Early Comprehensive Cardiovascular Magnetic Resonance Imaging in Patients With Myocardial Infarction With Nonobstructive Coronary Arteries

Antiplatelet Treatment Strategy in MINOCA Patients: Predictors of Decision Making in Clinical Practice and Prognostic Implications

Background/Objectives: Large clinical trials have established the optimal antiplatelet strategy in the wide spectrum of coronary artery disease. However, data are scarce regarding MINOCA and the aim of our study is to present data from the current clinical practice. Methods: A total of 151 patients were included in this study after exclusion of 27 patients with myocarditis and other diagnoses. A cardiac magnetic resonance (CMR) performed at 123/151 patients demonstrated an ischemic pattern of late gadolinium enhancement (LGE) confirming the diagnosis of true acute myocardial infarction (AMI) in 42 cases (28%). Based on multimodality imaging and clinical judgement, Takotsubo syndrome (TTS) was diagnosed in 55 patients (36%), whereas CMR failed to reveal abnormal findings in 54 cases (36%), categorized as MINOCA of unknown origin. Results: Regarding antithrombotic prescriptions at discharge, 38% of patients received dual antiplatelet (DAPT) or dual antithrombotic therapy (DAT, 1 antiplatelet plus 1 anticoagulant), 49.7% received single antiplatelet (SAPT) or anticoagulant, and 12% received no antithrombotic treatment. Univariate analysis showed that the likelihood of prescribing DAPT or DAT was associated with left ventricular ejection fraction (LVEF) (r = 0.202, p = 0.013), atherosclerotic lesions on coronary angiography (r = 0.303, p < 0.001), prior use of anticoagulants (r = -0.258, p = 0.001), and marginally with the INTERTAK score (r = -0.198, p = 0.044). A multivariable model, adjusted for age, LVEF, ECG abnormalities, and history of anticoagulant use, confirmed the independent association between angiographic evidence of atherosclerosis and the decision for DAPT/DAT (OR: 0.334, 95% CI: 0.307-0.813, p < 0.001). However, the initial treatment decision did not seem to impact 2-year prognosis in our population. Conclusions: Our study results reveal that decision making in the antithrombotic strategy for MINOCA patients poses a challenge in clinical practice. More robust data are required for definite conclusions on the prognostic implications.

Incremental value of coronary computed tomography angiography in addition to invasive coronary angiography in MINOCA

Patients with the working diagnosis myocardial infarction with nonobstructive coronary arteries (MINOCA) have diverse underlying causes warranting further investigations. Despite the documented superiority of coronary computed tomography angiography (CCTA) over invasive coronary angiography (ICA) in plaque detection, the former is not routinely recommended for MINOCA patients, highlighting a knowledge gap regarding CCTA's incremental value. The objective of this study is to assess the prevalence and extent of coronary atherosclerosis in MINOCA patients using CCTA, and to evaluate the incremental value of CCTA over ICA alone in detecting coronary atherosclerosis. The data from 163 MINOCA patients who underwent both CCTA and ICA in two prospective studies were retrospectively analyzed to compare the occurrence and distribution of coronary atherosclerotic plaques detected with ICA versus CCTA, evaluating CCTA's incremental value. CCTA detected coronary atherosclerosis in 48% of subjects; ICA did so in 47%. Notable disagreement, reflected by kappa values of 0.34 (95% confidence interval [CI] 0.19-0.48) across all segments and 0.41 (95% CI 0.27-0.55) for proximal segments (both p < 0.0001), highlighted discrepancies between CCTA and ICA in the detection of atherosclerosis presence and location. Combining CCTA with ICA provided significant incremental value in detecting atherosclerosis in coronary segments (p < 0.001). MINOCA patients frequently exhibit non-obstructive coronary plaques. Agreement between CCTA and ICA is poor. CCTA provides valuable additional information on atherosclerotic segments. Therefore, CCTA should be recognized as a complementary tool to ICA, aiding risk assessment and treatment decisions in the context of MINOCA.

Adherence to secondary preventive treatment following myocardial infarction with and without obstructive coronary artery disease

BACKGROUND

Secondary preventive medications following myocardial infarction (MI) reduce the risk of new cardiovascular events. Discontinuation and suboptimal adherence are common and affect prognosis. However, there is limited knowledge regarding adherence in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA). We therefore aim to evaluate the adherence to guideline recommended medications in patients with MINOCA and myocardial infarction with obstructive coronary arteries (MI-CAD).

METHODS

This was a Swedish nationwide observational study of MI patients recorded in the SWEDEHEART registry between 2006─2017. A total of 9,138 MINOCA and 107,240 MI-CAD patients were followed for a mean 5.9 years. Initiation of therapy, implementation determined using medication possession ratio, and persistence rates during different time periods were calculated.

RESULTS

Patients with MINOCA were less frequently prescribed secondary preventive medications than MI-CAD. The percentage of patients taking medication as prescribed were lower in MINOCA than in MI-CAD at all time points; during months 6─12 after discharge: aspirin 94.8% vs 97.2% (p < 0.001), statins 90.3% vs 94.7% (p < 0.001), and ACEI/ARBs 97.7% vs 98.5% (p = 0.002) and at 12 months: aspirin 84.4% vs 93.7% (p < 0.001), statins 83.8% vs 94.8% (p < 0.001), ACEI/ARBs 85.0% vs 92.2% (p < 0.001) and beta blockers 80.4% vs 89.6% (p < 0.001).

