Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA): A Review of the Current Position

Myocardial Infarction With Non-obstructive Coronary Arteries: A Clinical Conundrum

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is defined by the presence of positive cardiac biomarkers with clinical evidence of infarction, the absence of significant coronary stenosis (≥50%) on angiography, and the lack of alternative diagnosis for the index presentation. MINOCA poses a diagnostic and therapeutic challenge due to the various pathophysiologic mechanisms underlying its presentation. Coronary artery plaque disruption is recognized as a crucial mechanism contributing to MINOCA. Plaque rupture and thrombus formation with subsequent myocardial ischemia may occur without significant luminal narrowing. A high index of suspicion is needed to make an early diagnosis. Here, a 68-year-old African American male patient presented with substernal chest pain, nonspecific ST segment changes on electrocardiogram, and elevation in cardiac biomarkers only one day after undergoing diagnostic cardiac catheterization that revealed non-obstructed coronary arteries. This case provides an example of MINOCA occurring secondary to suspected coronary artery plaque disruption in the setting of recent cardiac catheterization.

Early versus late cardiac magnetic resonance in the diagnosis of myocardial infarction with non-obstructive coronary arteries

INTRODUCTION AND OBJECTIVES

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for about 10% of all acute myocardial infarctions (AMI). Therapeutic strategies and prognosis depend on the underlying etiology, and a multimodal approach is essential. The objectives of this study were to characterize the group of patients diagnosed with MINOCA and to valuate the diagnostic yield of cardiovascular magnetic resonance (CMR).

METHODS

This was a retrospective, observational, and analytical study, including 516 patients admitted for a non-ST-elevation MI and with no significant coronary disease on coronary angiography between January 2016 and September 2021.

RESULTS

After the inclusion criteria, 163 patients remained of the 516 admitted to the study. They were divided into four groups based on the CMR results: MINOCA (n=51), Takotsubo syndrome (n=37), myocarditis (n=33), and without diagnosis (n=42). Most patients diagnosed with MINOCA were female with a mean age of 61.06±13.83 years. CMR identified the diagnosis in 74.2% of patients admitted for suspected acute MI, in which coronary angiography showed the absence of significant obstructions. The median time between hospital admission and CMR was significantly shorter in the groups that had a diagnosis compared with the group with no diagnosis (p=0.038), with a significant increase in diagnostic profitability if CMR was performed up to 14 days after admission (p=0.022). There were no deaths of cardiovascular etiology during the follow-up period.

CONCLUSIONS

CMR was fundamental as it identified the diagnosis in three out of four patients; it should be performed in the first 14 days.

Ejection Fraction-Related Differences of Baseline Characteristics and Outcomes in Troponin-Positive Patients without Obstructive Coronary Artery Disease

Background: The development and course of myocardial infarction with non-obstructive coronary artery (MINOCA) disease is still not fully understood. In this study, we aimed to examine the baseline characteristics of in-hospital outcomes and long-term outcomes of a cohort of troponin-positive patients without obstructive coronary artery disease based on different left ventricular ejection fractions (LVEFs). Methods and results: We included a cohort of 254 patients (mean age: 64 (50.8-75.3) years, 120 females) with suspected myocardial infarction and no obstructive coronary artery disease (MINOCA) in our institutional database between 2010 and 2021. Among these patients, 170 had LVEF ≥ 50% (84 females, 49.4%), 31 patients had LVEF 40-49% (15 females, 48.4%), and 53 patients had LVEF < 40% (20 females, 37.7%). The mean age in the LVEF ≥ 50% group was 61.5 (48-73) years, in the LVEF 40-49% group was 67 (57-78) years, and in the LVEF < 40% group was 68 (56-75.5) years (p = 0.05). The mean troponin value was highest in the LVEF < 40% group, at 3.8 (1.7-4.6) µg/L, and lowest in the LVEF ≥ 50% group, at 1.1 (0.5-2.1) µg/L (p = 0.05). Creatine Phosphokinase (CK) levels were highest in the LVEF ≥ 50% group (156 (89.5-256)) and lowest in the LVEF 40-49% group (127 (73-256)) (p < 0.05), while the mean BNP value was lowest in the LVEF ≥ 50% group (98 (48-278) pg/mL) and highest in the <40% group (793 (238.3-2247.5) pg/mL) (p = 0.001). Adverse in-hospital cardiovascular events were highest in the LVEF < 40% group compared to the LVEF 40-49% group and the LVEF ≥ 50% group (56% vs. 55% vs. 27%; p < 0.001). Over a follow-up period of 6.2 ± 3.1 years, the all-cause mortality was higher in the LVEF < 40% group compared to the LVEF 40-49% group and the LVEF ≥ 50% group. Among the different factors, LVEF < 40% and LVEF 40-49% were associated with an increased risk of in-hospital cardiovascular events in the multivariable Cox regression analysis. Conclusions: LVEF has different impacts on in-hospital cardiovascular events in this cohort. Furthermore, LVEF influences long-term all-cause mortality.

Chemokine Fractalkine and Non-Obstructive Coronary Artery Disease-Is There a Link?

Non-obstructive coronary artery disease (NO-CAD) constitutes a heterogeneous group of conditions collectively characterized by less than 50% narrowing in at least one major coronary artery with a fractional flow reserve (FFR) of ≤0.80 observed in coronary angiography. The pathogenesis and progression of NO-CAD are still not fully understood, however, inflammatory processes, particularly atherosclerosis and microvascular dysfunction are known to play a major role in it. Chemokine fractalkine (FKN/CX3CL1) is inherently linked to these processes. FKN/CX3CL1 functions predominantly as a chemoattractant for immune cells, facilitating their transmigration through the vessel wall and inhibiting their apoptosis. Its concentrations correlate positively with major cardiovascular risk factors. Moreover, promising preliminary results have shown that FKN/CX3CL1 receptor inhibitor (KAND567) administered in the population of patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), inhibits the adverse reaction of the immune system that causes hyperinflammation. Whereas the link between FKN/CX3CL1 and NO-CAD appears evident, further studies are necessary to unveil this complex relationship. In this review, we critically overview the current data on FKN/CX3CL1 in the context of NO-CAD and present the novel clinical implications of the unique structure and function of FKN/CX3CL1 as a compound which distinctively contributes to the pathomechanism of this condition.

