Guidelines for the management of myocardial infarction/injury with non-obstructive coronary arteries (MINOCA): a position paper from the Dutch ACS working group

Coronary artery thromboembolism as a cause of myocardial infarction with non-obstructive coronary arteries (MINOCA)

Acute myocardial infarction (AMI) usually represents the clinical manifestation of atherothrombotic coronary artery disease (CAD) resulting from atherosclerotic plaque rupture. However, there are cases in which coronary angiography or coronary computed tomography angiography reveals patients with acute coronary syndrome with non-obstructive CAD. This clinical entity is defined as myocardial infarction with non-obstructive coronary arteries (MINOCA) and often is considered as a clinical dynamic working diagnosis, that needs further investigations for the establishment of a final etiological diagnosis. The main causes of a MINOCA working diagnosis include atherosclerotic, non-atherosclerotic (vessel-related and non-vessel related) and thromboembolic causes This literature review is aimed at investigating the major thromboembolic causes in patients presenting with MINOCA in regards of their etiology, pathophysiological mechanisms, as well as diagnostic and treatment methods.

MINOCA biomarkers: Non-atherosclerotic aspects

Myocardial infarction in the absence of obstructive coronary artery disease (MINOCA) is an important subtype of myocardial infarction. Although comprising less than 50% stenosis in the main epicardial coronary arteries, it constitutes a severe health risk. A variety of approaches have been recommended, but definitive diagnosis remains elusive. In addition, the lack of a comprehensive understanding of underlying pathophysiology makes clinical management difficult and unpredictable. This review highlights ongoing efforts to identify relevant biomarkers in MINOCA to improve diagnosis, individualize treatment and better predict outcomes.

Myocardial Tissue Characterization in Patients with Hypertensive Crisis, Positive Troponin, and Unobstructed Coronary Arteries: A Cardiovascular Magnetic Resonance-Based Study

Hypertensive crisis can present with cardiac troponin elevation and unobstructed coronary arteries. We used cardiac magnetic resonance (CMR) imaging to characterize the myocardial tissue in patients with hypertensive crisis, elevated cardiac troponin, and unobstructed coronary arteries. Patients with hypertensive crisis and elevated cardiac troponin with coronary artery stenosis <50% were enrolled. Patients with troponin-negative hypertensive crisis served as controls. All participants underwent CMR imaging at 1.5 Tesla. Imaging biomarkers and tissue characteristics were compared between the groups. There were 19 patients (63% male) with elevated troponin and 24 (33% male) troponin-negative controls. The troponin-positive group was older (57 ± 11 years vs. 47 ± 14 years, p = 0.015). The groups had similar T2-weighted signal intensity ratios and native T1 times. T2 relaxation times were longer in the troponin-positive group, and the difference remained significant after excluding infarct-pattern late gadolinium enhancement (LGE) from the analysis. Extracellular volume (ECV) was higher in the troponin-positive group (25 ± 4 ms vs. 22 ± 3 ms, p = 0.008) and correlated strongly with T2 relaxation time (rs = 0.701, p = 0.022). Late gadolinium enhancement was 32% more prevalent in the troponin-positive group (82% vs. 50%, p = 0.050), with 29% having infarct-pattern LGE. T2 relaxation time was independently associated with troponin positivity (OR 2.1, p = 0.043), and both T2 relaxation time and ECV predicted troponin positivity (C-statistics: 0.71, p = 0.009; and 0.77, p = 0.006). Left ventricular end-diastolic and left atrial volumes were the strongest predictors of troponin positivity (C-statistics: 0.80, p = 0.001; and 0.82, p < 0.001). The increased T2 relaxation time and ECV and their significant correlation in the troponin-positive group suggest myocardial injury with oedema, while the non-ischaemic LGE could be due to myocardial fibrosis or acute necrosis. These CMR imaging biomarkers provide important clinical indices for risk stratification and prognostication in patients with hypertensive crisis.

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 non-obstructive coronary arteries: Etiology, diagnosis, treatment and prognosis

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for 10% of myocardial infarctions. Previously, patients were thought to have good prognosis, but evidence-based management and treatment strategies were scarce. Today, researchers and physicians recognize MINOCA as a condition with non-trivial mortality and morbidity. Therapeutic strategies are highly dependent on the underlying disease mechanism in each patient. However, to reach a diagnosis of MINOCA, a multimodal approach is required and, even with an optimal work-up, the cause remains unknown in 8-25% of patients. Research has been growing and position papers from the European Society of Cardiology (ESC) and the American Heart Association/American College of Cardiology have been published, and MINOCA has been included in the more recent ESC guidelines on myocardial infarction. Nonetheless, some clinicians still assume that the absence of coronary obstruction excludes the possibility of acute myocardial infarction. Therefore, in the present paper, we aim to compile and present the available data on the etiology, diagnosis, treatment, and prognosis of MINOCA.

