Coronary Artery Calcification in the Asian Population: An Overview of the Results from the Korea Initiatives on Coronary Artery Calcification Registry

Incremental prognostic value of triglyceride glucose index additional to coronary artery calcium score in asymptomatic low-risk population

BACKGROUND

The triglyceride glucose (TyG) index has been suggested as a reliable surrogate marker of insulin resistance which is a substantial risk factor for atherosclerotic cardiovascular disease (ASCVD). Several recent studies have shown the relationship between the TyG index and cardiovascular disease; however, the role of the TyG index in coronary artery calcification (CAC) progression has not been extensively assessed especially in low-risk population.

METHODS

We enrolled 5775 Korean adults who had at least two CAC evaluations. We determined the TyG index using ln (fasting triglycerides [mg/dL] x fasting glucose [mg/dL]/2). The CAC progression was defined as either incident CAC in a CAC-free population at baseline or an increase of ≥ 2.5 units between the square roots of the baseline and follow-up coronary artery calcium scores (CACSs) of subjects with detectable CAC at baseline.

RESULTS

CAC progression was seen in 1,382 subjects (23.9%) during mean 3.5 years follow-up. Based on the TyG index, subjects were stratified into four groups. Follow-up CACS and incidence of CAC progression were markedly elevated with rising TyG index quartiles (group I [lowest]:17.6% vs. group II:22.2% vs. group III:24.6% vs. group IV [highest]: 31.3%, p < 0.001). In multivariate logistic regression analysis, the TyG index was independent predictor of CAC progression (odds ratio: 1.57; 95% confidence interval: 1.33 to 1.81; p < 0.001) especially in baseline CACS ≤ 100 group.

CONCLUSION

The TyG index is an independent predictor of CAC progression in low-risk population. It adds incremental risk stratification over established factors including baseline CACS.

Case report: 68 yo Chinese-American woman with high HDL-C and ischemic stroke attributed to intracranial atherosclerotic stenosis

Atherosclerotic cardiovascular disease (ASCVD) events are the most common cause of death in the United States and for most individuals who experience these events, may be predicted by risk identification tools. ASCVD risk calculators enable a clinician-patient discussion and the presence of risk-enhancing factors may further inform decision-making with respect to preventive pharmacotherapy, especially statin prescription. In cases where the decision of whether to treat with medicine is unclear, coronary artery calcium scoring by computed tomography offers enhanced risk stratification and may allow both clinicians and patients to feel more at ease with the decision to withhold statin therapy. Despite this thoughtful approach, individual risk may still be underestimated. We present a case of a woman whose family history suggested increased short- and long-term ASCVD risk due to intracranial atherosclerosis, but whose tests suggested a more equivocal indication for treatment. Neither she nor her clinician appreciated the presence of significant enough risk to persevere through minor statin side effects for primary prevention, but she was lucky to have survived without appreciable harm from an acute cerebrovascular event and is now able to pursue an appropriate secondary preventive strategy. We discuss how exceptional characteristics may mislead clinicians, including misperception about lower risk due to gender, East Asian predisposition to intracranial more than coronary atherosclerosis, high levels of high density lipoprotein cholesterol (HDL-C), and CACS = 0.