Prognostic value of plasma neutrophil gelatinase-associated lipocalin in patients with heart failure.

BACKGROUND Neutrophil gelatinase-associated lipocalin (NGAL) is an early marker of kidney injury. We sought to assess the prognostic value of this biomarker in patients with stable chronic heart failure (HF). METHODS We studied 61 patients with chronic systolic HF who had been receiving optimal medical treatment for at least six months. Biomarkers were measured at baseline and included plasma NGAL, microalbuminuria, serum creatinine, and B-type natriuretic peptide (BNP). Estimated glomerular filtration rate (eGFR) was also calculated. Mean follow-up was 10.6±6.6 months. The primary endpoint was time to first cardiovascular event, defined as a combination of cardiovascular death, HF hospitalization or emergency department visit due to HF. Variables independently related to events were determined using a Cox proportional hazards model. RESULTS Fifteen (24.6%) patients reached the primary endpoint. Patients with events were more likely to have worse renal function at baseline and also higher NGAL levels (median 316 [interquartile range 122-705] vs. 107 [78-170]; p=0.006). NGAL correlated significantly with creatinine (r=0.50; p<0.0001), albuminuria (r=0.33; p=0.008), and eGFR (r=-0.47; p=0.0001) but not with BNP (r=0.003; p=0.97). The best NGAL cutoff as determined by ROC curve analysis was 179 ng/ml. Event-free survival was lower in patients with NGAL above this cutoff. Variables independently related to events were NGAL (HR 1.0035, 95% CI 1.0019-1.0052; p<0.0001) and male gender (HR 5.9, 95% CI 1.22-28.6; p=0.028). CONCLUSION NGAL correlated with other biomarkers of renal function but not with BNP and was independently associated with outcomes.