Triglyceride-Glucose Index Lacks Predictive Value for Adverse CV Prognosis in Nondiabetic PCI

The triglyceride-glucose index (TyG index) is an ineffective predictive factor for cardiovascular prognosis in patients without diabetes who underwent percutaneous coronary intervention, according to research results published in Frontiers in Endocrinology.

In a prospective, observational cohort study, researchers evaluated the relationship between the TyG index and adverse cardiovascular prognosis in a group of patients without diabetes who underwent PCI.

Consecutive patients with coronary artery disease (CAD) who underwent PCI in a single Chinese hospital during 2013 were enrolled in the study. Baseline data, including age, sex, BMI, smoking status, CAD type, hypertension history, hyperlipidemia, stroke, PCI, and coronary artery bypass graft (CABG) were included. Patients also underwent imaging and laboratory examinations for numerous parameters.

After completing coronary angiography and PCI, researchers recorded the characteristics of coronary stenosis and the diameter and number of stents in each patient. Patients were followed up at 1, 6, 12, and 24 months. The primary study endpoint was major adverse cardiovascular and cerebrovascular events (MACCE) including all-cause mortality, nonfatal MI, nonfatal stroke, and target vessel revascularization. Secondary outcomes included MACE, all-cause death, nonfatal MI and stroke, and target vessel revascularization.

A total of 5489 participants without diabetes (mean age, 57.20±10.22 years; 79.4% men; 22.3% with obesity and 60.6% with hypertension) were included in the study. More than half were current smokers (58.7%) and 24.7% had previously undergone either PCI or CABG.

Participants were grouped based on baseline TyG index level (tertile 1 n=1830, tertile 2 n=1830, tertile 3 n=1829). There were significant between-group differences in age, BMI, history of hyperlipidemia, stroke, and smoking, CAD type, percentage of diffuse and CTO disease, and laboratory parameters like HbA1c, fasting blood glucose, cholesterol, C-reactive protein, and creatinine.

All patients completed 2 years of follow-up (mean, 29.0 months). In total, 386 MACCE events, 296 MACE events, 55 all-cause deaths, 40 nonfatal Mis, 81 nonfatal strokes, and 248 target vessel revascularizations were recorded. Kaplan-Meier survival analyses indicated no statistical discrepancy between the 3 groups in terms of all endpoints.

Cox regression analyses were also implemented. Univariate Cox regression analyses indicated that age; previous PCI or stroke; multivessel, CTO, or ISR disease; SYNTAX score; number of stents; left ventricular ejection fraction; fasting blood glucose; HbA1c; and high sensitivity C-reactive protein were all correlated with MACCE. The TyG index, previous PCI, multivessel, CTO, or ISR disease, SYNTAX score, stent diameter, left ventricular ejection fraction, HbA1c, and triglycerides were all related to MACE.

Results of multivariate analyses, which were adjusted for conventional risk factors and potential hazard factors that were “notably associated” cardiovascular events in univariate analyses, demonstrated that previous stroke SYNTAX score, and left ventricular ejection fraction were all independently related to MACCE rather than the TyG index (hazard ratio, 0.77; 95% CI, 0.56-1.16). Stent diameter and SYNTAX score were both independently correlated with MACE rather than the TyG index (HR, 0.79; 95% CI, 0.29-2.15).

Through subgroup analyses, researchers further assessed the influence of TyG level on adverse cardiovascular prognosis by age (>65 or ≤65 years), sex, BMI (≥28 or <28 kg/m²), admission diagnosis (angina or AMI), fasting blood glucose (≥5.6 or <5.6 mmol/L), HbA1c (>5.7% or <5.7%) triglycerides (>1.7 or ≤1.7 mmol/L) and low-density lipoprotein cholesterol (LDL-C) (≥1.8 or <1.8 mmol/L).

Results of these subgroup analyses showed that TyG level was an independent predictive factor for MACCE in those with lower LDL-C, but not higher LDLC.

Study limitations include the single center nature and the inclusion of only Chinese patients, which limits generalizability, no recordings of abdominal or hip circumference, and records of the TyG index only at the time of hospitalization.

“The TyG index was not independently relevant to adverse cardiovascular events in nondiabetic patients who underwent PCI,” the researchers concluded. “More large-scale prospective research should be carried out…to explore the predictive effect of this index in nondiabetic patients who receive PCI, especially in patients with well-controlled LDL-C.”

Reference

Yang J, Tang Y-D, Zheng Y, et al. The impact of the triglyceride-glucose index on poor prognosis in nondiabetic patients undergoing percutaneous coronary intervention. Front Endocrinol. 2021;12:710240. doi:10.3389/fendo.2021.710240