An incidental finding of extensive coronary calcium was an independent risk factor for subsequent adverse cardiovascular events.

Increasingly, radiologists are reporting calcification of coronary arteries as an incidental finding on computed tomography (CT) performed for lung cancer screening. How common is this finding, and is it an independent risk factor for subsequent adverse coronary events? To address these questions, researchers in Ottawa, Canada, conducted a retrospective study that involved 1500 current or former smokers with no history of myocardial infarction or coronary revascularisation who underwent CT lung cancer screening.

Half the patients had mild-to-moderate coronary calcium, and 30% had extensive coronary calcium, according to a scheme outlined by the authors. During mean follow up of 51 months, the incidence of adverse cardiovascular events was 5.5% in patients with extensive calcium and 2.0% in both those with mild-to-moderate calcium and those with no calcium. In an analysis adjusted for cardiovascular risk factors, the higher incidence of adverse cardiovascular events in patients with extensive coronary calcium was significant (hazard ratio, 2.06).

Comment: I have noticed that radiologists are reporting coronary calcium more frequently on lung CT reports during the past few years. In this study, the prevalence was quite high, perhaps because two-thirds of participants were current (and not former) smokers. In patients with no history of cardiovascular disease, a report of substantial coronary calcification should prompt a revisiting of that patient’s risk factor management; in some cases, I have used this finding as a ‘tie-breaker’ for patients who have been on the fence about starting statin therapy.

Allan S. Brett, MD, Clinical Professor of Medicine, University of Colorado School of Medicine, Aurora, USA.

Caires MC, et al. Prognostic importance of extensive coronary calcium on lung cancer screening chest computed tomography. CMAJ 2024; 196: E1362-E1369.

This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine.