Albuminuria in heart failure: what do we really know?

PURPOSE OF THE REVIEW To describe the role of albuminuria as a risk marker for heart failure and a predictor for treatment effect on heart failure prognosis. RECENT FINDINGS The level of albumin in the urine is a predictor of heart failure in the general population and in patients with cardiovascular risk, such as those with diabetes. Mild elevations of albuminuria, in the microalbuminuria range, appear to be associated with impaired systemic endothelial function. This increases the chance of developing hypertension, diabetes and cardiovascular disease, ultimately leading to heart failure. Higher levels of albuminuria, in the proteinuric range, reflect marked renal pathology, which increases cardiovascular risk due to renal function decline. In patients with established heart failure, microalbuminuria is highly prevalent (30%). Although more frequent in diastolic than systolic dysfunction, it appears to indicate a worse prognosis in the latter class. Diabetes is a multiplier of risk, probably due to bidirectional relationship between diabetes and heart failure. Treatment with drugs that intervene in the renin-angiotensin-aldosterone system (RAAS) lowers albuminuria and is associated with prevention of the onset and worsening of heart failure and other cardiovascular disorders. SUMMARY Albuminuria is associated with increased heart failure risk. Lowering of albuminuria using RAAS inhibitors appears to lower the risk for heart failure.