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.

Early recurrence of attack after myocardial infarction with non-obstructive coronary arteries: a case report

Background

Diagnostic strategies depend on non-standardized workup, and the causes of myocardial infarction with non-obstructive coronary arteries remain unclear for some patients. Intracoronary imaging is recommended for detecting the missed causes by coronary angiography. Myocardial infarction with non-obstructive coronary arteries is a heterogeneous entity; a meta-analysis of myocardial infarction with non-obstructive coronary artery studies demonstrated that all-cause mortality rate at 1 year is 4.7%, and its prognosis is not so favourable.

Case summary

A 62-year-old man without remarkable medical history complained of acute chest pain at rest, which resolved at his arrival. Although echocardiography and electrocardiogram exhibited normal findings, the concentration of high-sensitive cardiac troponin T increased up to 0.384 from 0.04 ng/mL. Coronary angiography was performed, and mild stenosis of the proximal right coronary artery was detected. He was discharged without catheter intervention and medications as he reported no symptoms. He returned 8 days later because of inferoposterior ST-segment elevation myocardial infarction with ventricular fibrillation. Emergent coronary angiography showed that the mild stenosis of the proximal right coronary artery had progressed to total occlusion. Optical coherence tomography after thrombectomy revealed rupture of the thin-cap fibroatheroma and protruding thrombus.

Discussion

Patients presenting with myocardial infarction with non-obstructive coronary arteries and plaque disruption and/or thrombus detected by optical coherence tomography do not show normal coronaries on coronary angiography. Aggressive investigation into plaque disruption using intracoronary imaging is recommended even if coronary angiography demonstrates mild stenosis to prevent a fatal attack for suspicious cases of myocardial infarction with non-obstructive coronary arteries.

Evaluations of coronary microvascular dysfunction in a patient with thrombotic microangiopathy and cardiac troponin elevation: a case report

Background

Thrombotic microangiopathy (TMA) syndromes include thrombotic thrombocytopenic purpura (TTP) and haemolytic uremic syndrome, and contribute to myocardial infarction and multiple organ failure. Although coronary microvascular dysfunction (CMD) is the key for understanding the pathophysiology of cardiac involvement in TMA, there is limited knowledge on the recovery from CMD in patients with TMA.

Case summary

An 80-year-old woman was brought to the emergency department due to worsening back pain, dyspnoea on exertion, jaundice, and fever. Although she had typical TTP symptoms and elevated cardiac troponin level, ADAMTS13 activity was preserved (34%), leading to the diagnosis of TMA with myocardial infarction. She underwent plasma exchange and was administered aspirin and prednisolone. Magnetic resonance imaging revealed iliopsoas abscess, which is a possible aetiologic factor of sepsis-related TTP. She had impaired coronary flow reserve (CFR) with angiographically non-obstructive epicardial coronary arteries. Improved CFR was observed on follow-up, suggesting existence of transient CMD caused by TMA. After treatment of the iliopsoas abscess with antibiotics for 3 months, she was discharged without any adverse complications.

Discussion

Coronary microvascular dysfunction is an underlying mechanism of myocardial infarction, with or without epicardial obstructive coronary artery stenosis. TMA is characterized by pathological lesions caused by endothelial cell damage in small terminal arteries and capillaries, with complete or partial occlusion caused by platelet and hyaline thrombi. CMD and its recovery are keys for understanding the natural history of cardiac involvement in TMA. In vivo evaluations of CMD can provide mechanistic insights into the cardiac involvement in TMA.

Association of stress hyperglycemia ratio and poor long-term prognosis in patients with myocardial infarction with non-obstructive coronary arteries

BACKGROUND

Stress hyperglycemia ratio (SHR) is a novel biomarker of true acute hyperglycemia condition and is associated with a worse prognosis in patients with myocardial infarction (MI). However, the effects of SHR in the setting of MI with non-obstructive coronary arteries (MINOCA) have not been investigated. This study aimed to explore the association between SHR and long-term clinical outcomes among MINOCA patients.

METHODS

A total of 410 MINOCA patients were included in the final analysis of this study. The patients were divided into three groups based on the SHR tertiles: [SHR1 group (SHR ≤ 0.73), (n = 143); SHR2 group (SHR 0.73-0.84), n = 131; and SHR3 group (SHR ≥ 0.84), n = 136]. Follow-up for major adverse cardiovascular events (MACE) was conducted on all patients. Cox regression and Kaplan-Meier curve analysis were used to evaluate the relationship between SHR and MACE. The receiver operating curve (ROC) analysis was applied to obtain the optimal cut-off value of SHR for predicting clinical MACE.

