Randomized placebo-controlled, double-blind trial of ketanserin in claudicants. Changes in claudication distance and ankle systolic pressure. PACK Claudication Substudy.

The effect of ketanserin on intermittent claudication (measured by treadmill walking distance and ankle systolic pressure) was assessed in 594 patients, a subset of the 3,899 patients who composed a double-blind study of the effect of ketanserin on cardiovascular events. Complete data sets at the beginning and end of 1 year's treatment with ketanserin or placebo were available in 436 patients. There was no difference between the groups in the improvement in pain-free treadmill walking distance. The placebo effect on treadmill walking distance increased continuously for at least 1 year at the rate of about 15% every 6 months. There was no significant change in either group in the ankle systolic pressure at the end of the treatment period but in the group given ketanserin, brachial systolic pressure was decreased and the ankle to arm systolic pressure ratio therefore increased. There was only a very weak association between treadmill walking distance and ankle to arm systolic pressure ratio both at the beginning and in terms of change over 1 year. Therefore, this pressure ratio is probably not a useful way of assessing the effects of medical treatment of claudication.