European multicenter study on propionyl-L-carnitine in intermittent claudication

OBJECTIVES This study was performed to identify a target population of clau dicants for propionyl-L-carnitine treatment. BACKGROUND Previous studies suggest that the efficacy of propionyl-L-carnit ine in intermittent claudication is greater in patients with severe functio nal impairment than in those with mild walking disability. METHODS After run-in, 485 claudicant patients were randomized to placebo or propionyl-L-carnitine (1 g bid, po) and then stratified on the basis of ma ximal walking distance (cutoff point 250 m) and maximal walking distance va riability (cutoff Feint 25%). Treatment lasted 12 months. Walking capacity was assessed by treadmill and quality of life by a questionnaire exploring various aspects of daily life. RESULTS In the target population, that is, patients who at baseline walked less than or equal to 250 m and showed a maximal walking distance variabili ty less than or equal to 25%, per-protocol analysis showed that the effect of propinyl-L-carnitine was significantly greater than that with placebo fo r both maximal walking distance and initial claudication distance (ICD). In the intention-to-treat population, maximal walking distance increased by 6 2 +/- 14% on propionyl-L-carnitine and by 46 +/- 9% (p < 0.05) on placebo, while no difference between treatments was observed for ICD. The beneficial effect of propionyl-L-carnitine mas confirmed when data of the target popu lation were pooled with these of patients who at baseline walked less than or equal to 250 m and showed a >25% maximal walking distance <50% variabili ty. Actually, maximal walking distance increased by 98 +/- 16% in the propi onyl-L-carnitine group and by only 54 +/- 10% in the placebo group (p < 0.0 1). The corresponding values for ICD were 99 +/- 21% and 51 +/- 8% (p < 0.0 5). For patients with baseline maximal walking distance >250 m, no differen ce between treatments was observed. CONCLUSIONS Claudicants with maximal walking distance less than or equal to 250 m benefited from the use of propionyl-L-carnitine, with improvement in walking distance and quality of life. However, patients with mild function al impairment (i.e., walking distance >250 m) showed no response to propion yl-L-carnitine. (C) 1999 by the American College of Cardiology.