Randomized clinical trial of angiotensin-converting enzyme inhibitor, ramipril, in patients with intermittent claudication

BACKGROUND: The aim was to investigate the effect of ramipril on clinical parameters in patients with peripheral arterial disease. METHODS: Patients with intermittent claudication were randomized to receive ramipril or placebo for 24 weeks in a double-blind study. Outcome measures were walking distance, arterial stiffness measurement and quality of life (QoL). RESULTS: A total of 33 patients were included (25 men; mean(s.d.) age 64.6(7.8) years); 14 received ramipril and 19 placebo. After 24 weeks, ramipril improved maximum treadmill walking distance by an adjusted mean (95 per cent confidence interval, c.i.) of 131 (62 to 199) m (P = 0·001), improved treadmill intermittent claudication distance by 122 (56 to 188) m (P = 0.001) and improved patient-reported walking distance by 159 (66 to 313) m (P = 0.043) compared with placebo. Ramipril reduced carotid femoral pulse wave velocity by -1.47 (95 per cent c.i. -2.40 to -0.57) m/s compared with placebo (P = 0.002). Resting ankle : brachial pressure index (ABPI) improved slightly in both ramipril and placebo groups (0.02 (95 per cent c.i. -0.08 to 0.11) versus 0.03 (-0.05 to 0.10); P = 0.830). Ramipril had a slight, non-significant effect on QoL physical domains compared with placebo. CONCLUSION: Ramipril improved walking distance in patients with claudication; however, this improvement was not related to improved ABPI but might have been due to ramipril reducing arterial stiffness. REGISTRATION NUMBER: NCT01037530 (http://www.clinicaltrials.gov).