Angina Frequency After Acute Myocardial Infarction In Patients Without Obstructive Coronary Artery Disease

The PROMISE of Precision Medicine in Myocardial Infarction with Non-Obstructive Coronary Arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a working diagnosis encompassing several pathophysiological mechanisms with specific treatments and different prognoses. Despite the absence of obstructive coronary artery disease, MINOCA has proven to be associated with a significant risk of mortality, angina burden, and socioeconomic costs. However, due to the heterogeneous nature of this clinical condition and the absence of randomized clinical trials, evidence supporting a standardized diagnostic algorithm and the clinical management of these patients is lacking. The PROMISE trial is the first randomized clinical trial evaluating the effectiveness of a precision medicine approach strategy in improving the outcomes and quality of life of patients with MINOCA, offering new insights into personalized treatment strategies. This review article discusses the promise of a precision medicine approach in patients with MINOCA, highlighting the potential innovations and challenges of a personalized medicine strategy in MINOCA.

Understanding Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA): a comprehensive meta-analysis of clinical characteristics, management, and prognosis compared to MI with the Obstructive Coronary Artery (MIOCA)

BACKGROUND

MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) represents a unique subset of acute coronary syndrome, distinct from MIOCA (Myocardial Infarction with Obstructive Coronary Arteries) and a control group. This study systematically compares their prevalence, clinical characteristics, management strategies, and outcomes to improve understanding and treatment approaches.

METHODS

This systematic review and meta-analysis followed PRISMA guidelines across multiple databases up to 2024. STATA 17 was used for statistical analyses, and the Newcastle-Ottawa Scale was employed to assess study quality.

RESULTS

One-hundred and twelve studies, including 5,908,768 patients, were analyzed. The pooled prevalence of MINOCA among patients undergoing coronary angiography was 8.92% (95% CI: 8.90-8.94). MINOCA patients were generally younger, predominantly female, and more likely to present with atypical chest pain and dyspnea compared to MIOCA patients. Laboratory findings showed higher levels of CRP, BNP, and fibrinogen in MINOCA patients, suggesting inflammation and microvascular dysfunction as key mechanisms. In contrast, MIOCA patients had higher rates of diabetes and dyslipidemia, highlighting differences in pathophysiological processes. Medication use differed between the groups, with MINOCA patients more likely to be prescribed anticoagulants and β-blockers. Prognostically, MINOCA patients experienced significantly lower rates of adverse short- and long-term outcomes, including major adverse cardiac events (MACE) and cardiovascular death, compared to MIOCA patients.

CONCLUSIONS

This study demonstrated that patients with MINOCA have a better prognosis compared to those with MIOCA and are at a lower risk of serious cardiac events. Based on the findings of this study, we emphasize that microcirculation and vascular spasm are the main mechanisms involved in MINOCA. Considering these findings, it is suggested that a better management strategy for MINOCA patients can be established by precisely defining diagnostic criteria and focusing on anti-inflammatory treatments and risk factor control.

Mental health status and quality-of-life after an acute myocardial infarction with non-obstructive coronary arteries or takotsubo syndrome: A systematic review

BACKGROUND

Myocardial infarction with non-obstructive coronary arteries (MINOCA) and takotsubo syndrome (TS) are both characterised by lack of significant coronary artery stenoses and a higher prevalence of mental health disorders preceding the event. Currently, little is known about their pathological aetiologies and subsequent treatment plans, giving cause for concern among those affected. The objective of this review is to provide a comprehensive overview of mental health status and quality of life (QoL) in MINOCA- and TS-patients after the acute event, compared to both cardiac and non-cardiac populations, and over time.

METHODS

A systematic search was conducted via Cochrane Library, CINAHL, PyschINFO, PubMed, ASSIA, Web of Science, Scopus and Embase from inception to May 2024. The review was registered in PROSPERO and methods, and results were reported in accordance with the PRISMA guidelines. Quality assessment and risk of bias were evaluated using the Newcastle-Ottawa Scale for cross-sectional and cohort studies.

RESULTS

Sample sizes ranged from 13 to 5,322 participants. The risk of bias was high in 18/28, medium in 7/28, and low in 3/28 studies. Across the symptoms assessed, MINOCA- and TS-patients reported worse mental health status or QoL than non-cardiac groups in 10/13 studies, and cardiac groups in 10/20 studies. Investigating change over time, 1/5 studies found deteriorating mental health status, 3/5 reported improved mental health status or QoL and 1/5 reported no change in MINOCA- and TS-patients.

CONCLUSIONS

Patients with MINOCA or TS seem to have worse mental health status and QoL after the acute event than non-cardiac individuals, but it is yet difficult to conclude whether mental distress and QoL are equal or worse compared to CHD-patients. There is no convincing evidence that mental health status or QoL of MINOCA- and TS- patients naturally improve over time after the acute event. Among the studies evaluated, risk of bias was high. More high-quality studies are needed, investigating mental health status and QoL among MINOCA- and TS-patients.

Unveiling the Longitudinal Journey: 3-Year Follow-up of Women with MINOCA and INOCA in a Specialized Heart Centre

Background

Myocardial infarction with no obstructive coronary arteries (MINOCA), and ischemia with no obstructive coronary arteries (INOCA), are female-predominant conditions; clinical trials are lacking to guide medical management for the common underlying vasomotor etiologies. Data on long-term outcomes of (M)INOCA patients following attendance at a women's heart centre (WHC) are lacking.

Methods

Women diagnosed with MINOCA (n = 51) or INOCA (n = 112) were prospectively followed for 3 years at the Leslie Diamond WHC (LDWHC) in Vancouver. Baseline characteristics, diagnoses, chest-pain type, major adverse cardiac events, hospital encounters, medications, and Seattle Angina Questionnaire (SAQ) responses were compared between the baseline and 3-year timepoints. The χ2 test was used to compare categorical variables; the Student t test was used for continuous variables.

Results

MINOCA patients had significantly more nonexertional chest pain and more diagnoses of vasospasm than did INOCA patients, who had more exertional chest pain and more diagnoses of coronary microvascular dysfunction. Following the baseline timepoint, both groups had significant reductions in cardiovascular emergency room visits, with INOCA patients also experiencing fewer cardiovascular hospitalizations. At 3 years, the most commonly prescribed medications were calcium-channel blockers, long-acting nitrates, and beta-blockers, with MINOCA patients having more acetylsalicylic acid use, and INOCA patients having more short-acting nitrate and ranolazine prescriptions. Both groups observed significant improvements in SAQ scores, with greater improvements observed in INOCA patients. Patients with depression or who were prescribed ranolazine at 3 years had worse SAQ scores at baseline.

Conclusions

The 3-year outcomes of (M)INOCA patients indicate that the LDWHC's comprehensive care model effectively improves diagnostic clarity, reduces the number of hospital encounters, optimizes medication management, and improves self-reported patient well-being.

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.

Prognostic Value of PRECİSE DAPT Score on Short- and Long-Term Outcomes in MINOCA Patients with Acute Coronary Syndrome

BACKGROUND

Myocardial infarction with non-obstructive coronary arteries (MINOCA) constitutes a significant subset of acute myocardial infarctions (AMI) with uncertain prognostic markers. Early risk assessment is crucial to identify MINOCA patients at risk of adverse outcomes.

