Yousef Shahin1, John Cockcroft2, Ian Chetter1
1University of Hull, Hull, United Kingdom; 2Cardiff University, Cardiff, United Kingdom.
OBJECTIVES: We have previously shown that the angiotensin converting enzyme inhibitor, ramipril, improved walking distance and reduced arterial stiffness in patients with intermittent claudication. In this analysis on the same cohort of patients, we investigated whether ramipril's ability to improve walking distance is dependent on its ability to reduce arterial stiffness.
METHODS: Thirty-three patients (25 males, mean age: 65+/-7.8) with intermittent claudication were randomized to receive ramipril (n=14) or placebo (n=19) for 24 weeks in a double-blind fashion. Walking distance was assessed using a standard treadmill test (1.6 mph at 10% incline) and arterial stiffness indices were assessed using the SphygmoCor device.
RESULTS: After 24 weeks, ramipril improved maximum treadmill walking distance; adjusted mean change difference (95% confidence interval); by 130.5 meters (61.8 meters to 199.2 meters) longer than placebo (p=0.001) and improved treadmill intermittent claudication distance by 121.9 meters (55.9 meters to 187.8 meters) longer than placebo (p=0.001). Ramipril reduced carotid femoral pulse wave velocity (PWVcf) by -1.47 m/s (-2.4 m/s to -0.57 m/s) compared to placebo (p=0.002) and reduced augmentation index (AIx) by -10.8% (-14.1% to -7.5%) compared to placebo (p<0.001). Changes in walking distance from baseline showed significant inverse correlations with changes in indices of arterial stiffness (PWVcf, r=-0.43, p=0.021; AIx, r=-0.50, p=0.006; AIx adjusted to 75 beats/minute, r=-0.50, p=0.006; central pulse pressure, r=-0.45, p=0.039). Correlations remained significant after adjusting for heart rate and mean arterial pressure.
CONCLUSIONS: Ramipril improves walking distance in patients with intermittent claudication. This improvement is partly due to ramipril's ability to reduce arterial stiffness.
AUTHOR DISCLOSURES: I. Chetter: Nothing to disclose; J. Cockcroft: ,Research Grants; Y. Shahin: Nothing to disclose.
Posted April 2013