Prevalence of asymptomatic coronary disease in fibrosing idiopathic interstitial pneumonias

Background Because of growing body of interest on the association between fibrosing idiopathic interstitial pneumonias (f-IIP) and ischaemic heart disease, we initiated this prospective study to evaluate the prevalence of asymptomatic coronary artery disease (CAD) in patients with f-IIP. Methods Forty-two patients with f-IIP underwent noninvasive screening for CAD that included (a) a chest CT examination enabling calculation of the coronary artery calcium (CAC) score, then depiction of coronary artery stenosis; and (b) stress myocardial perfusion scintigraphy (MPS). Patients with significant coronary abnormalities, defined by a CAC score >400 or coronary artery stenosis >50% at CT and/or perfusion defect >5% at MPS, were referred to the cardiologist. Coronary angiography was indicated in presence of a perfusion defect >10% at MPS or significant left main or proximal left anterior descending stenosis whatever MPS findings. Results Combining CT and MPS, significant abnormalities were detected in 32/42 patients (76%). The cardiologist: (a) did not consider further investigation in 21 patients (CT abnormalities but no ischaemia at MPS: 12/21; false-positive findings at MPS: 3/21; poor respiratory condition: 6/21); (b) proceeded to coronary angiography in 11 patients which confirmed significant stenoses in 5 patients (5/42; 12%). In the worst-case-scenario (i.e., inclusion of 6 patients with significant coronary artery abnormalities who were not investigated due to poor respiratory condition), the prevalence of CAD reached 26% (11/42). Conclusion In the studied population of patients with f-IIP, asymptomatic CAD ranged between 12% and 26%.