Cause Of Myocardial Infarction With Non-obstructive Coronary Arteries Research Articles

MINOCA as the result of coronary artery aneurysm thrombosis.

Myocardial infarction (MI) can be caused by many factors. In addition to the typical obstruction or stenosis of the coronary arteries, there is heterogenic MI with non-obstructive coronary arteries (MINOCA). A rare cause of MINOCA is the thrombosis of a coronary artery aneurysm (CAA). This current case report describes a male patient with CAA thrombosis as the cause of MINOCA following surgery for a mucoepidermoid carcinoma. The patient underwent angiography that identified three CAAs that were located as follows: (i) in the proximal part of the left anterior descending artery (5.55 mm); (ii) in the distal part of the circumflex artery (8.05 mm); and (iii) in the distal part of the right coronary artery (6.61 mm). Thrombotic masses were identified within all three structures. The patient received balloon angioplasties without stent implanting and recovered well. The patient was also notable for the presence of two brain artery aneurysms that were the cause of the previous strokes that he had experienced. This case report also reviews the literature in order to: (i) summarize the aetiological factors and clinical manifestations of CAA; (ii) discuss the diagnostic methods for CAA; (iii) describe the medical and surgical management of CAA; and (iv) assess the prognosis of this rare clinical event.

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

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). 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. 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). 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.

A Personalized Approach for Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries.

Myocardial infarction with non-obstructive coronary arteries (MINOCA) includes coronary embolism, dissection, spasm and microvascular dysfunction, as well as plaque rupture or erosion (causing 50% stenosis). In the most recent studies, events that can be classified as MINOCA account for approximately 6-8% of all diagnoses of acute myocardial infarction (AMI). Clinical suspect may suggest the need for additional diagnostic procedures beyond the usual coronary angiography, such as cardiac imaging or provocative tests. Cardiac magnetic resonance (CMR) is essential for both validating the diagnosis and ruling out other conditions with a comparable clinical presentation. The prognosis is not as good as previously believed; rather, it is marked by morbidity and mortality rates comparable to those of other types of AMI. Identification of the underlying causes of MINOCA is recommended by current guidelines and consensus documents in order to optimize treatment, enhance prognosis, and encourage prevention of recurrent myocardial infarction. In this narrative review, we have outlined the various causes of MINOCA and their specific therapies in an attempt to identify a personalized approach to its treatment.

MINOCA due to vasospasm compared to other mechanisms: patients characteristics, evolution and prognosis

Abstract Introduction coronary vasospasm is a common cause of MINOCA (myocardial infarction with non-obstructive coronary arteries). The aim of this study is to compare characteristics and prognosis of patients (pts) with MINOCA due to vasospasm (MINOCA-V) vs those with MINOCA due to other causes (MINOCA-O). Methods we included all MINOCA pts between January 2015-December 2022. The definitions of MINOCA and vasospasm were based on European Clinical Guidelines. The diagnosis of vasospasm was made in the cath lab or with non-invasive bedside tests (ergonovine). The follow-up analysis included major adverse cardiovascular events (MACE: death from any cause, cardiovascular readmission, reinfarction and stroke). The median follow-up was 59.5 months [36-75]. Results there were a total of 120 MINOCA pts, of which 19 (16%) were MINOCA-V and 101 (84%) MINOCA-O (embolism, dissection, type II infarction, unknown). Regarding the clinical profile of MINOCA-V, they were fewer women (21 vs 49% p=0.03), younger (mean age 56±11 vs 63±15 p=0.03) and more smokers (78.9 vs 50.5% p=0.02). There were no significant differences in cocaine use (7.7 vs 5.5% p=0.75) or other baseline characteristics (Table 1). Not only there was a higher percentage of pts with ST elevation at admission in the vasospasm group (53 vs 12% p<0.01), but also they presented with a higher elevation of biochemical markers of myocardial damage (MMD), both troponin (125.11±203.8 vs 609.48±1661.2 ng/L,p<0.01) and CK (201±272.4 vs 338.75±384.3 U/L p=0.01). There were no significant differences in renal function (Cr 1.4±1.8 vs 1.1±1.5mg/dL p=0.15) and cholesterol levels (163.05±48 vs 172.6±65.7mg/dL p=0.99). The use of magnetic resonance imaging to complete diagnosis did not differ between both groups (26vs37% p=0.34), although it was more effective when approaching the etiology in MINOCA-O (0 vs 18%, p=0.04). The duration of admission was similar between both groups (6±4 days in MINOCA-V vs 5±4 in MINOCA-O, p=0.78). The treatment at discharge was different, being greater the use of nitrates (53vs10% p<0.01) and calcium antagonists (CA), both not dyhidropyridines (53 vs 7% p<0.01) and dihydropyridines (53 vs23% p=0.01) in MINOCA-V and less that of beta-blockers (BB) (0 vs 62% p<0.01) and acetylsalicylic acid (ASA) (32vs73% p<0.01). During follow-up, the evolution was similar in terms of mortality (HR 1.81 IC95%[0.33-10] p=0.2) and MACE (HR 1.76 IC95%[0.69-4.51] p=0.17). No differences were found in cardiovascular readmissions (HR 1.04 IC95%[0.35-3.07] p=0.29), stroke (no cases in both groups) and reinfarction (HR 1.3 IC95%[0.25-6.81] p=0.57). Conclusion we conclude that pts with MINOCA-V are more likely to be male, younger and smokers than MINOCA-O. They usually present with ST elevation and increased elevation of MMD. Treatment at discharge is different: with greater use of nitrates and CA and lower ASA and BB. The prognosis is similar in both groups with no significant differences in mortality or MACE.

