Diagnostic work-up and therapeutic implications in MINOCA: need for a personalized approach

Precision Medicine in Acute Coronary Syndromes

Nowadays, current guidelines on acute coronary syndrome (ACS) provide recommendations mainly based on the clinical presentation. However, greater attention is being directed to the specific pathophysiology underlying ACS, considering that plaque destabilization and rupture leading to luminal thrombotic obstruction is not the only pathway involved, albeit the most recognized. In this review, we discuss how intracoronary imaging and biomarkers allow the identification of specific ACS endotypes, leading to the recognition of different prognostic implications, tailored management strategies, and new potential therapeutic targets. Furthermore, different strategies can be applied on a personalized basis regarding antithrombotic therapy, non-culprit lesion revascularization, and microvascular obstruction (MVO). With respect to myocardial infarction with non-obstructive coronary arteries (MINOCA), we will present a precision medicine approach, suggested by current guidelines as the mainstay of the diagnostic process and with relevant therapeutic implications. Moreover, we aim at illustrating the clinical implications of targeted strategies for ACS secondary prevention, which may lower residual risk in selected patients.

An update on the mechanisms of Takotsubo syndrome: "At the end an acute coronary syndrome"

Takotsubo syndrome (TTS) is an acute reversible form of myocardial dysfunction, often preceded by a physical or emotional stressful event, that acts as a trigger. Despite, recent advances in the comprehension of the mechanisms leading to TTS, its pathophysiology is far from being completely understood. However, several studies seem to suggest that an acute coronary microvascular dysfunction may represent a crucial pathogenic mechanism involved in TTS occurrence. In this article, we aim to review the complex pathophysiology of TTS and the possible different mechanisms underlying this clinical condition, focusing on the role of coronary microvascular dysfunction and the remaining knowledge's gaps in the field.

Prognostic factors of MINOCA and their possible mechanisms

Objective

Despite not showing substantial stenosis of coronary arteries, Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) presents with myocardial ischemia injury, thus having a grave prognosis and a high risk of long-term complications. This necessitates increased clinical attention and exploration of its root causes to prevent a similar crisis.

Methods

Research on MINOCA is limited, especially in terms of its clinical attributes, long-term outlook, risk stratification, and prognosis-linked cardiometabolic risk factors. This review aims to fill these gaps, providing an extensive overview of clinical trials and studies on MINOCA to separate the issue from the presence of non-obstructive coronary arteries in cardiac patients.

Results

It has been found that MINOCA patients still face a high risk of long-term adverse events. Due to social and physiological factors, the hospital mortality rate is higher among women, and they are also more susceptible to MINOCA. Cardiac metabolic risk factors, including disorder of glucose and lipid metabolism, as well as changes in serum CysC levels, have significant impacts on the occurrence and prognosis of MINOCA.

Conclusions

Further research is still needed to fully understand the complex biological mechanisms underlying the prognostic factors of MINOCA. A profound understanding of these factors could reveal potential targets for improving prognosis, thereby indicating new strategies for managing this cardiovascular condition.

CMR reclassifies the majority of patients with suspected MINOCA and non MINOCA

AIMS

In ∼5-15% of all cases of acute coronary syndromes (ACS) have unobstructed coronaries on angiography. Cardiac magnetic resonance (CMR) has proven useful to identify in most patients the underlying diagnosis associated with this presentation. However, the role of CMR to reclassify patients from the initial suspected condition has not been clarified. The aim of this study was to assess the proportion of patients with suspected MINOCA, or non-MINOCA, that CMR reclassifies with an alternative diagnosis from the original clinical suspicion.

