ACE-inhibitor therapy at relatively high doses and risk of renal worsening in chronic heart failure.

BACKGROUND Renoprotective effect of ACE-inhibitors has been questioned in case of decreased effective circulating volume, like in right or biventricular chronic heart failure. OBJECTIVE To detect clinical predictors of renal worsening in CHF patient population characterized by two types of ACE-inhibitor dosing regimens. METHODS According to a retrospective cohort design, we followed 2 groups of patients with CHF - whether right or biventricular -, all in III NYHA class treated with ACE-inhibitors (enalapril or lisinopril), and with left ventricular ejection fraction (LVEF) < 50%, by distinguishing them by ACE-inhibitor dosing: average-low (<10 mg per day) or "high" dose (>10 mg per day) of enalapril or lisinopril. Worsened renal failure (ARD) was defined by Cr increase >30% from baseline. Cox proportional hazards model was used to identify the predictors of ARD among the following variables: ACE-inhibitors "high" dose, age, basal LVEF, history of repeated intensive intravenous loop diuretic therapies (IV diur), diabetes, basal Cr, history of hypertension, systolic blood pressure < 100 mm Hg. RESULTS 57 patients were recruited, of whom 15 were treated with ACE-inhibitor "high" dose. During a mean follow-up of 718 days, ARD occurred in 17 (29.8%) patients. Only ACE-inhibitor "high" dose (HR: 12.4681 C.I.: 2.1614-71.9239 p=0.0050) and basal Cr (HR: 1.2344 C.I.: 1.0414-1.4632 p=0.0157) were shown to predict ARD. Moreover, ACE-inhibitor "high" doses were shown to fail to predict ARD in both CHF without IV diur and CHF with diabetes. CONCLUSION In III NYHA class CHF, ACE-inhibitor "high" doses and a higher basal Cr predicted ARD. Nephrotoxicity related to ACE-inhibitor "high" doses was increased by IV diur, whereas it was not detected in CHF patients with diabetes.