Sex-related differences in coronary vasomotor disorders: Comparisons between Western and Japanese populations

Sex-related differences in the prevalence of cardiac disorders have been elucidated beyond races. Angina/ischemia with nonobstructive coronary artery disease (AINOCA) is often observed in females. Coronary microvascular dysfunction (CMD) and coronary epicardial spasm (CES) are the principal cause of AINOCA. The clinical outcomes of Western patients with CMD were less satisfactory than expected, while the prognosis of Japanese patients with CES treated with medications including calcium channel blockers was favorable. However, the incidence and clinical features of coronary spasm endotypes were different between Western and Japanese populations. Furthermore, sex-related differences in the clinical manifestations and outcomes of patients with different spasm endotypes remain uncertain beyond race. In this article, we will review the sex differences in Japanese AINOCA patients with coronary vasomotor disorders, including CMD and CES, and compare them with those of Western patients.

Absence of High Lipoprotein(a) Levels Is an Independent Predictor of Acute Myocardial Infarction without Coronary Lesions

The pathophysiological mechanisms underlying Myocardial Infarction with Non-Obstructive Coronary Artery Disease (MINOCA) are still under debate. Lipoprotein (a) [Lp(a)] has proinflammatory and prothrombotic actions and has been involved in the pathogenesis of atherosclerosis. However, no previous studies have linked Lp(a) levels with the probability of developing MINOCA. Moreover, the relationship between MINOCA and the plasma levels of other proatherogenic and proinflammatory molecules such as Interleukin-18 (IL18) and proprotein convertase subtilisin/kexin type 9 (PCSK9) has not been studied. We conducted a prospective, multicenter study involving 1042 patients with acute myocardial infarction (AMI). Seventy-six patients had no significant coronary lesions. All patients underwent plasma analysis on admission. MINOCA patients were younger (57 (47-68) vs. 61 (52-72) years; p = 0.010), more frequently female (44.7% vs. 21.0%; p < 0.001), and had lower rates of diabetes and of Lp(a) > 60 mg/dL (9.2% vs. 19.8%; p = 0.037) than those with coronary lesions; moreover, High Density Lipoprotein cholesterol (HDL-c) levels were higher in MINOCA patients. The absence of Lp(a) > 60 mg/dL and of diabetes were independent predictors of MINOCA, as well as female sex, high HDL-c levels, and younger age. IL-18 and PCSK9 levels were not predictors of MINOCA. During a follow-up of 5.23 (2.89, 7.37) years, the independent predictors of the primary outcome (acute ischemic events or death) in the whole sample were Lp(a) > 60 mg/dL, older age, low estimated Glomerular Filtration rate (eGFR), hypertension, previous heart failure (HF), coronary artery bypass graft, use of insulin, and no therapy with acetylsalicylic acid. In conclusion, in AMI patients, the absence of high Lp(a) levels, as well high HDL-c levels, were independent predictors of the inexistence of coronary artery disease. High Lp (a) levels were also an independent predictor of ischemic events or death.

Relationships between indicators of prothrombotic activity and coronary microvascular dysfunction in patients with myocardial infarction with obstructive and non-obstructive coronary artery disease

The relationship between prothrombotic activity and coronary microvascular dysfunction (MVD) is limited. This study aimed to perform a comparative analysis of the relationship between prothrombotic activity and MVD in patients with myocardial infarction without obstructive coronary artery disease (MINOCA) and myocardial infarction with obstructive coronary artery disease (MI-CAD).

MATERIAL AND METHODS

A total of 37 patients were enrolled in the study; the main group included 16 MINOCA patients, and 21 MI-CAD patients were included in the control group. Blood samples for protein C, antithrombin, WF, plasminogen, and homocysteine were performed on the 4th ± 1 day of admission. CZT-SPECT data were used to determine the standard indices of myocardial perfusion dis-orders (SSS, SRS, and SDS), as well as stress and rest myocardial blood flow (MBF), myocardial flow reserve (MFR), and difference flows (DF). MVD was defined as MFR (≤ 1.91 ml/min); coronary slow flow (CSF) was defined as corrected TIMI frame count (21 ± 3).