Abstract 13906: Electrocardiographic Correlates of Cardiac MRI Findings in Women With MINOCA

Introduction: Myocardial infarction with nonobstructive coronary arteries (MINOCA) is identified in 6-15% of patients with MI and disproportionately affects women. Cardiac magnetic resonance (CMR) imaging is important to identify the cause of MINOCA but is restricted by its technical complexity and limited accessibility. The electrocardiogram (ECG), a simple, readily available tool, may predict features associated with abnormal CMR. Methods: Women with a diagnosis of MI and <50% angiographic stenosis in all epicardial vessels were enrolled in the Women’s Heart Attack Research Program (HARP), a prospective, multicenter, observational study. Participants had CMR at a median of 6 days from MI (n=116). A CMR core laboratory interpreted images while blinded to clinical data and ECGs. Abnormal CMR findings included late gadolinium enhancement (LGE) or myocardial edema. The patient’s presenting ECG was analyzed. ECGs with ≥2 uninterpretable leads or with bundle branch block were excluded. ECGs were assessed for T-wave inversions (TWI), pathologic Q waves (QW), fractionated QRS (fQRS), and ST segment depression or elevation. The DETERMINE score is 2x the number of leads (#) with QW + # fQRS + # TWI, excluding leads V1 and aVR (maximum score 40). Results: (Figure, Table): Among 112 women with MINOCA, CMR abnormality was more likely in women with DETERMINE score ≥3 vs <3 (86% vs 65%, p = 0.01). DETERMINE score ≥3 was associated with abnormal CMR on logistic regression (OR 3.4, p = 0.01). Patients with any TWI were more likely to have abnormal CMR than those with no TWI (84% vs 64%, p = 0.02), and were more likely to have LGE on CMR (61% vs 34%, p = 0.005). In those with a DETERMINE score of 0, CMR was abnormal in 62% vs 78% with DETERMINE score ≥1 (p=0.09), and LGE was present in 28% vs 54%, p = 0.01. Conclusion: ECG abnormalities were associated with abnormal CMR among women with MINOCA. The ECG may provide risk stratification for CMR, but the absence of QW, fQRS and TWI does not preclude CMR abnormality.

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

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

Underlying Causes of Myocardial Infarction with Nonobstructive Coronary Arteries: Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging Pilot Study.

