Clinical Features of Japanese Smokers with Initially Diagnosed Coronary Artery Disease: Association of Calcium-Channel Blocker Use with Onset of Acute Myocardial Infarction (Original)

Background : Smoking is an important risk factor for coronary artery disease (CAD). We evaluated the initial clinical presentation of CAD and factors associated with the onset of CAD in smokers. Methods : Among 2,567 consecutive patients who underwent coronary angiography at our institution, 405 patients in whom CAD was diagnosed for the first time were divided into 140 smokers and 265 nonsmokers (including 108 never smokers and 157 former smokers) and reviewed. The initial clinical presentation of CAD, which was either angina pectoris or acute myocardial infarction (AMI) and unstable angina pectoris ; risk factors ; and previous medications were compared between smokers and nonsmokers. In addition, the initial clinical presentation of CAD was examined according to the use of the medication most strongly associated with preventing CAD among previously administered drugs in each group. Results : The prevalence of AMI was significantly higher in smokers (47.1%) than in nonsmokers (23.8%, p<0.001). The rates of calcium-channel blocker (CCB) use and statin use were lower in smokers. Univariate analysis of patient subgroups based on the use of CCBs or statins revealed that the prevalence of AMI was lower only in smokers using CCB than in smokers not using CCBs. Adjusted multivariate analysis revealed that only CCB use was associated with a reduced risk of AMI in smokers (odds ratio, 0.43 ; 95% CI ; 0.19 to 0.96 ; p=0.04). Conclusion : AMI as the initial clinical presentation of CAD is observed more commonly in smokers than in nonsmokers. While smoking cessation is the primary strategy for preventing CAD, CCB use is associated with a reduced incidence of AMI in Japanese smokers and is, therefore, a potential strategy for preventing CAD. (Jikeikai Med J 2014 ; 61 : 43-51)