RESULTS

We performed a step-by-step analysis of prothrombotic activity of the hemostasis system in binary logistic regression for MINOCA patients to identify factors associated with MVD (MFR ≤ 1.91 ml/min). A predictive model was developed to estimate the probability of reduced MFR. A low MFR is related to only plasminogen in MINOCA patients, whereas only wall motion score index (WMSI) in MI-CAD group was associated with a low MFR.

CONCLUSION

This small-scale study revealed the relationship between indicators of prothrombotic activity and MVD. The key factors that affect MVD in MINOCA patients was plasminogen, whereas, in patients with MI-CAD, WMSI was the key factor. Measurements of MVD may enhance the risk stratification and facilitate future targeting of adjunctive antithrombotic therapies in MINOCA and MI-CAD patients.

[Takotsubo Syndrome: cardiovascular complication of stroke]

An 82-year-old woman, Katz A, with a history of type 2 diabetes mellitus and high blood pressure, was admitted for ischemic stroke complicated by Takotsubo´s syndrome with subsequent readmission for atrial fibrillation after discharge. These three clinical events have criteria to be integrated as a Brain Heart Syndrome, which is a high-risk condition for mortality.

MINOCA: One Size Fits All? Probably Not—A Review of Etiology, Investigation, and Treatment

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of conditions that include both atherosclerotic (coronary plaque disruption) and non-atherosclerotic (spontaneous coronary artery dissection, coronary artery spasm, coronary artery embolism, coronary microvascular dysfunction, and supply–demand mismatch) causes resulting in myocardial damage that is not due to obstructive coronary artery disease. Failure to identify the underlying cause may result in inadequate and inappropriate therapy in these patients. The cornerstone of managing MINOCA patients is to identify the underlying mechanism to achieve the target treatment. Intravascular imaging is able to identify different morphologic features of coronary plaques, while cardiac magnetic resonance is the gold standard for detection of myocardial infarction in the setting of MINOCA. In this review, we summarize the relevant clinical issues, contemporary diagnosis, and treatment options of MINOCA.

Automated Detection of Myocardial Infarction and Heart Conduction Disorders Based on Feature Selection and a Deep Learning Model

An electrocardiogram (ECG) is an essential piece of medical equipment that helps diagnose various heart-related conditions in patients. An automated diagnostic tool is required to detect significant episodes in long-term ECG records. It is a very challenging task for cardiologists to analyze long-term ECG records in a short time. Therefore, a computer-based diagnosis tool is required to identify crucial episodes. Myocardial infarction (MI) and conduction disorders (CDs), sometimes known as heart blocks, are medical diseases that occur when a coronary artery becomes fully or suddenly stopped or when blood flow in these arteries slows dramatically. As a result, several researchers have utilized deep learning methods for MI and CD detection. However, there are one or more of the following challenges when using deep learning algorithms: (i) struggles with real-life data, (ii) the time after the training phase also requires high processing power, (iii) they are very computationally expensive, requiring large amounts of memory and computational resources, and it is not easy to transfer them to other problems, (iv) they are hard to describe and are not completely understood (black box), and (v) most of the literature is based on the MIT-BIH or PTB databases, which do not cover most of the crucial arrhythmias. This paper proposes a new deep learning approach based on machine learning for detecting MI and CDs using large PTB-XL ECG data. First, all challenging issues of these heart signals have been considered, as the signal data are from different datasets and the data are filtered. After that, the MI and CD signals are fed to the deep learning model to extract the deep features. In addition, a new custom activation function is proposed, which has fast convergence to the regular activation functions. Later, these features are fed to an external classifier, such as a support vector machine (SVM), for detection. The efficiency of the proposed method is demonstrated by the experimental findings, which show that it improves satisfactorily with an overall accuracy of 99.20% when using a CNN for extracting the features with an SVM classifier.

Pitfalls and pearls in the imaging of cardiac ischemia

Coronary artery disease is the most common cause of cardiac ischemia and a leading cause of death globally. There are multiple imaging modalities which can assess cardiac ischemia, in particular coronary CT calcium score, coronary CT angiography, and cardiac MRI. Each of these modalities offers insight into the overall patient picture. However, coronary CT and cardiac MRI are not free from limitations. This article will review the roles of CT and MRI in cardiac imaging, mimics, technical limitations, and potential pitfalls that may be encountered.