METHODS AND RESULTS

A retrospective cohort of patients in a tertiary cardiology centre was identified from a registry database. Patients who were referred for CMR for investigation of suspected MINOCA, and a diagnosis pre- and post-CMR was recorded to determine the proportion of diagnoses reclassified. A total of 888 patients were identified in the registry. CMR reclassified diagnosis in 78% of patients. Diagnosis of MINOCA was confirmed in only 243 patients (27%), whilst most patients had an alternative diagnosis (73%): myocarditis n = 217 (24%), Takotsubo syndrome n = 115 (13%), cardiomyopathies n = 97 (11%), and normal CMR/non-specific n = 216 (24%).

CONCLUSION

In a large single-centre cohort of patients presenting with ACS and unobstructed coronary arteries, most patients had a non-MINOCA diagnosis (73%) (myocarditis, Takotsubo, cardiomyopathies, or normal CMR/non-specific findings), whilst only a minority had confirmed MINOCA (27%). Performing CMR led to reclassifying patients' diagnosis in 78% of cases, thus confirming its important clinical role and underscoring the clinical challenge in diagnosing MINOCA and non MINOCA conditions.

Chinese expert consensus on the diagnosis and treatment of coronary microvascular diseases (2023 Edition)

Since the four working groups of the Chinese Society of Cardiology issued first expert consensus on coronary microvascular diseases (CMVD) in 2017, international consensus documents on CMVD have increased rapidly. Although some of these documents made preliminary recommendations for the diagnosis and treatment of CMVD, they did not provide classification of recommendations and levels of evidence. In order to summarize recent progress in the field of CMVD, standardize the methods and procedures of diagnosis and treatment, and identify the scientific questions for future research, the four working groups of the Chinese Society of Cardiology updated the 2017 version of the Chinese expert consensus on CMVD and adopted a series of measures to ensure the quality of this document. The current consensus has raised a new classification of CMVD, summarized new epidemiological findings for different types of CMVD, analyzed key pathological and molecular mechanisms, evaluated classical and novel diagnostic technologies, recommended diagnostic pathways and criteria, and therapeutic strategies and medications, for patients with CMVD. In view of the current progress and knowledge gaps of CMVD, future directions were proposed. It is hoped that this expert consensus will further expedite the research progress of CMVD in both basic and clinical scenarios.

Non-ST-segment elevation myocardial infarction with non-obstructive coronary arteries due to a type-A thymoma: A case report

Introduction

Myocardial infarction with non-obstructive coronary arteries (MINOCA) has become an increasingly recognized subgroup in patients with acute myocardial infarction, with a recent cohort study reporting a prevalence of 8.8%. This report describes a patient who presented with non-ST-segment elevation myocardial infarction (NSTEMI) due to an incidental anterior mediastinal mass.

Case presentation

An 80-year-old woman presented to our emergency department with a chief complaint of progressive shortness of breath associated with retrosternal chest pain for one day duration. Computed tomography (CT) angiogram of the chest was conducted, which revealed an anterior mediastinal mass. Upon admission, the patient developed an acute episode of recurrent severe chest pain, which was diagnosed as an NSTEMI. Emergent cardiac catheterization was performed because of unstable vital signs; however, the results showed no evidence of atherosclerotic changes in the major coronary arteries, compatible with the diagnosis of MINOCA. The mediastinal mass was later confirmed to be a type A thymoma on CT-guided biopsy.

Conclusion

Myocardial infarction in patent coronary arteries due to an anterior mediastinal mass is rare. Further studies are needed to standardize the diagnosis and management protocols for the potential etiologies of MINOCA.

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.

Myocardial infarction with nonobstructive coronary arteries: the need for precision medicine

PURPOSE OF REVIEW

Myocardial infarction with nonobstructive coronary arteries (MINOCA) represents about 6-8% of all patients with myocardial infarction (MI), and several pathophysiological mechanisms showed to be involved in this heterogeneous clinical condition. Of note, MINOCA proved to be associated with a significant risk of mortality, angina burden and socioeconomic costs.

RECENT FINDINGS

Results from randomized clinical trials evaluating the clinical effectiveness of a comprehensive diagnostic algorithm, along with the acute and long-term management of patients with MINOCA, are pending.

