Association of Autoimmune Diseases With Coronary Atherosclerosis Severity and Ischemic Events

Background: Some autoimmune diseases carry elevated risk for atherosclerotic cardiovascular disease (ASCVD), yet the underlying mechanism and the influence of traditional risk factors remain unclear. Objectives: This study sought to determine whether autoimmune diseases independently correlate with coronary atherosclerosis and ASCVD risk and whether traditional cardiovascular risk factors modulate the risk. Methods: The study included 85,512 patients from the Western Denmark Heart Registry undergoing coronary computed tomography angiography. A diagnosis of 1 of 18 autoimmune diseases was assessed. Adjusted OR (aOR) for any plaque, any coronary artery calcification (CAC), CAC of >90th percentile, and obstructive coronary artery disease as well as adjusted HR (aHR) for ASCVD were calculated. Results: During 5.3 years (Q1-Q3: 2.8-8.2 years) of follow-up, 3,832 ASCVD events occurred. A total of 4,064 patients had a diagnosis of autoimmune disease, which was associated with both presence of any plaque (aOR: 1.29; 95% CI: 1.20-1.40), any CAC (aOR: 1.28; 95% CI: 1.19-1.37), and severe CAC of >90th percentile (aOR: 1.53; 95% CI: 1.39-1.68), but not with having obstructive coronary artery disease (aOR: 1.04; 95% CI: 0.91-1.17). Patients with autoimmune diseases had a 46% higher risk (aHR: 1.46; 95% CI: 1.29-1.65) for ASCVD. Traditional cardiovascular risk factors were strongly associated with future ASCVD events, and a favorable cardiovascular risk factor profile in autoimmune patients was associated with similar to 54% lower risk compared to patients with presence of risk factors (aHR: 0.46; 95% CI: 0.27-0.81). Conclusions: Autoimmune diseases were independently associated with higher burden of coronary atherosclerosis and higher risk for future ASCVD events, with risk accentuated by traditional cardiovascular risk factors. These findings suggest that autoimmune diseases increase risk through accelerated atherogenesis and that cardiovascular risk factor control is key for improving prognosis in patients with autoimmune diseases.