Cause Of Acute Coronary Syndrome Research Articles

Circulating microRNAs as potential biomarkers for coronary plaque rupture.

Coronary plaque rupture is the most common cause of acute coronary syndrome. However, the timely biomarker-based diagnosis of plaque rupture remains a major unmet clinical challenge. Balloon dilatation and stent implantation during percutaneous coronary intervention (PCI) could cause plaque injury and rupture. Here we aimed to assess the possibility of circulating microRNAs (miRNAs) as biomarkers of acute coronary plaque rupture by virtue of the natural model of PCI-induced plaque rupture. Stable coronary artery disease patients underwent PCI with single stent implantation were recruited and a three-phase approach was conducted in the present study: (i) profiling of plasma miRNAs in a group of patients before (0 h) and after balloon dilatation for 1 h (1 h vs. 0 h), (ii) replication of significant miRNAs in the second group of patients (1 h vs. 0 h), (iii) validation of a multi-miRNAs panel in the third group of patients (0.5 h, 1 h vs. 0 h). Out of 24 miRNAs selected for replication, 6 miRNAs remained significantly associated with plaque rupture. In the validation phase, combinations of miR-483-5p and miR-451a showed the highest area under the receiver-operating-characteristic curve (AUC) (0.982; CI: 0.907-0.999) in patients with plaque rupture for 0.5 h; combinations of miR-483-5p and miR-155-5p showed the highest AUC (0.898; CI: 0.790-0.962) after plaque rupture for 1 h. In conclusion, using a profiling-replication-validation model, we identified 3 miRNAs including miR-155-5p, miR-483-5p and miR-451a, which may be biomarkers for the early identification of plaque rupture.

Abstract 400: Statin and Ezetimibe Differently Affect Spontaneous Atherothrombotic Occlusion in a Rabbit Model of Plaque Erosion

Background: Atherothrombosis of a coronary artery with plaque erosion is a major cause of acute coronary syndrome; however, its pathological mechanism and the effects of lipid-lowering therapy are unknown. We have recently reported the CuVIC Trial showing that ezetimibe added to statins improves coronary endothelial function associated with reductions in serum oxysterols in patients after coronary stenting (Takase, et al. ATVB 2017, in press). Methods and Results: We performed balloon injury in iliofemoral arteries in male Japanese white rabbits fed with high cholesterol diet and infused with angiotensin II. We examined the occurrence of atherothrombosis by echography 3 times/week, which were subsequently confirmed by angiography. Histochemical analysis revealed the lack of PECAM1-positive endothelial layer in the atherothrombotic sites. In treatment protocol, animals were divided into 3 groups; 1. Control, 2. Ezetimibe 0.6 mg/kg/day, and 3. Rosuvastatin 1.0 mg/kg/day, resulting total cholesterol 2514+/-179, 1716+/-111, and 1403+/-174, respectively after 8 weeks. Oral treatment with Ezetimibe significantly reduced atherothrombotic occlusion. Although there was no difference in the extent of arterial stenosis among 3 groups, treatment with ezetimibe was associated with better re-endothelialization and less tissue factor (TF)-positive areas in the intima. Serum oxysterols including 7-ketocholesterol (7KC) were lower in the Ezetimibe group. Serum from the model rabbits or 7KC induced TF in cultured SMCs. TF induction by the serum from the Ezetimibe group was significantly less compared with other groups. Conclusions: We established a valid animal model of spontaneous atherothromobotic occlusion in rabbits, which mimicked plaque erosion observed in human coronary arteries. Reduction in serum oxysterols with ezetimibe may prevent atherothrombosis from plaque erosion, by accelerating re-endothelialization and inhibiting TF expression in injured arteries.

Development Of An Atherothrombotic Occlusion In The Rabbit Carotid Artery: Accessed By New Computerized B- Mode Ultrasound Image Processing Technology And Histopathology

