D. Lambert

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

OBJECTIVES 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.

Computed tomography angiography for the evaluation of carotid atherosclerotic plaque: correlation with histopathology of endarterectomy specimens.

Background and Purpose— The goal of this study was to determine the efficacy of CT angiography for the characterization of plaque morphology and composition in carotid atherosclerotic disease. Methods— Fifty-five patients undergoing carotid endarterectomy were imaged preoperatively with single-slice spiral CT angiography. One hundred sixty-five endarterectomy sections were examined histologically at selected levels through the distal common and proximal internal carotid arteries. Plaque density was measured (in Hounsfield units) on axial CT sections, and the presence or absence of ulceration was noted. These observations were compared with the histological findings at corresponding levels. Data were analyzed with 2-sample t tests and 1-way analysis of variance (ANOVA). Results— ANOVA testing showed a statistically significant decrease in CT attenuation values with increasing plaque lipid but with a very high standard deviation of values. No other histological factor showed a statistically significant link with CT attenuation. Plaque ulceration was detected by CT with a sensitivity of 60% and a specificity of 74%. Conclusions— Analysis of plaque attenuation with single-slice spiral CT does not give useful information concerning plaque composition. The predictive value of CT for the detection of plaque ulceration was moderate. Single-slice CT angiography is insufficiently robust to be a useful tool for the characterization of carotid plaque composition and morphology.

Predictors of Acute and Persisting Ischemic Brain Lesions in Patients Randomized to Carotid Stenting or Endarterectomy

Background and Purpose— We investigated predictors for acute and persisting periprocedural ischemic brain lesions among patients with symptomatic carotid stenosis randomized to stenting or endarterectomy in the International Carotid Stenting Study. Methods— We assessed acute lesions on diffusion-weighted imaging 1 to 3 days after treatment in 124 stenting and 107 endarterectomy patients and lesions persisting on fluid-attenuated inversion recovery after 1 month in 86 and 75 patients, respectively. Results— Stenting patients had more acute (relative risk, 8.8; 95% confidence interval, 4.4–17.5; P<0.001) and persisting lesions (relative risk, 4.2; 95% confidence interval, 1.6–11.1; P=0.005) than endarterectomy patients. Acute lesion count was associated with age (by trend), male sex, and stroke as the qualifying event in stenting; high systolic blood pressure in endarterectomy; and white matter disease in both groups. The rate of conversion from acute to persisting lesions was lower in the stenting group (relative risk, 0.4; 95% confidence interval, 0.2–0.8; P=0.007), and was only predicted by acute lesion volume. Conclusions— Stenting caused more acute and persisting ischemic brain lesions than endarterectomy. However, the rate of conversion from acute to persisting lesions was lower in the stenting group, most likely attributable to lower acute lesion volumes. Clinical Trial Registration —URL: www.isrctn.org. Unique identifier: ISRCTN25337470.