Myocardial Infarction With Non-obstructive Coronary Arteries: Risk Factors and Associated Comorbidities

Myocardial infarction with non-obstructive coronary arteries (MINOCA), despite a lower burden of coronary atherosclerosis, has a non-negligible prognostic impact. The label of MINOCA includes an array of different aetiologies and pathologic conditions, thus the identification of the underlying disease is crucial to patient management. Myocardial infarction with obstructive coronary artery disease and MINOCA share only some risk factors and comorbid conditions. While traditional cardiovascular risk factors have a lower prevalence in MINOCA patients, atypical ones—e.g., anxiety, depression, and autoimmune diseases—are much more frequent in this population. Other conditions—e.g., pregnancy, cancer, and anti-cancer therapy—can predispose to or even induce MINOCA through various mechanisms. The evidence of such risk factors for MINOCA is still scarce and contradicting, as no randomised controlled trials exist in this field. In our work, we performed a review of registries, clinical studies, and case reports of MINOCA, in order to summarise the available data and analyse its possibile pathogenic mechanisms.

Unraveling the Multitude of Etiologies in Myocardial Infarction With Nonobstructive Coronary Arteries

Although recent studies revealed suboptimal outcomes in patients with myocardial infarction with nonobstructive coronary arteries (MINOCAs), the underlying etiology remains unknown in most patients. Therefore, adequate treatment modalities have not yet been established. We aimed to assess demographics, treatment strategies, and long-term clinical outcome in MINOCA subgroups. We retrospectively analyzed data from a large, prospective observational study of patients with acute coronary syndrome admitted to the Isala hospital in Zwolle, The Netherlands between 2006 and 2014. Patients with MINOCA were divided into subgroups based on the underlying cause of the event. From 7,693 patients, 402 patients (5%) concerned MINOCA. After the exclusion of missing cases (n = 47), 5 subgroups were distinguished: "true" acute myocardial infarction (10%), perimyocarditis (13%), cardiomyopathy (including Takotsubo cardiomyopathy) (19%), miscellaneous causes (21%), and an indeterminate group (38%). Patients with cardiomyopathy were predominantly women (78%) and showed the highest incidence of major adverse cardiovascular events at 30 days follow-up (7%; p = 0.012), 1 year (19%; p = 0.004), and mortality at long-term follow-up (27%; p = 0.010) compared with any other MINOCA subgroup. The cardiomyopathy group was followed by the indeterminate group, with major adverse cardiovascular events rates of 1% and 5%, respectively, and 17% long-term all-cause mortality. In conclusion, long-term prognosis in MINOCA depends on the underlying etiology. Prognosis is worst in the cardiomyopathy group followed by the indeterminate group. This underlines the importance of revealing the diagnosis to ultimately optimize treatment.

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.

Myocardial Infarction with Non-Obstructive Coronary Artery Disease: The Labyrinth of Investigations. Case Report and Review of the Literature

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) accounts for approximately 5–15% of acute myocardial infarctions (MI). This infarction type raises a series of questions about the underlying mechanism of myocardial damage, the diagnostic pathway, optimal therapy, and the outcomes of these patients when compared to MI associated with obstructive coronary artery disease. We present the case of a 60-year-old patient with multiple cardiovascular risk factors and comorbidities who is admitted in an emergency setting. The patient is known with a conservatively treated inferior myocardial infarction which occurred 3 months prior, with reduced left ventricular ejection fraction. Emergency coronary angiography revealed normal epicardial coronary arteries, which led to further investigations of the underlying cause. Considering the absence of epicardial and microvascular spasm, CMR (cardiac magnetic resonance) confirmation of two transmural myocardial infarctions in the territories tributary to coronary arteries, and a high index of myocardial resistance in culprit arteries, we concluded the diagnosis of MINOCA due to the microvascular endothelial dysfunction. Although the concept of MINOCA was devised almost a decade ago, and these patients are an important part of MI presentations, it still represents a diagnostic challenge with multiple explorations required to establish the precise etiology.

Syndrome of Nonobstructive Coronary Artery Diseases: A Comprehensive Overview of Open Artery Ischemia

Syndromes of cardiac ischemia with nonobstructive coronary arteries have been increasingly recognized as a clinical entity with heterogeneous clinical presentations, commonly encountered in women. Knowledge of pathophysiology and clinical risk factors is key to ensuring appropriate diagnostic evaluation and management for these often-neglected patients. In this review, we discuss the epidemiology, risk factors, and clinical presentations of these syndromes. We provide algorithms for diagnosis and management of these entities based on current scientific knowledge and highlight some of the key knowledge gaps and ongoing trials in this emerging field.

