Background: Plasma renin activity (PRA) may be limited to angiotensinogen levels, which decrease in patients with heart failure (HF) because of liver congestion.
Methods and results: To evaluate whether the plasma active renin concentration (ARC) is a more useful prognostic predictor than PRA, the plasma levels of ARC, PRA, angiotensin II, aldosterone, brain natriuretic peptide (BNP), norepinephrine, and hemodynamic parameters were measured in 214 consecutive HF patients who were already taking angiotensin-converting enzyme inhibitors (ACEI) or angiotensin-receptor blockers (ARB). Median follow-up period was 1,197 days. Of the clinical variables, including pulmonary capillary wedge pressure, right atrial pressure, left ventricular ejection fraction, and neurohumoral factors, only high plasma levels of log ARC (p<0.0001) and log BNP (p=0.0009), but not log PRA, were significant independent prognostic predictors. Log ARC/PRA ratio was significantly higher in nonsurvivors than in survivors. Log ARC/PRA significantly correlated with pulmonary capillary wedge pressure (r=0.305, p<0.0001), right atrial pressure (r=0.222, p=0.0011), and log BNP (r=0.242, p=0.0004).
Conclusions: Plasma ARC is superior to PRA and a high plasma ARC is an independent prognostic predictor in HF patients who are already receiving ACEI or ARB.