Risk of Thrombosis in Patients Presenting with Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA)

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

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

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.

Precision medicine in Myocardial Infarction With Non-obstructive Coronary Disease (MINOCA): A comprehensive review

Cardiovascular diseases, particularly myocardial infarction (MI), are a significant cause of mortality globally. Traditional MIs are commonly linked to substantial coronary artery blockage. However, a distinct subset of patients experience MI with non-obstructive coronary arteries, known as MINOCA. Imaging techniques, such as invasive coronary angiograms, are employed to diagnose MI or assess predisposition to one. Coronary angiograms help visualize vessel blockages; however, these blockages are absent in MINOCA cases, posing a diagnostic challenge. Precision medicine aims to introduce new diagnostic tools to assist in early diagnosis and further management of MINOCA. As percutaneous coronary intervention (PCI) does not benefit MINOCA patients, medical management tailored to the specific pathophysiological mechanism of MINOCA is employed. For example, if MINOCA is attributed to plaque disruption with or without plaque thrombus formation, the fundamental treatments may include statins, agents that modulate the renin-angiotensin system (RAS), and antiplatelet therapies. On the other hand, if coronary artery spasm is identified as the primary cause, essential intervention involves the use of calcium channel blockers. This approach has been previously utilized in patients with vasospastic angina and could be utilized in MINOCA, although research specific to MINOCA is ongoing. Therefore, the handling of MINOCA underscores the necessity for a tailored therapeutic strategy that corresponds to the underlying physiological mechanism responsible for the patient's clinical symptoms. Ongoing research initiatives are directed at expanding the availability of these treatments, uncovering new biomarkers, creating advanced diagnostic instruments, and establishing a more individualized approach for managing MINOCA patients.

Pathophysiology of Myocardial Infarction With Nonobstructive Coronary Artery Disease: A Contemporary Systematic Review

Background

Myocardial infarction with nonobstructive coronary artery disease (MINOCA) is defined as acute myocardial infarction (AMI) with angiographically nonobstructive coronary artery disease. MINOCA represents 6% of all AMI cases and is associated with increased mortality and morbidity. However, the wide array of pathophysiological factors and causes associated with MINOCA presents a diagnostic conundrum. Therefore, we conducted a contemporary systematic review of the pathophysiology of MINOCA.

Methods

A comprehensive systematic review of MINOCA was carried out through the utilization of the PubMed database. All systematic reviews, meta-analyses, randomized controlled trials, and cohort studies available in English or French that reported on the pathophysiology of MINOCA published after January 1, 2013 were retained.

Results

Of the 600 identified records, 80 records were retained. Central to the concept of MINOCA is the definition of AMI, characterized by the presence of myocardial damage reflected by elevated cardiac biomarkers in the setting of acute myocardial ischemia. As a result, a structured approach should be adopted to thoroughly assess and address clinically overlooked obstructive coronary artery disease, and cardiac and extracardiac mechanisms of myocyte injury. Once these options have been ruled out, a diagnosis of MINOCA can be established, and the appropriate multimodal assessment can be conducted to determine its specific underlying cause (plaque disruption, epicardial coronary vasospasm, coronary microvascular dysfunction, and coronary embolism and/or spontaneous coronary dissection or supply-demand mismatch).

Conclusions

Integrating a suitable definition of AMI and understanding the pathophysiological mechanisms of MINOCA are crucial to ensure an effective multimodal diagnostic evaluation and the provision of adequate tailored therapies.

MINOCA biomarkers: Non-atherosclerotic aspects

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

Coeliac Disease: A Rare Cause of Myocardial Infarction With Non-Obstructive Coronary Arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) poses a diagnostic dilemma. Identifying the underlying etiology is essential to ensuring appropriate management. Cardiac magnetic resonance (CMR) is a valuable tool that can aid clinicians for that purpose. Coeliac disease (CD) is characterized by hypercoagulability and a thrombotic state and represents an exceptional cause of MINOCA. We report the case of a 28-year-old woman who presented with chest pain. The diagnosis of non-ST-elevation MI was obtained based on ECG abnormalities and elevated troponin levels. Coronary angiography was normal. CMR showed late gadolinium enhancement in the lateral left ventricular wall, confirming the diagnosis of MINOCA. A duodenal biopsy allowed the diagnosis of CD. Anticoagulation and a gluten-free diet proved beneficial, with a good outcome after a five-year follow-up. This case highlights the essential role of CMR in MINOCA investigations and the importance of thorough etiological assessment in young patients with no cardiovascular risk factors.

