Association of longitudinal triglyceride levels with cardiovascular events in multivessel coronary artery disease

Abstract

Aims: The impact of longitudinal fluctuations in triglyceride levels on clinical outcomes in stable coronary artery disease (CAD) is yet to be clarified. This study aims to assess the association between increased upward variability in longitudinal fasting triglyceride levels and the incidence of cardiovascular events during long-term follow-up in patients with multivessel CAD.

Methods and results: This cohort study included 1020 patients with multivessel CAD in the Medicine, Angioplasty, or Surgery Study Registry of the Heart Institute, University of São Paulo, from June 1995 to March 2010. Of 1020 patients with multivessel CAD, 886 had complete clinical and fasting triglyceride levels information during a mean follow-up period of 10.0 years, with a mean of 9.2 triglyceride measurements for each patient. The composite endpoint of death, myocardial infarction, ischaemic stroke, or unplanned myocardial revascularization occurred in 357 patients. A 100 mg/dL increase in the longitudinal triglyceride levels was significantly associated with a 19% higher risk of the combined endpoint [hazard ratio (HR), 1.19 (95% confidence interval (CI), 1.05-1.34); P = 0.008] in the unadjusted analysis. After multivariable adjustment for key baseline factors, this elevation in longitudinal triglyceride levels was associated with a 26% greater risk of the composite endpoint [HR, 1.26 (95% CI, 1.10-1.41); P < 0.001]. Triglyceride variability was also assessed according to baseline triglyceride levels (<150 and ≥ 150 mg/dL). These analyses showed that 100 mg/dL increase in the < 150 mg/dL group was associated with higher cardiovascular risk-HR 1.49 (95% CI, 1.00-1.93, P = 0.029)-compared with the ≥ 150 mg/dL group, HR 1.15 (95% CI, 0.99-1.39, P = 0.214)-both after multivariable analyses.

Conclusion: Increased upward variation of longitudinal fasting triglyceride levels was independently associated with higher rates of cardiovascular outcomes in patients with multivessel CAD. This association was especially observed in individuals with previously controlled triglyceride levels but not in those with elevated baseline levels.

Lay summary: Triglycerides are intricately associated with metabolic disorders that contribute to atherosclerotic events; however, the relationship between individual triglyceride trajectories and adverse cardiovascular outcomes in individuals with stable coronary artery disease (CAD) remains unclear. Using a cohort of 1020 patients with chronic CAD under long-term follow-up, we observed that greater triglyceride variability was associated with an increased cardiovascular risk, and this risk remained significant in individuals who previously had controlled triglyceride levels compared with those with persistently altered levels since baseline.

Keywords: Cardiovascular events; Coronary artery disease; Triglyceride variation.