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

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.