CONCLUSION

The rates of initiation, implementation, and persistence of secondary preventive medications were high in both MINOCA and MI-CAD patients during the first 5 years after MI. The lower rates in patients with MINOCA may be partially due to uncertainties regarding the diagnosis of MINOCA, differences in patient characteristics, and psychosocial factors. Suboptimal medical adherence in patients with MINOCA may adversely affect prognosis as previously demonstrated in MI-CAD patients.

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.

Rationale and design of the cyclosporine in Takotsubo syndrome (CIT) trial

BACKGROUND

Takotsubo syndrome (TTS) is associated with substantial morbidity and mortality, even though ejection fraction frequently recovers spontaneously. TTS has been suggested to be caused by catecholamine excess leading to myocardial inflammation as an additional driver of cardiac damage and impaired outcome. Currently, no evidence-based treatment exists. In a preclinical model of catecholamine-driven TTS, cyclosporine A (CsA) bolus therapy significantly improved outcome, likely mediated via suppression of calcineurin-driven inflammation. The Cyclosporine In Takotsubo syndrome (CIT) trial is a pilot multicenter double-blinded randomized placebo-controlled trial (RCT) to investigate the impact of CsA bolus therapy in patients suffering from acute TTS.

STUDY DESIGN AND OBJECTIVES

This RCT is designed to investigate the impact of repetitive CsA bolus therapy vs. placebo in acute high-risk TTS patients with an increased risk of intrahospital complications and long-term mortality. The main goal is to reduce myocardial damage quantified by AUC of a centrally measured high-sensitive cardiac Troponin T (hs-cTnT) over 72 hours (primary endpoint). Therefore, patients with TTS will be randomized 1:1 after angiography and receive an intravenous bolus of 2.5 mg/kg CsA or an equivalent amount of placebo immediately after baseline measurements. At 12 and 24 hours additional doses of the study drug will be applied accumulating to 7.5 mg/kg in the intervention group. After baseline laboratory measurements (including hs-cTnT) and echocardiography (TTE), serum parameters will be measured again at 3 hours and every 12 hours from baseline. TTE imaging will be performed at 24, 48 and 72 hours, and cardiac magnetic resonance imaging (CMR) at 24 to 96 hours. Left ventricular function recovery, myocardial edema (CMR), in-hospital complications, length of hospital stay, 30-day and 1-year composite cardiovascular outcome, as well as Kansas City Cardiomyopathy Questionnaire self-assessment are included as secondary endpoints.

CONCLUSIONS

The CIT trial is designed to assess the safety and potential benefit of CsA on hs-cTnT release as an established marker of myocardial injury in high-risk TTS patients. The results of this trial may reveal CsA as a first pathophysiology-driven treatment option of TTS and enable a phase III follow-up trial powered for clinical outcome parameters as primary endpoint.

CLINICAL TRIALS IDENTIFIER

NCT05946772.

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.

Electrocardiographic correlates of cardiac magnetic resonance findings in women with myocardial infarction with non-obstructive coronary arteries

BACKGROUND

Myocardial infarction with nonobstructive coronary arteries (MINOCA) occurs in 6-15 % of MI patients. Cardiac magnetic resonance (CMR) imaging identifies MINOCA etiologies, but access may be limited.

METHODS

We assessed associations between the index electrocardiogram (ECG) and CMR in MINOCA. Women with MI and < 50 % angiographic stenosis in all vessels were prospectively enrolled at 16 sites. CMR (median 6d from MI) was analyzed for late gadolinium enhancement (LGE), myocardial edema, and wall motion. We assessed ECGs for T-wave inversions (TWI), Q-waves (QW), ST-elevations (STE), ST-depressions (STD), and fragmented QRS complexes (fQRS). We calculated the DETERMINE score (# leads TWI + # fQRS +2*[# QW], excluding aVR, V1).

RESULTS

Among 112 women with interpretable ECG, 81.3 % (91/112) had abnormal ECG; 50 % (56/112) had ≥1 TWI. CMR was abnormal in 74.1 % (83/112), with LGE in 49.1 % (55/112) and myocardial edema in 61.6 % (69/112). DETERMINE score ≥ 3 was associated with abnormal CMR (adjusted odds ratio [aOR] aOR 6.06 [1.89, 24.6], p = 0.002) and LGE (aOR 3.10 [1.26, 8.00], p = 0.013), but not edema (aOR 1.86 [0.80, 4.43], p = 0.152). TWI was also associated with abnormal CMR and LGE after adjustment (aOR 3.13 [1.08, 10.1], p = 0.036, aOR 3.23 [1.27, 8.63], p = 0.013, respectively), but not edema (aOR 1.26 [0.54, 2.96], p = 0.589). Specificity for abnormal CMR was 0.83 for DETERMINE score ≥ 3 and 0.75 for TWI. No other ECG findings were associated with CMR abnormality.

CONCLUSION

DETERMINE score ≥ 3 and the presence of any TWI were associated with abnormal CMR and with LGE in MINOCA. Our findings demonstrate that the index ECG can provide insight on CMR findings but without sensitivity or specificity required to forgo the CMR. We reaffirm the central role of CMR in elucidating MINOCA pathophysiology.