OBJECTIVES

This study aimed to evaluate the predictive capacity of the PRECISE-DAPT score in assessing short- and long-term prognoses in MINOCA patients presenting with ST-segment elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (NSTEMI).

METHODS

Among 741 MINOCA patients, the PRECISE-DAPT score was computed to analyze its association with in-hospital and follow-up major adverse cardiovascular events (MACE). Parameters showing significance in MACE (+) groups underwent statistical analysis: univariate logistic regression for in-hospital events and univariate Cox regression for follow-up events. For statistical significance, a predefined level of α = 0.05 was adopted. Parameters demonstrating significance proceeded to multiple logistic regression for in-hospital events and multivariate Cox regression for follow-up events.

RESULTS

In-hospital MACE occurred in 4.1% of patients, while 58% experienced follow-up MACE. Hemoglobin levels and the PRECISE-DAPT Score were identified as independent parameters for in-hospital MACE. Furthermore, ejection fraction (EF%) and the PRECISE-DAPT Score emerged as independent predictors of follow-up MACE.

CONCLUSIONS

The study revealed that a higher PRECISE-DAPT score was significantly associated with increased risks of both in-hospital and long-term major adverse cardiovascular events in MINOCA patients presenting with acute coronary syndrome (ACS), underscoring the score's potential in risk stratification for this patient cohort.

BACKGROUND

_ PRECISE-DAPT score predicts MACE risk in MINOCA patients.

BACKGROUND

_ Hemoglobin level and PRECISE-DAPT score predict in-hospital MACE.

BACKGROUND

_ Ejection fraction and PRECISE-DAPT score predict long-term MACE.

Prevalence, Clinical Features, Treatment, and Outcomes in Patients With Myocardial Infarction With Non-Obstructive Coronary Arteries

AIM

To study clinical and demographic characteristics, treatment options, and clinical outcomes in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) compared with patients with myocardial infarction with obstructive coronary arteries (MIOCA).

MATERIAL AND METHODS

This single-center prospective observational study included 712 successive patients diagnosed with acute myocardial infarction (MI), who routinely underwent direct coronary angiography. Based on the presence of stenosing coronary atherosclerosis, the patients were divided into two groups: MIOCA (coronary stenosis ≥50%) and MINOCA (coronary stenosis <50% without other, alternative causes). Clinical outcomes included in-hospital and long-term overall mortality, and cardiovascular rehospitalization. The median follow-up was 1.5 years.

RESULTS

MINOCA was diagnosed in 73 (10.3%) patients, 37 (50%) of whom were women. The median age of patients with MINOCA was 61 years and in the MIOCA group 65 years. No significant differences in cardiovascular risk factors were found between patients with MINOCA and MIOCA. In 53.4% of cases, the cause of MINOCA was a discrepancy between the myocardial oxygen demand and supply, and in 35.6% of cases, the cause was hypertensive crisis and pulmonary edema. The factors associated with MINOCA included an age ≤58 years, female gender, absence of the ST-segment elevation, absence of areas of impaired local contractility, and presence of aortic stenosis and bronchopulmonary infection. Patients with MINOCA were less likely to be prescribed acetylsalicylic acid, P2Y12 inhibitors, dual antiplatelet therapy, beta-blockers, and statins (p<0.05). Data on long-term outcomes were available for 87.5% of patients (n=623). The prognosis of patients with MIOCA was comparable for in-hospital mortality (1.5% vs. 6.2%; p=0.161) and long-term overall mortality (6.1% vs. 14.7%; p=0.059). Cardiovascular rehospitalizations were more frequent in the MINOCA group (33.3% vs. 21.5%; p=0.042).

CONCLUSION

The prevalence of MINOCA in our study was 10.3% among all patients with acute MI. MINOCA patients had comparable generally recognized cardiovascular risk factors with MIOCA patients. MINOCA patients had a comparable prognosis for in-hospital and long-term mortality and more often required cardiovascular rehospitalization.

MI and Non-obstructive Coronary Arteries

MI and non-obstructive coronary arteries (MINOCA) is recognized as an important contributor to adverse cardiovascular outcomes in both men and women but is particularly prevalent in young women. Multiple coronary mechanisms such as coronary plaque disruption, coronary artery spasm, coronary microvascular dysfunction, spontaneous coronary artery dissection, and coronary thromboembolism can trigger MINOCA. Beyond routine left heart catheterization, invasive intracoronary imaging and cardiac MRI can help to clarify the cause of MINOCA. Conditions such as myocarditis, takotsubo syndrome, and cardiomyopathy are on the differential as alternate explanations in those suspected of MINOCA. Identification of the underlying cause in a case of MINOCA has therapeutic implications. While long-term management of MINOCA is not standardized, angiotensin converting enzyme inhibitors and statins appear to be of benefit. In this review, we discuss the prevalence and pathophysiology of MINOCA, diagnostic considerations, and current treatment approaches to manage this high-risk group of patients.

Transient Left Ventricular Dysfunction from Cardiomyopathies to Myocardial Viability: When and Why Cardiac Function Recovers

Transient left ventricular dysfunction (TLVD), a temporary condition marked by reversible impairment of ventricular function, remains an underdiagnosed yet significant contributor to morbidity and mortality in clinical practice. Unlike the well-explored atherosclerotic disease of the epicardial coronary arteries, the diverse etiologies of TLVD require greater attention for proper diagnosis and management. The spectrum of disorders associated with TLVD includes stress-induced cardiomyopathy, central nervous system injuries, histaminergic syndromes, various inflammatory diseases, pregnancy-related conditions, and genetically determined syndromes. Furthermore, myocardial infarction with non-obstructive coronary arteries (MINOCA) origins such as coronary artery spasm, coronary thromboembolism, and spontaneous coronary artery dissection (SCAD) may also manifest as TLVD, eventually showing recovery. This review highlights the range of ischemic and non-ischemic clinical situations that lead to TLVD, gathering conditions like Tako-Tsubo Syndrome (TTS), Kounis syndrome (KS), Myocarditis, Peripartum Cardiomyopathy (PPCM), and Tachycardia-induced cardiomyopathy (TIC). Differentiation amongst these causes is crucial, as they involve distinct clinical, instrumental, and genetic predictors that bode different outcomes and recovery potential for left ventricular function. The purpose of this review is to improve everyday clinical approaches to treating these diseases by providing an extensive survey of conditions linked with TLVD and the elements impacting prognosis and outcomes.

Sex differences in patients presenting with acute coronary syndrome: a state-of-the-art review

Cardiovascular conditions in the spectrum of acute coronary syndromes are characterized by sex differences with regard to pathophysiology, risk factors, clinical presentation, invasive and pharmacologic treatment, and outcomes. This review delves into these differences, including specific subsets like myocardial infarction with non-obstructed coronary arteries or Spontaneous Coronary Artery Dissection, and alternative diagnoses like Takotsubo cardiomyopathy or myocarditis. Moreover, practical considerations are enclosed, on how a sex-specific approach should be integrated in clinical practice: in fact, personal history should focus on female-specific risk factors, and hormonal status and hormonal therapy should be assessed. Moreover, physical and psychological stressors should be investigated, particularly in the event of Spontaneous Coronary Artery Dissection or Takotsubo cardiomyopathy.

