Coronary Atherosclerotic Plaque Vulnerability Rather than Stenosis Predisposes to Non-ST Elevation Acute Coronary Syndromes

Abstract

Background. Non-ST elevation acute coronary syndromes (NSTE-ACS) may arise from moderately stenosed atherosclerotic lesions that suddenly undergo transformation to vulnerable plaques complicated by rupture and thrombosis. Objective. Assessment and tissue characterization of the coronary atherosclerotic lesions among NSTE-ACS patients compared to those with stable angina. Methodology. Evaluation of IVUS studies of 312 coronary lesions was done by 2 different experienced IVUS readers, 216 lesions in 66 patients with NSTE-ACS (group I) versus 96 lesions in 50 patients with stable angina (group II). Characterization of coronary plaques structure was done using colored-coded iMap technique. Results. The Syntax score was significantly higher in group I compared to group II (18.7 ± 7.8 vs. 8.07 ± 2.5, p=0.001). Body mass index (BMI) was significantly higher in group II while triglycerides levels were higher in group I (P=0.01 & P=0.04, respectively). History of previous MI and PCI was significantly higher in group I (P=0.016 & P=0.001, respectively). The coronary lesions of NSTE-ACS patients had less vessel area (9.86 ± 3.8 vs 11.36 ± 2.9, p=0.001), stenosis percentage (54.7 ± 14.9% vs 68.6 ± 8.7%, p=0.001), and plaque burden (54.4 ± 14.7 vs 67.8 ± 9.8, p=0.001) with negative remodeling index (0.95 ± 20 vs 1.02 ± 0.14, p=0.008) compared to the stable angina group. On the other hand, they had more lipid content (21.8 ± 7.03% vs 7.26 ± 3.47%, p=0.001), necrotic core (18.08 ± 10.19% vs 15.83 ± 4.9%, p=0.02), and calcifications (10.4 ± 5.2% vs 4.19 ± 3.29%, p=0.001) while less fibrosis (51.67 ± 7.07% vs 70.37 ± 11.7%, p=0.001) compared to the stable angina patients. Syntax score and core composition especially calcification and lipid content were significant predictors to NSTE-ACS. Conclusions. The vulnerability rather than the stenotic severity is the most important factor that predisposes to non-ST segment elevation acute coronary syndromes. The vulnerability is related to the lesion characteristics especially lipidic core and calcification while lesion fibrosis favours lesion stability.

Predictors of Coronary Plaque Vulnerability in Patients with Stable Coronary Artery Disease

“…В настоящее время оптимальная медикаментозная терапия остается ключевым методом первичной и вторичной профилактики острых коронарных событий. Реваскуляризация миокарда уменьшает симптомы ишемии и улучшает качество жизни, но не всегда предотвращает развитие ОКС [6,7]. Но, несмотря на проводимую терапию, сохраняется риск неблагоприятного исхода.…”

ST-elevation Myocardial Infarction and Multivessel Coronary Artery Disease – A Critical Review of Current Practice, Evidence and Meta-analyses

“…Indeed, intravascular ultrasound studies have shown that, compared with chronic coronary disease, in acute coronary syndromes, the incidence of unstable features is higher also in non-culprit lesions. [27][28][29] Often, these lesions appear only moderately stenotic at angiography, in part due to positive vessel remodelling. This is consistent with the previous observation, reported over many years, that the extent of luminal narrowing is a poor predictor of subsequent acute events.…”

Plato's allegory of the cave and the paradigm of complete revascularization in STEMI

“… 11 , 12 , 13 Thus, cardiovascular events are more related to the degree of vulnerability of the coronary plaque than to the severity of coronary stenosis. 14 It would be more appropriate to assess the degree of atherosclerotic plaque instability by optical coherence tomography or coronary intravascular ultrasound instead of assessing the hemodynamic severity of the plaque by visual assessment or FFR, as has been done in most RCTs. Moreover, diffuse coronary spasms are frequently present in the acute phase of STEMI, and this may lead to an overestimation of stenosis severity in nonculprit vessels.…”