Patients with established coronary heart disease (CHD) with higher triglyceride levels had an increased risk of 22-year mortality, according to a study published in Circulation: Cardiovascular Quality and Outcomes.
The association between elevated triglycerides and all-cause mortality in patients with CHD has long been debated, the study authors pointed out. Previously, the role of triglycerides has been mostly studied in patients without CHD, and data available on patients with CHD have been limited to smaller studies with short follow-up periods. Therefore, the researchers sought to investigate a larger cohort of patients with proven disease.
They wrote, “Elevated triglycerides in patients with established CHD are associated with a long-term mortality risk that is independent of HDL-C [high-density lipoprotein cholesterol] levels. “Even among [patients] with triglycerides >100 mg/dL, the higher mortality risk could be detected. Severe hypertriglyceridemia (triglycerides >500 mg/dL) denotes a population with particularly increased mortality risk.”
The study cohort included 15 355 patients who were screened for the Bezafibrate Infarction Prevention trial. Researchers obtained 22-year mortality data from the national registry, and divided the patients into 5 groups according to strata of fasting serum triglycerides.
The groups were categorized by low-normal triglycerides (<100 mg/dL), high-normal triglycerides (100-149 mg/dL), borderline hypertriglyceridemia triglycerides (150-199 mg/dL), moderate hypertriglyceridemia triglycerides (200=499 mg/dL), and severe hypertriglyceridemia triglycerides (≥500 mg/dL). After adjusting for age and sex, researchers found that survival rates were 41% (low-normal group), and 37%, 36%, 35%, and 25% in the progressively higher triglyceride groups, respectively (P=.001).
For every 1 unit of natural logarithm (Ln), triglycerides elevation was associated with a 6% increased risk of 22-year all-cause mortality (P<.016). This risk was increased by 68% in patients with severe hypertriglyceridemia when compared with patients with low or normal triglycerides levels (P<.001).
This study was not without its own limitations, including minimal follow-up data after screening visits, a lack of data concerning cause of death, and that the analysis was not adjusted for possible variations in fasting triglycerides levels over time.
“It is noteworthy that the associated [mortality] risk is attenuated after adjustment for other risk factors and comorbidities, possibly denoting the complex association between triglyceride levels and mortality, where elevated triglycerides exert both a direct biological effect and also represent a marker of more advanced atherosclerosis,” the authors wrote.
“Multiple strategies to raise HDL-C levels as a primary goal have failed to date to show clinical benefit,” they added. “There is growing evidence suggesting a causal role between triglycerides and cardiovascular risk and that treating high triglyceride levels in addition to treating high LDL-C [low-density lipoprotein cholesterol] may be beneficial.”
Klempfner R, Erez A, Sagit BZ, et al. Elevated triglyceride level is independently associated with increased all-cause mortality in patients with established coronary heart disease: Twenty-two year follow up of the Bezafibrate Infarction Prevention Study and Registry. Circ Cardiovasc Qual Outcomes. 2016; doi: 10.1161/circoutcomes.115.002104.