Scientific statements recommend multimodality imaging in myocardial infarction with non-obstructive coronary arteries (MINOCA) to define the underlying cause. We evaluated the diagnostic yield of intravascular optical coherence tomography (OCT) and cardiac magnetic resonance (CMR) in the MINOCA setting. In this prospective, single center, observational pilot study, we enrolled patients with MINOCA without previous coronary interventions. All patients underwent three vessel OCT, followed by CMR. Imaging results were combined to determine the mechanism of MINOCA, when possible. We enrolled 10 patients in this pilot study. Women constituted 50% of the analyzed population. The mean age of patients was 52 years. ST-segment elevation was found in 30% of patients. A possible culprit lesion was identified by OCT in 70% of participants, most commonly plaque rupture or erosion. An ischemic pattern of CMR abnormalities was identified in 70% of participants. Myocarditis and Tako-Tsubo were identified in 30%. A cause of MINOCA was identified in all patients using multimodality imaging, while using OCT alone identification occurred in only 70% of patients. In this pilot study, multimodality imaging with OCT and CMR identified potential mechanisms in all patients with a diagnosis of MINOCA, and it has the potential to guide medical therapy for secondary prevention.

FOCUS GROUP: IMPROVING THE KNOWLEDGE OF PATIENTS ON WOMEN'S HEART HEALTH SELF-CARE MANAGEMENT

FOCUS GROUP: IMPROVING THE KNOWLEDGE OF PATIENTS ON WOMEN'S HEART HEALTH SELF-CARE MANAGEMENT

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.

Myocardial Bridging is Significantly Related to Myocardial Infarction with Non-Obstructive Coronary Artery Disease

Myocardial infarction with non obstructive coronary arteries (MINOCA) is a complex working diagnosis including coronary and non-coronary causes, like spontaneous coronary dissection, coronary thrombosis or embolism, myocarditis and cardiomyopathy. The prevalence of MINOCA is increasing, but the underlying etiology remains undetermined in more than 10% of cases. Hypotheses on the potential contributing role of myocardial bridge (MB) in takotsubo cardiomyopathy and coronary artery spasm (CAS) have been raised. We aim to investigate the relationship between MB and MINOCA. An observational retrospective study was conducted on 15,036 patients who had been referred for coronary angiography and who fulfilled the Definition of Myocardial Infarction. The study population was divided into STEMI and Non-STEMI patients, from which we defined two main groups: the MINOCA group and the coronary artery disease (CAD) group. The prevalence of MB was calculated in each group ( Fig. 1 ). The distribution of angiographic MB among the groups was significantly greater in the MINOCA group (2.9% vs. 0.8%, P < 0.001). MINOCA accounted for 14.5% of spontaneous myocardial infarctions, and the clinical presentation was frequently NSTEMI rather than STEMI (84.3% vs. 15.7%, P < 0.001). Adjusted multivariate analyses showed a positive association between MB and MINOCA [OR = 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. The main finding of the present study was that MB is an independent predictor for MINOCA, increasing the corresponding risk by threefold. Because MB prevalence differed significantly between the controls (CAD group) and in the MINOCA group, which was positively correlated to MB, it seems likely that MB would be a potential cause of MINOCA. Future prospective studies are necessary to highlight the physiologic significance of MB in some MINOCA patients.

Abstract 10785: Cardiac Magnetic Resonance Imaging and Optical Coherence Tomography in Patients with a Clinical Diagnosis of Myocardial Infarction with Non-Obstructive Coronary Arteries - A Systematic Review and Meta-Analysis

