Coronary calcium in autoimmune diseases: A systematic literature review and meta-analysis

Autoimmune diseases (AID) share various clinical signs and symptoms and pathophysiological mechanisms including the increased risk of cardiovascular disease. The coronary artery calcium score (CACS) is potentially useful in improving the cardiovascular risk assessment. The aim of this study was to evaluate CACS in six AIDs analyzed as a group compared with controls through a systematic literature review (SLR) and meta-analysis.A literature search (Medline/OVID, Lilacs, Embase, and Cochrane/OVID) up to January 6, 2021 was made (PROSPERO CRD42020197182). Observational studies (patients with six AIDs: rheumatoid arthritis [RA], systemic lupus erythematosus [SLE], Sjögren's syndrome, systemic sclerosis, dermatopolymyositis, and antiphospholipid syndrome) compared with controls were included. CACS, reported in Agatston units, was the primary outcome in both groups. Mean differences and a random-effects model (DerSimonian and Laird) were calculated.Nineteen articles were meta-analyzed (4568 subjects: 2142 AID and 2426 controls). Mean age was 48.1 and 44.2 years, respectively and 75.6% and 84.9% were women, respectively. Of cases, 52.9% had RA, 44.4% SLE and 2.7% had systemic sclerosis. The pooled analysis showed a higher CACS in patients with AIDs (7.42; 95% CI 1.79 to 13.05; chi2-p = 0.01) compared with controls. Meta-regression models showed that age in cases and controls reduced the difference in CACS between groups (p < 0.05), HDL had an inverse relationship (p = 0.04), and CRP levels had a directly proportional relationship with CACS in cases (p = 0.036).The quantitative results of this meta-analysis suggest that CACS is higher in patients with AID, possibly due to chronic exposure to pro-inflammatory molecules. These results have clinical implications since the finding of highly elevated CACS in patients with AID will enable physicians and researchers to develop a risk stratification model that includes CACS as one of the screening tools for detecting coronary atherosclerosis in these patients.