Sex-specific and ethnicity-specific differences in MINOCA

Suspected myocardial infarction with non-obstructive coronary arteries (MINOCA) has received increasing attention over the past decade. Given the heterogeneity in the mechanisms underlying acute myocardial infarction in the absence of obstructive coronary arteries, the syndrome of MINOCA is considered a working diagnosis that requires further investigation after diagnostic angiography studies have been performed, including coronary magnetic resonance angiography and functional angiography. Although once considered an infrequent and low-risk form of myocardial infarction, recent data have shown that the prognosis of MINOCA is not as benign as previously assumed. However, despite increasing awareness of the condition, many questions remain regarding the diagnosis, risk stratification and treatment of MINOCA. Women seem to be more susceptible to MINOCA, but studies on the sex-specific differences of the disease are scarce. Similarly, ethnicity-specific factors might explain discrepancies in the observed prevalence or underlying pathophysiological mechanisms of MINOCA but data are also scarce. Therefore, in this Review, we provide an update on the latest evidence available on the sex-specific and ethnicity-specific differences in the clinical features, pathophysiological mechanisms, treatment and prognosis of MINOCA.

Coronary microvascular dysfunction and myocardial infarction with non-obstructive coronary arteries: Where do we stand?

In the past decade, scientific and clinical research has provided a translational perspective on myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA). MINOCA is characterized by clinical documentation of an acute MI but angiography shows no significant coronary artery obstruction (stenosis <50%). The prevalence of MINOCA is estimated to range from approximately 6 to 10% among MI patients, and those with this condition have a poor prognosis, experiencing high rates of mortality, rehospitalization, and socioeconomic burden. MINOCA represents a major unmet need in cardiovascular medicine, with uncertain clinical management. It is a complex condition that can be caused by various factors, including atherosclerosis, plaque rupture, coronary vasospasm, and microvascular dysfunction. Effective management of MINOCA depends on identifying the underlying mechanism of the infarction, thus a systematic diagnostic approach is recommended. Contemporary data shows that a significant number of patients exhibit structural and functional abnormalities in coronary microcirculation, which is referred to as coronary microvascular dysfunction (CMD). CMD plays a crucial role in patients with signs and symptoms of myocardial ischemia and non-obstructive coronary artery stenosis, including MINOCA. Furthermore, conducting a thorough evaluation of coronary function can have significant prognostic and therapeutic implications, since personalized patient management strategies based on this assessment have been shown to improve symptoms and prognosis. Therefore, an accurate and timely diagnosis of CMD is essential for effective patient management, which can be achieved through various invasive and non-invasive methods. This review will discuss the pathophysiological understanding, current diagnostic techniques, and management strategies of patients with MINOCA and CMD.

Diagnostic Puzzles and Cause-Targeted Treatment Strategies in Myocardial Infarction with Non-Obstructive Coronary Arteries: An Updated Review

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a distinct subtype of myocardial infarction (MI), occurring in about 8-10% of spontaneous MI cases referred for coronary angiography. Unlike MI with obstructive coronary artery disease, MINOCA's pathogenesis is more intricate and heterogeneous, involving mechanisms such as coronary thromboembolism, coronary vasospasm, microvascular dysfunction, dissection, or plaque rupture. Diagnosing MINOCA presents challenges and includes invasive and non-invasive strategies aiming to differentiate it from alternative diagnoses and confirm the criteria of elevated cardiac biomarkers, non-obstructive coronary arteries, and the absence of alternate explanations for the acute presentation. Tailored management strategies for MINOCA hinge on identifying the underlying cause of the infarction, necessitating systematic diagnostic approaches. Furthermore, determining the optimal post-MINOCA medication regimen remains uncertain. This review aims to comprehensively address the current state of knowledge, encompassing diagnostic and therapeutic approaches, in the context of MINOCA while also highlighting the evolving landscape and future directions for advancing our understanding and management of this intricate myocardial infarction subtype.

Health-related quality-of-life up to one year after myocardial infarction with non-obstructive coronary arteries

AIMS

Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) are a heterogenous group and previous studies indicate a decreased Health-related quality-of-life (HRQoL) compared with patients with myocardial infarction with obstructive coronary artery disease and healthy individuals. However, longitudinal data are scarce. Therefore, the aim was to explore HRQoL among patients with MINOCA during a one-year period after the acute event in comparison with a group of healthy individuals and to describe HRQoL in patients with Takotsubo Syndrome (TTS).

METHODS AND RESULTS

Patients with MINOCA were recruited from five hospitals in the Stockholm region (SMINC-2 study, clinical trials: NCT2318498). Patients responded to the HRQoL questionnaire RAND-36 between days 2-4, after 6 and 12 months respectively. A sample of population-based individuals was used as a comparison group. A total of 142 MINOCA patients, (70% women) mean age of 56 years, responded. A population-based sample of 317 volunteers (66% women) mean age of 57 years. Patients with MINOCA scored lower than the comparison group in the domains role functioning physical, social functioning, and role functioning emotional (P = 0.01-0.02) at 12 months. In these domains of HRQoL there was no improvement in MINOCA patients during 12 months follow-up. In the domains of energy/fatigue vitality and emotional well-being the scores improved and were similar to the comparison group at 12 months. Patients with TTS scored generally lower on RAND-36 than MINOCA patients without TTS.

CONCLUSION

Physical, social, and emotional functioning did not improve during the first year after MINOCA, indicating a need for increased follow-up including psychological support.

Atrial and ventricular arrhythmia predictors with electrocardiographic parameters in myocardial infarction with non-obstructive coronary artery disease (MINOCA)

BACKGROUND

The clinical importance and recognition of myocardial infarction with non-obstructive coronary artery disease (MINOCA) is increasing. Nevertheless, no studies are investigating the risk of atrial fibrillation and ventricular arrhythmia in MINOCA patients. This study aimed to determine the risk of arrhythmia with electrocardiographic predictors in MINOCA patients.

METHODS

In this study, patients diagnosed with MINOCA and stable out-patients without significant lesions in their coronary arteries were compared. Morphology-voltage-Pwave duration electrocardiography (MPV ECG) score was used to determine atrial arrhythmia risk. QT interval and QT dispersion Tpeak-Tend time and Tpeak-Tend/QT interval were used to determine ventricular arrhythmia risk.