Atrial fibrillation versus non-atrial fibrillation coronary embolism

BACKGROUND

Coronary embolism (CE) is an uncommon cause of non-atherosclerotic acute myocardial infarction (AMI). Although atrial fibrillation (AF) is the main cause of CE, evidence of clinical, biochemical, echocardiographic, angiographic findings and outcomes of AF CE is lacking.

METHODS

We retrospectively analyzed 85 consecutive patients with CE that was diagnosed based on criteria encompassing clinical, angiographic and diagnostic imaging findings. We classified patients according to AF CE or non-AF CE.

RESULTS

Forty-five patients presented with AF CE (53%). Patients with AF CE were older (76 ± 12 vs. 63 ± 14 years; p < 0.001) and had more often chronic kidney disease (24% vs. 5%; p = 0.01). AF CE had lower estimated glomerular filtration rate at admission (59 ± 18 vs. 77 ± 16 ml/min/1.73 m2; p < 0.001) and higher brain natriuretic peptide levels (512 ± 417 vs. 210 ± 479 pg/ml; p = 0.02). Coronary arteriography revealed a higher incidence of coronary artery obstruction in the AF CE group (73% vs. 38%; p = 0.001) without differences in interventional management. The AF CE group showed higher left atrial volume index (LAVI) (42 ± 15 vs. 25 ± 12 ml/m2; p < 0.001) and showed lower left atrium ejection fraction (LAEF) (32 ± 17 vs. 49 ± 17%; p = 0.001). In the multivariable analysis AF CE (OR 10 [95% CI 1.04-95; p = 0.046]) and LAEF (OR 0.94 [95% CI 0.88-0.99; p = 0.02]) were associated with worse in-hospital outcomes. Moreover, in the multivariable analysis, prior stroke (OR 12.5 [95% CI 1.1-137; p = 0.04]) and LAVI (OR 1.1 [95% CI 1.03-1.14; p = 0.003]) were independently associated with worse long-term outcomes.

CONCLUSION

AF CE has specific characteristics compared to non-AF-CE and it is associated with more in-hospital events. Furthermore, atrial cardiopathy is associated with worse in-hospital and long-term outcomes in this setting.

Familial risk of myocardial infarction with non-obstructive and obstructive coronary arteries -A nation-wide cohort study

BACKGROUND AND AIMS

The familial risk among patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) is unknown. Previous studies of family history in myocardial infarction (MI), have not made a distinction between MINOCA and MI due to coronary artery disease (MI-CAD), based on angiographic findings. We therefore sought to investigate familial risk of MI without and with obstructive coronary arteries.

METHODS

Register-based cohort study with a total of 15,462 MINOCA cases, 204,424 MI-CAD cases, 38,220 control subjects without MI and with non-obstructive coronary arteries. First-degree relatives were identified 1995-2020. Cox proportional hazard regression models were used to compare familial risk in MINOCA and MI-CAD with control subjects.

RESULTS

During a mean follow-up of 8.1 ± 4.2 years, MINOCA occurred in 1.0% of first-degree relatives with MINOCA whereas MI-CAD occurred in 9.7% of first-degree relatives of MINOCA. The age- and sex-adjusted hazard ratio (HR) for a MINOCA-relative experiencing MINOCA and MI-CAD, compared to control subjects, was 0.99 (95% confidence interval [CI] 0.80-1.23) and 1.10 (95% CI 1.03-1.18), respectively. During a mean follow-up of 8.5 ±4.8 years, MI-CAD occurred in 12.2% of first- degree relatives with MI-CAD with age- and sex-adjusted HR 1.43 (95% CI 1.37-1.49).

CONCLUSIONS

No increased familial risk of MINOCA was observed for MINOCA-patients whereas there was an increased familial risk for MI-CAD when compared to control subjects. These results may indicate that genetic factors and shared environmental factors within a family leading to CAD are important also for MINOCA, thus MI-CAD and MINOCA could share underlying mechanisms.

Cardiovascular Magnetic Resonance Imaging of Takotsubo Syndrome: Evolving Diagnostic and Prognostic Perspectives

Takotsubo syndrome (TS) is a temporary form of left ventricular (LV) dysfunction characterized by a distinct pattern of LV impairment, often triggered by a physical or emotional stressful event. Historically, TS was considered a benign condition due to its prompt restoration of myocardial function and generally excellent outcomes. However, recent studies have shown that complications similar to those seen after myocardial infarction can occur, necessitating careful monitoring of these patients. Among noninvasive imaging techniques, cardiovascular magnetic resonance (CMR) is becoming increasingly important in evaluating patients with TS. CMR offers a unique ability to noninvasively assess myocardial tissue characteristics, allowing for detecting the typical features of TS, such as specific wall motion abnormalities and myocardial edema. Beyond its well-established diagnostic utility in the clinical management of TS, CMR has also proven valuable in prognosis and risk stratification for these patients. Advances in CMR, including myocardial strain and parametric mapping have expanded its role in the diagnosis, prognosis, and follow-up of these patients. This review aims to provide a comprehensive overview of the potential applications of CMR in the diagnostic and prognostic evaluation of TS patients. It explores the emerging use of novel CMR imaging biomarkers that may enhance diagnosis, improve prognostic accuracy, and contribute to the overall management of these patients.

Cardiovascular Magnetic Resonance Before Invasive Coronary Angiography in Suspected Non-ST-Segment Elevation Myocardial Infarction

BACKGROUND

In suspected non-ST-segment elevation myocardial infarction (NSTEMI), this presumed diagnosis may not hold true in all cases, particularly in patients with nonobstructive coronary arteries (NOCA). Additionally, in multivessel coronary artery disease, the presumed infarct-related artery may be incorrect.

