Left Circumflex Coronary Artery as the Culprit Vessel in ST-Segment-Elevation Myocardial Infarction

Evaluation of Nonculprit Coronary Artery Lesions in Patients with Acute ST-Segment Elevation Myocardial Infarction

Background:

Multivessel coronary artery disease is a common finding during the primary percutaneous coronary intervention in patients with acute ST-segment elevation myocardial infarction (STEMI). It might be a cause for recurrent attacks. This study aimed to evaluate nonculprit lesions (NCLs) encountered in the three major epicardial coronary arteries.

Methods:

Patients with STEMI who underwent PPCI and matched the study inclusion criteria were enrolled. They were evaluated clinically, biomedically, and coronary angiographically. The coronary angiography analysis was examined by four cardiologists using the Quantitative Coronary Artery Analysis software. The data was analyzed statistically.

Results:

Of the 154 patients included in the study, 130 (84.4%) were males and 24 (15.6%) were females, with a mean age of 52.92 ± 13.14 years. Five hundred seventy-four NCLs were found in 132 (85.7%) patients. Nonobstructive lesions with stenosis less than 70% of vessel diameter were more frequent than obstructive lesions. The left circumflex coronary artery (LCX) was the first one of the three major arteries to be affected by obstructive NCLs. The obstructive NCLs were 128 in number; found in 78 (50.4%) patients; 65 (50.8%) of them were in LCX; 32 (25%) were in left anterior descending (25%); and 31 (24.2%) were in right coronary artery.

Conclusions:

NCLs are common among STEMI patients. LCX obstructive NCLs are comparable to those in the other two major epicardial coronary arteries, with respect to frequency and severity of luminal stenosis.

Spatial Multiplexed Protein Profiling of Cardiac Ischemia-Reperfusion Injury

BACKGROUND

Reperfusion therapy is critical to myocardial salvage in the event of a myocardial infarction but is complicated by ischemia-reperfusion injury (IRI). Limited understanding of the spatial organization of cardiac cells, which governs cellular interaction and function, has hindered the search for targeted interventions minimizing the deleterious effects of IRI.

METHODS

We used imaging mass cytometry to characterize the spatial distribution and dynamics of cell phenotypes and communities in the mouse left ventricle following IRI. Heart sections were collected from 12 cardiac segments (basal, mid-cavity, apical, and apex of the anterior, lateral, and inferior wall) and 8 time points (before ischemia [I-0H], and postreperfusion [R-0H, R-2H, R-6H, R-12H, R-1D, R-3D, R-7D]), and stained with 29 metal-isotope-tagged antibodies. Cell community analysis was performed on reconstructed images, and the most disease-relevant cell type and target protein were selected for intervention of IRI.

RESULTS

We obtained a total of 251 multiplexed images, and identified 197 063 single cells, which were grouped into 23 distinct cell communities based on the structure of cellular neighborhoods. The cellular architecture was heterogeneous throughout the ventricular wall and exhibited swift changes following IRI. Analysis of proteins with posttranslational modifications in single cells unveiled 13 posttranslational modification intensity clusters and highlighted increased H3K9me3 (tri-methylated lysine 9 of histone H3) as a key regulatory response in endothelial cells during the middle stage of IRI. Erasing H3K9 methylation, by silencing its methyltransferase Suv39h1 or overexpressing its demethylase Kdm4d in isolated endothelial cells, attenuated cardiac dysfunction and pathological remodeling following IRI. in vitro, H3K9me3 binding significantly increased at endothelial cell function-related genes upon hypoxia, suppressing tube formation, which was rescued by inhibiting H3K9me3.

CONCLUSIONS

We mapped the spatiotemporal heterogeneity of cellular phenotypes in the adult heart upon IRI, and uncovered H3K9me3 in endothelial cells as a potential therapeutic target for alleviating pathological remodeling of the heart following myocardial IRI.

Effect of Presence of Ramus Intermedius Artery on Location of Culprit Lesions in Acute Left Circumflex Coronary Artery Occlusion

BACKGROUND AND AIM

Coronary artery anatomy frequently affects location of atherosclerotic plaques and subsequent culprit lesions. We sought to clarify whether presence or absence of Ramus Intermedius coronary artery (RI) would affect location of culprit lesions in acute left circumflex (LCX) coronary artery occlusion.

