Coronary artery calcification is prevalent in systemic sclerosis and is associated with adverse prognosis

Coronary artery calcification assessed on thoracic computed tomography represents the calcific component of established coronary artery disease, is a biomarker of total atheromatous plaque burden and predicts mortality. Systemic sclerosis is a pro-inflammatory condition, and inflammation is also a driver of coronary artery disease. We assessed coronary artery calcification prevalence, mortality risk and potential clinical impact on primary prevention in a cohort of patients with systemic sclerosis, differentiated by clinical phenotype including the presence of interstitial lung disease and pulmonary arterial hypertension.

Retrospective analysis of 258 computed tomographies in systemic sclerosis patients from three prospectively maintained clinical and research databases at a single tertiary rheumatology/pulmonary hypertension (PH) service between March 2007 and September 2020 (mean age = 65 ± 12, 14% male). Co-morbidities, statin prescription and all-cause mortality were recorded. Patients were subtyped according to underlying systemic sclerosis complications. Computed tomographies were re-reviewed for coronary artery calcification; severity was graded using a 4-point scale per vessel and summed for total coronary artery calcification score. The impact of reporting coronary artery calcification was assessed against pre-existing statin prescriptions.

Coronary artery calcification was present in 58% (149/258). Coronary artery calcification was more prevalent in systemic sclerosis-pulmonary arterial hypertension than in systemic sclerosis subgroups with interstitial lung disease or without pulmonary arterial hypertension, controlling for age, sex, co-morbidities and smoking status (71%; χ ²(13) = 81.4; p < 0.001). The presence and severity of coronary artery calcification were associated with increased risk of mortality independently of age and co-morbidities (hazard ratio = 2.8; 95% confidence interval = 1.2-6.6; p = 0.018). The 'number needed to report' coronary artery calcification presence to potentially impact management was 3.

Coronary artery calcification is common in systemic sclerosis. Coronary artery calcification predicts mortality independently of age and confounding co-morbidities which suggests this finding has clinical relevance and is a potential target for screening and therapeutic intervention.