Effect of statin treatment on coronary plaque progression - A serial coronary CT angiography study

Objectives: Statins have been shown to reduce plaque progression using data on intravascular ultrasound, carotid intima-media thickness and coronary artery calcium scans. However, there is little data on effects of statins on plaque progression using Coronary CTA. The objective is to evaluate the effect of statin therapy on plaque progression using serial Coronary CTA (CCTA). Methods: The study included 100 consecutive patients who underwent serial Coronary CTA (mean follow up: 406±92 days) for evaluation of CAD without known prior heart disease or revascularization. We performed volumetric assessment of low attenuation plaque (LAP<30 Hounsfield units), non-calcified (NCP) and calcified plaque volumes at baseline and follow up scans for vessels >2mm in diameter. Patients who received statins were compared to those that did not. Results: Total plaque progression was significantly reduced among statin user compared to non-statin users (-33.3mm³±90.5 vs. 31.0mm³±84.5, p=0.0006). Statin users had significantly reduced progression of NCP volume (-47.7mm³±71.9 vs. 13.8mm³±76.6, p<0.001) and significantly reduced progression of LAP volume (-12.2mm³±19.2 vs. 5.9mm³±23.1, p<0.0001). When we compared for remodeling index, no statistical difference was found between the two groups (p=0.25) and a non-significant trend toward calcium progression (29.3mm³±67.9 vs. 10.0mm³±53.2, p=0.133). After adjustment for cardiovascular risk factors, mean plaque volume difference between statin and non-statin users was statistically significant for both LAP and NCP volumes (-18.1, 95% CI:-26.4,-9.8 for LAP;-101.7, 95% CI:-162.1,-41.4 for NCP; p<0.001) respectively. Conclusion: Statin therapy resulted in significantly lower progression of LAP and NCP plaques compared to non-statin users.