RESULTS

A total of 155 patients were included in our study. Seventy-seven of these patients were in the MINOCA group. There was no statistically significant difference between the two groups in MPV ECG score (1.95 ± 1.03 vs 1.68 ± 1.14, p = 0.128). P-wave voltage, P-wave morphology and P-wave duration, which are components of the MPV ECG score, were not statistically significantly different. The QRS complex duration (90.21 ± 14.87 vs 82.99 ± 21.59 ms, p = 0.017), ST interval (271.95 ± 45.91 vs 302.31 ± 38.40 ms, p < 0.001), corrected QT interval (438.17 ± 43.80 vs 421.41 ± 28.39, p = 0.005) and QT dispersion (60.75 ± 22.77 vs 34.19 ± 12.95, p < 0.001) were statistically significantly higher in the MINOCA group. The Tpeak-Tend (89.53 ± 32.16 vs 65.22 ± 18.11, p < 0.001), Tpeak-Tend/QT interval (0.2306 ± 0.0813 vs 0.1676 ± 0.0470, p < 0.001) and Tpeak-Tend/corrected QT interval (0.2043 ± 0.6997 vs 0.1551 ± 0.4310, p < 0.001) ratios were also significantly higher in patients with MINOCA.

CONCLUSIONS

In the MINOCA patients, there was no increase in the risk of atrial fibrillation based on ECG predictors. However, it was shown that there could be a significant increase in the risk of ventricular arrhythmia. We believe this study could be helpful for specific recommendations concerning duration of hospitalisation and follow up in MINOCA patients.

Do Chest Pain Characteristics in Patients with Acute Myocardial Infarction Differ between Those with and without Obstructive Coronary Artery Disease?

The universal definition of acute myocardial infarction (MI) requires both evidence of myocardial injury and myocardial ischaemia. In MINOCA (MI with non-obstructive coronary arteries), patients must fulfil this MI criteria, but is their chest pain similar to those who have MI with obstructive CAD (MICAD)? This study compares prospectively collected chest pain features between patients with MINOCA and MICAD. Utilising the Coronary Angiogram Database of South Australia (CADOSA), consecutive MI patients were categorized as MINOCA or MICAD based on angiographic findings. Chest pain data were collected via direct patient interviews by trained staff members. Of 6811 consecutive patients fulfilling a clinical MI diagnosis, 411 (6.0%) were MINOCA, and 5948 MICAD. The MINOCA patients were younger, more often female and had less cardiovascular risk factors than those with MICAD. There were no significant differences in chest pain characteristics between the MINOCA and MICAD cohorts in relation to pain location, quality, associated symptoms, or duration. In conclusion, MINOCA patients have chest pain characteristics that are indistinguishable from MICAD patients, suggesting that their pain is ischaemic in nature. Thus, in the presence of positive myocardial injury markers, ischaemic chest pain fulfils the universal criteria for MI, despite the absence of obstructive coronary artery disease.

MINOCA and INOCA: Role in Heart Failure

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

MINOCA Associated with a Myocardial Bridge: Pathogenesis, Diagnosis and Treatment

Myocardial bridging (MB) is the most frequent congenital coronary anomaly characterized by a segment of an epicardial coronary artery that passes through the myocardium. MB is an important cause of myocardial ischemia and is also emerging as a possible cause of myocardial infarction with non-obstructed coronary arteries (MINOCA). There are multiple mechanisms underlying MINOCA in patients with MB (i.e., MB-mediated increased risk of epicardial or microvascular coronary spasm, atherosclerotic plaque disruption and spontaneous coronary artery dissection). The identification of the exact pathogenetic mechanism is crucial in order to establish a patient-tailored therapy. This review provides the most up-to-date evidence regarding the pathophysiology of MINOCA in patients with MB. Moreover, it focuses on the available diagnostic tools that could be implemented at the time of coronary angiography to achieve a pathophysiologic diagnosis. Finally, it focuses on the therapeutic implications associated with the different pathogenetic mechanisms of MINOCA in patients with MB.

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

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

Sex differences in treatment and outcomes amongst myocardial infarction patients presenting with and without obstructive coronary arteries: a prospective multicentre study

Aims

Women have an increased prevalence of myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA). Whether sex differences exist in the outcomes of patients with MI and obstructive coronary arteries (MIOCA) vs. MINOCA remains unclear. We describe sex-based differences in diagnosis, treatment, and clinical outcomes of patients with MINOCA vs. MIOCA.

Methods and results

A large-scale cohort study of patients with ST/non-ST elevation MI undergoing coronary angiography (01/2015-12/2019). Patient demographics, diagnosis, prescribed discharge medications, in-hospital complications, and follow-up data were prospectively collected. A total of 13 202 participants were included (males 68.2% and females 31.8%). 10.9% were diagnosed with MINOCA. Median follow-up was 4.62 years. Females (44.8%) were as commonly diagnosed with MINOCA as males (55.2%), unlike the male preponderance in MIOCA (male, 69.8%; female, 30.2%). Less secondary prevention medications were prescribed at discharge for MINOCA than MIOCA. There was no difference in mortality risk between MINOCA and MIOCA [in-hospital: adjusted odds ratio (OR) 1.32, 95% confidence interval (CI) 0.74-2.35, P = 0.350; long term: adjusted hazard ratio (HR) 1.03, 95% CI 0.81-1.31, P = 0.813]. MINOCA patients had reduced mortality at long-term follow-up if prescribed secondary prevention medications (aHR 0.64, 95% CI 0.47-0.87, P = 0.004). Females diagnosed with MIOCA had greater odds of in-hospital and 1-year mortality than males (aOR 1.50, 95% CI 1.09-2.07, P = 0.014; aHR 1.18, 95% CI 1.01-1.38, P = 0.048).

Conclusion

MINOCA patients have similar mortality rates as MIOCA patients. MINOCA patients were less likely than those with MIOCA to be discharged with guideline-recommended secondary prevention therapy; however, those with MINOCA who received secondary prevention survived longer. Females with MIOCA experienced higher mortality rates vs. males.

Clinical Predictors and Prognosis of Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) without ST-Segment Elevation in Older Adults

A non-neglectable percentage of patients with non-ST elevation myocardial infarction (NSTEMI) show non-obstructive coronary arteries (MINOCA). Specific data in older patients are scarce. We aimed to identify the clinical predictors of MINOCA in older patients admitted for NSTEMI and to explore the long-term prognosis of MINOCA. This was a single-center, observational, consecutive cohort study of older (≥70 years) patients admitted for NSTEMI between 2010 and 2014 who underwent coronary angiography. Univariate and multivariate Cox regression were performed to analyze the association of variables with MINOCA and all-cause mortality and with major adverse cardiac events (MACE), defined as a combined endpoint of all-cause mortality and nonfatal myocardial infarction and a combined endpoint of cardiovascular mortality, nonfatal myocardial infarction, and unplanned revascularization. The registry included 324 patients (mean age 78.8 ± 5.4 years), of which 71 (21.9%) were diagnosed with MINOCA. Predictors of MINOCA were female sex, left bundle branch block, pacemaker rhythm, chest pain at rest, peak troponin level, previous MI, Killip ≥2, and ST segment depression. Regarding prognosis, patients with obstructive coronary arteries (stenosis ≥50%) and the subgroup of MINOCA patients with plaques <50% had a similar prognosis; while MINOCA patients with angiographically smooth coronary arteries had a reduced risk of MACE. We conclude that the following: (1) in elderly patients admitted for NSTEMI, certain universally available clinical, electrocardiographic, and analytical variables are associated with the diagnosis of MINOCA; (2) elderly patients with MINOCA have a better prognosis than those with obstructive coronary arteries; however, only those with angiographically smooth coronary arteries have a reduced risk of all-cause mortality and MACE.

