Renal function, neurohormonal activation, and survival in patients with chronic heart failure

Background-Because renal function is affected by chronic heart failure (CHF ) and it relates to both cardiovascular and hemodynamic properties, it shou ld have additional prognostic value. We studied whether renal function is a predictor for mortality in advanced CHF, and we assessed its relative cont ribution compared with other established risk factors. In addition, we stud ied the relation between renal function and neurohormonal activation. Methods and Results-The study population consisted of 1906 patients with CH F who were enrolled in a recent survival trial (Second Prospective Randomiz ed study of Ibopamine on Mortality and Efficacy). In a subgroup of 372 pati ents, plasma neurohormones were determined. The baseline glomerular filtrat ion rate (GFR(c)) was calculated using the Cockroft Gault equation. GFR, wa s the most powerful predictor of mortality; it was followed by New York Hea rt Association functional class and the use of angiotensin-converting enzym e inhibitors. Patients in the lowest quartile of GFR(c) values (<44 mL/min) had almost 3 times the risk of mortality (relative risk, 2.85; P<0.001) of patients in the highest quartile (>76 mL/min). Impaired left ventricular e jection fraction (LVEF) was only modestly predictive (P=0.053). GFR(c) was inversely related with N-terminal atrial natriuretic peptide (ANP; r=-0.53) and, to a lesser extent, with ANP itself (r=-0.35; both P<0.001). Conclusions-Impaired renal function (GFR(c)) is a stronger predictor of mor tality than impaired cardiac function (LVEF and New York Heart Association class) in advanced CHF, and it is associated with increased levels of N-ter minal ANP. Moreover, impaired renal function was not related to LVEF, which suggests that factors other than reduced cardiac output are causally invol ved.