Lung cancer screening in heavy smokers with chest Computed Tomography (CT) is also an opportunity to diagnose other asymptomatic smoking-related complications. The objective of our study was to evaluate the prevalence of coronary artery calcification (CAC) on chest CT in a population of HIV-infected heavy smokers, and to identify risk factors for CAC.
Post-hoc analysis of systematic chest CT scans performed during the ANRS EP48 HIV-CHEST multicentre study, which evaluated the feasibility of early lung cancer diagnosis in HIV-infected heavy smokers. Subjects were aged ≥ 40 years, had a history of smoking of at least 20 pack-years, a CD4 T-lymphocyte nadir cell count < 350 cells/µl, and a current CD4-T cell count > 100 cells/µl. We used a modified, published, semi-quantitative CAC score. Two radiologists reviewed the images, and discordant scores were discussed until consensus. Factors associated with presence of CAC were identified using a logistic regression model.
The 396 subjects enrolled had a median age of 50 years, 83% were men, median pack-years of smoking was 30, 90% of subjects had a HIV viral load < 50 copies/mL, and median last CD4 count was 574 cells/μL. CAC were observed in 266 (67%, 95% confidence interval (CI) [63; 72]) subjects, and 57 subjects (14.5%) had a CAC score ≥ 4, which has been shown to be significantly associated with cardiovascular death. In multivariate analysis, older age (per 10 years increase, with an odd ratio (OR) of 2.29, 95% CI [1.72; 4.04]), male sex (OR 2.00, 95% CI [1.17; 3.42]) and duration of antiretroviral treatment (per 5 years increase, OR 1.27, 95% CI [1.05; 1.54]) were associated with CAC. Cannabis inhalation, smoking in pack-years, nadir CD4 levels, last CD4 count, hepatitis C co-infection and a last HIV viral load < 50 copies/ml were not associated with CAC.
In a population of HIV-infected heavy smokers, CAC prevalence was high (67%) on chest CT scans, and was associated with age and sex as well as antiretroviral treatment duration, but neither immunological nor virological factors. Chest CT assessment in HIV-infected smokers should include CAC scoring, but whether subjects with a high CAC score should benefit from screening for silent myocardial ischemia remains to be determined.