Prevalence and Clinical Correlates of Radiologically Detected Coronary Artery Disease in Chronic Obstructive Pulmonary Disease: A Cross-Sectional Observational Study

Abstract

Abstract Rationale Unrecognized coronary artery disease (CAD) may contribute to adverse outcomes in chronic obstructive pulmonary disease (COPD). Improved identification of at-risk groups could inform better preventive care. Objectives We aimed to evaluate the burden and relationships of radiologically detectable CAD in COPD, establish the frequency of occult disease, and examine potential cardiovascular screening methods. Methods Using computed tomography (CT) coronary angiography, we prospectively evaluated CAD in 50 patients with COPD compared with age- and sex-matched controls. In those with COPD, the relationship of CAD to cardiac symptoms (chest pain, dyspnea), functional capacity (6-minute-walk distance), exacerbations, and inflammation was assessed. The performance of screening tests (cardiovascular risk scores, biomarkers, and thoracic CT–derived coronary artery calcium score) were evaluated using receiver operating characteristic curves. Measurements and Main Results CAD was present in 88% of patients with COPD (42% had obstructive [⩾50% stenosis of any vessel] and 28% severely obstructive [⩾70%] disease). Rates of obstructive (OR, 3.1; 95% CI, 1.1–8.9; P = 0.037) and severely obstructive CAD (OR, 10.1; 95% CI, 1.9–52.7; P = 0.006) were higher in those with COPD than in controls. In the COPD group, those with CAD had greater functional impairments but not greater dyspnea scores, and 75% reported no chest pain or prior ischemic heart disease. CAD was more extensive in those with increased systemic inflammation (fibrinogen, C-reactive protein, and leukocyte and neutrophil counts), bronchial wall thickening, and sputum bacterial growth but bore no relation to exacerbation frequency. The thoracic CT–derived coronary artery calcium score was an effective screening tool, with areas under the curve of 0.98 (95% CI, 0.95–1.00) for CAD and 0.89 (95% CI, 0.79–1.00) for obstructive CAD. Conclusions CT coronary angiography–detected CAD is common in patients with COPD but correlates poorly with symptoms and conventional risk scores. Radiological screening with standard (non ECG-gated) CT of the thorax might improve detection and outcome in this patient group.