Background: Myocardial Infarction with Non-Obstructive Coronary arteries (MINOCA) is defined as acute Myocardial Infarction (MI) despite the absence of severe coronary artery stenosis on angiography (i.e., stenosis severity &lt;50%) and no specific alternative diagnosis (e.g., sepsis, pulmonary embolism). MINOCA remains a serious diagnostic and therapeutic challenge given the various possible underlying etiologies. Cardiac Magnetic Resonance Imaging (CMR) can distinguish between acute myocarditis (AM), MI, and Takotsubo cardiomyopathy (TCM) which are some of the commonest causes of MINOCA. Hence, The European Society of Cardiology (ESC) recommend CMR in all MINOCA patients with an unclear etiology. Intracoronary Optical coherence tomography (OCT) is a high-resolution imaging modality that allows for assessment of the integrity of the atheroma. We aimed to study the efficacy of CMR and OCT in detecting the etiology in MINOCA patients, which has the potential to guide medical therapy. Methods: A systematic search was made in PubMed, Medline and Cochrane database. Search terms used: Myocardial infarction, Coronary angiography, Normal coronary arteries, CMR, and OCT. Inclusion criteria was fulfilled by 18 studies. Meta-analysis and meta-regression was performed with 14 studies due to increased heterogeneity. Results: A total of 2474 patients were included in the meta-analysis. The mean age of all the patients was 51.5 and 56.4% were men. CMR was able to establish diagnosis in 74% of the patients; 30.4% had AM, 21.3% had true MI and 12% had TCM. Upon meta-regression the demographic variables, cardiovascular risk factors, troponin levels and C-reactive protein levels did not have any association with AM or MI. Incorporation of OCT with CMR was better at finding the etiology than either modalities individually. Conclusion: CMR is integral in finding the cause of MINOCA. Coupling coronary OCT and CMR is better than either techniques alone at identifying the etiology.

Characteristics and Risk Factors of Yemeni Patients Presenting with Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA).

Background:Myocardial infarction with non-obstructive coronary artery (MINOCA) is a syndrome, which requires both clinical documentation of ST-elevation myocardial infarction (STEMI) (abnormal cardiac biomarker, ischemic symptoms, and electrocardiography changes) and detection of nonobstructive coronary arteries. The purpose of this study is to determine the incidence of and characteristics of patients with MINOCA in the Yemeni population.Methods:Consecutive patients admitted between January and June 2019 at Al-Thawra Hospital, Sana’a (Yemen), with STEMI diagnosis were enrolled in this study. Demographic, clinical, echocardiographic, and coronary angiography characteristics of patients were noted.ResultsMINOCA was identified in 63 patients (25%) out of 249 admitted with STEMI diagnosis at Al-Thawra Hospital. The mean age of MINOCA patients was similar to obstructive coronary group; however, they were more often females and less frequently with diabetes and family history of coronary artery disease. Other risk factors like smoking, arterial hypertension, dyslipidemia, and oral tobacco were similar. Conversely, the percentage of Khat chewers was significantly higher in the MINOCA patients (P < 0.01) as compared to obstructive group.Conclusions:The relatively high incidence of MINOCA in our country and the long list of multiple potential causes of MINOCA should open further working diagnosis after coronary angiography and further efforts for defining the cause of myocardial infarction in each individual patient in Middle East countries.

Acute coronary syndrome: Uncommon presentation of multiple endocrine neoplasia.

IntroductionMyocardial infarction is usually due to thrombotic occlusion of a coronary vessel caused by rupture of a vulnerable atherosclerosis plaque. There is also the acute myocardial infarction with no evidence of relevant stenosis of the coronary artery, known as myocardial infarction with non-obstructive coronary arteries (MINOCA) such as Takotsubo, myocarditis and catecholamine induced cardiomyopathy. Pheochromocytoma is one of the causes of MINOCA. This association is rare but it may delay diagnosis and must be known in order to provide the best chance at early detection.This work has been reported in the line with the SCARE criteria.Presentation of the caseWe report a case of a 49 year-old man, admitted to our department for a recurrence of myocardial infarction with angiographically normal coronary arteries. During his hospitalization the patient complained of intestinal haemorrhage. The abdominal Computed tomographic scan revealed bilateral adrenal mass. The diagnosis of pheochromocytoma was made and confirmed by a high level of normetanephirnes and metanephrines.DiscussionThe coexistence of multiple endocrine neoplasia type 2 and myocardial infarction appears to be a rare association rather than a coincidence.ConclusionIn this case we highlight the importance of thorough history taking and investigation for the determining the aetiology of MINOCA. As a reversible cause of myocardial dysfunction, catecholamine-induced cardiomyopathy can occur as a feature of multiple endocrine neoplasia. The prognosis depends greatly on early diagnosis and prompt medical and surgical treatment, which are unfortunately often delayed because of the challenging diagnosis in many cases.

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.