Identification of candidate genes and pathways in limonin-mediated cardiac repair after myocardial infarction

BACKGROUND

Myocardial infarction (MI) resulting from acute coronary ischemia may cause significant morbidity and mortality, and microRNAs play a vital role in this pathophysiology. Limonin (LIM) is a natural medicine from citrus fruit that protects organs against ischemic diseases, but the candidate genes and pathways associated with cardioprotection are unknown.

METHODS

MI was induced by ligating the left anterior descending coronary in male Sprague-Dawley rats. LIM was orally administered for 7 days after the induction of MI. Subsequently, the hearts were collected to examine significant changes in microRNAs and mRNAs among the control (CON), MI, and LIM + MI groups. Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and protein-protein interaction (PPI) networks were used to identify the biological functions and signaling pathways of differentially expressed mRNAs. Candidate genes were validated by RT-qPCR.

RESULTS

Compared to the CON group, MI caused significant changes in the expression of 26 microRNAs and 1979 mRNAs. The bioinformatics analysis showed that inflammation, apoptosis, and oxidation were enriched in GO terms, while RAP1, PI3K/AKT, RAS, and cGMP-PKG were enriched in KEGG pathways. In addition, compared to the MI group, LIM induced significant changes in the expression of 4 microRNAs and 173 mRNAs. The differentially expressed mRNAs were related to collagen biosynthesis, the immune response, extrinsic apoptosis, and tight junctions. One microRNA (rno-miR-10a-5p) and 2 mRNAs (IGLON5 and LMX1A) were differentially expressed among the CON, MI, and LIM + MI groups.

CONCLUSIONS

Our results suggest that the rno-miR-10a-5p-IGLON5/LMX1A axis may be a candidate pathway and promising target through which LIM alleviates MI-induced cardiac dysfunction.

Spontaneous Coronary Artery Dissection with Sudden Cardiac Arrest in a Female Patient During Her Postpartum Period: A Case Report and Review

Patient: Female, 29-year-old

Final Diagnosis: Spontaneous coronary artery dissection

Symptoms: Cardiac arrest

Medication: —

Clinical Procedure: —

Specialty: Critical Care Medicine

Importance of confirming the underlying diagnosis in patients with myocardial infarction and non-obstructive coronary arteries (MINOCA): a single-centre retrospective cohort study

BACKGROUND

Many patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) are discharged without a known aetiology for their clinical presentation. This study sought to assess the effect of this 'indeterminate MINOCA' diagnosis on the prevalence of recurrent cardiovascular events and presentations to the Cardiac Emergency Department (CED).

METHODS

We retrospectively analysed all patients meeting the diagnostic MINOCA criteria presenting at a large secondary hospital between January 2017 and April 2019.

PARTICIPANTS

Patients were divided into the (1) 'indeterminate MINOCA', or (2) 'MINOCA with diagnosis' group. The primary outcome was the occurrence of major adverse cardiac events (MACE) defined as the composite of all-cause mortality, non-fatal myocardial infarction, stroke and any revascularisation procedure. Secondary outcomes were all recurrent visits at the CED, and MACE including unplanned cardiac hospitalisation.

RESULTS

In 62/198 (31.3%) MINOCA patients, a conclusive diagnosis was found (myocardial infarction, (peri)myocarditis, cardiomyopathy, or miscellaneous). MINOCA patients with a confirmed diagnosis were younger compared to those with an indeterminate diagnosis (56.7 vs. 62.3 years, p = 0.007), had higher maximum troponin-T [238 ng/L vs. 69 ng/L, p < 0.001] and creatine kinase (CK) levels [212U/L vs. 152U/L, p = 0.007], and presented more frequently with electrocardiographic signs of ischaemia (71.0% vs. 47.1%, p = 0.002). Indeterminate MINOCA patients more often showed recurrent CED presentations (36.8% vs. 22.6%, p = 0.048), however the occurrence of cardiovascular events was equal (8.8 vs. 8.1%, p = 0.86). Multivariable analysis showed that elevated levels of troponin-T and CK, ST-segment deviation on electrocardiography, reduced left ventricular ejection fraction, regional wall motion abnormalities, and performance of additional examination methods were independent predictors for finding the underlying MINOCA cause.