Myocardial Infarction with Nonobstructive Coronary Arteries

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is an important subtype of myocardial infarction (MI) that occurs in approximately 6-8% of patients with spontaneous MI who are referred for coronary angiography. MINOCA disproportionately affects women, but men are also affected. Pathogenesis is more variable than in MI with obstructive coronary artery disease (MI-CAD). Dominant mechanisms include atherosclerosis, thrombosis, and coronary artery spasm. Management of MINOCA varies based on the underlying mechanism of infarction. Therefore, systematic approaches to diagnosis are recommended. The combination of invasive coronary angiography, multivessel intracoronary imaging, provocative testing for coronary spasm, and cardiac magnetic resonance imaging provides the greatest diagnostic yield. Current clinical practice guidelines for the secondary prevention of MI are based largely on data from patients with MI-CAD. Thus, optimal medications after MINOCA are uncertain. Clinical trials focused on the treatment of patients with MINOCA are urgently needed to define optimal care.

Precision medicine versus standard of care for patients with myocardial infarction with non-obstructive coronary arteries (MINOCA): rationale and design of the multicentre, randomised PROMISE trial

Myocardial infarction with non-obstructive coronary arteries (MINOCA) represents about 6-8% of patients presenting with myocardial infarction (MI), and it is associated with a significant risk of mortality, rehospitalisation, and angina burden, with high associated socioeconomic costs. It is important to note that multiple mechanisms may be responsible for MINOCA. However, to date, there are few prospective clinical trials on MINOCA and the treatment of these patients is still not defined, most likely because of the multiple underlying pathogenic mechanisms. The PROMISE trial is a randomised, multicentre, prospective, superiority, phase IV trial that will include 180 MINOCA patients randomised 1:1 to a "precision-medicine approach", consisting of a comprehensive diagnostic workup and pharmacological treatment specific for the underlying cause, versus a "standard of care" approach, consisting of routine diagnostic workup and standard medical treatment for acute coronary syndrome. The aim of this study is to evaluate if the "precision-medicine approach" will improve the angina status, evaluated using the Seattle Angina Questionnaire summary score, at 12 months (primary endpoint). Secondary endpoints include the rate of major adverse cardiovascular events at 12-month follow-up, the related primary and secondary healthcare costs, and the ability of cardiac magnetic resonance to evaluate the different mechanisms of MINOCA. Of importance, the results derived from this trial may pave the way for a new pathophysiology-driven approach with cause-target therapies personalised for the mechanisms of MINOCA (ClinicalTrials.gov: NCT05122780).

Coronary artery disease in women

Cardiovascular disease is the leading global cause of death in women but remains underdiagnosed and undertreated. Health professionals play an important role in improving the heart health of Australian women. Routine heart health checks should be offered to all women 45 years of age and older and to all Aboriginal and Torres Strait Islander women 30 years of age and older. Cardiovascular risk assessment in women must include traditional and sex-specific risk factors, including their pregnancy history and early-onset menopause. Women with pregnancy-related hypertensive and metabolic disorders have an increased long-term cardiovascular risk and require close monitoring. Women with acute coronary syndrome may not experience classical chest pain. More often, they experience cardiovascular events in the absence of obstructive coronary disease and have poorer cardiovascular outcomes. The recognition of sex-specific differences and more sex-specific trials are key to improving clinical outcomes.

Ischemia and no obstructive coronary arteries (INOCA): A narrative review

Myocardial ischemia with no obstructive coronary arteries (INOCA) is a chronic coronary syndrome condition that is increasingly being recognized as a substantial contributor to adverse cardiovascular mortality and outcomes, including myocardial infarction and heart failure with preserved ejection fraction (HFpEF). While INOCA occurs in both women and men, women are more likely to have the finding of INOCA and are more adversely impacted by angina, with recurrent hospitalizations and a lower quality of life with this condition. Abnormal epicardial coronary vascular function and coronary microvascular dysfunction (CMD) have been identified in a majority of INOCA patients on invasive coronary function testing. CMD can co-exist with obstructive epicardial coronary artery disease (CAD), diffuse non-obstructive epicardial CAD, and with coronary vasospasm. Epicardial vasospasm can also occur with normal coronary arteries that have no atherosclerotic plaque on intravascular imaging. While all predisposing factors are not clearly understood, cardiometabolic risk factors, and endothelium dependent and independent mechanisms that increase oxidative stress and inflammation are associated with microvascular injury, CMD and INOCA. Cardiac autonomic dysfunction has also been implicated in abnormal vasoreactivity and persistent symptoms. INOCA is under-recognized and under-diagnosed, partly due to the heterogenous patient populations and mechanisms. However, diagnostic testing methods are available to guide INOCA management. Treatment of INOCA is evolving, and focuses on cardiac risk factor control, improving ischemia, reducing atherosclerosis progression, and improving angina and quality of life. This review focuses on INOCA, relations to HFpEF, available diagnostics, current and investigational therapeutic strategies, and knowledge gaps in this condition.

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.

Optical coherence tomography in the diagnosis of myocardial infarction with non-obstructive coronary arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a working diagnosis and requires identification of the underlying causes to optimize treatment, improve prognosis, and prevent the recurrence of myocardial infarction. According to the literature, the prognosis of patients diagnosed with MINOCA is comparable to the group of patients with myocardial infarction (MI) and significant stenosis of the coronary arteries. Intracoronary imaging is a crucial diagnostic tool used in identifying epicardial causes of MINOCA that are not visible in coronary angiography. Optical coherence tomography (OCT) provides the highest spatial resolution, simultaneously allowing detailed visualization of plaque pathology in individuals with MINOCA and identifying the cause of MI in up to 80% of patients. Common causes of a MINOCA may include plaque disruption, spontaneous coronary artery dissection (SCAD), coronary artery spasm, and coronary thromboembolism. The optimization of pharmacological treatment in this group of patients, especially dual antiplatelet therapy and statins, improves the prognosis. Data on the indications for invasive treatment of patients with MINOCA based on OCT findings are insufficient. There is a strong need for research comparing treatment strategies, especially in high-risk lesions visualized in OCT. The main aim of this review is to demonstrate the usefulness of OCT in determining the mechanism of MINOCA.

Mechanisms of Coronary Ischemia in Women

PURPOSE OF REVIEW

Obstructive coronary artery disease is a major cause of ischemia in both men and women; however, women are more likely to present with ischemia in the setting of no obstructive coronary arteries (INOCA) and myocardial infarction with no obstructive coronary arteries (MINOCA), conditions that are associated with adverse cardiovascular prognosis despite absence of coronary stenosis. In this review, we focus on mechanisms of coronary ischemia that should be considered in the differential diagnosis when routine anatomic clinical investigation leads to the finding of non-obstructive coronary artery disease on coronary angiography in the setting of acute myocardial infarction.