Myocardial infarction with non-obstructive coronary artery disease, a retrospective cohort study: Are plaque disruption and other pathophysiological mechanisms the same disease?

Backgound/Aim: Myocardial infarction with non-obstructive coronary arteries (MINOCA) is an increasingly recognized entity. Recent studies have shown that MINOCA is not a benign syndrome, with younger MINOCA patients having outcomes comparable to their myocardial infarction with obstructive coronary artery disease (MI-CAD) counterparts. In this study, we will describe the demographic, clinical and angiographic characteristics of MINOCA patients in our hospital. Methods: In this retrospective cohort study, all patients who underwent coronary angiography with the diagnosis of acute coronary syndrome during September 2016-April 2019 were screened and those with MINOCA were detected. We described the demographic, clinical, and angiographic characteristics of MINOCA patients and compared the etiologic and pathophysiological mechanisms. Results: A total of 3855 patients with acute coronary syndrome were screened and 155 were diagnosed with MINOCA, with a total prevalence of 4.02%. Among them, 48.4% were female and the overall mean age was 55.04 (13.57) years. Plaque disruption was the most common cause of MINOCA (48.4%), which was followed by microvascular dysfunction and slow flow (9.7%). We compared plaque disruption and other causes to find that age (58.31 (13.76) vs 51.89 (12.68) P=0.003), hypertension (37 (48.7%) vs 25 (31.6%) P=0.034), prior coronary artery disease history (16 (21.1%) vs 2 (2.5%) P=0.001) and creatinine clearance (67.35 (IQR: 25.8) vs 74.0 (IQR: 28.58) P=0.009) were higher in patients with plaque disruption than those without. Conclusion: MINOCA is a diagnosis of exclusion with numerous potential causes. The etiological and pathophysiological mechanisms of plaque disruption are different from other causes of MINOCA and the correct treatment approach determines the prognosis.

Coronary Optical Coherence Tomography and Cardiac Magnetic Resonance Imaging to Determine Underlying Causes of Myocardial Infarction With Nonobstructive Coronary Arteries in Women.

Myocardial infarction with nonobstructive coronary arteries (MINOCA) occurs in 6% to 15% of myocardial infarctions (MIs) and disproportionately affects women. Scientific statements recommend multimodality imaging in MINOCA to define the underlying cause. We performed coronary optical coherence tomography (OCT) and cardiac magnetic resonance (CMR) imaging to assess mechanisms of MINOCA. In this prospective, multicenter, international, observational study, we enrolled women with a clinical diagnosis of myocardial infarction. If invasive coronary angiography revealed <50% stenosis in all major arteries, multivessel OCT was performed, followed by CMR (cine imaging, late gadolinium enhancement, and T2-weighted imaging and T1 mapping). Angiography, OCT, and CMR were evaluated at blinded, independent core laboratories. Culprit lesions identified by OCT were classified as definite or possible. The CMR core laboratory identified ischemia-related and nonischemic myocardial injury. Imaging results were combined to determine the mechanism of MINOCA, when possible. Among 301 women enrolled at 16 sites, 170 were diagnosed with MINOCA, of whom 145 had adequate OCT image quality for analysis; 116 of these underwent CMR. A definite or possible culprit lesion was identified by OCT in 46.2% (67/145) of participants, most commonly plaque rupture, intraplaque cavity, or layered plaque. CMR was abnormal in 74.1% (86/116) of participants. An ischemic pattern of CMR abnormalities (infarction or myocardial edema in a coronary territory) was present in 53.4% (62/116) of participants undergoing CMR. A nonischemic pattern of CMR abnormalities (myocarditis, takotsubo syndrome, or nonischemic cardiomyopathy) was present in 20.7% (24/116). A cause of MINOCA was identified in 84.5% (98/116) of the women with multimodality imaging, higher than with OCT alone (P<0.001) or CMR alone (P=0.001). An ischemic cause was identified in 63.8% of women with MINOCA (74/116), a nonischemic cause was identified in 20.7% (24/116) of the women, and no mechanism was identified in 15.5% (18/116). Multimodality imaging with coronary OCT and CMR identified potential mechanisms in 84.5% of women with a diagnosis of MINOCA, 75.5% of which were ischemic and 24.5% of which were nonischemic, alternate diagnoses to myocardial infarction. Identification of the cause of MINOCA is feasible and has the potential to guide medical therapy for secondary prevention. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02905357.