SUMMARY

In this review article, we aim at providing an overview of the clinical features, diagnostic work-up and the therapeutic management of patients presenting with MINOCA, highlighting the recent acquisition along with the remaining important knowledge gaps in this field.

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.

Sleep Quality, Sleep Duration, and the Risk of Adverse Clinical Outcomes in Patients With Myocardial Infarction With Non-obstructive Coronary Arteries

Background

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous entity with varying underlying etiologies and occurs in ~5–10% of patients with acute myocardial infarction. Sleep disorders and short sleep duration are common phenomena experienced by patients with coronary heart disease and are associated with poor clinical outcomes. However, the association between sleep quality, sleep duration, and the MINOCA prognosis is less clear.

Methods

We performed a prospective observational study of 607 patients with MINOCA between February 2016 and June 2018. The mean follow-up period was 3.9 years. Sleep quality and sleep duration were measured by the Chinese version of the Pittsburgh Sleep Quality Index. The primary endpoint was all-cause mortality, and the secondary endpoint was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death, non-fatal myocardial infarction, stroke and heart failure hospitalization.

Results

During the follow-up period, all-cause death occurred in 69 participants and 105 participants developed MACE. The Kaplan–Meier survival analysis demonstrated a significant association between poor sleep quality and all-cause mortality (log-rank P = 0.005) and MACE (log-rank P = 0.004). Multivariable Cox regression model indicated that poor sleep quality was an independent predictor of all-cause mortality as well as MACE [adjusted hazard ratio (HR) = 1.649; 95% confidence interval (CI), 1.124–2.790; P < 0.001; and adjusted HR = 1.432; 95% CI, 1.043–2.004; P = 0.003, respectively]. For sleep duration, short sleep duration (<6 h/d) was significantly associated with an increased risk of all-cause mortality and MACE (adjusted HR = 1.326; 95% CI, 1.103–1.812; P = 0.004; and adjusted HR = 1.443; 95% CI, 1.145–1.877; P < 0.001, respectively), whereas long sleep duration was not (>8 h/d). A poorer sleep profile (including poor sleep quality and short sleep duration) was associated with a 149.4% increased risk of death (HR = 2.494; 95% CI, 1.754–4.562; P < 0.001) and a 96.7% increased risk of MACE (HR = 1.967; 95% CI, 1.442–3.639; P < 0.001) than those with neither.

Conclusion

Sleep disorders were common among Chinese patients with MINOCA. Poor sleep quality and short sleep duration were independently associated with an increased risk of all-cause mortality and MACE in the MINOCA population. Meanwhile, a poor sleep profile has an additive effect with regard to cardiovascular risks; in these populations, efforts should be made to improve both sleep quality and sleep duration for secondary cardiovascular prevention.

Clinical Trial Registration

http://www.chictr.org.cn, identifier: ChiCTR2000040701.

The Role of Cardiac Magnetic Resonance in Myocardial Infarction and Non-obstructive Coronary Arteries

Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) accounts for 5–15% of all presentations of acute myocardial infarction. The absence of obstructive coronary disease may present a diagnostic dilemma and identifying the underlying etiology ensures appropriate management improving clinical outcomes. Cardiac magnetic resonance (CMR) imaging is a valuable, non-invasive diagnostic tool that can aide clinicians to build a differential diagnosis in patients with MINOCA, as well as identifying non-ischemic etiologies of myocardial injury (acute myocarditis, Takotsubo Syndrome, and other conditions). The role of CMR in suspected MINOCA is increasingly recognized as emphasized in both European and American clinical guidelines. In this paper we review the indications for CMR, the clinical value in the differential diagnosis of patients with suspected MINOCA, as well as its current limitations and future perspectives.