OBJECTIVES

This study sought to assess the diagnostic utility of cardiac magnetic resonance (CMR) before invasive coronary angiogram (ICA) in suspected NSTEMI.

METHODS

A total of 100 consecutive stable patients with suspected acute NSTEMI (70% male, age 62 ± 11 years) prospectively underwent CMR pre-ICA to assess cardiac function (cine), edema (T2-weighted imaging, T1 mapping), and necrosis/scar (late gadolinium enhancement). CMR images were interpreted blinded to ICA findings. The clinical care and ICA teams were blinded to CMR findings until post-ICA.

RESULTS

Early CMR (median 33 hours postadmission and 4 hours pre-ICA) confirmed only 52% (52 of 100) of patients had subendocardial infarction, 15% transmural infarction, 18% nonischemic pathologies (myocarditis, takotsubo, and other forms of cardiomyopathies), and 11% normal CMR; 4% were nondiagnostic. Subanalyses according to ICA findings showed that, in patients with obstructive coronary artery disease (73 of 100), CMR confirmed only 84% (61 of 73) had MI, 10% (7 of 73) nonischemic pathologies, and 5% (4 of 73) normal. In patients with NOCA (27 of 100), CMR found MI in only 22% (6 of 27 true MI with NOCA), and reclassified the presumed diagnosis of NSTEMI in 67% (18 of 27: 11 nonischemic pathologies, 7 normal). In patients with CMR-MI and obstructive coronary artery disease (61 of 100), CMR identified a different infarct-related artery in 11% (7 of 61).

CONCLUSIONS

In patients presenting with suspected NSTEMI, a CMR-first strategy identified MI in 67%, nonischemic pathologies in 18%, and normal findings in 11%. Accordingly, CMR has the potential to affect at least 50% of all patients by reclassifying their diagnosis or altering their potential management.

The Spectrum of Coronary Artery Disease in Elite Endurance Athletes-A Long-Standing Debate: State-of-the-Art Review

Physical activity is recommended for the prevention of primary and secondary cardiovascular (CV) disease as it is linked to a number of health benefits, especially CV. However, recent research suggests that high-volume, long-term endurance exercise may hasten rather than slow the coronary atherosclerosis progression. This contentious theory has generated a great discussion and is still a major source of doubt when it comes to the clinical treatment of coronary artery disease (CAD) in athletes. CAD is the primary cause of sudden cardiac death in athletes over 35 years. Thus, recent studies evaluated the prevalence of CAD in athletes and its clinical and prognostic implications. Indeed, many studies have shown a relationship between endurance sports and higher volumes of coronary calcified plaque as determined by computed tomography. However, the precise pathogenetic substrate for the existence of an increased coronary calcification burden among endurance athletes remains unclear. Moreover, the idea that coronary plaques in elite athletes present a benign morphology has been cast into doubt by some recent studies showing potential association with adverse cardiovascular events. This review aims to analyze the association between physical activity and CAD, explaining possible underlying mechanisms of atherosclerotic progression and non-ischemic coronary lesions, focusing primarily on clinical and prognostic implications, multimodal evaluation, and management of CAD in endurance athletes.

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.

How to Use Cardiac Magnetic Resonance Imaging in Myocardial Infarction With Nonobstructive Coronary Arteries

The working diagnosis Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA) is being increasingly recognized with the common use of high-sensitivity troponins and coronary angiography, accounting for 5% to 10% of all acute myocardial infarction presentations. Cardiac magnetic resonance (CMR) imaging is pivotal in patients presenting with suspected MINOCA, mainly to delineate those with a nonischemic cause, for example, myocarditis and Takotsubo syndrome, from those with true ischemic myocardial infarction, that is, MINOCA. The optimal timing for CMR imaging in patients with suspected MINOCA has been uncertain and, until recently, not been examined prospectively. Previous retrospective studies have indicated that the diagnostic yield decreases with time from the acute event. The SMINC studies (Stockholm Myocardial Infarction with Normal Coronaries) show that CMR should be performed early in all patients with the working diagnosis of MINOCA, with the possible exception of patients who are clearly identified as having Takotsubo syndrome as determined by echocardiography. In addition to CMR imaging, other investigations of importance in selected patients may be pulmonary artery computed tomography to exclude pulmonary embolism, optical coherence tomography to identify plaque disruption, and acetylcholine provocation to identify coronary artery spasm. Imaging of patients with the working diagnosis MINOCA, which is centered on CMR together with supplemental investigations, results in a clear diagnosis in approximately three-quarters of the patients. This is a good example of personalized medicine, because a correct diagnosis will not only increase the satisfaction of the individual patient but also result in optimizing treatment without harming the patient.

Timing of cardiac magnetic resonance and diagnostic yield in patients with myocardial infarction with nonobstructive coronary arteries

INTRODUCTION AND OBJECTIVES

The present study sought to establish the diagnostic yield of cardiovascular magnetic resonance (CMR) in a large cohort of patients admitted with myocardial infarction (MI) with nonobstructive coronary artery disease (MINOCA) based on the timing of referral to CMR.

