Albuminuria: Associated With Heart Failure Severity and Impaired Clinical Outcomes

Urinary albumin to creatinine ratio (UACR) is common in patients with heart failure (HF) and may have an impact on clinical outcome. We evaluated the effect of UACR on clinical outcome in a real-world cohort of patients with HF.

All patients with HF at a health maintenance organization were followed for cardiac-related hospitalizations and death.

The study cohort included 4668 patients with HF and was divided into 3 groups based on UACR: normal-range albuminuria (2085 patients; 45%), microalbuminuria (1769 patients; 38%), and macroalbuminuria (814 patients; 17%). Microalbuminuria and macroalbuminuria were both associated with increasing age, diabetes mellitus, hypertension, peripheral vascular disease, atrial fibrillation, and New York Heart Association class III/IV. Microalbuminuria and macroalbuminuria were directly associated with decreased event-free survival from death and death and cardiovascular hospitalizations. Cox regression analysis after adjustment for significant predictors demonstrated that microalbuminuria was associated with increase in mortality (hazard ratio, 1.18; 95% confidence interval, 1.18-1.38; P = 0.03) and macroalbuminuria (hazard ratio, 1.33; 95% confidence interval, 1.10-1.61; P < 0.001). Albuminuria was also an independent predictor of death and cardiovascular hospitalizations. Analysis of albuminuria as a continuous parameter (natural logarithm transformed) showed that UACR was an independent predictor of mortality, and cardiovascular hospitalizations. Subclinical albuminuria (UACR 12-29 μg/mg) was directly associated with reduced survival. Cox regression analysis using restricted cubic splines demonstrated an independent continuous increase in mortality with increasing albuminuria (P < 0.0001 adjusted linear model).

Albuminuria provides important information regarding several detrimental processes in HF and is a significant predictor of a worse outcome.