METHODS

The study included 180 patients, 100 with a diagnosis of non-ST elevation myocardial infarction (NSTEMI) and 80 with ST elevation myocardial infarction (STEMI). All culprit lesions were located in the LCX coronary artery. RI group included 45 patients and the No RI group included 135 patients.

RESULTS

Culprit LCX lesions were similarly located at a comparable distance from LCX ostium in both groups and the presence of RI was not associated with significantly more proximally located culprit LCX lesions (34.7 ± 15.2 mm compared to 30.8 ± 17.9 mm respectively, p > 0.05). The frequency distribution of culprit lesions' distance from LCX ostium showed no significant difference between both groups in any of the segments studied (10 mm each). There was no significant difference between both groups regarding markers of myocardial necrosis size as cardiac biomarkers (peak cardiac troponin-T 1077.4 ± 361.2 pg/dl vs 926 ± 462.2 pg/dl respectively, p = 0.13), (peak creatine kinase-MB 232.2 ± 81 ng/dl vs 194.7 ± 99.2 ng/dl respectively, p = 0.07) or left ventricular ejection fraction (EF 46.3 ± 6.3% vs 48.3 ± 8.3% respectively, p = 0.76).

CONCLUSION

Presence of RI coronary artery, as an additional flow divider, may not be associated with more proximal culprit lesions, compared to its absence, in cases of acute LCX coronary artery occlusion. Possible underlying pathophysiologic mechanisms remain to be clarified.

Frequency of Thrombolysis in Myocardial Infarction III Flow in Patients With Primary Percutaneous Coronary Intervention: Not All Culprit Vessels Are Completely Occluded in ST Elevation Myocardial Infarction

Background

ST elevation myocardial infarction (STEMI) is classically characterized by total occlusion of the culprit coronary artery. However during primary percutaneous coronary intervention (PCI) thrombolysis in myocardial infarction (TIMI) 0 flow is not observed in all patients' culprit arteries in angiographic views. This study was conducted to find out the frequency of TIMI flow in acute STEMI patients in view of the above concept. The aim of this study was to evaluate the frequency of pre-procedural TIMI III flow in those patients who underwent primary PCI for acute STEMI in a public sector hospital in Karachi, Pakistan.

Methodology

This study is an audit of already saved data in the catheterization laboratory of the National Institute of Cardiovascular Diseases (NICVD), Karachi, that was collected prospectively from January 2016 to December 2018. These data were collected after taking consent from those patients who presented to hospital within 12 hours of symptoms and underwent primary PCI. Data were entered and analyzed on Statistical Package for the Social Sciences (SPSS) version 19 (IBM Corp., Armonk, NY, USA).

Results

A total of 8018 patients were included in this study who presented with STEMI and underwent primary PCI. Out of them 80.9% were males. Hypertension was the leading risk factor in 54.1% (4340) of patients. TIMI III flow was present in 11.4% of patients before primary PCI, while TIMI 0, I and II flow were present in 57.1%, 15.1%, and 16.3% of patients respectively (p<0.001). Fourteen percent of patients with TIMI III flow were of age group 51 to 60 years. Among those who had TIMI III flow, 11.2% were those with door to balloon time of <90 minutes. In 11% of cases, left anterior descending (LAD) artery had TIMI III flow as compared to other vessels (p<0.001). The length of the lesion was significantly smaller in patients who had TIMI III flow compared to those who had TIMI 0-II flow.

Conclusions

This study revealed that not all patients with acute STEMI had totally occluded culprit coronary artery but some of them had angiographic TIMI I-III flow in the infarct-related artery. Further studies are needed to find the reason for re-establishment of flow in the culprit vessel in STEMI patients before PCI.

