CIGARETTE-SMOKING ACCELERATES CAROTID-ARTERY INTIMAL HYPERPLASIA IN ADOSE-DEPENDENT MANNER

Background and Purpose Intimal hyperplasia is the single most importan t cause of early restenosis after carotid endarterectomy. Cigarette sm oking is an independent risk factor associated with peripheral vascula r disease and cerebrovascular accidents. We undertook a dose-response experiment to determine the effect of cigarette smoke on development o f intimal hyperplasia in a rat carotid artery intimal injury model. Me thods Seventy-two rats were divided into six equal groups and underwen t standardized balloon injury to the carotid artery. Each group receiv ed 0 (controls), 1, 2, 3, 6, or 8 cigarettes per day for 4 weeks. Resu ltant intimal hyperplasia was expressed as a percentage of original lu men replaced by intimal hyperplasia. Results Percent intimal hyperplas ia development (+/- SD) was as follows: controls (0 cigarettes per day ), 17.7 +/- 13.2; 1 cigarette per day, 22.8 +/- 15.0; 2 cigarettes per day, 20.0 +/- 14.7; 3 cigarettes per day, 19.2 +/- 12.1; 6 cigarettes per day, 43.5 +/- 15.5; and 8 cigarettes per day, 36.7 +/- 9.8. Six a nd 8 cigarettes per day significantly increased the development of int imal hyperplasia after intimal injury (P < .01). Conclusions High-dose cigarette smoke accelerates development of intimal hyperplasia and ma y pose a significant risk factor in developing carotid restenosis.