Non-HDL Cholesterol and Triglycerides: Implications for Coronary Atheroma Progression and Clinical Events

Objectives - Non-high-density lipoprotein cholesterol (non-HDLC) levels reflect the full burden of cholesterol transported in atherogenic lipoproteins. Genetic studies suggest a causal association between elevated triglycerides (TGs)-rich lipoproteins and atherosclerosis. We evaluated associations between achieved non-HDLC and TG levels on changes in coronary atheroma volume. Approach and Results - Data were analyzed from 9 clinical trials involving 4957 patients with coronary disease undergoing serial intravascular ultrasonography to assess changes in percent atheroma volume (ΔPAV) and were evaluated against on-treatment non-HDLC and TG levels. The effects of lower (<100 mg/dL) versus higher (≥100 mg/dL) achieved non-HDLC levels and lower (<200 mg/dL) versus higher (≥200 mg/dL) achieved TG levels were evaluated in populations with variable on-treatment low-density lipoprotein cholesterol (LDLC) </≥70 mg/dL and C-reactive protein </≥2 mg/L and in patients with or without diabetes mellitus. On-treatment non-HDLC levels linearly associated with ΔPAV. Overt PAV progression (ΔPAV>0) was associated with achieved TG levels >200 mg/dL, respectively. Lower on-treatment non-HDLC and TG levels associated with significant PAV regression compared with higher non-HDLC and TG levels across all levels of LDLC and C-reactive protein and irrespective of diabetic status (P<0.001 across all comparisons). ΔPAV were more strongly influenced by changes in non-HDLC (β=0.62; P<0.001) compared with changes in LDLC (β=0.51; P<0.001). Kaplan-Meier sensitivity analyses demonstrated significantly greater major adverse cardiovascular event rates in those with higher versus lower non-HDLC and TG levels, with an earlier separation of the non-HDLC compared with the LDLC curve. Conclusions - Achieved non-HDLC levels seem more closely associated with coronary atheroma progression than LDLC. Plaque progression associates with achieved TGs, but only above levels of 200 mg/dL. These observations support a more prominent role for non-HDLC (and possibly TG) lowering in combating residual cardiovascular risk.