METHODS

Consecutive patients referred to CMR from January 2009 to February 2022 with a working diagnosis of MINOCA were retrospectively evaluated. Cine, T2-weighted, early, and late gadolinium-enhanced images were acquired and analyzed. The frequency of the underlying diagnosis and the association between timing of CMR and relative frequency of each diagnosis were assessed.

RESULTS

We included 207 patients (median age 50 years, 60% men). Final diagnosis after CMR was achieved in 91% of the patients (myocarditis in 45%, MI in 20%, tako-tsubo cardiomyopathy in 19%, and other cardiomyopathies in 7%). The performance of CMR within 7 days of admission with MINOCA (median, 5 days; 117 patients) allowed a higher diagnostic yield compared with CMR performed later (median, 10 days; 88 patients) (96% vs 86%, P=.02). Although myocarditis was the most frequent diagnosis in both groups according to time to CMR, its frequency was higher among patients with a CMR performed within the first 7 days (53% vs 35%, P=.02). The frequency of other underlying diagnoses was not influenced by CMR timing.

CONCLUSIONS

CMR led to an underlying diagnosis of MINOCA in 91% of patients and its diagnostic yield increased to 96% when CMR was performed within 7 days of admission. The most frequent diagnosis was myocarditis..

Early versus late cardiac magnetic resonance in the diagnosis of myocardial infarction with non-obstructive coronary arteries

INTRODUCTION AND OBJECTIVES

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for about 10% of all acute myocardial infarctions (AMI). Therapeutic strategies and prognosis depend on the underlying etiology, and a multimodal approach is essential. The objectives of this study were to characterize the group of patients diagnosed with MINOCA and to valuate the diagnostic yield of cardiovascular magnetic resonance (CMR).

METHODS

This was a retrospective, observational, and analytical study, including 516 patients admitted for a non-ST-elevation MI and with no significant coronary disease on coronary angiography between January 2016 and September 2021.

RESULTS

After the inclusion criteria, 163 patients remained of the 516 admitted to the study. They were divided into four groups based on the CMR results: MINOCA (n=51), Takotsubo syndrome (n=37), myocarditis (n=33), and without diagnosis (n=42). Most patients diagnosed with MINOCA were female with a mean age of 61.06±13.83 years. CMR identified the diagnosis in 74.2% of patients admitted for suspected acute MI, in which coronary angiography showed the absence of significant obstructions. The median time between hospital admission and CMR was significantly shorter in the groups that had a diagnosis compared with the group with no diagnosis (p=0.038), with a significant increase in diagnostic profitability if CMR was performed up to 14 days after admission (p=0.022). There were no deaths of cardiovascular etiology during the follow-up period.

CONCLUSIONS

CMR was fundamental as it identified the diagnosis in three out of four patients; it should be performed in the first 14 days.

European Association of Cardiovascular Imaging survey on cardiovascular multimodality imaging in acute myocarditis

AIMS

To assess the current role of cardiac imaging in the diagnosis, management, and follow-up of patients with acute myocarditis (AM) through a European Association of Cardiovascular Imaging survey.

METHODS AND RESULTS

A total of 412 volunteers from 74 countries responded to the survey. Most participants worked in tertiary centres (56%). All participants had access to echocardiography, while 79 and 75% had access to cardiac computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR), respectively. Less than half (47%) had access to myocardial biopsy, and only 5% used this test routinely. CMR was performed within 7 days of presentation in 73% of cases. Non-ischaemic late gadolinium enhancement (LGE, 88%) and high-signal intensity in T2-weighted images (74%) were the most used diagnostic criteria for AM. CCTA was preferred to coronary angiography by 47% of participants to exclude coronary artery disease. Systematic prescription of beta-blockers and angiotensin-converting enzyme inhibitors was reported by 38 and 32% of participants. Around a quarter of participants declared considering LGE burden as a reason to treat. Most participants (90%) reported performing a follow-up echocardiogram, while 63% scheduled a follow-up CMR. The main reason for treatment discontinuation was improvement of left ventricular ejection fraction (89%), followed by LGE regression (60%). In two-thirds of participants, the decision to resume high-intensity sport was influenced by residual LGE.

CONCLUSION

This survey confirms the high utilization of cardiac imaging in AM but reveals major differences in how cardiac imaging is used and how the condition is managed between centres, underlining the need for recommendation statements in this topic.

[Myocardial Infarction with no obstructive coronary arteries: Imaging plays a central role]

Myocardial infarction with non-obstructive coronary lesion (MINOCA) represents a non-negligible percentage of the proportion of myocardial infarctions (≈6%). Moreover, the long-term prognosis is poor, with an annual mortality rate of 2%. This high mortality rate may be explained by the fact that MINOCA represents a heterogeneous group, and the diagnosis of pathology is poorly understood. It is essential to be aware of this clinical presentation, and to follow the different diagnostic strategies, in order to identify the etiological mechanism, and thus set up a suitable treatment. Many tools are available to support diagnosis, notably in the fields of imaging, the principal contributors being coronary angiography, coronary physiology and pharmacological testing, as well as endo-coronary imaging and cardiac MRI. This review will provide an update on the definition, epidemiology, diagnostic strategies and treatment options for patients with MINOCA.

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.

Value of a short non-contrast CMR protocol in MINOCA

OBJECTIVES

To evaluate the diagnostic performance of a short non-contrast CMR (ShtCMR) protocol relative to a matched standard comprehensive CMR (StdCMR) protocol in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA).