Approach to Imaging of Patients Presenting With Acute Coronary Syndrome With No Culprit Lesion Identified at Angiography

Chest pain is a common chief complaint among patients presenting to the emergency department. However, in the scenario where the clinical presentation is consistent with acute coronary syndrome and no culprit lesions are identified on angiography, clinicians and cardiac imagers should be informed of the differential diagnosis and appropriate imaging modalities used to investigate the potential causes. This review describes an imaging-based algorithm that highlights the diagnostic possibilities, their differentiating imaging features, and the important role of cardiovascular magnetic resonance imaging for narrowing the differential diagnosis.

Myocardial infarction with nonobstructive coronaries (MINOCA) following rabies postexposure prophylaxis: A case report

Key Clinical Message

This case underscores the importance of considering myocardial infarction with nonobstructive coronary arteries (MINOCA) in patients experiencing acute chest pain following rabies vaccination, emphasizing the need for heightened awareness and further research into the association between MINOCA and Rabies vaccination.

Abstract

Rabies is a vaccine-preventable deadly viral disease prevalent in Asia and Africa that causes thousands of deaths annually. Rabies pre (PrEP) and postexposure prophylaxis (PEP) is highly effective in annulling rabies-associated deaths. The adverse reactions following rabies vaccination are typically mild. Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a rare condition, and its association with rabies vaccination is unprecedented. We present a case of a 43-year-old male with MINOCA following Rabies PEP. A 43-year-old male, nonsmoker and nonalcoholic, presented to the ER with complaints of acute onset left sided chest pain following the completion of the third dose of intradermal rabies vaccine, whose clinical features, ECG changes and lab reports were suggestive of acute presentation of inferior wall MI. Coronary angiography was performed, which however revealed normal coronaries with only slow flow being noted in the left anterior descending (LAD) artery. Echocardiography later showed a normal study with no other relevant diagnosis unveiled on further investigations. Hence a diagnosis of vaccine-induced MINOCA was made. Treatment included antiplatelet therapy, statins, and beta-blockers. MINOCA following rabies vaccination is an unprecedented finding. The clear etiology behind this couldn't be ascertained. The patient's treatment was conventional, emphasizing the need for further research and clinical trials in MINOCA diagnosis and management. This case highlights the need for clinicians to consider MINOCA in patients with acute chest pain post-rabies vaccination. Further research is essential to unravel the association between MINOCA and rabies vaccination, paving the way for optimal management strategies.

Clinical outcomes of myocardial infarction with non-obstructive coronary arteries presenting with diabetic ketoacidosis: a propensity score-matched analysis

INTRODUCTION AND OBJECTIVE

There is a paucity of data on patients with myocardial infarction with nonobstructive coronary arteries (MINOCA) and a decompensated diabetic state, diabetic ketoacidosis (DKA). Therefore, we aimed to investigate the outcomes of patients with MINOCA presenting with or without DKA.

METHODS

We conducted this retrospective propensity score-matched analysis from January 1, 2015, to December 4, 2022. The patients with a principal admission diagnosis of ST-Elevation MI (STEMI) and discharge labeled as MINOCA (ICD-10-CM code 121.9) with DKA were analyzed. We performed a comparative analysis for MINOCA with and without DKA before and after propensity score matching for primary and secondary endpoints.

RESULTS

Three thousand five hundred sixty-three patients were analyzed, and 1150 (32.27%) presented with DKA, while 2413 (67.72%) presented as non-DKA. The DKA cohort had over two-fold mortality (5.56% vs. 1.19%; p = 0.024), reinfarction (5.82% vs. 1.45%; p = 0.021), stroke (4.43% vs. 1.36%; p = 0.035), heart failure (6.89% vs. 2.11%; p = 0.033), and cardiogenic shock (6.43% vs. 1.78%; p = 0.025) in a propensity score-matched analysis. There was an increased graded risk of MINOCA with DM (RR (95% CI): 0.50 (0.36-0.86; p = 0.023), DKA (RR (95% CI): 0.46 (0.24-0.67; p = 0.001), and other cardiovascular (CV) risk factors.

CONCLUSION

DKA complicates a portion of MINOCA and is associated with increased mortality and major adverse cardiovascular events (MACE).

Sex differences in the management of atherosclerotic cardiovascular disease

Disparities between women and men persist in the diagnosis, treatment, and prognosis of atherosclerotic cardiovascular disease (ASCVD). Despite growing attention to sex-based differences in cardiovascular care, there are continued disparities in short- and long-term outcomes. Such disparities highlight the need to identify pathophysiologic differences in treatment patterns for stable ischemic heart disease, non-ST elevation myocardial infarction (NSTE-ACS), ST-elevation myocardial infarction (STEMI), and myocardial infarction with non-obstructive coronary arteries (MINOCA). The role of age as an effect modifier should also be considered given that young women diagnosed with ACS continue to experience increased rates of in-hospital mortality and major adverse cardiovascular events. Both patient-directed and systems-based approaches remain integral to improve outcomes in cardiovascular care. While inadequate representation of women in clinical trials remains a barrier to the implementation of evidence-based therapies, a growing body of data has established the efficacy and safety of medications in women across acute coronary syndromes. This review seeks to feature existing data on the differential treatment guidelines, care implementation, and cardiovascular outcomes between women and men, highlighting next directions for clinical investigation.

