Beneficial effects of smoking cessation on the short-term prognosis for variant angina--validation of the smoking status by urinary cotinine measurements.

To examine whether smoking cessation would improve the short-term prognosis for patients with variant angina, 37 smokers with variant angina who were discharged after the complete disappearance of angina by medical treatment with calcium blockers were advised to stop smoking and were followed-up for 1 year. Urinary cotinine radioimmunoassay was used to evaluate their current smoking status. Patients with a urinary cotinine concentration above 50 ng/ml were classified as current smokers. The prevalence of smokers was underestimated by self-reports (11% by self-reports vs. 35% by urinary cotinine measurements after 3 months; 17% by self-reports vs. 36% by urinary cotinine measurements after 1 year). The presence of angina during the first 3 months was significantly (P < 0.05) more prevalent in those who continued to smoke (8/13, 62%) than in those who succeeded in smoking cessation (5/24, 21%) when the current smoking status was determined by urinary cotinine measurements. Smoking cessation definitely improved the prognosis for variant angina even during a relatively short follow-up period.