CONCLUSIONS

Only in one-third of MINOCA patients a conclusive diagnosis for the acute presentation was identified. Recurrent CED visits were more often observed in the indeterminate MINOCA group, while the occurrence of cardiovascular events was similar across groups.

TRIAL REGISTRATION

Retrospectively registered.

Coronary artery spasm-induced acute myocardial infarction in patients with myocardial infarction with non-obstructive coronary arteries

Coronary artery spasm-induced acute myocardial infarction (CASIAMI) is one of the etiologies of myocardial infarction with non-obstructive coronary arteries (MINOCA). We retrospectively analyzed the incidence and clinical characteristics of Japanese patients with CASIAMI and non-obstructive coronary arteries. We experienced 62 patients with MINOCA (10 thrombosis, 7 unknown causes, and 45 CASIAMI) among 991 patients with suspected AMI. Pharmacological spasm provocation testing was performed in 37 patients. CASIAMI without obstructive coronary arteries was found in 4.5% of patients with suspected AMI and was observed in 73% of patients with MINOCA. Patients with CASIAMI were frequently males and had relatively small AMIs. Spontaneous spasm was recognized in 8 patients. We could reproduce provoked spasm in 37 patients with MINOCA, including 23 patients with multiple spasm. No patients died during the follow-up period. The clinical outcomes in patients with CASIAMI under optimal coronary vasodilators were satisfactory.

Recent insights into pathophysiology and management of mechanical complications of myocardial infarction

PURPOSE OF REVIEW

Mechanical complications of myocardial infarction are a group of postischemic events and include papillary muscle rupture resulting in ischemic mitral regurgitation, ventricular septal defect, left ventricle free wall rupture, pseudoaneurysm, and true aneurysm. Advances made in management strategies, such as the institution of 'Code STEMI' and percutaneous interventions, have lowered the incidence of these complications. However, their presentation is still associated with increased morbidity and mortality. Early diagnosis and appropriate management is crucial for facilitating better clinical outcomes.

RECENT FINDINGS

Although the exact timing of a curative intervention is not known, emerging percutaneous and transcatheter approaches and improving mechanical circulatory support (MCS) devices have greatly enhanced our ability to manage and treat some of the complications postinfarct.

SUMMARY

Although the incidence of mechanical complications of myocardial infarction has decreased over the past few decades, these complications are still associated with high rates of morbidity and mortality. The combination of early and accurate diagnosis and subsequent appropriate management are imperative for optimizing clinical outcomes. Although more randomized clinical trials are needed, mechanical circulatory support devices and emerging therapeutic strategies can be offered to carefully selected patients.

Review Article--Clinical Overview of Myocardial Infarction Without Obstructive Coronary Artey Disease (MINOCA)

The term myocardial infarction with non-obstructive coronary arteries (MINOCA) applies to patients who have clinical evidence of AMI but coronary angiography reveals no coronary obstructions and an alternative diagnosis is not possible. It is a heterogenous group of disease. Its prognosis, predictors of mortality and optimum management is unclear. In this review, we present a disease overview for MINOCA including the clinical features, adopted definitions, prevalence, diagnosis, treatment, and prognosis.

A Rare Cause of ST-Segment Elevation Myocardial Infarction in COVID-19: MINOCA Syndrome

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is defined as having a stenosis of less than 50% or no stenosis in coronary angiography in a patient diagnosed with myocardial infarction.

Because of its thrombogenic predisposition in COVID-19, the diagnosis of MINOCA syndrome is rarely thought in the patients with ST-segment elevation myocardial Infarction on electrocardiogram. In this case report, we discuss a 47-year-old male patient diagnosed with MINOCA who was followed up with respiratory failure due to COVID-19 viral pneumonia in intensive care unit. His 12-lead electrocardiogram showed “inferior STEMI”. A 30-40% stenosis was also shown in the midportion of left anterior descending artery in emergency coronary angiography. The patient had a normal computed tomographic pulmonary angiography and was discharged with a full recovery.

MINOCA may be triggered by hyperinflammation or various processes due to COVID-19. To explain these processes associated with MINOCA syndrome, further clinical trials are needed.