Acute myocardial infarction after initially diagnosed with unprovoked venous thromboembolism: A case report

BACKGROUND

Protein C deficiency is typically associated with venous thromboembolism; however, arterial thrombosis has been reported in several cases. We report the case of a patient with pulmonary thromboembolism and deep vein thrombosis following acute myocardial infarction with high thrombus burden.

CASE SUMMARY

A 40-year-old man was diagnosed with pulmonary thromboembolism and deep vein thrombosis without any provoking factors. The patient was treated with anticoagulants for six months, which were then discontinued. Three months after the discontinuation of anticoagulant therapy, the patient was hospitalized with chest pain and diagnosed with acute myocardial infarction with high thrombus burden. Additional tests revealed protein C deficiency associated with thrombophilia. The patient was treated with anticoagulants combined with dual antiplatelet agents for 1 year after percutaneous coronary intervention, and no recurrent events were reported during a follow-up period of 5 years.

CONCLUSION

Recurrent thromboembolic events including acute myocardial infarction with thrombus should be considered an alarming sign of thrombophilia.

Dual Antiplatelet Therapy: A Concise Review for Clinicians

Dual antiplatelet therapy (DAPT) combines two antiplatelet agents to decrease the risk of thrombotic complications associated with atherosclerotic cardiovascular diseases. Emerging data about the duration of DAPT is being published continuously. New approaches are trying to balance the time, benefits, and risks for patients taking DAPT for established cardiovascular diseases. Short-term dual DAPT of 3-6 months, or even 1 month in high-bleeding risk patients, is equivalent in terms of efficacy and effectiveness compared to long-term DAPT for patients who experienced percutaneous coronary intervention in an acute coronary syndrome setting. Prolonged DAPT beyond 12 months reduces stent thrombosis, major adverse cardiovascular events, and myocardial infarction rates but increases bleeding risk. Extended DAPT does not significantly benefit stable coronary artery disease patients in reducing stroke, myocardial infarction, or cardiovascular death. Ticagrelor and aspirin reduce cardiovascular events in stable coronary artery disease with diabetes but carry a higher bleeding risk. Antiplatelet therapy duration in atrial fibrillation patients after percutaneous coronary intervention depends on individual characteristics and bleeding risk. Antiplatelet therapy is crucial for post-coronary artery bypass graft and transcatheter aortic valve implantation; Aspirin (ASA) monotherapy is preferred. Antiplatelet therapy duration in peripheral artery disease depends on the scenario. Adding vorapaxar and cilostazol may benefit secondary prevention and claudication, respectively. Carotid artery disease patients with transient ischemic attack or stroke benefit from antiplatelet therapy and combining ASA and clopidogrel is more effective than ASA alone. The optimal duration of DAPT after carotid artery stenting is uncertain. Resistance to ASA and clopidogrel poses an incremental risk of deleterious cardiovascular events and stroke. The selection and duration of antiplatelet therapy in patients with cardiovascular disease requires careful consideration of both efficacy and safety outcomes. The use of combination therapies may provide added benefits but should be weighed against the risk of bleeding. Further research and clinical trials are needed to optimize antiplatelet treatment in different patient populations and clinical scenarios.

Coronary microvascular dysfunction and cardiovascular disease: Pathogenesis, associations and treatment strategies

Coronary microvascular dysfunction (CMD) is a high-risk factor for a variety of cardiovascular events. Due to its complex aetiology and concealability, knowledge of the pathophysiological mechanism of CMD is still limited at present, which greatly restricts its clinical diagnosis and treatment. Studies have shown that CMD is closely related to a variety of cardiovascular diseases, can aggravate the occurrence and development of cardiovascular diseases, and is closely related to a poor prognosis in patients with cardiovascular diseases. Improving coronary microvascular remodelling and increasing myocardial perfusion might be promising strategies for the treatment of cardiovascular diseases. In this paper, the pathogenesis and functional assessment of CMD are reviewed first, along with the relationship of CMD with cardiovascular diseases. Then, the latest strategies for the treatment of CMD and cardiovascular diseases are summarized. Finally, urgent scientific problems in CMD and cardiovascular diseases are highlighted and future research directions are proposed to provide prospective insights for the prevention and treatment of CMD and cardiovascular diseases in the future.

MINOCA and INOCA: Role in Heart Failure

PURPOSE OF REVIEW

Infarction (MINOCA) and ischaemia (INOCA) with non-obstructive coronary disease are recent non-conventional presentations of coronary syndromes that are increasingly recognised in the clinical arena, particularly with the availability of new cardiovascular imaging techniques. Both are related to heart failure (HF). MINOCA is not associated with benign outcomes, and HF is among the most prevalent events. Regarding INOCA, microvascular dysfunction has also been found to associate with HF, particularly with preserved ejection fraction (HFpEF).

RECENT FINDINGS

Regardless of the several aetiologies underlying HF in MINOCA, it is likely related to LV dysfunction, where secondary prevention is not yet clearly established. Regarding INOCA, coronary microvascular ischaemia has been associated to endothelial dysfunction leading ultimately to diastolic dysfunction and HFpEF. MINOCA and INOCA are clearly related to HF. In both, there is a lack of studies on the identification of the risk factors for HF, diagnostic workup and, importantly, the appropriate primary and secondary prevention strategies.