Introduction: Thrombus formation on a disrupted atherosclerotic soft plaque is a key event that leads to atherothrombosis. Atherothrombosis is one of the leading causes of acute coronary syndrome and ischemic stroke. Our ability to test new protocols for the treatment of atherothrombotic stenosis in humans is limited for obvious ethical reasons; therefore, a precise understanding of the mechanism of atherothrombotic occlusion in human carotid artery, which give rise to thrombosis, emboli and stroke, requires a suitable animal model that would mimic the same characteristics well.Aims: The aim of this study was to generate an easily reproducible and inexpensive experimental rabbit carotid model of atherothrombotic occlusion with morphological similarities to the human disease and the subsequent assessment of the reliability of new computerized B- mode ultrasound image processing technology in the study of lumen area stenosis in this model.Methods: Briefly, male New Zealand white rabbits were submitted to common carotid artery atherothrombotic occlusion by primary balloon injury followed 1.5% cholesterol- rich diet injury for eight weeks and finally perivascularly severe cold injury. All of the rabbits' arteries were imaged by B-mode ultrasound weekly, after which the rabbits were sacrificed, and their vessels were processed for histopathology. Ultrasound longitudinal view images from three cardiac cycles were processed by a new computerized analyzing method based on dynamic programming and maximum gradient algorithm for measurement of instantaneous changes in arterial wall thickness and lumen diameter in sequential ultrasound images.Results: Histopathology results showed progressive changes, from the lipid-laden cells and fibrous connective tissue proliferation, fibrolipid plaque formation, resulting in vessel wall thickening, remodeling, neovascularization and lumen narrowing (before perivascularly severe cold injury using liquid nitrogen) up to atherothrombotic occlusion (after perivascularly severe cold injury using liquid nitrogen) in the treatment group respect to other groups (P < 0.05).Conclusion: In conclusion we successfully developed a new rabbit carotid artery model of atherothrombotic occlusion, which is not only quickly and easily reproducible and inexpensive, but also without mortality and similar to the condition seen in patients. The merits of our model render the evaluation of carotid artery atherothrombotic stenosis and its treatment strategies more feasible in humans. This condition in rabbits can be properly assessed by our new computerized B-mode ultrasound image processing technology.

Role of Optical Coherence Tomography in Diagnosis and Treatment of Patients with Acute Coronary Syndrome

Acute coronary syndrome (ACS) is the main cause of death worldwide and the leading cause of disease burden in high-income countries. ACS refers to a constellation of clinical symptoms that are compatible with acute myocardial ischemia. It describes a spectrum of clinical manifestations that result from a common pathophysiological process. The most common cause of ACS are rupture of an atherosclerotic lesion containing a large necrotic core and a thin fibrous cap followed by acute luminal thrombosis. It was thought that a high-resolution imaging modality would be ideal to detect high-risk plaques before their disruption and the formation of an occlusive thrombus. Optical coherence tomography has proven to be an invaluable tool in early detection of high-risk plaques and particularly in the understanding of ACS. This review focuses on the current evidence for the role of optical coherence tomography in the diagnosis and treatment of patients with ACS.

Neutrophil-to-lymphocyte Ratio and Its Relation with Markers of Inflammation and Myocardial Necrosis in Patients with Acute Coronary Syndrome.

Introduction:Inflammation plays an important role in atherosclerosis which is the primary cause of acute coronary syndrome (ACS) that encompasses acute myocardial infarction (AMI) and unstable angina (UA).Objective:To investigate and characterize white blood cells (WBC) count, differential blood count in peripheral blood and neutrophil to lymphocyte ratio (NLR) in patients by the type of ACS.Patients and methods:The cross-sectional study included 100 patients with ACS (50 males, 50 females), aged 41 to 91 years, classified into two groups: AMI group (n=50) and UA group (n=50). Patients were hospitalized at the Clinic for Heart Diseases, University Clinical Center of Sarajevo. From patients’ medical histories the following data were obtained: WBC, neutrophil, eosinophil and basophil granulocytes count, monocyte and lymphocyte count, levels of high sensitive troponin I (hsTnI), creatine kinase MB (CK-MB) and C-reactive protein (CRP). The results were analyzed using software package SPSS, version 19.0.Results:Average WBC count, neutrophil granulocytes, and monocytes were significantly higher in AMI group than in UA group (p = 0.001, p < 0.0005, p = 0.03, respectively). Eosinophil count was significantly lower in patients with AMI (p = 0.022). NLR was significantly higher in AMI group in relation to patients with UA (p = 0.001). Significantly higher values of hsTnI and CK-MB were established in patients with AMI. NLR correlated significantly positive with the values of hsTnI, CK-MB, CRP, WBC and neutrophil count, and significantly negative with lymphocyte count.Conclusion:Average values of NLR were significantly higher in patients with AMI in relation to patients with UA, indicating the importance of this inflammatory marker in discrimination of clinical forms of ACS. A positive correlation was established between NLR and markers of myocardial necrosis, and between NLR and CRP, indicating the importance of NLR in the assessment of the extent of the myocardial lesion and in inflammation intensity assessment in ACS.