RESULTS

A total of 92 patients developed MACE during the mean 34 months of follow-up. A significant increase in MACE was observed in the SHR3 group compared to the SHR1 and SHR2 groups (35.3% vs. 15.4% and 16.8%, respectively; P < 0.001). The Kaplan-Meier curves demonstrate that SHR3 patients had the highest MACE risk compared to SHR1 and SHR2 patients (log-rank P < 0.001). In addition, when both SHR tertiles and diabetes status were considered, those with SHR3 and diabetes had the highest hazard of MACE (log-rank P < 0.001). Multivariate Cox regression analysis showed that the SHR3 is associated with a 2.465-fold increase in the risk of MACE (adjusted HR, 2.465; 95% CI 1.461-4.159, P = 0.001). The ROC curve analysis showed that the optimal SHR cut-off value for predicting clinical MACE among MINOCA was 0.86.

CONCLUSION

Our data indicates, for the first time, that SHR is independently associated with poor long-term prognosis in patients suffering from MINOCA. The optimal SHR cut-off value for predicting clinical MACE among MINOCA patients was 0.86. These findings suggest that SHR may play a potential role in the cardiovascular risk stratification of the MINOCA population.

Is Takotsubo cardiomyopathy still looking for its own nosological identity?

Despite several efforts to provide a proper nosological framework for Takotsubo cardiomyopathy (TCM), this remains an unresolved matter in clinical practice. Several clinical, pathophysiologic and histologic findings support the conceivable hypothesis that TCM could be defined as a unique pathologic entity, rather than a distinct subset of myocardial infarction with non-obstructive coronary arteries. Further investigations are needed in order to define TCM with the most appropriate disease taxonomy.

Myocardial bridging is significantly associated to myocardial infarction with non-obstructive coronary arteries

BACKGROUND

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a common disorder characterized by the presence of clinical criteria for acute myocardial infarction in the absence of obstructive coronary artery disease on angiography. We aim to investigate the relationship between myocardial bridging (MB) and MINOCA.

METHODS AND RESULTS

An observational retrospective study was conducted on 15 036 patients who had been referred for coronary angiography and who fulfilled the Fourth Universal Definition of Myocardial Infarction. The study population was divided into ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients, from which we defined two main groups: the MINOCA group and the coronary artery disease (CAD) group. Statistical analyses were carried out by using SPSS, version 20. The prevalence of angiographic MB among the groups was significantly greater in the MINOCA group (2.9% vs. 0.8%). MINOCA accounted for 14.5% of spontaneous myocardial infarction, and the clinical presentation was more frequently NSTEMI rather than STEMI (84.3% vs. 15.7%). After adjusting for confounders, multivariate analyses showed a positive association between MB and MINOCA [odds ratio = 3.28, 95% CI (2.34; 4.61) P < 0.001]. Cardiovascular risk factors were less common in the MINOCA population, which was younger and more often female.

CONCLUSION

MB is a risk factor for MINOCA. Because MB prevalence differed significantly between the controls (CAD group) and cases (MINOCA group), which were positively associated to MB, it seems likely that MB would be a potential cause of MINOCA. Investigations for MB in MINOCA cases and especially in NSTEMI patients seem necessary.

Presentation and outcome of myocardial infarction with non-obstructive coronary arteries in coronavirus disease 2019

Among the cardiac complications of coronavirus disease 2019 (COVID-19), one increasingly reported in the literature is myocardial infarction with non-obstructive coronaries (MINOCA). We reviewed all reported cases of MINOCA in COVID-19 patients to summarize its clinical features, evaluation, and treatment. We performed a literature search in Pubmed using the search terms ‘COVID-19’ and ‘MINOCA’ or ‘non-obstructive coronaries’. Among the reported cases, the mean age was 61.5 years (SD ± 13.4), and 50% were men. Chest pain was the presenting symptom in five patients (62.5%), and hypertension was the most common comorbidity (62.5%). ST-elevation was seen in most patients (87.5%), and the overall mortality rate was 37.5%. MINOCA in COVID-19 is an entity with a broad differential diagnosis. Therefore, a uniform algorithm is needed in its evaluation to ensure timely diagnosis and management.

MINOCA-induced apical ballooning case report: a diagnostic conundrum

Background 

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a recently described phenomenon where no flow-limiting lesions are noted on coronary angiography in a patient with electrocardiogram changes, elevated cardiac biomarkers, and symptoms suggesting acute myocardial infarction. Patients with MINOCA can also potentially develop structural cardiac defects through ischaemic injury. Therefore, the absence of a flow-limiting lesion on angiography coupled with structural defects (e.g. apical ballooning) can very easily result in a diagnosis of Takotsubo cardiomyopathy (TTC). This can lead to potentially serious consequences since treatment options between TTC and MINOCA are different.

