Association between pleural plaques and coronary heart disease

Objective The aim of this study was to verify a clinical impression that pa tients with coronary hear? disease disproportionately frequently have calci fied pleural plaques. Methods Chest X-rays were collected from 148 patients referred consecutivel y to the Helsinki University Central Hospital for coronary angiography and from 100 consecutive lung cancer patients seen at the same hospital. The ra diographs were analyzed for the presence of calcified pleural plaques accor ding to the classification the international Labour Office. A generalized l inear model with binomial distribution and log link was used to estimate th e relative risks and their 95% confidence intervals (95% CI). Results The prevalence of calcified pleural plaques was 35% for the coronar y patients and 19% for the lung cancer patients. Calcified pleural plaques were more common among the men than the women, and the risk increased with age. The relative risk of calcified pleural plaques, adjusted for age and g ender, was 2.19 (95% CI 1.44-3.32) for the coronary patients as compared wi th the lung cancer patients. Conclusions Further studies with better information on past exposure to asb estos and other potential risk factors are warranted to confirm the observa tions and to examine whether the association between coronary heart disease and calcified pleural plaques is related to an etiologic or an individual susceptibility factor common to both of these conditions.