[Therapy with ACE inhibitors in chronic heart failure and limited kidney function]

Renal function in 31 patients with mild to moderate heart failure (NYHA Classes II-III) was studied before and during treatment with ACE-inhibitors. Maximal treatment doses were based on randomization: captopril 3 x 12.5 mg or lisinopril or enalapril, both 1 x 10 mg. Before therapy and at the end of titration phase (after 6 days) glomerular filtration rate and renal blood flow were determined from inulin and PAH clearance (steady-state method). In the total study group the median arterial pressure significantly decreased from 94 mmHg to 84 mmHg (p < 0.01), whereas glomerular filtration rate was only moderately, however, significantly reduced from 103 ml/min to 97 ml/min (median values, p < 0.01). Renal blood flow, however, increased from 372 ml/min to 403 ml/min (p < 0.01). Changes in glomerular filtration rate (GFRd) were significantly dependent on those of renal blood flow (GFRd = 0.07 RPFd - 9.2; p < 0.05). All three ACE-inhibitors showed similar changes in glomerular filtration rate and renal blood flow. Ten of the patients had additionally received cyclooxygenase inhibitors. With respect to severity of heart failure and renal function these patients did not differ from the remaining 21 patients of the group. In both groups, a decrease of glomerular filtration rate was found, however, in those patients who had received acetylsalicylic acid there was no increase of renal blood flow.

A small, however significant decrease of glomerular filtration rate is already seen in patients with mild to moderate heart failure treated with ACE-inhibitors. Increase of renal blood flow counteracts the decrease of glomerular filtration rate. During concomitant application of acetylsalicylic acid the increase of renal blood flow remains absent.