Systemic sclerosis is an independent risk factor for increased coronary artery calcium deposition

Objective: Endothelial dysfunction and inflammation are pathogenic mechanisms common to systemic sclerosis (SSc) and atherosclerosis. This study was undertaken to examine the relationship between coronary atherosclerosis, as assessed by the coronary artery calcium score (CACS), and conventional cardiovascular and disease-specific risk factors in SSc patients.

Methods: The CACS was measured by computed tomography, and cardiovascular risk factors were examined in SSc patients and compared with controls matched for age, sex, and glycemic status. Disease activity score, antiphospholipid antibodies, high-sensitivity C-reactive protein level, and erythrocyte sedimentation rate were measured in SSc patients. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined.

Results: We recruited 53 SSc patients (50 women and 3 men) and 106 controls. The patients had a mean ± SD age of 53.1 ± 12.9 years and a median disease duration of 9 years. Compared to controls, SSc patients had significantly lower low-density lipoprotein (LDL) cholesterol levels (P = 0.001), high-density lipoprotein cholesterol levels (P = 0.01), diastolic blood pressure, waist circumference, and body mass index and were more likely to be receiving vasodilators (all P < 0.001). There was a significantly higher proportion of SSc patients among subjects with more severe coronary calcification (CACS ≥ 101) compared to those with lesser severity (CACS <100) (56.5% versus 29.4%; P = 0.01). Multiple logistic regression analysis revealed SSc to be an independent determinant for a CACS ≥ 101 (OR 10.89 [95% CI 2.21-53.75], P = 0.003) together with age and LDL cholesterol level after adjustment for other cardiovascular risk factors. Among disease-specific factors, only disease duration (OR 1.14 [95% CI 1.02-1.27], P = 0.02) was independently associated with more severe coronary calcification (CACS ≥ 101).

Conclusion: Our findings indicate that SSc is an independent risk factor for coronary calcification, in addition to the conventional risk factors for coronary atherosclerosis, such as age and hypertension.