Clomiphene Associated Inferior STEMI in a Young Female due to Right Coronary Artery Dissection

Nonatherosclerotic spontaneous coronary artery dissection (NA-SCAD) is an uncommon cause of myocardial infarction. It most commonly affects females in the perimenopausal age. NA-SCAD has been associated with many predisposing factors including pregnancy and hormonal therapy for both contraception and ovulation induction. The presented case is a previously healthy 41-year-old woman diagnosed with inferior ST-elevation myocardial infarction due to right descending coronary artery dissection associated with recent use of clomiphene monotherapy for ovulation induction (a previously fertile woman), which was not previously reported. Learning Objectives. Emergency physicians (EPs) should be aware about NA-SCAD as a cause of acute coronary syndrome (ACS) especially in perimenopausal women even with no risk factors. NA-SCAD occurs more commonly in the postpartum period and in females following hormonal therapy. Here, clomiphene monotherapy was reported as a possible contributing factor to NA-SCAD. Guidelines for NA-SCAD management are not up to date, and EPs should avoid some interference before the final diagnosis of the cause of myocardial infarction.

Visible Thrombus and Ruptured Plaque in Right Coronary Artery

Atherosclerotic plaque rupture and subsequent thrombosis are major pathophysiological mechanisms as cause of acute coronary syndromes. Patients with stable obstructive coronary artery disease may live for many years without any cardiovascular events through only risk factor modification and prompt medical treatment. However patients with minimal coronary artery disease may experience premature cardiovascular events moreover death. Thus, plaque stabilization may be much important rather than struggle with stenosis. We report a case of NSETMI with ruptured atherosclerotic plaque and subsequent thrombosis as a culprit lesion in right coronary artery.

Emergency Department Presentation of Patients with Spontaneous Coronary Artery Dissection

BackgroundSpontaneous coronary artery dissection (SCAD) is an infrequently recognized but potentially fatal cause of acute coronary syndrome (ACS) that disproportionately affects women. Little is currently known about how patients with SCAD initially present. ObjectivesWe sought to describe patients who presented to the emergency department (ED) with symptoms of SCAD to improve providers’ awareness and recognition of this condition. Patients and MethodsWe performed a retrospective medical record review of all patients who presented to the ED of a single academic medical center from January 1, 2002 through October 31, 2015 and were subsequently diagnosed with SCAD by angiography. These patients were identified by International Classification of Diseases, Ninth Revision codes and a Boolean search of the diagnosis field of the medical record. Data regarding patients’ presentations and course were abstracted by two independent reviewers. ResultsWe identified 20 episodes of SCAD involving 19 patients, all of whom were female. The majority of patients had 0–1 conventional cardiovascular disease risk factors. Most patients had chest pain (85%), initial electrocardiograms without evidence of ischemia (85%), and elevated initial troponin (72%). The most common diagnosis in providers’ differential was acute coronary syndrome (ACS). ConclusionPatients with SCAD present with similar symptoms compared to patients with ACS caused by atherosclerotic disease, but have different risk profiles. Providers should consider SCAD in patients presenting with symptoms concerning for ACS, especially in younger female patients without traditional cardiovascular disease risk factors, as their risk may be significantly underestimated with commonly used ACS risk-stratifiers.

Cardiac Rehabilitation for Patients with Spontaneous Coronary Artery Dissection

Background: Spontaneous coronary artery dissection (SCAD) is an uncommon and under-diagnosed cause of acute coronary syndrome, especially in young women. Increasing clinical awareness with use of invasive angiography has led to an increase of patients with a SCAD diagnosis. Little is known about the effects of cardiac rehabilitation (CR) in patients with SCAD especially in Australia. Aim: To examine the effect of cardiac rehabilitation in patient who present with SCAD. Methods: We reviewed clinical data collected prospectively from January 1994 to December 2015 for patients with angiographically-diagnosed SCAD who commenced CR. This included demographics, precipitant behaviour, cardiac risk factors, functional capacity, quality of life (QOL), morbidity and mortality. Results: Thirteen SCAD patients (mean age 46±10.9 years; 69% female; 69% STEMI; 39% Indian background) commenced the CR service. Precipitant behaviour was physical (46%), emotional (15%) and sedentary (39%). The initial event was complicated by pericarditis (46%) and/or VF arrest (23%). Cardiac risk factors were current smoking (38%), dyslipidaemia (69%), history of depression (29%), and active lifestyle (77%). CR outcomes included an increase in functional capacity (pre-program 8±3.1 METS: post-program 11.1±2.8 METS; p=0.02), a reduction in waist circumference (1.5 cm) and total cholesterol levels (p<0.01), an increase in QOL domains of Vitality and Social–Functioning (p=0.05), and a 100% smoking cessation rate. One patient (0.8%) was readmitted with pericarditis but returned and completed the CR program. There was no mortality associated with exercise stress testing and/ or CR. Conclusion: CR for patients following SCAD appears safe and effective in a traditional program setting.