OCT and CMR for the Diagnosis of Patients Presenting With MINOCA and Suspected Epicardial Causes

ObjectivesAmong all patients presenting with myocardial infarction with nonobstructive coronary arteries (MINOCA), epicardial causes may be suspected when there is a correlation between electrocardiogram (ECG) changes and regional wall motion abnormalities (WMAs). We evaluated the diagnostic yield of intravascular optical coherence tomography (OCT) and cardiac magnetic resonance (CMR) in this specific setting. BackgroundOCT is able to identify different morphologic features of coronary plaques that are well known causes of MINOCA. Furthermore, CMR has become the gold standard for detection of myocardial infarction in the setting of MINOCA. MethodsIn a prospective 2-center study, consecutive patients with MINOCA including ECG features of ischemia associated with corresponding WMAs underwent OCT and CMR. ResultsForty patients (mean age: 50 ± 11 years, 62.5% male, 32.5% with ST-segment elevation) were enrolled. Coronary arteries were normal on coronary angiography in 10 patients (25%); 18 patients (45%) presented minimal lumen irregularities, whereas the remaining 12 patients (30%) showed mild to moderate (≥30% but <50%) coronary lesions. Plaque rupture, eruptive calcific nodule, plaque erosion, lone thrombus, and spontaneous coronary artery dissection were found in 14 (35%), 1 (2.5%), 12 (30%), 3 (7.5%), and 2 (5%) patients, respectively. Acute myocardial infarction was evident at CMR in 31 of 40 patients (77.5%). Twenty-three patients (57.5%) had a substrate and/or diagnosis supported by both techniques with an evident relationship between the findings obtained by the 2 techniques. By coupling OCT with CMR, a substrate and/or diagnosis was found in 100% of cases. ConclusionsOCT coupled with CMR can provide a clear substrate and/or diagnosis in the vast majority of patients presenting with MINOCA including ECG features of ischemia associated with corresponding WMAs.

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

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

Myocardial Infarction with Non-Obstructive Coronary Arteries: Contemporary Diagnostic and Management Approaches

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is diagnosed in the absence of anatomically significant stenoses (&lt;50% of lumen diameter) on coronary angiography and characterized by heterogeneity of etiologic factors. Recently, the mechanisms of MINOCA as well as the performance of diagnostic algorithms and therapeutic strategies have been extensively studied. The purpose of this review is to reflect the current concepts regarding the etiology and pathogenesis of MINOCA, diagnostic work-up methods and individualized treatment approaches. The article covers contemporary epidemiologic data, demographic and clinical patients’ characteristics and principal causes of MINOCA. We discuss aspects of disease definition and classification of related conditions involving troponin increase in the presence of normal coronary arteries. The importance of management strategy personalization for individual patients is stressed alongside stratification of risks of recurrent cardiovascular events. This review reflects key points from international consensus statements published by leading experts and suggests promising directions for future research.

Troponin-Positive Non-Obstructive Coronary Arteries and Myocardial Infarction with Non-Obstructive Coronary Arteries: Definition, Etiologies, and Role of CT and MR Imaging.

In approximately 10% of patients with acute myocardial infarction (MI), angiography does not reveal an obstructive coronary stenosis. This is known as myocardial infarction with non-obstructive coronary arteries (MINOCA), which has complex and multifactorial causes. However, this term can be confusing and open to dual interpretation, because MINOCA is also used to describe patients with acute myocardial injury caused by ischemia-related myocardial necrosis. Therefore, with regards to this specific context of MINOCA, the generic term for MINOCA should be replaced with troponin-positive with non-obstructive coronary arteries (TpNOCA). The causes of TpNOCA can be subcategorized into epicardial coronary (causes of MINOCA), myocardial, and extracardiac disorders. Cardiac magnetic resonance imaging can confirm MI and differentiate various myocardial causes, while cardiac computed tomography is useful to diagnose the extracardiac causes.