European multicenter study on propionyl-L-carnitine in intermittent claudication.
OBJECTIVE
This study was performed to identify a target population of claudicants for propionyl-L-carnitine treatment.


BACKGROUND
Previous studies suggest that the efficacy of propionyl-L-carnitine in intermittent claudication is greater in patients with severe functional 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, p.o.) and then stratified on the basis of maximal walking distance (cutoff point 250 m) and maximal walking distance variability (cutoff point 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 < or = 250 m and showed a maximal walking distance variability < or = 25%, per-protocol analysis showed that the effect of propinyl-L-carnitine was significantly greater than that with placebo for both maximal walking distance and initial claudication distance (ICD). In the intention-to-treat population, maximal walking distance increased by 62 +/- 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 was confirmed when data of the target population were pooled with those of patients who at baseline walked < or = 250 m and showed a > 25% maximal walking distance < 50% variability. Actually, maximal walking distance increased by 98 +/- 16% in the propionyl-L-carnitine group and by only 54 +/- 10% in the placebo group (p < 0.01). The corresponding values for ICD were 99 +/- 21% and 51 +/- 8% (p < 0.05). For patients with baseline maximal walking distance > 250 m, no difference between treatments was observed.


CONCLUSIONS
Claudicants with maximal walking distance < or = 250 m benefited from the use of propionyl-L-carnitine, with improvement in walking distance and quality of life. However, patients with mild functional impairment (i.e., walking distance > 250 m) showed no response to propionyl-L-carnitine.
Brevetti
G
G
Department of Medicine, University Federico II, Napoli, Italy. brevetti@unina.it
Diehm
C
C
Lambert
D
D
D002316:Cardiotonic Agents / Q000627:therapeutic use*; D002331:Carnitine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004311:Double-Blind Method; D005060:Europe; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D016896:Treatment Outcome
D002316:Cardiotonic Agents; C003223:propionylcarnitine; D002331:Carnitine