Reversal of peripheral microvascular dysfunction during long-term treatment with the angiotensin-converting enzyme inhibitor fosinopril in congestiveheart failure

Background: Treatment with angiotensin-converting enzyme (ACE) inhibitors i n congestive heart failure (CHF) improves cardiac and peripheral hemodynami c function and exercise performance. However, studies on the effects of lon g-term treatment with an ACE inhibitor on the neurogenic and nonneurogenic regulation and structural microangiopathy of the peripheral microvasculatur e in CHF are lacking. Methods and Results: We investigated the effect of 12 weeks of treatment wi th the ACE inhibitor fosinopril on peripheral microvascular function in a d ouble-blind, placebo-controlled study of 12 patients treated with fosinopri l and 10 patients treated with placebo. All had moderate CHF, Microvascular blood flow and resistance were calculated after application of the local i sotope washout method in relaxed and nonrelaxed calf vascular beds in the s upine position and during head-up tilt. Skeletal muscle vascular resistance was reduced in the fosinopril group (46 +/- 6 to 30 +/- 1 mm Hg.mL(-1) 100 g.min +/- standard error; P < .05) and differed compared with the effect o f placebo (P < .05) where no change was seen (37 +/- 11 to 55 +/- 13 mm Hg. mL(-1) 100 g.min; not significant [NS]). Also, skin minimal vascular resist ance was reduced during fosinopril treatment (13 +/- 0.6 to 11 +/- 0.7 mm H g-mL(-1).100 g, min; P < .05) and differed compared with the effect of plac ebo (P < .05) with absence of change (12 +/- 1.6 to 14 +/- 1.4 mm Hg.mL(-1) 100 g min; NS). Conclusions: These results suggest that long-term ACE inhibitor treatment w ith fosinopril in patients with CHF improves hemodynamic status to as far a s the peripheral microvascular level in both the relaxed and nonrelaxed mic rocirculation of the lower leg.