RECENT FINDINGS

There are multiple mechanisms that contribute to MINOCA, including atherosclerotic plaque disruption, coronary artery spasm, coronary microvascular dysfunction (CMD), coronary embolism and/or thrombosis, and spontaneous coronary artery dissection. Non-coronary causes such as myocarditis or supply-demand mismatch should also be considered on the differential when there is an unexplained troponin elevation. Use of advanced imaging and diagnostic techniques to determine the underlying etiology of MINOCA is feasible and helpful, as this has the potential to guide management and secondary prevention. Failure to identify the underlying cause(s) may result in inappropriate treatment and inaccurate counseling to patients. MINOCA predominates in young women and is associated with a guarded prognosis. The diagnosis of MINOCA should prompt further investigation to determine the underlying cause of troponin elevation. Patients with INOCA and MINOCA are heterogeneous, and response to treatments can be variable. Large randomized controlled trials to determine longer-term optimal medical therapy for management of these conditions are under investigation.

Clinical outcomes of patients with coronary microvascular dysfunction in absence of obstructive coronary atherosclerosis

Up to 50% of patients presenting with stable, mainly exercise-induced, chest pain and 10-20% of those admitted to hospital with chest pain suggesting an acute coronary syndrome show normal or near-normal coronary arteries at angiography. Coronary microvascular dysfunction (CMD) is a major cause of symptoms in these patients. However, controversial data exist about their prognosis. In this article, we critically review characteristics and results of the main studies that assessed clinical outcome of patients with angina chest pain and nonobstructive coronary artery disease presenting with either a stable angina pattern or an acute coronary syndrome. Published data indicate that the patients included in most studies are heterogeneous and a major determinant of clinical outcome is the presence of atherosclerotic, albeit not obstructive, coronary artery disease. Long-term prognosis seems instead excellent in patients with totally normal coronary arteries and a syndrome of CMD-related stable angina (microvascular angina). On the other hand, the prognostic impact of CMD in patients presenting with an acute coronary syndrome needs to be better assessed in future studies.

ST-Elevation Acute Myocardial Infarction in a Young Man

Acute myocardial infarction (AMI) in young patients is very rare, but the incidence has increased over years past at younger ages, likely due to the presence of multiple risk factors. We present the first known case of ST-elevation AMI (STEMI) in a young man. A 22-year-old Japanese man was transferred to our hospital due to suddenly occurred anterior chest pain. An electrocardiogram revealed ST elevation in anteroseptal leads together with reciprocal ST depression in inferior leads. An emergency coronary angiogram was performed, revealing a 100% occlusion at segment 6 of the coronary artery and we established a diagnosis of STEMI. The lesion was expanded to 0% stenosis through plain old balloon angioplasty, after which a third-generation drug-eluting stent was installed there. Afterwards, the patient was discharged on day 17. In this case, a combination of mild six risk factors plus family history of hypertension might lead to this atypical event.

Role of cardiac CT in the diagnostic evaluation and risk stratification of patients with myocardial infarction and non-obstructive coronary arteries (MINOCA): rationale and design of the MINOCA-GR study

INTRODUCTION

Myocardial infarction with non-obstructive coronary arteries (MINOCA) occurs in 5%-15% of all patients with acute myocardial infarction. Cardiac MR (CMR) and optical coherence tomography have been used to identify the underlying pathophysiological mechanism in MINOCA. The role of cardiac CT angiography (CCTA) in patients with MINOCA, however, has not been well studied so far. CCTA can be used to assess atherosclerotic plaque volume, vulnerable plaque characteristics as well as pericoronary fat tissue attenuation, which has not been yet studied in MINOCA.

METHODS AND ANALYSIS

MINOCA-GR is a prospective, multicentre, observational cohort study based on a national registry that will use CCTA in combination with CMR and invasive coronary angiography (ICA) to evaluate the extent and characteristics of coronary atherosclerosis and its correlation with pericoronary fat attenuation in patients with MINOCA. A total of 60 consecutive adult patients across 4 participating study sites are expected to be enrolled. Following ICA and CMR, patients will undergo CCTA during index hospitalisation. The primary endpoints are quantification of extent and severity of coronary atherosclerosis, description of high-risk plaque features and attenuation profiling of pericoronary fat tissue around all three major epicardial coronary arteries in relation to CMR. Follow-up CCTA for the evaluation of changes in pericoronary fat attenuation will also be performed. MINOCA-GR aims to be the first study to explore the role of CCTA in combination with CMR and ICA in the underlying pathophysiological mechanisms and assisting in diagnostic evaluation and prognosis of patients with MINOCA.

ETHICS AND DISSEMINATION

The study protocol has been approved by the institutional review board/independent ethics committee at each site prior to study commencement. All patients will provide written informed consent. Results will be disseminated at national meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT4186676.

Ischemia and no obstructive coronary arteries in patients with stable ischemic heart disease

A large proportion of patients with suspected obstructive coronary artery disease (CAD) is found to have ischemia with no obstructive coronary artery disease (INOCA). Based on current evidence, these patients are at increased risk of adverse cardiovascular events, even though they have no obstructive CAD. Importantly, INOCA is associated with recurrent clinical presentations with chest pain, impaired functional capacity, reduced health-related quality of life, and high healthcare costs. Underlying coronary microvascular dysfunction (CMD), through endothelium-dependent and independent mechanisms contribute to these adverse outcomes in INOCA. While non-invasive and invasive diagnostic testing has typically focused on identification of obstructive CAD in symptomatic patients, functional testing to detect coronary epicardial and microvascular dysfunction should be considered in those with INOCA who have persistent angina. Current diagnostic methods to clarify functional abnormalities and treatment strategies for epicardial and/or microvascular dysfunction in INOCA are reviewed.

Clinical characteristics and outcome in patients with ST-segment and non-ST-segment elevation myocardial infarction without obstructive coronary artery: an observation study from Chinese population

Background

The disparity between ST-segment and non-ST-segment elevation myocardial infarction without obstructive coronary artery (STE-MINOCA and NSTE-MINOCA) are unclear. Our study aims to compare the clinical features and outcomes in patients with STE-MINOCA and NSTE-MINOCA.

Methods

This cross-sectional study consecutively enrolled patients diagnosed with acute myocardial infarction (AMI) from January 2013 to January 2020. MINOCA were identified as angiographic stenosis < 50%. Clinical characteristics, angiographic features, and clinical outcomes of STE-MINOCA and NSTE-MINCOA were documented. The primary endpoint was composite events in the different time periods.

Results

A total of 1966 AMI patients were screened, 107 (5.4%) were diagnosed as MINOCA. Among, there were 34 (31.8%) of STE-MINOCA and 73 (68.2%) of NSTE-MINOCA. STE-MINOCA group were younger, had lower N-terminal pro-brain natriuretic peptide (NT-proBNP), and smaller left atrial diameter (P < 0.05). Dual antiplatelet therapy (DAPT) was more likely to be prescribed to STE-MINOCA patients (P = 0.015). During median follow-up time of 24.5 months, STE-MINOCA group also demonstrated lower risks for primary endpoint and cardiovascular-related (CVS) rehospitalization. In univariate Cox regression analyses, NSTE-MINOCA showed an increased risk of long-term primary endpoint (HR 2.57, 95 CI%: 1.10–6.02) and CVS-related rehospitalization (HR 3.14, 95% CI: 1.16–8.48). After adjusting for NT-proBNP and DAPT, NSTE-MINOCA remained an independent risk factor for CVS-related rehospitalization in long-term follow-up (HR 2.78, 95% CI: 1.03–7.49).

