Microalbuminúria como marcador prognóstico em pacientes com insuficiência cardíaca crônica

Abstract

&#65279;Background: Microalbuminuria has been described as a risk factor for progressive cardiovascular and renal diseases. Little is known about its prevalence and prognostic value in patients (pts) with established heart failure (HF). Objectives: To determine the prevalence and prognostic value of microalbuminuria in patents with chronic heart failure. Methods: From June 2007 through September 2009, 92 patients with chronic HF were prospectively included. Mean age was 63.7 12.2 and 37 (40.7%) were male. Mean left ventricle ejection fraction (LVEF) was 52.6 17.5% and 52 (56.5%) had HF with normal ejection fraction (LVEF>50%). Pts under dialysis were excluded. Urinary albumin concentration (UAC) was determined in first morning spot sample of urine and microalbuminuria was defined as UAC 20-200 mg/L. Cardiac events were considered as a combined endpoint of HF hospitalizations, emergency department visits for HF or cardiac deaths, in a mean follow-up of 11 6.1 months. The relation of UAC and cardiac events was evaluated with Cox proportional hazard model. &#65279;Results: Thirty eight (41.3%) pts had microalbuminuria and no patient had overt albuminuria. Median, lowest, and highest values of UAC in the population as a whole were 20.9, 0.83, and 137.8, respectively. Pts with microalbuminuria had lower LVEF than the rest of the subjects (36.7 12.4% vs 45.2 8.2%, p=0.042), but no differences in rates of hypertension or diabetes mellitus were observed Twenty seven (29.3%) pts had an event during the follow-up. UAC was higher in patients with events (median 59.8 vs 18 mg/L, p=0.0005). Using Receiver Operating Characteristic Curve, a cutpoint of 35 mg/L had sensitivity of 59.3 and specificity of 89.5 (AUC=0.74). Event-free survival was lower in pts with UAC >35 mg/L as compared with UAC< 35 mg/L (p<0.0001). Variables independent related to cardiac events were UAC (p<0.0001, hazard ratio=1.02, 95% CI=1.01 to 1.03 per 1-U increase of UAC), and previous myocardial infarction (p=0,025, hazard ratio 3.11, 95% IC=1.15 to 8.41). Conclusion: Microalbuminuria is a powerful prognostic marker in pts with chronic HF.