Interaction between cigarette smoking and high-sensitivity C-reactive protein in the development of coronary vasospasm in patients without hemodynamically significant coronary artery disease.

BACKGROUND

Interaction between 2 major risk factors, cigarette smoking and high-sensitivity C-reactive protein (hs-CRP), has not been evaluated in patients with coronary vasospasm (CV) without hemodynamically significant coronary artery disease.

METHODS

From 1999 to 2005, patients undergoing diagnostic coronary angiography with or without proven CV and without coronary stenosis >50% were evaluated. A total of 621 subjects (335 and 286 with and without CV, respectively) were enrolled in the study. The levels of hs-CRP, measured immediately before coronary angiography, were examined in a subset of 314 patients.

RESULTS

Subjects with CV were likely to be older, men, current smokers, and have high hs-CRP levels. The most significant factors for CV were smoking and hs-CRP. In the nonsmoker group, elevated risk of developing CV was only demonstrated in patients with the highest hs-CRP tertile (>5.01 mg/L, P = 0.012). In the smoker group, however, a positively monotonic trend of association was demonstrated between hs-CRP tertile and CV risk, with multivariate-adjusted odds ratios of 1.11, 3.09 (P = 0.012), and 4.12 by the hs-CRP tertiles, suggesting that smokers developed CV at a lower hs-CRP level than nonsmokers and there was a positive interaction between smoking and hs-CRP.

CONCLUSIONS

The smokers developed CV at a lower hs-CRP level compared with the nonsmokers. A positive interaction between smoking and hs-CRP was demonstrated for this disease in our study population.