission ECG predicted worse survival rate at 84 months; survival probability significantly decreased in the fQRS(+) group compared with fQRS(-) group (P < 0.0001).

Conclusions: Presence of narrow fQRS is associated with worse NYHA functional class in patients hospitalized for decompensated HF. Narrow fQRS predicts cardiovascular mortality in a specific subgroup of systolic HF patients, namely those hospitalized for decompensated HF of both ischemic and nonischemic causes.