Triglycerides and the Risk of Atherosclerotic Cardiovascular Events Across Different Risk Categories.

Aims: To investigate the association between triglyceride levels and major adverse cardiovascular events (MACE) in primary and secondary prevention cohorts.

Methods: This retrospective study was conducted with a nationwide health insurance claims database, which included approximately 3.8 million participants with medical checkups between January 2005 and August 2020 in Japan. The participants were classified into primary prevention (n=3,415,522) and secondary prevention (n=29,806) cohorts based on cardiovascular or cerebrovascular disease history. Each participant was categorized as having very low (triglyceride ＜50 mg/dL), low normal (50-99), high normal (100-149), or hypertriglyceridemia (≥ 150). The primary prevention cohort was further stratified into low-, intermediate-, and high-risk groups according to atherosclerotic cardiovascular diseases risk. Outcome was MACE, including acute myocardial infarction (AMI), unstable angina, ischemic stroke, and cardiac death.

Results: Over a mean follow-up of 3.25 years, 0.3% and 2.6% MACE occurred in primary and secondary prevention, respectively. Hypertriglyceridemia was associated with high risk of MACE in the primary prevention, but not in the secondary prevention. A significant interaction was observed between prevention categories and the association of TG levels with MACE in those with TG ＜150 mg/dL and ischemic stroke in those with TG ≥ 150 mg/dL. The population-attributable fraction for hypertriglyceridemia in primary prevention was 4.1% for MACE. In primary prevention, lower risks of AMI were observed in the lower TG category compared to the current threshold.

Conclusions: This study suggests distinct triglyceride thresholds for MACE risk in primary and secondary prevention cohorts, requiring further prospective validation for clinical implementation.