Three-Vessel Spontaneous Coronary Artery Dissection in an Old Woman

Spontaneous coronary artery dissection (SCAD) is one of the rare causes of acute coronary syndrome. Regarding the etiology, it is classified broadly into 2 groups: atherosclerotic and non-atherosclerotic. It is more common in females and left anterior descending coronary artery is the most commonly involved artery. Optimal therapy for SCAD is not well-defined. Treatment options include a conservative approach, percutaneous intervention, and bypass grafting surgery. We present an old woman with three-vessel SCAD. She was admitted with acute coronary syndrome. By angiography, SCAD was identified in all three coronary arteries. Her case was discussed by our heart team and she underwent bypass surgery. Her postoperative course was uneventful and she was discharged from the hospital in good clinical condition.

High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis.

Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions.

A case of spontaneous coronary artery dissection in early pregnancy managed by PCI

Spontaneous coronary artery dissection is a rare cause of acute coronary syndrome in pregnant and peripartum women. This report presents a rare case of spontaneous coronary artery dissection in early pregnancy managed by coronary angioplasty and, combined obstetric and cardiac care, resulting in the delivery of a normal infant through cesarean section.

SPONTANEOUS CORONARY DISSECTION AND FIBROMUSCULAR DYSPLASIA: A PATHOLOGICAL AND MORPHOMETRIC ANALYSIS

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome (ACS), and sudden cardiac death, affecting young adults. Fibromuscular dysplasia (FMD) has recently been reported to be a common underlying etiology for SCAD. A total of nine SCAD cases (63 sections) were

SPONTANEOUS CORONARY ARTERY DISSECTION: HEART TEAM APPROACH IN MANAGING AN UNCOMMON BUT SERIOUS CAUSE OF MYOCARDIAL INFARCTION

Spontaneous Coronary Artery Dissection (SCAD) is a rarely encountered but serious cause of acute coronary syndrome that occurs mostly in young women. A 31-year-old female presented to an outside hospital (OSH) with cardiac arrest 9 days postpartum. The patient was breast feeding her baby when she

Spontaneous Coronary Artery Dissection in Young Women Presenting with Acute Coronary Syndrome

The pathophysiology of acute coronary syndrome (ACS) in women is complex and may involve non-atherosclerotic mechanisms. Spontaneous coronary artery dissection (SCAD) is a rare cause of ACS that predominantly affects younger women. However, limited information is available for its incidence, clinical course and outcomes compared to younger women with acute coronary syndrome (ACS) not associated with SCAD. Gender and Sex determinants of cardiovascular disease: From bench to beyond-Premature Acute Coronary Syndrome (GENESIS-PRAXY) study is multicenter prospective study of ACS patients aged 18 to 55 years. Detailed demographic, clinical, laboratory and outcome data were collected and coronary angiograms analyzed in a blinded manner. Among 383 women with ACS, 42 (11%) had SCAD confirmed by angiography. Multiple SCAD were present in 9 (21%) patients. Compared with no-SCAD patients, SCAD subjects were more likely to have absence of any cardiac risk factor (24% vs 7%, p=0.0001), lower LDL (2.5±0.9 vs 3.0±1.2 mmol/L, p=0.06) and higher HDL (2.3±4.7 vs 1.1±0.5 mmol/L p=0.0002) levels. Single vessel disease was more common (81% vs. 50%, p=0.0002) and SYNTAX score lower (8±6 vs. 12±8, p=0.002) in SCAD compared to no-SCAD patients. Coronary intervention was less commonly performed (43% vs 73%, p<0.0001) and TIMI 3 flow less commonly achieved (77% vs 93%, p=0.003) in SCAD compared with no-SCAD patients. The presence of autoimmune disease, connective tissue disorders were similar between the SCAD and no-SCAD group. Coronary hypertortuosity was identified in 95% of SCAD compared with 7% of no-SCAD patients, (p<0.0001). At 12 months follow up, SCAD patients were more likely to experience repeat hospitalization compared to no-SCAD patients (29% vs 16, p=0.04) with similar no difference in overall major adverse cardiac events (MACE). SCAD is an important and not infrequent cause of ACS in younger women. Despite a low risk factor and angiographic burden of atherosclerosis, a significant proportion of SCAD patients experience repeat hospitalization and MACE at one year. These findings underscore the need for greater understanding of SCAD mechanisms and better risk stratification for improving outcome in this high risk group.

