Background/Purpose:   Coronary atherosclerosis is a major cause of morbidity and mortality in SLE.  New technology, computed tomoangiography (CTA) can measure non-calcified coronary plaque (NCP), which is more inflammatory, unstable and more prone to rupture.  The aim of our current study was to determine the progression of noncalcified coronary plaque in SLE.

Methods:   Repeat computed tomoangiography (CTA) was done in 11 (73% female, 91% Caucasian, 9% African-American, mean age 53 years) SLE patients after a baseline CTA.  The CTA scans were evaluated quantitatively by a radiologist, using dedicated software.  The correlation coefficient between the overall NCP score between 2 observers was 0.93. The kappa statistic for the assessment of noncalcified plaque (present or absent) in the 71 vessel segments was 0.42.  The Noncalcified plaque score was the sum of plaque severity multiplied by the plaque composition, divided by the number of vessels examined. 

Results:   Figure 1 shows the baseline and second CTA results in these 11 patients.  Nearly all (9/11) had progression of noncalcified plaque.  One patient had no NCP and one patient had regression of noncalcified plaque.  Four of five patients who progressed on calcified plaque, also had progression of noncalcified plaque.  Out of 11 patients, 6 were on  statins, 2 mycophenolate mofetil and 1 azathioprine.  All 3 on immunosuppressants progressed.    

Figure 1:  Noncalcified Coronary Plaque Change Over Time in SLE Patients

*Immunosuppressive drug

Conclusion:   Noncalcified plaque – the most risky coronary plaque–progressed in the majority of SLE patients.  All those with progression were under the care of a dedicated cardiologist; 5 were on statin therapy.  Even the 3 on immunosuppression showed progression.  This, in particular, is disappointing, as in lupus mice, mycophenolate has been proven to reduce progression of atherosclerosis.  Our study proves that NCP can be the outcome in intervention trials in SLE.