MINOCA Phenotypes - A Challenge for Patient-Specific Management

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a puzzling clinical phenomenon with an unclear prognosis, characterized by evidence of myocardial infarction (MI) with normal or near-normal coronary arteries on angiography1. Currently, there are no guidelines for management, and many patients are discharged without a determined etiology, often meaning that optimal treatment gets postponed.We report three MINOCA case studies with main pathophysiological cardiac causes, particularly epicardial, microvascular, and non-ischemic, prompting differential management. The patients presented with acute chest pain, troponin raise, and no angiographically significant coronary disease.In this study, we analyzed the etiology, clinical diagnosis, and treatment of MINOCA concerning the relevant literature.MINOCA is considered to be a dynamic working diagnosis, including coronary, myocardial, and non-coronary disorders. Prospective studies and registries are needed to improve patient care and outcome.

Myocardial infarction with nonobstructive coronary arteries: from pathophysiology to therapeutic strategies

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a heterogeneous group of clinical entities characterized by clinical evidence of acute myocardial infarction (AMI) with normal or near-normal coronary arteries on coronary angiography (stenosis < 50%) and without an over the alternative diagnosis for the acute presentation. Its prevalence ranges from 6% to 11% among all patients with AMI, with a predominance of young, nonwhite females with fewer traditional risks than those with an obstructive coronary artery disease (MI-CAD). MINOCA can be due to either epicardial causes such as rupture or fissuring of unstable nonobstructive atherosclerotic plaque, coronary artery spasm, spontaneous coronary dissection and cardioembolism in-situ or microvascular causes. Besides, also type-2 AMI due to supply-demand mismatch and Takotsubo syndrome must be considered as a possible MINOCA cause. Because of the complex etiology and a limited amount of evidence, there is still some confusion around the management and treatment of these patients. Therefore, the key focus of this condition is to identify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, echocardiography, and coronary angiography represent the first-level diagnostic investigations, but coronary imaging with intravascular ultrasound and optical coherent tomography, coronary physiology testing, and cardiac magnetic resonance imaging offer additional information to understand the underlying cause of MINOCA. Although the prognosis is slightly better compared with MI-CAD patients, MINOCA is not always benign and depends on the etiopathology. This review analyzes all possible pathophysiological mechanisms that could lead to MINOCA and provides the most specific and appropriate therapeutic approach in each scenario.

Recurrent Angina in a Patient With Myocardial Infarction With Non-obstructive Coronary Arteries

The ubiquity of coronary angiography has increased the identification of myocardial infarction with non-obstructive coronary arteries. Currently among cardiologists, there is neither a consensus nor comprehensive diagnostic blueprint for accurate evaluation of patients with myocardial infarction with non-obstructive coronary arteries. We present a case of a patient with recurrent chest pain. A diagnosis of myocardial infarction with non-obstructive coronary arteries secondary to coronary artery vasospasm was determined with the use of multimodality imaging cardiac imaging.

Role of Intracoronary Imaging in Myocardial Infarction with Non-Obstructive Coronary Disease (MINOCA): A Review

Myocardial infarction with non-obstructive coronary artery disease occurs in 6% to 15% of all presentation of myocardial infarctions. The pathophysiologic mechanisms of MINOCA include epicardial vasospasm, coronary microvascular disorder, spontaneous coronary artery dissection, and coronary thrombus/embolism. The diagnosis is challenging, supported by intracoronary imaging with intravascular ultrasound (IVUS) and optical coherent tomography (OCT), coronary physiology testing, and cardiac magnetic resonance imaging (CMR). OCT is able to identify atherosclerotic causes of MINOCA (plaque erosion, plaque rupture, and calcified nodule) and nonatherosclerotic causes (spontaneous artery dissection, and spasm). In this review, we summarize the performance of the two intracoronary imaging modalities (IVUS and OCT) in MINOCA and discuss the importance of supplementing these modalities with CMR in order to drive target therapy.

Biomarkers as Prognostic Predictors and Therapeutic Guide in Critically Ill Patients: Clinical Evidence

A biomarker is a molecule that can be measured in a biological sample in an objective, systematic, and precise way, whose levels indicate whether a process is normal or pathological. Knowing the most important biomarkers and their characteristics is the key to precision medicine in intensive and perioperative care. Biomarkers can be used to diagnose, in assessment of disease severity, to stratify risk, to predict and guide clinical decisions, and to guide treatments and response to them. In this review, we will analyze what characteristics a biomarker should have and how to ensure its usefulness, and we will review the biomarkers that in our opinion can make their knowledge more useful to the reader in their clinical practice, with a future perspective. These biomarkers, in our opinion, are lactate, C-Reactive Protein, Troponins T and I, Brain Natriuretic Peptides, Procalcitonin, MR-ProAdrenomedullin and BioAdrenomedullin, Neutrophil/lymphocyte ratio and lymphopenia, Proenkephalin, NefroCheck, Neutrophil gelatinase-associated lipocalin (NGAL), Interleukin 6, Urokinase-type soluble plasminogen activator receptor (suPAR), Presepsin, Pancreatic Stone Protein (PSP), and Dipeptidyl peptidase 3 (DPP3). Finally, we propose an approach to the perioperative evaluation of high-risk patients and critically ill patients in the Intensive Care Unit (ICU) based on biomarkers.

Antiplatelet therapy in patients with myocardial infarction with non-obstructive coronary arteries: A clinical perspective

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of diseases with different pathological mechanisms, and it is uncertain whether the classical secondary prevention and treatment strategies for myocardial infarction in obstructive coronary artery disease (MI-CAD) are appropriate for patients with MINOCA. Therefore the choice of antiplatelet agents and the therapeutic effect may vary depending on the etiology and pathophysiological mechanisms of MINOCA. This requires our clinical and scientific researchers to properly design prospective studies to explore the pathophysiology of MINOCA and its corresponding etiology in greater depth, so as to understand the effectiveness and safety of medical therapies for different etiologies of MINOCA. Although the current observational studies do not show an obvious beneficial effect of antiplatelet therapy on MINOCA. We are eager to conduct specific prospective randomized controlled trials of antiplatelet agents to assess the specificity, efficacy and safety of different types of antiplatelet agents in patients with MINOCA of different etiologies.