Spontaneous, Postpartum Coronary Artery Dissection and Cardiogenic Shock with Extracorporeal Membrane Oxygenation Assisted Recovery in a 30-Year-Old Patient.

Coronary artery dissection is an infrequent cause of acute coronary syndrome in the general population. There is, however, a greater incidence of spontaneous coronary artery dissection (SCAD) in young women, especially in the peripartum period. However, the majority of cases have favorable outcomes with medical management or percutaneous coronary intervention; coronary artery bypass grafting (CABG) and transplantation are utilized in severe cases. This case is a one of a 30-year-old postpartum female with multivessel SCAD requiring CABG with subsequent biventricular failure and inability to wean from bypass. We believe this is the first reported case in which venoarterial extracorporeal membrane oxygenation (VA-ECMO) was used in the management of biventricular heart failure in a postpartum patient with SCAD.

Does T wave inversion in lead aVL predict mid-segment left anterior descending lesions in acute coronary syndrome? A retrospective study

ObjectivesLimited data are available regarding the predictive value of electrocardiographic T wave inversion in lead aVL for mid-segment left anterior descending (MLAD) lesions among patients with acute coronary syndrome (ACS).SettingRetrospective...

Is Acute Coronary Syndrome Secondary to Coronary Vasculitis Underestimated in Daily Cardiology Practice?

Acute coronary syndrome (ACS) is an increasing clinical diagnosis in daily practice. ACS is a life-threatening condition with high mortality rate if left untreated. The better-known risk factors for ACS are dyslipidemia, diabetes mellitus, hypertension2 and coronary vasospasm. Coronary vasculitis is the least appreciated cause of ACS that is subject to neglect among clinicians. Coronary vasculitis (CV) may occur as a single organ vasculitis (SOV) or in the context of specific systemic vasculitides. CV may be the initial presentation of specific systemic vasculitis. Current concept indicates the “worse prognosis” in myocardial infarction associated with elevated acute phase reactants, while these could be the critical point in missed-diagnosis of occult coronary vasculitis as classic cases with atherosclerosis of coronary vessels as the culprit mechanism. We suppose that if elevated CRP/ ESR be due to inflammatory process within the vessel wall, then a classic approach of anticoagulants, thrombolytic therapy or primary coronary angioplasty paradoxically could be dangerous13 and, vice versa, different look with using glucocorticoids could be lifesaving, the medication that later on proved that can improve prognosis in ACS and MI. So, with increasing prevalence of acute coronary syndromes in younger people, the possibility of underestimating coronary vasculitis is potentiated and emphasizing only on classic and common risk factors of ACS is not prudent.

Rare causes of acute coronary syndrome: in addition to coronary artery atherosclerosis

Rare causes of acute coronary syndrome: in addition to coronary artery atherosclerosis

Spontaneous Coronary Dissection: “Live Flash” Optical Coherence Tomography Guided Angioplasty

Optical Coherence tomography (OCT) is a light-based imaging modality which shows tremendous potential in the setting of coronary imaging. Spontaneous coronary artery dissection (SCAD) is an infrequent cause of acute coronary syndrome (ACS). The diagnosis of SCAD is made mainly with invasive coronary angiography, although adjunctive imaging modalities such as computed tomography angiography, IVUS, and OCT may increase the diagnostic yield. The authors describe a clinical case of a young woman admitted with the diagnosis of ACS. The ACS was caused by SCAD detected in the coronary angiography and the angioplasty was guided by OCT. OCT use in the setting of SCAD has been already described and the true innovation in this case was this unique use of OCT. The guidance of angioplasty with live and short images was very useful as it allowed clearly identifying the position of the guidewires at any given moment without the use of prohibitive amounts of contrast.