The effect of alcohol on atherosclerotic plaque composition and cardiovascular events in patients with arterial occlusive disease

OBJECTIVES: This study examined the association between alcohol use, the occurrence of cardiovascular events, and plaque phenotype in patients after femoral or carotid endarterectomy for arterial occlusive disease. Alcohol has been shown to have cardiovascular protective effects in patients with cardiovascular disease as well as in healthy individuals. Whether alcohol consumption induces changes in atherosclerotic plaque composition has not been investigated.

METHODS: Consecutive femoral (n = 224) and carotid (n = 693) endarterectomy specimens underwent histologic examination for the presence of collagen, calcifications, smooth muscle cells, macrophages, fat, and intraplaque thrombus. Patients were monitored for 3 years after the initial operation and investigated for the occurrence of cardiovascular events. Primary outcome was the composite end point "major cardiovascular event." Alcohol consumption was categorized as no alcohol use, 1 to 10 U/wk, or >10 U/wk.

RESULTS: The Kaplan-Meier estimate of the major cardiovascular event rate after 3 years of follow-up in the femoral group was 35% for no alcohol use and 21% for 1 to 10 U/wk, whereas only 10% of the group >10 U/wk sustained a major cardiovascular event (P = .010). The plaques of alcohol consumers in the femoral group contained significantly smaller lipid cores and less macrophage infiltration than in abstainers. In the carotid group, the major cardiovascular event rate was similar in all three groups, and in addition, no difference in plaque composition was observed.

CONCLUSIONS: This study shows an inverse relationship between alcohol use and major cardiovascular events after endarterectomy for lower extremity arterial occlusive disease, accompanied by a more stable plaque phenotype. However, no such relationship could be observed for patients with cerebrovascular disease.