Takotsubo Syndrome in Intensive Cardiac Care Unit: Challenges in Diagnosis and Management

Takotsubo syndrome (TTS) is an acute reversible form of myocardial dysfunction that is often associated with serious adverse in-hospital complications, including acute heart failure, cardiogenic shock and life-threatening arrythmias. In the absence of randomized clinical trials, its management in the acute phase is based on empirical supportive pharmacological and non-pharmacological measures.In this review article, we aimed at providing an overview of the acute clinical manifestations of patients presenting with TTS, highlighting the predictors of a worse short-term outcome, along with the challenges in therapeutic management of TTS-related complications in the acute care setting.

Clinical presentation and management of myocardial infarction with nonobstructive coronary arteries (MINOCA): A literature review

Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA), as the name implies, is an acute myocardial infarction (MI) in the absence of significant coronary artery obstruction. Diagnosis and management of such cases have been challenging. There are many etiologies of MINOCA including coronary artery spasm, coronary microvascular dysfunction, plaque disruption, spontaneous coronary thrombosis or emboli, spontaneous coronary artery dissection, or cardiomyopathies. In this paper, the pathophysiology, diagnostic work-up, and clinical management for each subtype are described, and an overarching approach on how to evaluate and manage a patient presenting with MINOCA.

Pathophysiology of Coronary Microvascular Dysfunction

Ischemic heart disease (IHD) is commonly recognized as the consequence of coronary atherosclerosis and obstructive coronary artery disease (CAD). However, a significant number of patients may present angina or myocardial infarction even in the absence of any significant coronary artery stenosis and impairment of the coronary microcirculation has been increasingly implicated as a relevant cause of IHD. The term "coronary microvascular dysfunction" (CMD) encompasses several pathogenic mechanisms resulting in functional and/or structural changes in the coronary microcirculation and determining angina and myocardial ischemia in patients with angina without obstructive CAD ("primary" microvascular angina), as well as in several other conditions, including obstructive CAD, cardiomyopathies, Takotsubo syndrome and heart failure, especially the phenotype with preserved ejection fraction. The pathogenesis of CMD is complex and involves the combination of functional and structural alterations leading to impaired coronary blood flow and resulting in myocardial ischemia. In the absence of therapies specifically targeting CMD, attention has been focused on the role of modifiable risk factors. Here, we provide updated evidence regarding the pathophysiological mechanisms underlying CMD, with a particular focus on the role of cardiovascular risk factors and comorbidities. Moreover, we discuss the specific pathogenic mechanisms of CMD across the different cardiovascular diseases, aiming to pave the way for further research and the development of novel strategies for a precision medicine approach.

Coronary Microvascular Dysfunction Across the Spectrum of Cardiovascular Diseases: JACC State-of-the-Art Review

Coronary microvascular dysfunction (CMD) encompasses several pathogenetic mechanisms involving coronary microcirculation and plays a major role in determining myocardial ischemia in patients with angina without obstructive coronary artery disease, as well as in several other conditions, including obstructive coronary artery disease, nonischemic cardiomyopathies, takotsubo syndrome, and heart failure, especially the phenotype associated with preserved ejection fraction. Unfortunately, despite the identified pathophysiological and prognostic role of CMD in several conditions, to date, there is no specific treatment for CMD. Due to the emerging role of CMD as common denominator in different clinical phenotypes, additional research in this area is warranted to provide personalized treatments in this "garden variety" of patients. The purpose of this review is to describe the pathophysiological mechanisms of CMD and its mechanistic and prognostic role across different cardiovascular diseases. We will also discuss diagnostic modalities and the potential therapeutic strategies resulting from recent clinical studies.

Redefining residual inflammatory risk after acute coronary syndrome

Over the last decades, inflammation proved to play a pivotal role in atherosclerotic plaque formation, progression and destabilization. Several studies showed that the patients presenting with acute coronary syndrome are at increased risk of adverse cardiovascular events at both short- and long-term follow-up. Results from different clinical trials highlighted that a residual inflammatory risk exist and targeting inflammation is a successful strategy in selected cases associated to an increased inflammatory burden. Recently, the optimization of intracoronary and multimodality imaging allowed to also assess the entity of local inflammation, thus encouraging the individuation of plaque characteristics that portend a higher risk of future cardiovascular events. In this short review, we aim to highlight the role of systemic and local inflammation in acute coronary syndromes, to provide a summarized overview of the possible medical strategies applicable in selected cases and to underline the diagnostic and prognostic potential of multimodality imaging.