METHODS

This multicenter retrospective study included patients with a working diagnosis of MINOCA who underwent a StdCMR between January 2019 and December 2020. An expert and a non-expert reader performed a blinded reading with the ShtCMR (long-axis cine images, T2w-STIR, T1- and T2-mapping). A consensus reading of the StdCMR (reference standard) was performed at least 3 months after the ShtCMR reading session. Readers were asked to report the following: (1) diagnosis; (2) level of confidence in their diagnosis with the ShtCMR; (3) number of myocardial segments involved, and (4) functional parameters.

RESULTS

A total of 179 patients were enrolled. The ShtCMR lasted 21 ± 9 min and the StdCMR 45 ± 11 min (p < 0.0001). ShtCMR allowed reaching the same diagnosis as StdCMR in 85% of patients when interpreted by expert readers (rising from 66% for poor confidence to 99% for good, p = 0.0001) and in 73% (p = 0.01) by non-expert ones (60% for poor vs 89% for good confidence, p = 0.0001). Overall, the ShtCMR overestimated the ejection fraction, underestimated cardiac volumes (p < 0.01), and underestimated the number of segments involved by pathology (p = 0.0008) when compared with the StdCMR.

CONCLUSION

The ShtCMR was found to be a debatable alternative to the StdCMR in patients with MINOCA. Nevertheless, when an experienced reader reaches a good or very good diagnostic confidence using the ShtCMR, the reader may choose to stop the examination, reducing the length of the CMR without affecting the patient's diagnosis.

CLINICAL RELEVANCE STATEMENT

A short non-contrast CMR protocol may be a viable alternative to standard protocols in selected CMR studies of patients with MINOCA, allowing for faster diagnosis while reducing time and resources and increasing the number of patients who can be scanned.

KEY POINTS

• The ShtCMR lasted 21 ± 9 min and the StdCMR 45 ± 11 min (p < 0.0001). • In 57% of patients with MINOCA, the experienced reader considers that contrast medium is probably not necessary for diagnosis without affecting the patient's diagnosis (99% of agreement rate between ShtCMR and StdCMR).

Prognostic Role of Early Cardiac Magnetic Resonance in Myocardial Infarction With Nonobstructive Coronary Arteries

BACKGROUND

Cardiac magnetic resonance (CMR) plays a pivotal diagnostic role in myocardial infarction with nonobstructive coronary arteries (MINOCA). To date, a prognostic stratification of these patients is still lacking.

OBJECTIVES

This study aims to assess the prognostic role of CMR in MINOCA.

METHODS

The authors assessed 437 MINOCA from January 2017 to October 2021. They excluded acute myocarditis, takotsubo syndromes, cardiomyopathies, and other nonischemic etiologies. Patients were classified into 3 subgroups according to the CMR phenotype: 1) presence of late gadolinium enhancement (LGE) and abnormal mapping (M) values (LGE+/M+); 2) regional ischemic injury with abnormal mapping and no LGE (LGE-/M+); and 3) nonpathological CMRs (LGE-/M-). The primary outcome was the presence of major adverse cardiovascular events (MACE). The mean follow-up was 33.7 ± 12.0 months and CMR was performed on average at 4.8 ± 1.5 days from the acute presentation.

RESULTS

The final cohort included 198 MINOCA; 116 (58.6%) comprised the LGE+/M+ group. During follow-up, MACE occurred significantly more frequently in MINOCA LGE+/M+ than in the LGE+/M- and normal-CMR (LGE-/M-) subgroups (20.7% vs 6.7% and 2.7%; P = 0.006). The extension of myocardial damage at CMR was significantly greater in patients who developed MACE. In multivariable Cox regression, %LGE was an independent predictor of MACE (HR: 1.123 [95% CI: 1.064-1.185]; P < 0.001) together with T2 mapping values (HR: 1.190 [95% CI: 1.145-1.237]; P = 0.001).

CONCLUSIONS

In MINOCA with early CMR execution, the %LGE and abnormal T2 mapping values were identified as independent predictors of adverse cardiac events at ∼3.0 years of follow-up. These parameters can be considered as high-risk markers in MINOCA.

Imaging patients with myocardial infarction with non-obstructive coronary arteries (MINOCA)

Myocardial infarction with non-obstructive coronary arteries (MINOCA) defines a heterogeneous group of atherosclerotic and non-atherosclerotic conditions, causing myocardial injury in the absence of obstructive coronary artery disease. Unveiling the mechanisms subtended to the acute event is often challenging; a multimodality imaging approach is helpful to aid the diagnosis. Invasive coronary imaging with intravascular ultrasound or optical coherence tomography should be used, when available, during index angiography to detect plaque disruption or spontaneous coronary artery dissection. Cardiovascular magnetic resonance has instead a key role among the non-invasive modalities, allowing the differentiation between MINOCA and its non-ischaemic mimics and providing prognostic information. This educational paper will provide a comprehensive review of the strengths and limitations of each imaging modality in the evaluation of patients with a working diagnosis of MINOCA.

Parametric cardiovascular magnetic resonance imaging in takotsubo syndrome: a case report

Background

Takotsubo syndrome (TTS) causes angina with ventricular dysfunction that can mimic acute coronary syndrome. Normal coronary angiography leads to cardiovascular magnetic resonance imaging (CMR) in the diagnostic pathway. Historically, TTS was thought to be associated with the absence of late gadolinium enhancement on CMR. This case report highlights the presence of late gadolinium enhancement in a case of TTS while demonstrating the other characteristic findings, including quantitative parametric T1/T2 mapping.