Conclusion

Although STE-MINOCA and NSTE-MINOCA patients showed similar clinical characteristics, NSTE-MINOCA group presented a worse long-term outcome mainly driven by CVS-related hospitalization which suggested that NSTE-MINOCA patients might also require prompt medical attention.

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.

Role of Multimodality Imaging in the Assessment of Myocardial Infarction With Nonobstructive Coronary Arteries: Beyond Conventional Coronary Angiography

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a heterogeneous clinical entity, encompassing multiple different causes, and a cause of substantial morbidity and mortality. Current guidelines suggest a multimodality imaging approach in establishing the underlying cause for MINOCA, which is considered a working diagnosis. Recent studies have suggested that an initial workup consisting of cardiac magnetic resonance and invasive coronary imaging can yield the diagnosis in most patients. Cardiac magnetic resonance is particularly helpful in excluding nonischemic causes that can mimic MINOCA including myocarditis and Takotsubo cardiomyopathy, as well as for long‐term prognostication. Additionally, intracoronary imaging with intravascular ultrasound or optical coherence tomography may be warranted to evaluate plaque composition, or evaluate for plaque disruption or spontaneous coronary dissection. The role of noninvasive imaging modalities such as coronary computed tomography angiography is currently being investigated in the diagnostic approach and follow‐up of MINOCA and may be appropriate in lieu of invasive coronary angiography in select patients. In recent years, many strides have been made in the workup of MINOCA; however, significant knowledge gaps remain in the field, particularly in terms of treatment strategies. In this review, we summarize recent society guideline recommendations and consensus statements on the initial evaluation of MINOCA, review contemporary multimodality imaging approaches, and discuss treatment strategies including an ongoing clinical trial.

Long-term outcome of patients with NSTEMI and nonobstructive coronary arteries by different angiographic subtypes

INTRODUCTION AND OBJECTIVES

Discordant data have been reported on the prognosis of myocardial infarction with nonobstructive coronary arteries (MINOCA). Moreover, few data are available on the impact of angiographic subtypes. The objectives of this study were to assess the prognostic impact on the long-term follow-up of the diagnosis of MINOCA and its angiographic subtypes.

METHODS

We included 591 consecutive patients with non-ST-segment elevation myocardial infarction (NSTEMI) who underwent coronary angiography. MINOCA was classified according to angiographic findings as smooth coronary arteries, mild irregularities (< 30% stenosis), and moderate atherosclerosis (30%-49% stenosis). The primary endpoint was a composite of mortality, nonfatal myocardial infarction, and revascularization (MACE) at a median of 5 years of follow-up.

RESULTS

A total of 121 patients (20.5%) showed no obstructive lesions. MINOCA was associated with a lower occurrence of MACE (P=.014; HR, 0.63; 95%CI, 0.44-0.91) and was confirmed as an independent factor in the multivariate analysis (P=.018; HR, 0.63; 95%CI, 0.43-0.92). On analysis of the separate components of the main endpoint, MINOCA was significantly associated with a lower rate of myocardial infarction and revascularization, but not with mortality. Analysis of angiographic subtypes among MINOCA patients showed that smooth coronary arteries were a statistically significant protective factor on both univariate and multivariate analysis, while mild irregularities and 30% to 49% plaques were associated with a higher risk of MACE.

CONCLUSIONS

MINOCA is associated with a lower rate of MACE, driven by fewer reinfarctions and revascularizations. Within the angiographic subtypes of MINOCA, smooth arteries were independently associated with a lower number of MACE.

Randomized Evaluation of Beta Blocker and ACE-Inhibitor/Angiotensin Receptor Blocker Treatment for Post Infarct Angina in Patients With Myocardial Infarction With Non-obstructive Coronary Arteries: A MINOCA-BAT Sub Study Rationale and Design

Introduction: Myocardial infarction with non-obstructive coronary arteries (MINOCA) occurs in ~10% of all patients with acute myocardial infarction (AMI), with an over-representation amongst women. Remarkably, it is estimated that as many as 1 in 4 patients with MINOCA experience ongoing angina at 12 months despite having no flow-restricting stenoses in their epicardial arteries. This manuscript presents the rationale behind Randomized Evaluation of Beta Blocker and Angiotensin-converting enzyme inhibitors/Angiotensin Receptor Blocker Treatment (ACEI/ARB) for Post Infarct Angina in MINOCA patients-The MINOCA BAT post infarct angina sub study. Methods: This trial is a registry-based, randomized, parallel, open-label, multicenter trial with 2 × 2 factorial design. The primary aim is to determine whether oral beta blockade compared with no oral beta blockade, and ACEI/ARB compared with no ACEI/ARB, reduce post infarct angina in patients discharged after MINOCA without clinical signs of heart failure and with left ventricular ejection fraction ≥40%. A total of 664 patients will be randomized into four groups; (i) ACEI/ARB with beta blocker, (ii) beta blocker only, (iii) ACEI/ARB only, or (iv) neither ACEI/ARB nor beta blocker and followed for 12 months. Results: The trial is currently recruiting in Australia and Sweden. Fifty six patients have been recruited thus far. Both sexes were equally distributed (52% women and 48% men) and the mean age was 56.3 ± 9.9 years. Conclusions: It remains unclear whether conventional secondary preventive therapies are beneficial to MINOCA patients in regard to post infarct angina. Existing registry-based literature suggest cardioprotective agents are less likely to be used in MINOCA patients. Thus, results from this trial will provide insights for future treatment strategies and guidelines specific to MINOCA patients.

Why the Term MINOCA Does Not Provide Conceptual Clarity for Actionable Decision-Making in Patients with Myocardial Infarction with No Obstructive Coronary Artery Disease

When acute myocardial injury is found in a clinical setting suggestive of myocardial ischemia, the event is labeled as acute myocardial infarction (MI), and the absence of ≥50% coronary stenosis at angiography or greater leads to the working diagnosis of myocardial infarction with non-obstructed coronary arteries (MINOCA). Determining the mechanism of MINOCA and excluding other possible causes for cardiac troponin elevation has notable implications for tailoring secondary prevention measures aimed at improving the overall prognosis of acute MI. The aim of this review is to increase the awareness that establishing the underlying cause of a MINOCA is possible in the vast majority of cases, and that the proper classification of any MI should be pursued. The initial diagnosis of MINOCA can be confirmed or ruled out based on the results of subsequent investigations. Indeed, a comprehensive clinical evaluation at the time of presentation, followed by a dedicated diagnostic work-up, might lead to the identification of the pathophysiologic abnormality leading to MI in almost all cases initially labeled as MINOCA. When a specific cause of acute MI is identified, cardiologists are urged to transition from the "all-inclusive" term "MINOCA" to the proper classification of any MI, as evidence now exists that MINOCA does not provide conceptual clarity for actionable decision-making in MI with angiographically normal coronary arteries.