Case summary 

We report a case of a patient presenting with features suggestive of TTC but where the final diagnosis was of a MINOCA that induced an apical ventricular septal defect (VSD). Reaching the correct diagnosis proved challenging given that there is no gold standard diagnostic modality for diagnosing MINOCA.

Conclusion 

Imaging adjuncts played a vital role in both diagnosing the underlying MINOCA as well as revealing and planning closure of the resultant VSD. Cardiovascular magnetic resonance imaging played an instrumental role in establishing the patient's primary pathology and in planning a remediation of the structural defect. Structural myocardial defects in a patient with a diagnosis of TTC should prompt clinicians to further investigate whether there is an underlying infarct aetiology (MINOCA).

Myocardial infarction with non-obstructive coronary arteries (MINOCA): Intracoronary imaging-based diagnosis and management

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is defined by clinical evidence of myocardial infarction (MI) with normal or near-normal coronary arteries on angiography. This condition is present in about 5% to 25% of patients presenting with acute coronary syndromes. MINOCA is a working diagnosis. Current guidelines and consensus recommend identification of underlying causes of MINOCA in order to optimize treatment, improve prognosis, and promote prevention of recurrent myocardial infarction. An accurate evaluation of patient history, symptoms and use of invasive and non-invasive imaging should lead to identification of epicardial or microvascular causes of MINOCA and differentiation from non-ischemic myocardial injury due to both cardiac (e.g. myocarditis) and non-cardiac disease (e.g. pulmonary embolism). In this review, we highlight the role of coronary imaging in differential diagnosis of patients presenting with MINOCA. Intravascular ultrasound and optical coherence tomography are well known technologies used in different settings from acute to chronic coronary syndromes. In MINOCA patients, coronary imaging could help to identify pathological alterations of the epicardial vessels that are not visible by coronary angiography such as plaque disruption, coronary dissection, coronary thromboembolism, coronary spasm, and coronary artery disease in patients presenting with takotsubo syndrome. In future, the widespread use of these technologies, in the right clinical context, could lead to optimization and personalization of treatment, and to better prognosis of patients presenting with MINOCA.

Recognition of acute myocardial infarction caused by spontaneous coronary artery dissection of first septal perforator

AIMS 

Spontaneous coronary artery dissection (SCAD) diagnosis is challenging as angiographic findings are often subtle and differ from coronary atherosclerosis. Herein, we describe characteristics of patients with acute myocardial infarction (MI) caused by first septal perforator (S1) SCAD.

METHODS AND RESULTS 

Patients were gathered from SCAD registries at Minneapolis Heart Institute and Vancouver General Hospital. First septal perforator SCAD prevalence was 11 of 1490 (0.7%). Among 11 patients, age range was 38-64 years, 9 (82%) were female. Each presented with acute chest pain, troponin elevation, and non-ST-elevation MI diagnosis. Initial electrocardiogram demonstrated ischaemia in 5 (45%); septal wall motion abnormality was present in 4 (36%). Angiographic type 2 SCAD was present in 7 (64%) patients with S1 TIMI 3 flow in 7 (64%) and TIMI 0 flow in 2 (18%). Initial angiographic interpretation failed to recognize S1-SCAD in 6 (55%) patients (no culprit, n = 5, septal embolism, n = 1). First septal perforator SCAD diagnosis was established by review of initial coronary angiogram consequent to cardiovascular magnetic resonance (CMR) demonstrating focal septal late gadolinium enhancement with corresponding oedema (n = 3), occurrence of subsequent SCAD event (n = 2), or second angiogram showing healed S1-SCAD (n = 1). Patients were treated conservatively, each with ejection fraction >50%.

CONCLUSION 

First septal perforator SCAD events may be overlooked at initial angiography and mis-diagnosed as 'no culprit' MI. First septal perforator SCAD prevalence is likely greater than reported herein and dependent on local expertise and availability of CMR imaging. Spontaneous coronary artery dissection events may occur in intra-myocardial coronary arteries, approaching the resolution limits of invasive coronary angiography.

