Background: Risk factors for pure coronary spasm are not known. Clinical observations have pointed to cigarette smoking, a known risk factor for obstructive coronary artery disease.
Methods and results: We conducted a case-neighborhood control study of premenopausal women, a population segment with the lowest prevalence of obstructive coronary artery disease. The cases were 21 premenopausal women (age range, 36-41 years) with angiographically proven coronary spasm. All coronary arteriograms were analyzed by two independent experienced cardiologists on two occasions. There were no differences between analyses; all cases had normal baseline coronary angiogram except for two, who had less than 20% coronary luminal stenosis in segments other than the site of the focal vasospasm. All cases had normal hemodynamics at rest, normal left ventricular function, and were in sinus rhythm. Ascertainment of the cases was done by angiographic demonstration of focal coronary spasm spontaneously or by ergonovine provocation. Six cases developed spontaneous coronary spasm before catheter engagement, and in 15, coronary spasm was induced by ergonovine provocation. Each case was asked to name as many as possible female neighborhood acquaintances of similar age and racial background who were willing to answer the same standardized questionnaire. The same standardized questionnaire was completed for each case and each control (n = 63). The standardized questionnaire was designed to obtain information on health characteristics, habits, socioeconomic status, and education. Only cigarette smoking was significantly more prevalent among coronary spasm cases. Cigarette smokers were 13 cases (62%) and 11 controls (17.5%) (p less than 0.001). The odds ratio was 7.7, with a 95% confidence interval of 2.6-23.1.
Conclusions: These findings suggest that there is a very strong association between cigarette smoking and pure coronary spasm in young women.