Diagnostic pathways in myocardial infarction with non-obstructive coronary artery disease (MINOCA)

When acute myocardial injury is found in a clinical setting suggestive of myocardial ischaemia, the event is labelled as acute myocardial infarction (AMI), and the absence of coronary stenosis angiographically 50% or greater leads to the working diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA). The initial diagnosis of MINOCA can be confirmed or ruled out based on the results of subsequent investigations. This narrative review discusses the downstream diagnostic approaches to MINOCA, and appraises strengths and limitations of invasive and non-invasive investigations for this condition. The aim of this article is to increase the awareness that establishing the underlying cause of a MINOCA is possible in the vast majority cases. Determining the cause of MINOCA and excluding other possible causes for cardiac troponin elevation has notable implications for tailoring secondary prevention measures aimed at improving the overall prognosis of AMI.

OCT Findings in MINOCA

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a working diagnosis for patients presenting with acute myocardial infarction without obstructive coronary artery disease on coronary angiography. It is a heterogenous entity with a number of possible etiologies that can be determined through the use of appropriate diagnostic algorithms. Common causes of a MINOCA may include plaque disruption, spontaneous coronary artery dissection, coronary artery spasm, and coronary thromboembolism. Optical coherence tomography (OCT) is an intravascular imaging modality which allows the differentiation of coronary tissue morphological characteristics including the identification of thin cap fibroatheroma and the differentiation between plaque rupture or erosion, due to its high resolution. In this narrative review we will discuss the role of OCT in patients presenting with MINOCA. In this group of patients OCT has been shown to reveal abnormal findings in almost half of the cases. Moreover, combining OCT with cardiac magnetic resonance (CMR) was shown to allow the identification of most of the underlying mechanisms of MINOCA. Hence, it is recommended that both OCT and CMR can be used in patients with a working diagnosis of MINOCA. Well-designed prospective studies are needed in order to gain a better understanding of this condition and to provide optimal management while reducing morbidity and mortality in that subset patients.

The Lancet women and cardiovascular disease Commission: reducing the global burden by 2030

Cardiovascular disease is the leading cause of death in women. Decades of grassroots campaigns have helped to raise awareness about the impact of cardiovascular disease in women, and positive changes affecting women and their health have gained momentum. Despite these efforts, there has been stagnation in the overall reduction of cardiovascular disease burden for women in the past decade. Cardiovascular disease in women remains understudied, under-recognised, underdiagnosed, and undertreated. This Commission summarises existing evidence and identifies knowledge gaps in research, prevention, treatment, and access to care for women. Recommendations from an international team of experts and leaders in the field have been generated with a clear focus to reduce the global burden of cardiovascular disease in women by 2030. This Commission represents the first effort of its kind to connect stakeholders, to ignite global awareness of sex-related and gender-related disparities in cardiovascular disease, and to provide a springboard for future research.

Prevalence, Clinical Factors, and Outcomes Associated With Myocardial Infarction With Nonobstructive Coronary Artery

BACKGROUND

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is an underrecognized clinical problem in patients presenting with acute coronary syndrome. Various clinical disorders lead to MINOCA thus making treatment and diagnosis a challenge. We aimed to compare the clinical factors and outcomes of patients with MINOCA versus obstructive disease [myocardial infarction due to coronary artery disease (MI-CAD)] in a largely rural health system.

METHODS

Between May 1, 2009 and June 24, 2019, all consecutive ST-segment elevation myocardial infarction patients at Essentia Health were prospectively examined. We categorized patients into MI-CAD (obstructive plaque ≥ 50% with revascularization) or MINOCA (obstructive plaque < 50% with exclusion of other alternative cause). Outcomes included 30-day and 1-year all-cause mortality, 30-day all-cause readmission and 30-day cardiac readmission.

RESULTS

There were 2170 patients included in the study; 2097 (96.6 %) had MI-CAD and 73 (3.4%) met the definition of MINOCA. Within the MINOCA group, the 3 most common presentations were supply-demand mismatch (28.8%), spontaneous coronary artery dissection (9.6%), and other etiology (60.3%). Only 10 (13 %) MINOCA patients had cardiac magnetic resonance imaging studies obtained within 6 months. MINOCA patients were younger 61.6 versus 63.4 years with higher left ventricular function 51.6% versus 50.4% with less likelihood of prior myocardial infarction 4.1% versus 15.5% or congestive heart failure 2.7% versus 6.3% (P < 0.05). Compared with MI-CAD patients, MINOCA patients had similar 30-day mortality (7.1% vs. 8.2%; P = 0.70), 1-year mortality (10.4% vs. 8.2 %; P = 0.55), and 30-day cardiac readmission (8.7% vs. 9.6%; P = 0.29). MINOCA patients were less likely to be discharged on aspirin, betablockers, angiotensin-converting enzyme inhibitor/angiotensin receptor blockers, or statins (P < 0.05).

CONCLUSION

Though there was no difference in readmission and mortality between MINOCA and MI-CAD; use of secondary prevention medications and cardiac rehabilitation referral was low in MINOCA patients. Prospective studies will be relevant to assess effective medical therapy to improve outcomes in MINOCA patients.

Myocardial infarct size and sex-related angiographic differences in myocardial infarction in nonobstructive coronary artery disease

BACKGROUND

Myocardial infarction in nonobstructive coronary artery disease (MINOCA) is a recently described infarct subtype. There are few studies that examine coronary artery disease (CAD) extent, MI size and type, and treatment differences at hospital discharge compared to myocardial infarction in obstructive coronary artery disease (MICAD), or that explore sex-specific MINOCA attributes of coronary anatomy and infarct size.

METHODS

Our study population consisted of a single tertiary-center of consecutive patients that had coronary angiography for acute MI between 2005 and 2015. The MI type at presentation, MI size and ejection fraction (post-MI), and gender differences between MINOCA patients were examined.

RESULT

Among 1698 cases with acute MI, 95 had MINOCA (5.6%). MINOCA patients were younger, more often had NSTEMI, lower peak cardiac troponin (cTn) values, and greater ejection fraction than MICAD patients (all P-values <0.005). At hospital discharge, 30-day re-admission rates were similar. MINOCA patients less frequently received optimal medical therapy. When women were analyzed, the 45 women with MINOCA had smaller MIs (P < 0.001) and greater ejection fraction (P = 0.002) than the 358 women with MICAD. Sex comparisons of the 95 MINOCA patients revealed women were older than men (P < 0.001), had lower mean peak cTn values (P < 0.001), greater ejection fraction (P = 0.02), and more single-vessel disease involvement than men (P < 0.0001).

CONCLUSION

The average MI size is smaller in MINOCA than MICAD patients, and there are sex-related differences in clinical presentation, coronary artery disease extent, and MI size. Re-admission rates are similar and MINOCA patients are less likely to receive guideline recommended medical therapy at discharge.