Cardiac Magnetic Resonance Assessment of the Protective Effect of Remote Ischemic Postconditioning on Coronary Microcirculation after Reperfusion Therapy for Acute ST-Segment Elevation Myocardial Infarction

This study intends to evaluate the characteristics of coronary microcirculatory function in patients with myocardial infarction undergoing reperfusion and its predictive value in assessing cardiac function, myocardial activity, recovery of ventricular wall motion after infarction, and distant myocardial remodeling by cardiac magnetic resonance technique (CMRI). Materials and Methods. The 293 cases of patients with myocardial infarction treated in our hospital from August 2017 to August 2021 were selected as the subjects of this retrospective study, 13 cases were shed due to transfer and moving, and the rest were divided into 140 cases each in the emergency and elective groups according to emergency percutaneous coronary intervention (PCI) and elective PCI. The patients' myocardial infarct volume ventricular volume, microcirculatory obstruction volume ventricular volume, microcirculatory obstruction volume/myocardial infarct volume, and LVEF, combined with BP and troponin T, were analysed by CMR for comparative analysis, hemodynamic, and cardiac function index differences. Results. The hemodynamics (CO, CI, SV, SI, LVSW1, and LCW) measured at different times were significantly different between the two groups; patients in the emergency group had significantly lower EDV and ESV than the elective group at 7-10 d postoperatively; and EDV, ESV, and LVEF improved in both groups after 3 months, while EDV, ESV, and LVEF improved significantly better in the emergency group than in the elective group, and the difference was statistically significant (P < 0.05). The myocardial infarct quality, VSM score, and ventricular wall motion abnormality score were significantly lower in the emergency group than in the elective group from 7 to 10 d after PCI; myocardial infarct quality, VSM score, and ventricular wall motion abnormality score improved in both groups at 3 months after PCI; and the degree of improvement of myocardial infarct quality and VSM score was significantly better in the emergency group than in the elective group (P < 0.05). Conclusion. Acute myocardial infarction patients with significant effect of emergency PCI treatment can be on their postmyocardial infarction left ventricular function, and in the treatment of coronary heart disease, myocardial infarction diagnosis has a certain reference value.

Predicting Patients With Troponin Positive Chest Pain and Unobstructed Coronary Arteries With Electrocardiogram, Troponin Kinetics and GRACE Score

BACKGROUND

Troponin positive chest-pain with unobstructed coronary arteries (TPCP-UCA), occurs in 6% of cases of patients presenting with acute coronary syndrome (ACS). Whilst TPCP-UCA patients are known to be younger with less cardiovascular risk factors when compared to obstructive coronary disease (MICAD), no validated methods exist to reliably delineate these two conditions prior to coronary angiography.

METHODS

We analysed 142 patients with MICAD and 127 patients with TPCP-UCA from 2015 to 2019. Several key predetermined clinical, biochemical and electrocardiograph (ECG) parameters, as well as Global Registry of Acute Coronary Events (GRACE) score, were collected for all patients. All TPCP-UCA patients underwent cardiac magnetic resonance imaging (cMRI).

RESULTS

Patients with TPCP-UCA were younger than MICAD (44 vs 68 yrs, p<0.01), and with less cardiac risk factors of hypertension (31% vs 68%, p<0.01), hypercholesterolaemia (23% vs 56%, p<0.01), diabetes (11% vs 45%, p<0.01), prior ischaemic heart disease (8% vs 42%, p<0.01) and smoking history (29% vs 50%, p<0.01). Peak troponin (MICAD 2,084.5 ng/L vs TPCP-UCA 847.0 ng/L, p=0.02), serial-to-initial troponin ratio (MICAD 13.5 vs TPCP-UCA 5.1, p<0.01), and peak-to-initial troponin ratio (MICAD 69.6 vs TPCP-UCA 14.0, p<0.01) were all higher in the MICAD group. GRACE scores were significantly different across the two cohorts (TPCP UCA 74 vs MICAD 106, p<0.01), with a receiver operator characteristic (ROC) curve statistic of 0.794 (95% CI 0.739-0.850). On ECG analysis, MICAD had greater prevalence and sum of ST depression (40% vs 19% p<0.01; 1.6 mm vs 0.44 mm, p<0.01) and T wave inversion (37% vs 17%, p<0.01), whilst TPCP-UCA had greater presence of PR depression (20% vs 3% p<0.01), and longer repolarisation (T wave peak to end 89 ms vs 83 ms, p=0.04; T wave peak to end/corrected QT 0.208 ms vs 0.193 ms, p=0.03). All TPCP-UCA patients underwent cMRI. Aetiology was found in 82% of cases, with the leading diagnosis being myocarditis (58%), followed by infarction (8%), whilst 18% had a normal cMRI.

CONCLUSIONS

TPCP-UCA is an important differential for patients presenting with ACS, and has several key demographic, biochemical and electrocardiographic differences. The present findings are hypothesis generating, thus prospective studies are required to determine and validate potential clinical utility.