Myocardial Infarction with Nonobstructive Coronary Artery Disease—Definition, Etiopathogenesis, Diagnosis, and Management

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a complex clinical syndrome that is characterized by evidence of acute myocardial infarction in the absence of significant epicardial coronary artery disease on angiography. The term “MINOCA” encompasses a group of heterogeneous diseases with varying underlying mechanisms and each with its own pathophysiology. Overlooked plaque rupture or erosion and coronary vasospasm are the most common causes of MINOCA and can be diagnosed by routine intracoronary imaging and vasoreactivity testing, respectively. Coronary microvascular dysfunction is a less recognized, albeit an important cause of morbidity in patients presenting with MINOCA. Although MINOCA is a rare presentation of acute coronary syndrome, it is not a benign disorder and can have adverse consequences if untreated. In this article, we aim to review the pathogenesis, clinical characteristics, and finally propose a systematic approach in the diagnosis and management of patients with MINOCA.

Diagnostic approach in patients with angina and no obstructive coronary artery disease: emphasising the role of the coronary function test

BACKGROUND

Many patients with angina do not have obstructive coronary artery disease (CAD), also referred to as "Ischaemia with No Obstructive Coronary Arteries" (INOCA). Coronary vascular dysfunction is the underlying cause of this ischaemic heart disease in as much as 59-89% of these patients, including the endotypes of coronary microvascular dysfunction and epicardial coronary vasospasm. Currently, a coronary function test (CFT) is the only comprehensive diagnostic modality to evaluate all endotypes of coronary vascular dysfunction in patients with INOCA.

OBJECTIVE

In this paper we discuss the relevance of performing a CFT, provide considerations for patient selection, and present an overview of the procedure and its safety.

METHODS

We reviewed the latest published data, guidelines and consensus documents, combined with a discussion of novel original data, to present this point of view.

RESULTS

The use of a CFT could lead to a more accurate and timely diagnosis of vascular dysfunction, identifies patients at risk for cardiovascular events, and enables stratified treatment which improves symptoms and quality of life. Current guidelines recommend considering a CFT in patients with INOCA and persistent symptoms. The safety of the procedure is comparable to that of a regular coronary angiography with physiological measurements. Non-invasive alternatives have limited diagnostic accuracy for the identification of coronary vascular dysfunction in patients with INOCA, and a regular coronary angiography and/or coronary computed tomography scan cannot establish the diagnosis.

CONCLUSIONS

A complete CFT, including acetylcholine and adenosine tests, should be considered in patients with INOCA.

Myocardial infarction with non-obstructive coronary arteries: To stent or not to stent? That is the question

Myocardial infarction with nonobstructive coronary arteries (MINOCA) in the context of acute ST elevation myocardial infarction (STEMI) is a challenging situation with no clear guidelines. In the absence of a consensus, optical coherence tomography (OCT) provides a better well-informed decision whether to stent or not. Herein, we report a case of MINOCA that underwent stenting of the proximal left anterior descending artery in the setting of extensive anterior wall STEMI in view of high-risk clinical presentation and OCT features of a ruptured plaque.

A valuable cardiac magnetic resonance investigation after MINOCA/takotsubo Syndrome: a case report

Myocardial infarction with non-obstructive coronary arteries is a working diagnosis that includes takotsubo cardiomyopathy/syndrome (TTS). Cardiac magnetic resonance (CMR) is useful for establishing the underlying aetiology of myocardial infarction with non-obstructive coronary arteries during the acute phase, but its role in follow-up is less well established. A 35-year-old man with several cardiac risk factors presented 3 days after his sister's death with biochemical and clinical features of acute myocardial infarction without coronary artery obstruction on angiography but with diagnostic features of TTS on CMR, including oedema but no late gadolinium enhancement. Subsequent CMR 3 months later revealed left ventricular late gadolinium enhancement suggesting previous acute myocardial infarction. Although the initial diagnosis of TTS was robust according to established criteria, it remained uncertain whether the later ischaemic injury was related to an ischaemic event at presentation or occurred in the intervening period. Nevertheless, CMR may have an extended role in the follow-up of these patients and may reveal additional, actionable pathology.

A Case of Acute Myocardial Injury – MINOCA or Myocarditis?

Myocardial infarction with non-obstructive coronary arteries (MINOCA) has been defined as clinical presentation of an acute coronary syndrome with laboratory evidence of myocardial necrosis, but with coronary stenosis of less than 50% on coronary angiography. On the other side, myocarditis is an inflammatory response triggered by viral, bacterial, fungal, lymphocytic, eosinophilic, or autoimmune myocardial injury, which may be associated with elevated myocardial necrosis serum biomarkers. We present the case of a young male patient with acute chest pain, ST-segment elevation, and high-sensitivity troponin levels of 22,162 ng/L.

