Remnant cholesterol and coronary atherosclerotic plaque burden assessed by computed tomography coronary angiography

Background and aims: There remains a substantial residual risk of ischaemic heart disease (IHD) despite optimal low-density lipoprotein cholesterol (LDLC) reduction. Part of this risk may be attributable to remnant cholesterol, which is carried in triglyceride-rich lipoproteins. We evaluated the relationship between remnant cholesterol and coronary atherosclerotic plaque burden assessed non-invasively by computed tomography coronary angiography (CTCA) in patients with suspected coronary artery disease (CAD). Methods and results: This was a multicentre study of 587 patients who had a CTCA and fasting lipid profile within 3 months. Calculated remnant cholesterol was total cholesterol minus LDLC minus high-density lipoprotein cholesterol (HDLC). Significant coronary atherosclerotic burden was defined as CT-Leaman score> 5 (CT-LeSc), an established predictor of cardiac events. Mean age was 61 +/- 12 years and mean pretest probability of CAD was 23.2 +/- 19.8%. LDLC levels were < 1.8 mmol/L in 134 patients (23%), of whom 82% were statin-treated. Patients with CT-LeSc> 5 had higher mean remnant cholesterol than those with CT-LeSc <= 5 (0.76 +/- 0.36 mmol/L vs. 0.58 +/- 0.33 mmol/L, p=0.01). On univariable analysis, remnant cholesterol (p=0.01), LDLC (p=0.002) and HDLC (p < 0.001) levels predicted CT-LeSc > 5, whilst triglycerides (p=0.79) had no association with CT-LeSc> 5. On multivariable analysis in the subset of patients with optimal LDLC levels, remnant cholesterol levels remained predictive of CTLeSc> 5 (OR 3.87, 95% confidence interval 1.34-7.55, p=0.004), adjusted for HDLC and traditional risk factors. Conclusions: Remnant cholesterol levels are associated with significant coronary atherosclerotic burden as assessed by CTCA, even in patients with optimal LDLC levels. Future studies examining whether lowering of remnant cholesterol can reduce residual IHD risk are warranted.