Myocardial Infarction Caused by an Enclosed Thrombus in a Patent Foramen Ovale

Paradoxical embolism in coronary artery is a rarely diagnosed clinical entity. In the majority of reported cases; the diagnostic of this pathology is « presumptive » based on certain criteria. It can be considered "proven" when the embolus is found lodged in the abnormal communication between the venous and arterial circulation; which is very rare. We herein report a case of myocardial infarction caused by a proven paradoxical coronary embolism through a patent foramen ovale. The authors highlight through this paper the contribution of echocardiography and particularly trans-esophageal echocardiography, especially if performed soon after presentation, for early diagnosis.

Myocardial infarction with non-obstructive coronary arteries as compared with myocardial infarction and obstructive coronary disease: outcomes in a Medicare population

AIMS

The prognosis of patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) is poorly understood. We examined major adverse cardiac events (MACE) defined as all-cause mortality, re-hospitalization for acute myocardial infarction (AMI), heart failure (HF), or stroke 12-months post-AMI in patients with MINOCA versus AMI patients with obstructive coronary artery disease (MICAD).

METHODS AND RESULTS

Multicentre, observational cohort study of patients with AMI (≥65 years) from the National Cardiovascular Data Registry CathPCI Registry (July 2009-December 2013) who underwent coronary angiography with linkage to the Centers for Medicare and Medicaid (CMS) claims data. Patients were classified as MICAD or MINOCA by the presence or absence of an epicardial vessel with ≥50% stenosis. The primary endpoint was MACE at 12 months, and secondary endpoints included the components of MACE over 12 months. Among 286 780 AMI admissions (276 522 unique patients), 16 849 (5.9%) had MINOCA. The 12-month rates of MACE (18.7% vs. 27.6%), mortality (12.3% vs. 16.7%), and re-hospitalization for AMI (1.3% vs. 6.1%) and HF (5.9% vs. 9.3%) were significantly lower for MINOCA vs. MICAD patients (P < 0.001), but was similar between MINOCA and MICAD patients for re-hospitalization for stroke (1.6% vs. 1.4%, P = 0.128). Following risk-adjustment, MINOCA patients had a 43% lower risk of MACE over 12 months (hazard ratio = 0.57, 95% confidence interval 0.55-0.59), in comparison to MICAD patients. This pattern was similar for adjusted risks of the MACE components.

CONCLUSION

This study confirms an unfavourable prognosis in elderly patients with MINOCA undergoing coronary angiography, with one in five patients with MINOCA suffering a major adverse event over 12 months.

Myocardial infarction with non-obstructive coronary arteries: A comprehensive review and future research directions

Acute coronary syndromes constitute a variety of myocardial injury presentations that include a subset of patients presenting with myocardial infarction with non-obstructive coronary arteries (MINOCA). This acute coronary syndrome differs from type 1 myocardial infarction (MI) regarding patient characteristics, presentation, physiopathology, management, treatment, and prognosis. Two-thirds of MINOCA subjects present ST-segment elevation; MINOCA patients are younger, are more often female and tend to have fewer cardiovascular risk factors. Moreover, MINOCA is a working diagnosis, and defining the aetiologic mechanism is relevant because it affects patient care and prognosis. In the absence of relevant coronary artery disease, myocardial ischaemia might be triggered by an acute event in epicardial coronary arteries, coronary microcirculation, or both. Epicardial causes of MINOCA include coronary plaque disruption, coronary dissection, and coronary spasm. Microvascular MINOCA mechanisms involve microvascular coronary spasm, takotsubo syndrome (TTS), myocarditis, and coronary thromboembolism. Coronary angiography with non-significant coronary stenosis and left ventriculography are first-line tests in the differential study of MINOCA patients. The diagnostic arsenal includes invasive and non-invasive techniques. Medical history and echocardiography can help indicate vasospasm or thrombosis, if one finite coronary territory is affected, or specify TTS if apical ballooning is present. Intravascular ultrasound, optical coherence tomography, and provocative testing are encouraged. Cardiac magnetic resonance is a cornerstone in myocarditis diagnosis. MINOCA is not a benign diagnosis, and its polymorphic forms differ in prognosis. MINOCA care varies across centres, and future multi-centre clinical trials with standardized criteria may have a positive impact on defining optimal cardiovascular care for MINOCA patients.

An atypical cause of myocardial infarction: case report of an obstructing papillary fibroelastoma of the aortic valve

BACKGROUND

Papillary fibroelastomas are rare primary cardiac tumours with a prevalence of 0.01% at autopsy. They are histologically benign tumours but have been demonstrated through case series to confer an increased risk of thrombo-embolism resulting in: transient ischaemic attack, stroke, myocardial infarction, and pulmonary and systemic embolization.