Case summary

A 69-year-old lady was admitted with chest pain and shortness of breath. She was found to have classical TTS with the characteristic wall motion abnormalities on echocardiogram, left ventricular angiogram, and CMR. Her CMR also demonstrated strongly positive myocardial T1/T2 mapping that matched the wall motion abnormalities and the less frequently described positive early and late gadolinium enhancement.

Discussion

This case highlights the diagnostic pathway in TTS and the ability of CMR to make a diagnosis in myocardial infarction with non-obstructed coronary arteries. We describe the characteristic cardiac imaging features of TTS while discussing the positive late gadolinium enhancement patterns that may help confirm the diagnosis.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

Reduced stress perfusion in myocardial infarction with nonobstructive coronary arteries

Myocardial infarction with nonobstructive coronary arteries (MINOCA) has several possible underlying causes, including coronary microvascular dysfunction (CMD). Early cardiovascular magnetic resonance imaging (CMR) is recommended, however cannot provide a diagnosis in 25% of cases. Quantitative stress CMR perfusion mapping can identify CMD, however it is unknown if CMD is present during long-term follow-up of MINOCA patients. Therefore, this study aimed to evaluate presence of CMD during long-term follow-up in MINOCA patients with an initial normal CMR scan. MINOCA patients from the second Stockholm myocardial infarction with normal coronaries study (SMINC-2), with a normal CMR scan at median 3 days after hospitalization were investigated with comprehensive CMR including stress perfusion mapping a median of 5 years after the index event, together with age- and sex-matched volunteers without symptomatic ischemic heart disease. Cardiovascular risk factors, medication and symptoms of myocardial ischemia measured by the Seattle Angina Questionnaire 7 (SAQ-7), were registered. In total, 15 patients with MINOCA and an initial normal CMR scan (59 ± 7 years old, 60% female), and 15 age- and sex-matched volunteers, underwent CMR. Patients with MINOCA and an initial normal CMR scan had lower global stress perfusion compared to volunteers (2.83 ± 1.8 vs 3.53 ± 0.7 ml/min/g, p = 0.02). There were no differences in other CMR parameters, hemodynamic parameters, or cardiovascular risk factors, except for more frequent use of statins in the MINOCA patient group compared to volunteers. In conclusion, global stress perfusion is lower in MINOCA patients during follow-up, compared to age- and sex-matched volunteers, suggesting that CMD may be a possible pathophysiological mechanism in MINOCA.Clinical Trial Registration: Clinicaltrials.gov identifier NCT02318498. Registered 2014-12-17.

Mortality in ST-Segment Elevation Myocardial Infarction With Nonobstructive Coronary Arteries and Mimickers

Importance

The clinical characteristics and prognosis of patients with ST-segment elevation myocardial infarction (STEMI) with nonobstructive coronaries (MINOCA) are largely unknown.

Objective

To assess differences in 5-year mortality in patients presenting with STEMI due to MINOCA and MINOCA mimickers as compared with obstructive disease.

Design, Setting, and Participants

A retrospective analysis of a prospective registry-based cohort study of consecutive STEMI activations at 3 regional Midwest STEMI programs. STEMI without a culprit artery and elevated troponin levels were categorized as MINOCA (absence of coronary artery stenosis >50% and confirmed or suspected coronary artery plaque disruption, epicardial coronary spasm, or coronary embolism/thrombosis) or MINOCA mimickers (takotsubo cardiomyopathy, myocarditis, or nonischemic cardiomyopathy). Data were analyzed from March 2003 to December 2020.

Main Outcomes and Measures

Adjusted Cox regression analysis was used to assess 5-year mortality risk in STEMI presenting with MINOCA and MINOCA mimickers in comparison with obstructive disease.

Results

Among 8560 consecutive patients with STEMI, mean (SD) age was 62 (14) years, 30% were female (2609 participants), and 94% were non-Hispanic White (4358 participants). The cohort included 8151 patients with STEMI due to obstructive disease (95.2%), 120 patients with MINOCA (1.4%), and 289 patients with MINOCA mimickers (3.8%). Patients were followed up for a median (IQR) of 7.1 (3.6-10.7) years. Patients with MINOCA and MINOCA mimickers were less likely to be discharged with cardiac medications compared with obstructive disease. At 5-year follow-up, mortality in STEMI presenting with obstructive disease (1228 participants [16%]) was similar to MINOCA (20 participants [18%]; χ21 = 1.1; log-rank P = .29) and MINOCA mimickers (52 participants [18%]; χ21 = 2.3; log-rank P = .13). In adjusted Cox regression analysis compared with obstructive disease, the 5-year mortality hazard risk was 1.93 times higher in MINOCA (95% CI, 1.06-3.53) and similar in MINOCA mimickers (HR, 1.08; 95% CI, 0.79-1.49).

Conclusions and Relevance

In this large multicenter cohort study of consecutive clinical patients with STEMI, presenting with MINOCA was associated with a higher risk of mortality than obstructive disease; the risk of mortality was similar in patients with MINOCA mimickers and obstructive disease. Further investigation is necessary to understand the pathophysiologic mechanisms involved in this high-risk STEMI population.