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

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

MINOCA: under recognized and affecting predominantly female patients-an Australian experience

BACKGROUND

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is now being recognized as an important clinical entity with prognostic implications. There are limited data in relation to MINOCA in our local Australian settings.

AIM

We investigated the prevalence, clinical characteristics, major adverse cardiovascular events (MACE), and 1-year mortality of patients with MINOCA at Peninsula Health.

METHOD

A single-center retrospective study of all adult patients aged ≥ 18 years who underwent invasive angiography from January 2018 to June 2020 was identified from medical records. We included patients who met the definition of MINOCA as per the 2019 AHA Statement. A simple descriptive statistical analysis was performed.

RESULTS

The prevalence of MINOCA at Peninsula Health was 10.9% (131/1199) with a median age of 62 (IQR 53-74). Female patients were predominant, comprising 64% (84/131) of these patients. Chest pain was the most common symptom in 92.3% (121/131) and 58.8% (77/131) had ECG changes. A total of 81% (106/131) had a normal left ventricular systolic function and 47% of patients (66/139) had no luminal disease on invasive angiography. A total of 15.9% (23/144) of patients with an initial working diagnosis of MINOCA were referred for CMR on discharge. MACE was 5.2% (6/115) over a median follow-up of 23 months. The all-cause mortality rate at 1 year was 0.7% (1/131).

CONCLUSION

The clinical prevalence rate of MINOCA at Peninsula Health is 10.9% with a MACE of 5.2%. MINOCA is recognized and the low rate of additional testing could be improved given the female predominance and prognostic implications.

Antiphospholipid antibodies in patients with myocardial infarction with and without obstructive coronary arteries

BACKGROUND

Recent studies demonstrate that prothrombotic antiphospholipid antibodies (aPL) are overrepresented in patients with myocardial infarction (MI) due to coronary artery disease (MICAD). However, it is not known whether aPL differ between the two subsets of MI: MICAD and MI with nonobstructive coronary arteries (MINOCA).

OBJECTIVES

To determine whether aPL are associated with MINOCA or MICAD, or with hypercoagulability as assessed by activated protein C-protein C inhibitor (APC-PCI) complex.

METHODS

Well-characterized patients with MINOCA (n = 98), age- and gender-matched patients with MICAD (n = 99), and healthy controls (n = 100) were included in a cross-sectional case-control study. Autoantibodies (IgA/G/M) targeting cardiolipin and β₂ glycoprotein-I and specific nuclear antigens were analyzed by multiplexed bead technology. The concentration of APC-PCI was determined as a measure of hypercoagulability by an immunofluorometric sandwich assay.

RESULTS

Both prevalence and titers of aPL of the IgG isotype (anti-cardiolipin and/or anti-β₂ glycoprotein-I) were higher in patients with MINOCA and MICAD than in controls. aPL IgG positivity was twice as frequent among patients with MICAD than MINOCA (11% vs. 6%, nonsignificant). We observed no group differences regarding aPL IgA/M or antibodies targeting specific nuclear antigens. Levels of APC-PCI were elevated in aPL IgG-positive compared to aPL IgG-negative MICAD patients.

CONCLUSIONS

aPL IgG, but not IgA/M, are enriched particularly in patients with MICAD but also in patients with MINOCA, as compared to controls. Interestingly, signs of hypercoagulability-measured by increased levels of the APC-PCI complex-were present in aPL IgG-positive MICAD patients, indicating an association with functional disturbances of the coagulation system.

Myocardial Infarction in Systemic Lupus Erythematosus: Incidence and Coronary Angiography Findings

An association between acute myocardial infarction (AMI) and systemic lupus erythematosus (SLE) has been suggested. The cause of AMI is presumed to be atherothrombosis. In the present study, the primary objective was to assess incident AMI cases and the secondary objective was to estimate the proportion of myocardial infarction with nonobstructive coronary arteries (MINOCA) in patients with SLE. All Swedish patients with SLE without AMI before 1996 (n = 4192) were followed for 20 years in the national patient registry. For each SLE patient, 10 age- and sex-matched controls without SLE and AMI before 1996 (n = 41 892) were identified. Data from patients and controls with AMI after 1996 were linked with the Swedish coronary angiography and angioplasty register; 549 (13%) and 3352 (8%) first AMIs occurred in patients with SLE and controls, respectively. The incidence of AMI was 9.6 (95% CI: 8.9-10.5) and 4.9 (95% CI: 4.8-5.1) events/1000 person-years in patients with SLE and controls, respectively. The proportion of MINOCA was 10.8% in patients with SLE and 13.8% in controls (P = .261), respectively. In conclusion, the incidence of AMI is increased in a European population of patients with SLE but there is no indication that the proportion of MINOCA is increased in these patients.

