The Relationship between Coronary Artery Movement Type andStenosis Severity with Acute Myocardial Infarction

Electrocardiographic findings for predicting the left anterior descending artery chronic total occlusion in patients with inferior ST-segment elevation myocardial infarction

In determining the culprit vessel responsible for inferior ST-segment elevation myocardial infarction (STEMI) as either the right coronary artery (RCA) or left circumflex (LCX), the electrocardiographic value has been validated. However, its ability to predict whether inferior STEMI is complicated by left anterior descending artery (LAD) chronic total occlusion remains uncertain. Based on the involvement of arteries other than the culprit vessels, 189 patients with inferior STEMI from our chest pain center were categorized into four groups: LAD occlusion group (n = 20), LAD stenosis > 50% group (n = 116), normal LAD group (n = 27), and other vessel stenosis > 50% group (n = 26). All groups underwent coronary angiography within 24 h of admission, and electrocardiogram (ECG) and clinical data were retrospectively analyzed. In the LAD occlusion group, hypertension was significantly more prevalent (P = 0.015). Although there was a trend toward higher previous cerebral infarction and lower diabetes prevalence in the Normal LAD group, neither was statistically significant (P = 0.070 and P = 0.088). The LAD occlusion group demonstrated the highest serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and the most reduced LVEF, with a higher susceptibility to cardiogenic shock (P < 0.01). This group also had a higher use of intra-aortic balloon pump (IABP) and a greater occurrence of ventricular fibrillation or tachycardia compared to the other groups (P < 0.05). The QRS duration in lead V4 (QRS V4) was 99.4 ± 19.1 ms in the LAD occlusion group, 87.5 ± 14.9 ms in the LAD stenosis group, 89.6 ± 11.4 ms in the normal LAD group, and 87.7 ± 11.7 ms in the other vessel stenosis group (P = 0.010). The difference between ST-segment depression in V4 and ST-segment elevation in lead III (ST V4↓- ST III↑) in the LAD occlusion group was the largest at -0.06 (-1.19, 1.05) mm (P = 0.029). ROC curve analysis revealed that the sensitivity of QRS V4 > 97.7ms and ST V4↓- ST III↑> 0 mm diagnosing inferior STEMI complicated with LAD occlusion was 54.5% and 50%, with a specificity of 75.1% and 78.0%, respectively. Multivariate logistic regression analysis indicated that QRS V4 (OR = 1.062, P = 0.003), ST V4↓- ST III↑ (OR = 1.641, P = 0.050), and Killip classification (OR = 2.115, P = 0.004) were all independent risk factors for LAD occlusion. In patients with inferior STEMI complicated by LAD occlusion without anterior myocardial infarction, cardiac function is poorer. The ST-segment deviation between the leads V4 and III, and the duration of QRS in the lead V4, can aid in diagnosis.

CircSLC8A1 and circNFIX can be used as auxiliary diagnostic markers for sudden cardiac death caused by acute ischemic heart disease

Sudden cardiac death (SCD) caused by acute ischemic heart disease (IHD) is a major cause of sudden death worldwide. Circular RNAs (circRNAs) are abundant in the heart and play important roles in cardiovascular diseases, but the role of circRNAs as biomarkers in the forensic diagnosis of SCD caused by acute IHD remains poorly characterized. To investigate the potential of two heart-enriched circRNAs, circNFIX and circSLC8A1, we explored the expression of these two circRNAs in different kinds of commonly used IHD models, and further verified their expressions in forensic autopsy cases. The results from both the IHD rat and H9c2 cell models revealed that circSlc8a1 level was upregulated, while the circNfix level was elevated in the early stage of ischemia and subsequently downregulated. The time-dependent expression patterns of the two circRNAs suggested their potential as SCD biomarkers. In autopsy cases, the results showed that the expression of these two circRNAs in the myocardium with acute IHD-related SCDs corresponded to the observations in the ischemic models. Further analysis related to myocardial ischemia indicated that circSLC8A1 showed high sensitivity and specificity for myocardial infarction and was positively correlated with creatine kinase MB in pericardial fluid. Downregulated circNFIX level could indicate the ischemic myocardial damage, and it was negatively correlated with the coronary artery stenosis grade. The combination of circSLC8A1 and circNFIX had better performance to discriminate IHD-related SCDs. The results suggested that circSLC8A1 and circNFIX may be used as auxiliary diagnostic markers for SCD caused by acute IHD in forensic medicine.

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

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.