Chronic Obstructive Pulmonary Disease in Patients with Catheter Diagnosed Coronary Artery Disease: Prevalence and Risk Factors

Background: Chronic obstructive pulmonary disease (COPD) and coronary artery disease (CAD) co-morbidity exists at different rates. This co-morbidity affects quality of life and increases mortality. In the developing world the prevalence of CAD is increasing but the prevalence of COPD is unknown. This study was designed to estimate the proportion of patients with CAD who have concomitant COPD and identify factors that may increase the likelihood of COPD in CAD patients. Methods: A cross sectional study that included consecutive adults with catheter diagnosed CAD recruited from two cardiac centers. Patients completed a COPD diagnosis validated questionnaire and performed spirometry using an electronic spirometer. COPD was diagnosed if patient score placed him/her in the high likelihood zone of having COPD, or if the FEV1 was less than 80 % predicted. Results were compared using chi-square test. Results: Fifty nine patients with CAD were studied. The mean age (SD) was 59 (9.7) years. Of these 59 patients; 27 (44%) had COPD diagnosed by either questionnaire or spirometry. COPD was significantly more among patients with single vessel disease compared with multiple vessel disease (p = 0.01). There was no difference in the number of smokers among patients with CAD and COPD, and CAD alone (p = 0.29). The prevalence of COPD increased with increasing age (p=0.003). Conclusion: In this group of patients with CAD more than two in five have concomitant COPD. The prevalence of COPD increases with age and is more in patients with single vessel disease compared with patients who have multiple vessel disease.