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.

Left ventricular end-diastolic pressure predicts in-hospital outcomes in takotsubo syndrome

AIMS

Takotsubo syndrome (TTS) is associated to serious adverse in-hospital complications. We evaluated the role of invasively assessed left ventricular end-diastolic pressure (LVEDP) for predicting in-hospital complications in TTS patients compared to the most widely used echocardiographic parameters of ventricular function.

METHODS AND RESULTS 

We prospectively enrolled 130 patients (mean age 71.2 ± 11.3 years, 114 [87.7%] female) with TTS. Invasive measurement of LVEDP was performed at the time of cardiac catheterization. The rate of in-hospital complications (composite of acute heart failure, life-threatening arrhythmias and all-cause death) was examined. In-hospital complications occurred in 37 (28.5%) patients. Patients who experienced in-hospital complications had a higher prevalence of neurological trigger and lower prevalence of emotional trigger, higher LVEDP and mean E/e' ratio and lower LV ejection fraction (LVEF) values compared to those who did not experience in-hospital complications. At multivariate logistic regression, higher LVEDP [odds ratio (OR) 1.12, 95% confidence interval (CI) [1.05-1.20], P < 0.001] and lower LVEF (OR 0.95, 95% CI [0.91-0.99], P = 0.011) remained independently predictors of in-hospital complications, while emotional trigger was associated to a lower risk (OR 0.24, 95% CI [0.06-0.96], P = 0.044). The area under the curve (AUC) for LEVDP in the prediction of in-hospital events was 0.776 (95% CI [0.69-0.86], P <0.001, with a sensitivity and specificity of 95% and 58% using a LVEDP cut-off value of 22.5 mmHg). The AUC was significantly higher for LVEDP than for E/e' ratio (P = 0.037).

CONCLUSIONS 

LVEDP measured at the time of catheterization may help in identifying TTS patients at higher risk of cardiovascular deterioration with relevant therapeutic implications.

Alternate recurrent coronary artery spasm and stress cardiomyopathy: a case report

Background

Coronary artery spasm (CAS) and stress cardiomyopathy (SC) have different characteristic clinical manifestations in the case of suspicious myocardial infarction with nonobstructive coronary arteries. Established recurrence rates of both conditions have been reported, however, alternate recurrent CAS and SC in the same individual have not been described.

Case presentation

A 59-year-old man suffered from atypical chest pain in the first episode, acute heart attack in the second and third episodes (totally 3 times over a period of approximately 5 years). During the first episode, he visited our hospital with mild paroxysmal chest pain without obvious inducement for approximately 2 years. He was underdiagnosed at that time without other obvious findings except the poor R wave progression in V1–3 leads revealed in electrocardiogram. At 4 months after the first episode, he suffered from a heart attack (the second episode) and was diagnosed with SC based on the coronary angiography (CAG) and left ventriculography findings of nonobstructive coronary arteries combined with a classic apical ballooning shape. At 31 months after the second episode, he suffered another heart attack (the third episode) and was diagnosed with CAS based on the CAG results of recoverable severe multivessel stenoses. During the episodes, partial reversible nature of apical hypokinesis was observed in echocardiogram. In retrospect, the patient suffered silent CAS in the first episode, SC in the second episode, and severe multivessel CAS in the third episode.

Conclusion

The unusual presentations observed in this case have not been reported. This case suggests that cardiologists should be aware of the possibility of alternate recurrent CAS and SC in the same individual. Provocative tests for spasm and cardiac magnetic resonance imaging might help gain more insights into this issue.