Coronary Artery Ectasia in the Pathophysiology of Myocardial Infarction With Nonobstructive Coronary Arteries

Coronary artery ectasia (CAE) is associated with an increased risk for acute myocardial infarction (AMI). A significant proportion of patients with AMI have no obstructive coronary artery disease (CAD), however, the underlying mechanism of myocardial infarction with nonobstructive coronary arteries (MINOCA) is poorly understood. Therefore, the present study aimed to investigate whether CAE has a role in the pathogenesis of MINOCA. A total of 1,284 patients who were admitted with a diagnosis of non-ST-segment elevation myocardial infarction were included in the study. Patients were divided into 2 groups according to the presence or absence of obstructive CAD (≥50% stenosis). Patients without obstructive CAD (MINOCA group) and patients with obstructive CAD (no-MINOCA group) were compared regarding the frequency of CAE. Additionally, the association between CAE and MINOCA was investigated. In the study participants, 101 patients (7.9%) were diagnosed with MINOCA, whereas 1,183 (92.1%) had AMI with obstructive CAD. Importantly, the frequency of patients with CAE was significantly higher in patients with MINOCA compared with those with obstructive CAD (22.8% vs 3.5%, p <0.001). Moreover, CAE was observed in 64 patients (4.9%). The frequency of MINOCA was found to be significantly higher in patients with CAE compared with patients without CAE (35.9% vs 6.4%, p <0.001). Furthermore, multivariate analysis demonstrated that the presence of CAE was an independent predictor of MINOCA in patients presented with a diagnosis of non-ST-segment elevation myocardial infarction (odds ratio 1.812, 95% confidence interval 1.376 to 2.581, p <0.001). In conclusion, CAE may be considered as a risk factor for MINOCA and may have a role in the pathophysiology of MINOCA.

Pathophysiology and mechanisms of Acute Coronary Syndromes: athero-thrombosis, immune-inflammation and beyond

INTRODUCTION

The pathophysiology of atherosclerosis and its acute complications, such as the Acute Coronary Syndromes (ACS), is continuously under investigation. Immunity and inflammation seem to play a pivotal role in promoting formation and grow of atherosclerotic plaques. At the same time, plaque rupture followed by both platelets' activation and coagulation cascade induction lead to intracoronary thrombus formation. Although these phenomena might be considered responsible of about 90% of ACS, in up to 5-10% of acute syndromes a non-obstructive coronary artery disease (MINOCA) might be documented. This paper gives an overview on athero-thrombosis and immuno-inflammation processes involved in ACS pathophysiology also emphasizing the pathological mechanisms potentially involved in MINOCA.

AREAS COVERED

The relationship between immuno-inflammation and atherothrombosis is continuously updated by recent findings. At the same time, pathophysiology of MINOCA still remains a partially unexplored field, stimulating the research of potential links between these two aspects of ACS pathophysiology.

EXPERT OPINION

Pathophysyiology of ACS has been extensively investigated; however, several grey areas still remain. MINOCA represents one of these areas. At the same time, many aspects of immune-inflammation processes are still unknown. Thus, research should be continued to shed a brighter light on both these sides of "ACS" moon.

Acute Fulminant Myocarditis After ChAdOx1 nCoV-19 Vaccine: A Case Report and Literature Review

According to recent literatures, myocarditis is an uncommon side effect of mRNA vaccines against COVID-19. On the other hand, myocarditis after adenovirus based vaccine is rarely reported. Here we report a middle-aged healthy female who had acute fulminant perimyocarditis onset 2 days after the first dose of ChAdOx1 vaccine (AstraZeneca) without any other identified etiology. Detailed clinical presentation, serial ECGs, cardiac MRI, and laboratory data were included in the report. Possible mechanisms of acute myocarditis after adenoviral vaccine was reviewed and discussed. To our knowledge, a few cases of myocarditis after Ad26.COV2.S vaccine were reported, and this is the first case report after ChAdOx1 vaccine.

Myocardial Infarction With Non-obstructive Coronary Arteries: An Updated Overview of Pathophysiology, Diagnosis, and Management

Myocardial infarction with non-obstructive coronary arteries (MINOCA) refers to acute myocardial infarction with normal or near-normal coronary arteries. The MINOCA is a heterogeneous group of conditions, and possible etiologies are coronary artery spasm, spontaneous coronary artery dissection, coronary thromboembolism, coronary plaque disruption, coronary microvascular dysfunction, supply and demand mismatch. It is more common in young adults, with women having a higher chance of getting MINOCA than men. Considering MINOCA as a clinically dynamic working diagnostic that needs further investigation rather than a “true” diagnosis is proposed. Optical coherence tomography (OCT), intravenous ultrasound (IVUS), cardiac MRI may be required to stratify the underlying mechanism. Due to the lack of evidence-based literature and prospective randomized controlled studies, therapeutic management is limited. Consequently, the strategy is patient-specific. The prognosis of MINOCA patients remains unclear and depends upon the underlying etiology. This article aims to review the literature about various aspects of MINOCA, including pathophysiology, diagnosis, prognosis, and treatment.

Acetylcholine Use in Modern Cardiac Catheterization Laboratories: A Systematic Review

BACKGROUND

The use of acetylcholine for the diagnosis of vasospastic angina is recommended by international guidelines. However, its intracoronary use is still off-label due to the absence of safety studies. We aimed to perform a systematic review of the literature to identify adverse events related to the intracoronary administration of acetylcholine for vasoreactivity testing to fill this gap.

METHODS AND RESULTS

We conducted a systematic review of observational studies and randomized controlled trials dealing with the intracoronary administration of acetylcholine. Articles were searched in MEDLINE (PubMed) using the MeSH strategy. Three independent reviewers determined whether the studies met the inclusion and exclusion criteria. A total of 434 articles were selected. Data concerning clinical characteristics, study population, acetylcholine dosage, and adverse effects were retrieved from the articles. Overall, 71,566 patients were included, of which only 382 (0.5%) developed one adverse event, and there were no fatal events reported (0%).

CONCLUSIONS

Intracoronary administration of acetylcholine in the setting of coronary spasm provocation testing is safe and plays a central role in the evaluation of coronary vasomotion disorders, making it worthy of becoming a part of clinical practice in all cardiac catheterization laboratories.