Urgent Pericardiocentesis Is More Frequently Needed After Left Circumflex Coronary Artery Perforation

Background: Coronary artery perforation (CAP) is a rare but potentially life-threatening complication of percutaneous coronary interventions (PCIs) due to the risk of cardiac tamponade. Strikingly, in contrast to numerous analyses of CAP predictors, only few studies were focused on the predictors of tamponade after PCI, once iatrogenic CAP has occurred. Our aim was to search for clinical and periprocedural characteristics, including the coronary artery involved, associated with the development of acute cardiac tamponade among patients experiencing CAP. Methods: From the medical records of nine centers of invasive cardiology in southern Poland, we retrospectively selected 81 patients (80% with acute myocardial infarction) who had iatrogenic CAP with a visible extravasation jet during angiography (corresponding to type III CAP by the Ellis classification, CAP_III) over a 15-year period (2005-2019). Clinical, angiographic and periprocedural characteristics were compared between the patients who developed acute cardiac tamponade requiring urgent pericardiocentesis in the cathlab (n = 21) and those with CAP_III and without tamponade (n = 60). Results: CAP_III were situated in the left anterior descending artery (LAD) or its diagonal branches (51%, n = 41), right coronary artery (RCA) (24%, n = 19), left circumflex coronary artery (LCx) (16%, n = 13), its obtuse marginal branches (7%, n = 6) and left main coronary artery (2%, n = 2). Acute cardiac tamponade occurred in 24% (10 of 41), 21% (4 of 19) and 37% (7 of 19) patients who experienced CAP_III in the territory of LAD, RCA and LCx, respectively. There were no significant differences in the need for urgent pericardiocentesis (37%) in patients with CAP_III in LCx territory (i.e., the LCx or its obtuse marginal branches) compared to CAP_III in the remaining coronary arteries (23%) (p = 0.24). However, when CAP_III in the LCx were separated from CAP_III in obtuse marginal branches, urgent pericardiocentesis was more frequently performed in patients with CAP_III in the LCx (54%, 7 of 13) compared to subjects with CAP_III in an artery other than the LCx (21%, 14 of 68) (p = 0.03). The direction of this tendency remained consistent regardless of CAP management: prolonged balloon inflation only (n = 26, 67% vs. 13%, p = 0.08) or balloon inflation with subsequent stent implantation (n = 55, 50% vs. 24%, p = 0.13). Besides LCx involvement, no significant differences in other characteristics were observed between patients according to the need of urgent pericardiocentesis. Conclusions: CAP_III in the LCx appears to lead to a higher risk of acute cardiac tamponade compared to perforations involving other coronary arteries. This association may possibly be linked to distinct features of LCx anatomy and/or well-recognized delays in diagnosis and management of LCx-related acute coronary syndromes.

Pattern of coronary arterial lesions amongst Saudi Arabians: a cross-sectional coronary fluoroscopic angiography study

Introduction

Coronary artery disease (CAD) is a major cardiovascular disease (CVD) that affects a large population globally. This study aimed at determining coronary arterial lesions (CAL), particularly in terms of age, gender, coronary artery/arteries involved, number of lesions, and dominant coronary artery in the Kingdom of Saudi Arabia (KSA).

Methods

A cross-sectional study was conducted at the King Khalid Hospital and Prince Sultan Centre for Health Care in Al-Kharj between January 2017 and March 2018. The patients with CAD lesion/s, fulfilling the inclusion criteria, were recruited from the cardiovascular medicine unit. Demographic information and the location and extent of their CAD lesions were extracted and documented in electronic case report form (eCRF). SPSS 22.0 was used for statistical analysis, and p value ≤ 0.05 was considered as significant.

Results

Of the 262 patients, male and female preponderance was 74.8% and 25.2%, respectively. The majority of the patients were adults above the age of 50 (72%). About half of all patients were active smokers (53%). Diabetes, hypertension, and hyperlipidaemia were recorded in 63%, 53.7% and 25% respectively. The incidence of cardiovascular lesions was documented after coronary angiography; left circumflex artery lesions had the highest incidence (85.3%), followed by left anterior descending artery lesions (82.4%) and right circumflex artery lesions (74.3%). Left main coronary artery lesions had the lowest incidence (10.3%). Most patients (59.6%) had three concomitant lesions, whereas a minority of patients had two (22.8%) and one lesion (17.7%).

Conclusion

The pattern of CALs is different among the Saudi population as compared to other countries.