AB1150 IMPLICATIONS OF CORONARY ARTERY CALCIUM AND ITS PROGRESSION AS MARKERS OF PLAQUE VULNERABILITY AND PATIENT RISK IN RHEUMATOID ARTHRITIS
Authors: George Karpouzas, Sarah Ormseth, Elizabeth Hernandez, Matthew Budoff
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Atherosclerotic plaque calcification represents a stabilizing physiologic process; calcified coronary plaques (CP) are less prone to rupture and yield lower risk of cardiovascular events (CVE) compared to non-calcified (NCP) or mixed- partially calcified- plaques (MP). Interestingly, higher coronary artery calcium score (CACS) and its progression associate with higher event risk in general patients. We, likewise, reported that CACS predicted cardiac events in rheumatoid arthritis (RA) patients independently of risk factors or cardiac risk scores. <h3>Objectives</h3> To address this paradox, we evaluated the contribution of vulnerable MP burden to CACS as well the influence of change in MP burden on CACS progression in RA patients who underwent coronary anatomy evaluation with computed tomography angiography (CCTA). <h3>Methods</h3> One hundred-one patients underwent a repeat CCTA within 83±3.6 months from baseline. Total number of segments with plaque (segment involvement score-SIS) and cumulative stenosis severity rendered by plaque over all evaluable segments (segment stenosis score-SSS) were computed for all participants. Coronary lesions were defined as non-calcified (NCP), mixed (MP) or calcified (CP). Generalized Linear Models predicted the contribution of MP and CP plaque burden to the baseline and follow-up CACS as well as the influence of change in the burden of the respective lesions on CACS progression. <h3>Results</h3> Mixed and CP burden (SSS-MP and SSS-CP respectively) strongly correlated with CACS at both baseline (r<sub>mp</sub>= 0.75 and r<sub>cp</sub>= 0.77, p&lt;0.001) and follow-up (r<sub>mp</sub>= 0.57 and r<sub>cp</sub>= 0.68, p&lt;0.0001), whereas non-calcified plaque did not (r<sub>ncp</sub>= -0.03, p=0.85 and -0.16, p=0.30 respectively). Both MP and CP burden comparably and significantly contributed to CACS magnitude at both times (table 1); MP accounted for 36.5% and 38.5% of explainable variance in CACS while CP accounted for 63.5% and 61.5% of it at baseline and follow-up respectively (all p&lt;0.001). Likewise, change in MP and CP burden from baseline to follow-up significantly contributed to and justified 27% and 73% of explainable CACS change variance. <h3>Conclusion</h3> The vulnerable MP and the more stable CP burden and their change significantly and collectively contributed to CACS at any time as well as its progression respectively in RA. Therefore, the MP burden and its change embody the vulnerability components within the higher baseline and progressing CACS scores explaining the higher CVE risk observed. Model 1: unadjusted, Model 2: age and gender adjusted, RW: Relative Weight <h3>Disclosure of Interests</h3> George Karpouzas Grant/research support from: Pfizer, Consultant for: Sanofi-Genzyme-Regeneron, Janssen, Roche-Genentech, Pfizer, Speakers bureau: BMS, Sanofi-Genzyme-Regeneron, Janssen, Roche-Genentech, Sarah Ormseth: None declared, Elizabeth Hernandez: None declared, Matthew Budoff: None declared