Effects of electrically conductive nano-biomaterials on regulating cardiomyocyte behavior for cardiac repair and regeneration

Myocardial infarction (MI) represents one of the most prevalent cardiovascular diseases, with a highly relevant and impactful role in public health. Despite the therapeutic advances of the last decades, MI still begets extensive death rates around the world. The pathophysiology of the disease correlates with cardiomyocyte necrosis, caused by an imbalance in the demand of oxygen to cardiac tissues, resulting from obstruction of the coronary flow. To alleviate the severe effects of MI, the use of various biomaterials exhibit vast potential in cardiac repair and regeneration, acting as native extracellular matrices. These hydrogels have been combined with nano sized or functional materials which possess unique electrical, mechanical, and topographical properties that play important roles in regulating phenotypes and the contractile function of cardiomyocytes even in adverse microenvironments. These nano-biomaterials' differential properties have led to substantial healing on in vivo cardiac injury models by promoting fibrotic scar reduction, hemodynamic function preservation, and benign cardiac remodeling. In this review, we discuss the interplay of the unique physical properties of electrically conductive nano-biomaterials, are able to manipulate the phenotypes and the electrophysiological behavior of cardiomyocytes in vitro, and can enhance heart regeneration in vivo. Consequently, the understanding of the decisive roles of the nano-biomaterials discussed in this review could be useful for designing novel nano-biomaterials in future research for cardiac tissue engineering and regeneration. STATEMENT OF SIGNIFICANCE: This study introduced and deciphered the understanding of the role of multimodal cues in recent advances of electrically conductive nano-biomaterials on cardiac tissue engineering. Compared with other review papers, which mainly describe these studies based on various types of electrically conductive nano-biomaterials, in this review paper we mainly discussed the interplay of the unique physical properties (electrical conductivity, mechanical properties, and topography) of electrically conductive nano-biomaterials, which would allow them to manipulate phenotypes and the electrophysiological behavior of cardiomyocytes in vitro and to enhance heart regeneration in vivo. Consequently, understanding the decisive roles of the nano-biomaterials discussed in the review could help design novel nano-biomaterials in future research for cardiac tissue engineering and regeneration.

[False positive troponinemia in patient with pneumothorax : a case report]

A 20-year-old patient is admitted to the emergency room for chest pain occurring in the context of recurrent left complete pneumothorax. Ultrasensitive troponinemia is elevated to 20 times normal. Myocardial distress is attributed to pneumothorax following the negativity of cardiological examinations (EKG, TTE, cardiac MRI). The pneumothorax is drained with a favorable evolution. This is the first reported case of pneumothorax associated with a significant elevation of troponin without ECG change, TakoTsubo syndrome, or myocardial inflammation. Several mechanisms are considered: rotation of the myocardium around its axis, increase in pulmonary vascular resistance with overload of right ventricular pressure, disturbance of coronary blood flow on significant mediastinal compression with decrease in systolo-diastolic myocardial perfusion.

MINOCA: a heterogenous group of conditions associated with myocardial damage

Myocardial infarction with non-obstructive coronary arteries (MINOCA) was first described over 80 years ago. The term has been widely and inconsistently used in clinical practice, influencing various aspects of disease classification, investigation and management. MINOCA encompasses a heterogenous group of conditions that include both atherosclerotic and non-atherosclerotic disease resulting in myocardial damage that is not due to obstructive coronary artery disease. In many ways, it is a term that describes a moment in the diagnostic pathway of the patient and is arguably not a diagnosis. Central to the definition is also the distinction between myocardial infarction and injury. The universal definition of myocardial infarction distinguishes acute myocardial infarction, including those with MINOCA, from other causes of myocardial injury by the presence of clinical evidence of ischaemia. However, these ischaemic features are often non-specific causing diagnostic confusion, and can create difficulties for patient management and follow-up. The purpose of this review is to summarise our current understanding of MINOCA and highlight important issues relating to the diagnosis, investigation and management of patients with MINOCA.

Acute coronary syndrome from scombroid poisoning: a narrative review of case reports

BACKGROUND

Scombroid syndrome constitutes a toxic illness caused by ingestion of improperly stored fish, usually contaminated by Gram-negative bacteria producing histamine and other toxins. Scombroid currently accounts for approximately 5% of food toxicities in the United States. Though cardiovascular complications are infrequent, some patients experienced acute coronary syndrome (ACS) on admission to hospital. This article focuses on the main pathophysiology, clinical features, therapy, and outcomes in scombroid-related ACS.

METHODS

Starting from the consolidated knowledge on histaminergic syndromes, we performed a literature search for studies describing patient series and single cases presenting at emergency department with scombroid toxicity complicated by myocardial ischemia.

RESULTS

After a pathophysiological overview on histaminergic syndromes, we carefully analyzed a dataset of 19 patients from 13 studies, published from 1997 to December 2020. Electrocardiographic, echocardiographic, angiographic features, clinical course, hospital complications, and therapeutic approach were described. Shared and differential aspects of scombroid ACS with typical atherosclerotic ischemia, Kounis, MINOCA and Takotsubo syndromes are also discussed.

CONCLUSION

An ischemic heart scombroid syndrome may occur in some patients after the eating of improperly stored fish food. Currently available studies indicate this as a benign condition, except for patients with history of coronary artery disease, previous ACS, or anaphylaxis. Of clinical concern, there is a potential of hemodynamic failure in the acute stage, even in apparently healthy people.

