PROGNOSTIC VALUE AND RELATIVE CUT-OFFS OF TRIGLYCERIDES PREDICTING CARDIOVASCULAR OUTCOME IN A LARGE REGIONAL-BASED ITALIAN DATABASE

Background Despite longstanding epidemiologic data on the association between increased serum triglycerides (TG) and cardiovascular (CV) events, the exact level at which risk begins to rise is unclear. The Working Group on Uric Acid and Cardiovascular Risk of the Italian Society of Hypertension has conceived a protocol aimed at searching for the prognostic cut-off value of TG in predicting CV events in a large regional-based Italian cohort. Methods Among 14,189 subjects aged 18 to 95 years followed-up for 11.2 (5.3-13.2) years, by means of receiver operating characteristic (ROC) curve the prognostic cut-off value of TG, able to discriminate combined CV events, was identified. The conventional (150 mg/dL) and the prognostic cut-off values of TG were used as independent predictors in separate multivariate Cox models adjusted for age, sex, body mass index, total and high-density lipoprotein cholesterol, serum uric acid, arterial hypertension, diabetes, chronic renal disease, smoking habit, use of antihypertensive and lipid lowering drugs. Results During 139,375 person-years of follow-up, 1601 participants experienced CV events. ROC curve showed that 89 mg/dL (95%CI 75.8-103.3, sensitivity 76.6, specificity 34.1, p<0.0001) was the prognostic cut-off value for CV events. Both cut-off values of TG, the conventional and the newly identified, were accepted as multivariate predictors in separate Cox analyses, the hazard ratios being 1.211 (95%CI 1.063-1.378, p=0.004) and 1.150 (95%CI 1.021-1.295, p=0.02), respectively. Conclusions Lower (89 mg/dL) than conventional (150 mg/dL) prognostic cut-off value of TG for CV events do exist and it is associated with increased CV risk in an Italian cohort. Clinical Perspective What is new? Evidence indicates that elevated triglyceride levels are related to cardiovascular events and mortality. However, the exact level at which risk begins to increase is unclear. In a large cohort of European subjects, a prognostic cut-off value of triglycerides lower (89 mg/dL) than the conventional one (150 mg/dL) was identified. What are the clinical implications? Triglyceride measurement must be considered an important part of the routine evaluation to manage cardiovascular risk. In primary prevention, subjects with triglycerides above 89 mg/dL should be carefully observed to prevent possible cardiovascular events.