A Rare Case of Myocardial Infarction with Nonobstructive Coronary Arteries Due to Hereditary Thrombophilia

The incidence of acute myocardial infarction with nonobstructive coronary arteries in young age less than 20 years in India due to hereditary thrombophilia is uncommon. Combined protein S and protein C deficiency has an increased tendency for coronary artery thrombosis in very young individuals. Acute myocardial infarction in young individuals has different risk factors profile, clinical presentation, and prognosis when compared with elderly population and hence incites the need for different approach in the management. Here we report a case of 17-year-old boy who presented with acute inferior wall myocardial infarction with nonobstructive coronary arteries due to hereditary protein C and protein S deficiency.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Prevalence and clinical profile of patients with myocardial infarction with non-obstructive coronary arteries in Turkey (MINOCA-TR): A national multi-center, observational study

OBJECTIVE

Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA) is a relatively new term that is characterized by clinical evidence of MI with normal or near-normal coronary arteries on coronary angiography (QCA). To date, there have been no population-based studies on the prevalence of MINOCA in Turkey. The aim of this nationwide study was to document the prevalence and demographics of MINOCA in a Turkish population.

METHODS

MINOCA-TR is national, multi-center, prospective, all-comer study that was conducted in 32 hospitals. All consecutive patients who were ≥18 years old, diagnosed with MI according to the Third Universal Definition of Myocardial Infarction, and had undergone QCA were included in the study. Patients with stable coronary artery disease, unstable angina pectoris, a history of revascularization, and type 4/5 MI were excluded.

RESULTS

A total of 1793 patients who were diagnosed with MI and had undergone QCA were screened between March 2018 and October 2018, of whom 1626 (mean age: 61.5±12.5 years, 70.7% male) were enrolled from 32 centers. The prevalence of MINOCA was 6.7% (n=109) in the overall study population. Compared with non-MINOCA patients, those with MINOCA were younger, had a higher prevalence of the female gender, and had a history of flu. The percentages of current smokers, ST-segment elevated myocardial infarction patients, and those with a history of hypertension, diabetes mellitus, and hyperlipidemia were significantly lower in MINOCA patients (p<0.05, for all). Also, the median left ventricular ejection fraction as seen on echocardiography and the ratio of Killip Class I status at presentation was significantly higher in MINOCA patients than in non-MINOCA patients (p<0.001). Patients with MINOCA received a preload dose of P2Y12 antagonist before QCA less often than non-MINOCA patients (p<0.001).

CONCLUSION

The prevalence of MINOCA in Turkey is 6.7% in patients who were admitted with MI. Also, as compared to non-MINOCA patients, the MINOCA patients were exposed to fewer traditional risk factors of coronary artery disease.

Peripartum myocardial infarction associated with coronary spasm and acquired protein S deficiency: A case report

RATIONALE

Coronary angiography (CAG) findings of acute myocardial infarction (AMI) in pregnant women are characterized by a high incidence of normal coronary arteries. This is the first report of AMI with normal coronary arteries during pregnancy, showing coronary spasm and pregnancy-related acquired protein S (PS) deficiency.

PATIENT CONCERNS

A 30-year-old Japanese woman was admitted to an emergency department. One hour before admission, she developed sudden onset of precordial discomfort, back pain, and dyspnea. She was a primigravida at 39 weeks' gestation and had no abnormality in the pregnancy thus far. She had no history of heart disease, diabetes, hypertension, dyslipidemia, deep vein thrombosis (DVT), smoking, or oral contraceptive use and no family history of ischemic heart disease, hemostasis disorder, or DVT. She did not take any medication.