ANMCO POSITION PAPER: Prognostic and therapeutic relevance of non-obstructive coronary atherosclerosis

Atherosclerosis often affects the coronary arterial tree. Frequently the disease does not translate in significant narrowing of the vessels, thus determining only a non-obstructive disease. This condition that is described as non-obstructive coronary artery disease (NobsCAD) should be distinguished from the absence of disease (i.e. smooth coronary arteries) as it carries a specific prognostic value. The detection and reporting of NobsCAD should prompt preventive measures that can be individualized upon the degree of the underlying burden of disease. The accompanying clinical condition, the other cardiovascular risk factors present, and the description of the severity and extent of NobsCAD should provide the framework for an individualized treatment that should also consider the best available scientific evidence and guidelines. The description of NobsCAD represents important information to be collected whenever a coronary angiogram (both invasive and non-invasive) is performed. Treating the patient according to the presence and extent of NobsCAD offers prognostic benefits well beyond those offered by considering only the traditional cardiovascular risk factors. In order to reach this goal, NobsCAD should not be confused with the absence of coronary atherosclerosis or even ignored when detected as if it was a trivial information to provide.

Prognostic value of statin therapy in patients with myocardial infarction with nonobstructive coronary arteries (MINOCA): a meta-analysis

BACKGROUND

Given the complex aetiology and a limited amount of evidence, the medical treatment (including statin use) of myocardial infarction with non-obstructive coronary artery disease (MINOCA) remains uncertain. The objective of the present study was to evaluate the effect of statin therapy on major cardiovascular events (MACE) and mortality in MINOCA patients.

METHODS

A systematic review and meta-analysis of time-to-event outcomes were performed of studies of statin therapy on MINOCA patients, reporting data from MACE or mortality, after searching the PubMed/MEDLINE, Embase, Science Direct, Scopus, Google Scholar, and Cochrane databases. A fixed-effects meta-analysis model was then applied.

RESULTS

Six observational studies of statin therapy on MINOCA, involving a total of 11,171 patients, were identified and considered eligible for analysis (9129 subjects received statin therapy while 2042 patients were part of the respective control arms). Quantitative analysis (5 studies were included) showed that statin use was associated with lower mortality (HR: 0.65; 95% CI: 0.56-0.75, I²: 0%). Also, the meta-analysis showed that statin therapy was associated with a lower incidence of MACE (HR: 0.78; 95% CI: 0.69-0.88, I²:27%).

CONCLUSION

Our data suggest that in a population with MINOCA, the use of statin therapy results in significant reduction on MACE and mortality. These results must be confirmed in future clinical trials.

Myocardial Infarction with Nonobstructive Coronary Arteries: A Diagnostic Challenge

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a significant cause of cardiovascular morbidity, especially among non-white women younger than 55 years. It is a working diagnosis that warrants further investigation due to its varied underlying pathophysiologic mechanisms. Investigations may be hampered by unavailability of testing modalities, cost, and the expertise to carry out the tests, as they are highly specialized. Clinical history is therefore important, especially in developing countries, to predict potential causes and institute empirical treatment without the luxury of tests. Some physicians are also unaware of this phenomenon and may dismiss symptoms as functional when a coronary angiogram shows nonobstructed coronary arteries, potentially resulting in patients suffering symptoms for longer and incurring extra cost. Most importantly, it leaves them at risk of major adverse cardiovascular events. This article presents a patient with atrial fibrillation who was diagnosed with MINOCA and highlights the diagnostic challenges in evaluating MINOCA.

Blood Plasma Serotonin and von Willebrand Factor as Biomarkers of Unstable Angina Progression Toward Myocardial Infarction

Aim: To investigate the serotonin and von Willebrand factor (vWF) concentrations among unstable angina (UA) patients without and with progression toward myocardial infarction (outcome) and to assess the utility of both as prognostic markers of UA complications. Materials and methods: In observational cohort study, we recruited 103 patients with ischemic heart disease (the median age 65.0 (59.0-69.0) years, 45 females (43.7%)). After full set of investigations including high sensitive Troponin I test and 28-day follow-up period, we defined three groups: Group 1 - stable angina patients (n=22) as control, Group 2 - UA patients without outcome (n=71), Group 3 - UA patients with outcome (n=10). We analyzed the blood plasma serotonin content by the ion-exchange chromatography with measurement of serotonin on fluorescence spectrophotometer. VWF concentration was determined by ELISA. We compared the concentrations of observed parameters among the groups with the Kruskal-Wallis test (with post-hoc Mann-Whitney test with Bonferroni-Holm correction). We assessed binary logistic models, receiver operating characteristic curves, calculated sensitivity (Se), specificity (Sp), and positive likelihood ratio (LR+) for each indicator. Results: We registered elevation in serotonin concentration and decline in vWF concentration in Group 3 in comparison with Group 2 (22.670 (20.687-24.927) μg/ml vs 11.980 (8.120-15.000) μg/ml, p< 0.001, and 0.117 (0.109-0.120) rel.units/ml vs 0.134 (0.127-0.143) rel.units/ml, p < 0.001) and Group 1 (12.340 (10.052-13.619) μg/ml, p < 0.001, and 0.137 (0.127-0.156) rel.units/ml, p < 0.001), respectively. No significant differences in serotonin and vWF concentrations between Group 1 and Group 2 were detected (p=0.81 and p=0.36, respectively). The probability of outcome increased significantly (by 60.7% and 59.7%, LR+ 19.0 [6.0, 60.0] and 18.0 [3.9, 80.0]) if serotonin concentration was above 21.575 μg/ml (Se=80.0%, Sp=95.8%, AUC=0.975) and vWF concentration was below 0.114 rel.units/ml (Se=50.0%, Sp=97.2%, AUC=0.973), respectively. Conclusions: Serotonin and vWF as biomarkers are demonstrated promising results for rule-in the patients with risk of short-term UA progression toward myocardial infarction.