A review of diagnosis, etiology, assessment, and management of patients with myocardial infarction in the absence of obstructive coronary artery disease

Myocardial infarction (MI) in the absence of obstructive coronary artery disease (MINOCA) is prevalent in around 5% of acute myocardial infarction (AMI) presentations. MINOCA is a heterogeneous entity with many different etiologies. It is important for health care providers to familiarize themselves with the disease process, presentation, and possible underlying causes in order to guide appropriate management strategies. In this article, the authors review the contemporary definition, etiologies and assessment, and management for AMI patients with MINOCA.

MINOCA: The caveat of absence of coronary obstruction in myocardial infarction

AIMS

Whether patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) have better outcomes than patients with obstructive coronary artery disease remains contradictory. The current study focussed on the clinical profile and prognosis of MINOCA patients.

METHODS AND RESULTS

We performed a retrospective analysis of patients with acute coronary syndrome (ACS) admitted to the Isala hospital in Zwolle, the Netherlands, between 2006 and 2014. A total of 7693 patients were categorized into three groups: MINOCA, single-vessel obstructive ACS (SV-ACS), and multi-vessel obstructive ACS (MV-ACS). MINOCA patients (5.2% of the total population) were more likely to be female (51.5% vs. 30.3% and 26.0% in SV-ACS and MV-ACS, respectively, p < 0.001 for both). The prevalence of risk factors in the MINOCA group was in between the SV-ACS and MV-ACS groups. Logistic regression revealed a lower odds of dying in SV-ACS (odds ratio (OR) = 0.70 (p = 0.04)) and a similar odds in MV-ACS (OR = 0.88, p = 0.45) compared to MINOCA.

CONCLUSIONS

Patients with MINOCA show an 'intermediate' risk profile with mortality rates in between those of both ACS groups. Hence, MINOCA should be recognised as a potential risk factor for mortality, requiring adequate treatment and follow-up.

Cardiovascular magnetic resonance in myocardial infarction with non-obstructive coronary arteries patients: A review

The diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) necessitates documentation of an acute myocardial infarction (AMI), non-obstructive coronary arteries, using invasive coronary angiography or coronary computed tomography angiography and no clinically overt cause for AMI. Historically patients with MINOCA represent a clinical dilemma with subsequent uncertain clinical management. Differential diagnosis is crucial to choose the best therapeutic option for ischemic and non-ischemic MINOCA patients. Cardiovascular magnetic resonance (CMR) is able to analyze cardiac structure and function simultaneously and provides tissue characterization. Moreover, CMR could identify the cause of MINOCA in nearly two-third of patients providing valuable information for clinical decision making. Finally, it allows stratification of patients with worse outcomes which resulted in therapeutic changes in almost half of the patients. In this review we discuss the features of CMR in MINOCA; from exam protocols to imaging findings.

Clinical presentation and 3-year outcomes of patients with acute coronary syndromes and non-obstructive coronary arteries on angiography

Background

With the emerging interest in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA), there is a need to define an even broader group of patients with the syndrome of myocardial ischemia with non-obstructive coronary arteries (INOCA). There are limited data on the clinical characteristics and prognoses of such patients who present with symptoms of acute coronary syndrome (ACS) and undergo urgent coronary angiography that reveals no significant lesions. The aim of this observational study was to compare patients with ACS INOCA and those with ACS with obstructive coronary artery disease (OCAD) both within unadjusted cohorts and with propensity score matched controls.

Methods and results

This observational study was based on the data from the Polish National Registry of Invasive Cardiology Procedures. Of 9744 patients included, 7624 had OCAD and 2120 had ACS INOCA. In unadjusted cohorts, the overall survival and incidence of major adverse cardiovascular events (MACE: death, cardiac arrest, myocardial infarction, stroke, and heart failure hospitalization) until 36 months were higher in patients with ACS OCAD. Following propensity matching, higher win ratios of death (p = 0.02), additional revascularizations by percutaneous coronary intervention or coronary artery bypass graft surgery (p<0.001), and cardiac hospitalization (p<0.001) were observed in these patients. In contrast, the win ratios of myocardial infarction (p = 0.74), heart failure hospitalization (p = 0.86), and MACE (p = 0.07) were not significantly different between the groups.

Conclusions

The prognosis of patients with ACS INOCA was more favorable than that of patients with ACS OCAD; however, the differences diminished after adjustments for the initial clinical profiles. An ACS incident should not be judged as trivial even when cardiac markers remain stable and no significant lesions are found on angiography.