Naftidrofuryl in intermittent claudication: a retrospective analysis.

A retrospective analysis was performed on all five published clinical trials in which naftidrofuryl was given at a dosage of 600 mg daily. Two studies were undertaken in France, two in Germany, and one in Great Britain. Data for the analysis, which included the presence of risk factors, treadmill walking distances, and cardiovascular critical events that occurred during the course of the study, were generated from the patients' original study file. Included in the analysis were 888 patients, 447 receiving naftidrofuryl and 441 receiving placebo. Although there were significant differences between the studies with regard to certain variables, distribution was comparable between the treatment groups justifying an analysis on the pooled sample. An intention-to-treat analysis based on a success/failure outcome was in favor of active treatment (p = 0.003) as was an analysis of change in pain-free walking distance (PFWD) (p < 0.002). None of the risk factors had any significant influence on change in PFWD. A further analysis indicated that there were significantly fewer cardiovascular critical events in the naftidrofuryl group than in the placebo group (p = 0.029). Because the incidence of cardiovascular critical events was lower in those patients who showed the greatest improvement in PFWD, and as surgical intervention was the most frequently encountered critical event, it is possible that treatment with naftidrofuryl may lead to a reduction or postponement of surgery. Such a finding would have implications for health-care resources.