Age-related Pancoronary Characteristics in Patients with ST-segment Elevation Myocardial Infarction

Background: Age-related vulnerable characteristics of pancoronary plaques in patients with ST-segment elevation myocardial infarction (STEMI) have not been systemically evaluated by optical coherence tomography (OCT). Therefore, we sought to explore the discrepancies in pancoronary characteristics between younger and older patients with STEMI through OCT. Methods: This retrospective single-center study included 588 patients who had STEMI and underwent three-vessel OCT through emergency percutaneous coronary intervention between October 2016 and September 2018. With a median age of 56 years as a cutoff, the patients were divided into a younger group (<= 56 years, n = 298) and an older group (>56 years, n = 290). Results: A total of 795 non-culprit plaques were found in 298 of the younger patients, whereas 858 non-culprit plaques were identified in 290 of the older patients. Fewer high-risk OCT plaques (15.8% vs. 23.1%; P = 0.025), as well as other structures (cholesterol crystals, P = 0.001; microchannels, P = 0.032; calcifications, P < 0.001; spotty calcifications, P < 0.001; large calcifications, P < 0.001; and thrombi, P = 0.001) were identified in younger patients than older patients, at the patient level. In addition, pancoronary vulnerability in younger patients was independently predicted by culprit plaque rupture {CLIMA-defined high-risk plaques (odds ratio [OR]: 3.179; 95% CI: 1.501 to 6.733; P = 0.003), non-culprit rupture (OR: 3.802; 95% CI: 1.604 to 9.014; P = 0.002), non-culprit thin-cap fibroatheroma (OR: 3.536; 95% CI: 2.051 to 6.094; P < 0.001)}, hypertension (OR: 1.920; 95% CI: 1.099 to 3.355; P = 0.022), and total cholesterol (OR: 1.094; 95% CI: 1.002 to 1.195; P = 0.045). In older patients with STEMI, the predictor was male sex (OR: 3.031; 95% CI: 1.352 to 6.795; P = 0.007). Conclusions: Among patients with STEMI, younger patients had limited vulnerable plaque characteristics, and pancoronary vulnerability was associated with culprit plaque rupture, hypertension, and total cholesterol. In contrast, older patients had greater pancoronary vulnerability with the single predictor of male sex, thus suggesting that traditional risk factors have limited applicability in predicting pancoronary vulnerability in older patients.