DIAGNOSIS

Electrocardiography showed ST-segment elevations in leads II, III, aVF, and V2-V6. Heart-type fatty acid-binding protein was positive. Echocardiography showed hypokinesis of the anterior interventricular septum and inferior wall. Continuous intravenous infusion of isosorbide dinitrate was initiated. Coronary computed tomography angiography revealed diffuse narrowing of the apical segment of the left anterior descending coronary artery. Three hours after admission, troponin T became positive, and the following enzymes reached their peak levels: creatine kinase (CK), 1,886 U/L; CK-muscle/brain, 130 U/L. She was diagnosed with transmural AMI due to severe coronary spasm and administered benidipine hydrochloride. Five hours after admission, premature membrane rupture occurred.

INTERVENTIONS

Emergency cesarean section was performed. There were no anesthetic or obstetrical complications during the operation. On postpartum day 1, the free PS antigen level was low (29%). On postpartum day 18, she was discharged with no reduction in physical performance.

OUTCOMES

Four months after the infarction, CAG showed normal coronary arteries. Acetylcholine provocation test showed diffuse vasospasm in the coronary artery. She was advised that her next pregnancy should be carefully planned. Two years after delivery, free PS antigen level was within normal range, at 86%. She had not experienced recurrence of angina during the 2-year period. Her child was also developing normally.

LESSONS

In addition to coronary spasm, pregnancy-related acquired PS deficiency may be involved in AMI etiology.

[Hemostatic Gene Polymorphisms in Acute Coronary Syndrome with Nonobstructive Coronary Atherosclerosis]

PURPOSE

to study distribution of genes of the coagulation system, unfavorable in relation to the risk of thrombosis, and their influence on serum parameters ofthe hemostasis system in patients with nonobstructive coronary atherosclerosis (NCA) and acute coronary syndrome (ACS).

MATERIALS AND METHODS

We included in this nonrandomized open study patients with ACS older than 18 years with intact coronary arteries or confirmed at coronary angiography stenosis &lt;50%. Genotypes of these patients were analyzed by 8 polymorphic variants of the hemostatic system genes which previously were found to be associated with the thrombophilia risk: F2 (20210 G&gt;A) rs1799963, F5 (1691 G&gt;A) rs6025, F7 (10976G&gt;A) rs6046, F13 (163 G&gt;T) rs5985, F1 (-455G&gt;A) rs1800790, GP Ia - Ila (807C&gt;t) rs1126643, GP Ilb-IIIa (1565 T&gt;C) rs5918, PAI-I (-6755G&gt;4G) rs1799889. Activities of protein C, Von Willebrand factor, plasminogen, and antithrombin III were also determined.

RESULTS

Of 913 patients with ACS in 30 (3.3%) with mean age 54±11 years we detected NCA. Acute myocardial infarction (AMI) was diagnosed in 24 (80%), unstable angina - in 6 (20%) patients. Only in 1 patient we found no carriage of thrombosis associated genotypes. The frequency of occurrence of the heterozygous genotype of the factor V gene was 1 (3%). Heterozygous genotype of the factor XIII was registered significantly more often in patients with present atherosclerotic lesion compared with those with intact coronary arteries. Mean activity of protein C was 103% [90; 110], antithrombin III - 96% [88; 103], Von Willebrand factor - 137% [114; 162], plasminogen - 109% [102; 112]. At admission lowering of antithrombin III and protein C activities was detected in 4 cases (13%). In dynamics level of these parameters was restored. Elevation of Von Willebrand factor activity at admission was detected in 14 cases (14%) and remained elevated one year after the index event. There was no association between of fibrinogen level, protein C activity, rs1800790 and rs6025 gene polymorphisms, respectively. One-year mortality was 7% (n=2). For one year occurred 1 AIM recurrence (3%), heart failure developed in 15 patients (50%), 11 patients (37%) were repetitively hospitalized due to all causes. No association was revealed between activity of studied blood serum markers and 1 -year outcomes (death, re-AIM, rehospitalization).

CONCLUSION

Among ACS patients 3.3% had NCA, what corresponded to the literature data. Carriage of at least 1 polymorphic variant of 8 thrombosis associated genes of the coagulation system was found in 97 % of patients with ACS and NCA. Distribution of these variants was like that in the European population and in patients with AIM at the background of stenosing atherosclerosis. Level of serum markers did not depend on distribution of polymorphic variants of the coagulation system genes, and presence of atherosclerotic coronary artery lesions. There was no association between hospital and long-term outcomes and distribution of polymorphic variants of thrombosis associated coagulation system genes, as well as levels of blood serum markers.