CASE SUMMARY

A 54-year-old woman presented with central chest pain radiating to her left arm. At presentation there was a significant troponin rise; initial high-sensitivity troponin-I (hsTn-I) 660 pg/mL increased to 3340 pg/mL at 6 h. Coronary angiogram did not reveal any obstructing coronary artery disease. Echocardiography revealed a rounded, mobile mass on the left coronary cusp of the aortic valve suspicious for papillary fibroelastoma. The patient underwent shave excision of the lesion. Intra-operatively it was noted that the mass intermittently sat within the ostium of the left main resulting in its occlusion. Histology confirmed a papillary fibroelastoma.

DISCUSSION

Primary cardiac tumours are rare but can cause life-threatening complications such as stroke, myocardial infarction, and cardiac arrest. In the literature, the mechanism of these complications is mainly attributed to thrombo-embolism. This case demonstrates the utility of echocardiogram in investigating and diagnosing a rare cause of myocardial infarction and highlights an unusual mechanism, that is tumour causing obstruction of the coronary ostium.

Prevalence of Anxiety and Depression Symptoms in Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries

BACKGROUND

Myocardial infarction with non-obstructive coronary arteries is a working diagnosis for several heart disorders. Previous studies on anxiety and depression in patients with myocardial infarction with non-obstructive coronary arteries are lacking. Our aim was to investigate the prevalence of anxiety and depression among patients with myocardial infarction with non-obstructive coronary arteries.

METHODS

We included 99 patients with myocardial infarction with non-obstructive coronary arteries together with age- and sex-matched control groups who completed the Beck Depression Inventory and the Hospital Anxiety and Depression Scale (HADS) 3 months after the acute event.

RESULTS

Using the Beck Depression Inventory, we found that the prevalence of depression in patients with myocardial infarction with non-obstructive coronary arteries (35%) was higher than in healthy controls (9%; P = .006) and similar to that of patients with coronary heart disease (30%; P = .954). Using the HADS anxiety subscale, we found that the prevalence of anxiety in patients with myocardial infarction with non-obstructive coronary arteries (27%) was higher than in healthy controls (9%; P = .002) and similar to that of patients with coronary heart disease (21%; P = .409). Using the HADS depression subscale, we found that the prevalence of depression in patients with myocardial infarction with non-obstructive coronary arteries (17%) was higher than in healthy controls (4%; P = .003) and similar to that of patients with coronary heart disease (13%; P = .466). Patients with myocardial infarction with non-obstructive coronary arteries and takotsubo syndrome scored higher on the HADS anxiety subscale than those without (P = .028).

CONCLUSIONS

This is the first study on the mental health of patients with myocardial infarction with non-obstructive coronary arteries to show that prevalence rates of anxiety and depression are similar to those in patients with coronary heart disease.

Predictors of adverse outcome in patients with myocardial infarction with non-obstructive coronary artery (MINOCA) disease

BACKGROUND

Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCAs) is an increasingly recognized entity. No previous study has evaluated predictors for new major adverse cardiacvascular events (MACEs) and death in patients with MINOCA.

METHODS

We conducted an observational study of MINOCA patients recorded between July 2003 and June 2013 and followed until December 2013 for outcome events. Out of 199,163 MI admissions, 9092 consecutive unique patients with MINOCA were identified. The mean age was 65.5 years and 62% were women. MACE was defined as all-cause mortality, rehospitalization for acute MI, ischemic stroke and heart failure. Hazard ratio and 95% confidence interval (HR; 95% CI) was calculated using Cox-regression.

RESULTS

A total of 2147 patients (24%) experienced a new MACE and 1254 patients (14%) died during the mean follow-up of 4.5 years. Independent predictors for MACE after adjustment, were older age (1.05; 1.04-1.06), diabetes (1.44; 1.21-1.70), hypertension (1.25; 1.09-1.43), current smoking (1.38; 1.15-1.66), previous myocardial infarction (1.38; 1.04-2.82), previous stroke (1.69; 1.35-2.11), peripheral vascular disease (1.55; 1.97-2.23), chronic obstructive pulmonary disease (1.63; 1.32-2.00), reduced left ventricular ejection fraction (2.00; 1.54-2.60), lower level of total cholesterol (0.88; 0.83-0.94) and higher level of creatinine (1.01; 1.00-1.03). Independent predictors for all cause death were age, current smoking, diabetes, cancer, chronic obstructive pulmonary disease, previous stroke, reduced left ventricular fraction, lower level of total cholesterol and higher levels of creatinine and CRP.

CONCLUSIONS

The clinical factors predicting new MACE and death of MINOCA patients seem to be strikingly similar to factors previously shown to predict new cardiovascular events in patients with MI and obstructive coronary artery disease.