A novel and simple cardiac magnetic resonance score (PE2RT) predicts outcome in takotsubo syndrome

OBJECTIVES

To find simple imaging-based features on cardiac magnetic resonance (CMR) that are associated with major adverse cardiovascular events (MACE) in takotsubo syndrome (TTS).

METHODS

Patients with TTS referred for CMR between 2007 and 2021 were retrospectively evaluated. Besides standard CMR analysis, commonly known complications of TTS based on expert knowledge were assessed and summarised via a newly developed PE2RT score (one point each for pleural effusion, pericardial effusion, right ventricular involvement, and ventricular thrombus). Clinical follow-up data was reviewed up to three years after discharge. The relationship between PE2RT features and the occurrence of MACE (cardiovascular death or new hospitalisation due to acute myocardial injury, arrhythmia, or chronic heart failure) was examined using Cox regression analysis and Kaplan-Meier estimator.

RESULTS

Seventy-nine patients (mean age, 68 ± 14 years; 72 women) with TTS were included. CMR was performed in a median of 4 days (IQR, 2-6) after symptom onset. Over a median follow-up of 13.3 months (IQR, 0.4-36.0), MACE occurred in 14/79 (18%) patients: re-hospitalisation due to acute symptoms (9/79, 11%) or chronic heart failure symptoms (4/79, 5%), and cardiac death (1/79, 1%). Patients with MACE had a higher PE2RT score (median [IQR], 2 [2-3] vs 1 [0-1]; p < 0.001). PE2RT score was associated with MACE on Cox regression analysis (hazard ratio per PE2RT feature, 2.44; 95%CI: 1.62-3.68; p < 0.001). Two or more PE2RT complications were strongly associated with the occurrence of MACE (log-rank p < 0.001).

CONCLUSIONS

The introduced PE2RT complication score might enable an easy-to-assess outcome evaluation of TTS patients by CMR.

KEY POINTS

• Complications like pericardial effusion, pleural effusion, right ventricular involvement, and ventricular thrombus (summarised as PE2RT features) are relatively common in takotsubo syndrome. • The proposed PE2RT score (one point per complication) was associated with the occurrence of major adverse cardiac events on follow-up. • Complications easily detected by cardiac magnetic resonance imaging can help clinicians derive long-term prognostic information on patients with takotsubo syndrome.

Role of Cardiac Magnetic Resonance Imaging and Troponin T in Definitive Diagnosis of Myocardial Infarction With Nonobstructive Coronary Arteries (MINOCA)

BACKGROUND

It is unknown whether the degree of high-sensitivity troponin T (hsTropT) elevation in patients with suspected myocardial infarction without obstructive coronary arteries (MINOCA) presentations can help predict the likelihood of an abnormal cardiac magnetic resonance (CMR) scan. In this study we describe the diagnostic utility of CMR in patients with MINOCA and assesses the effect of peak hsTropT levels at presentation on CMR diagnostic yield.

METHODS

Records of consecutive patients (n = 1407) referred for CMR at a tertiary referral hospital between January 2016 and September 2021 were reviewed. A total of 70 patients met the criteria of MINOCA including ischemic chest pain, elevated peak hsTropT, and nonobstructive coronary artery disease (< 50% stenosis). The peak hsTropT levels within 72 hours of admission were identified. CMR images were generated using a 3.0 T Siemens scanner. Predictors of having an abnormal CMR were evaluated.

RESULTS

CMR established a diagnosis in 71% (n = 50) of patients, with the most common CMR diagnosis being myopericarditis (n = 27; 39%). Time to CMR was an independent predictor of a normal CMR scan (odds ratio, 0.98; 95% confidence interval, 0.97-0.999). Peak hsTropT had a high diagnostic accuracy for identifying patients with an abnormal CMR scan (area under the receiver operator characteristic curve, 0.81; P < 0.001). The optimal hsTropT cutoff was 166 ng/L, with 72% sensitivity and specificity. A troponin value ≥ 166 ng/L was independently predictive of an abnormal CMR scan (odds ratio, 4.76; 95% confidence interval, 1.32-17.11).

CONCLUSIONS

HsTropT and early CMR imaging are independently predictive of an abnormal CMR scan in patients with MINOCA. Additionally, the use of a hsTropT cutoff provides incremental predictive value to clinical parameters and time to CMR scanning in determining an abnormal scan.

Contemporary Diagnosis and Management of Patients with MINOCA

PURPOSE OF REVIEW

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is defined as acute myocardial infarction (MI) with angiographically no obstructive coronary artery disease or stenosis ≤ 50%. MINOCA is diagnostically challenging and complex, making it difficult to manage effectively. This condition accounts for 6-8% of all MI and poses an increased risk of morbidity and mortality after diagnosis. Prompt recognition and targeted management are essential to improve outcomes and our understanding of this condition, but this process is not yet standardized. This article offers a comprehensive review of MINOCA, delving deep into its unique clinical profile, invasive and noninvasive diagnostic strategies for evaluating MINOCA in light of the lack of widespread availability for comprehensive testing, and current evidence surrounding targeted therapies for patients with MINOCA.

RECENT FINDINGS

MINOCA is not uncommon and requires comprehensive assessment using various imaging modalities to evaluate it further. MINOCA is a heterogenous working diagnosis that requires thoughtful approach to diagnose the underlying disease responsible for MINOCA further.

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.

Myocardial infarction with non-obstructive coronary arteries: Etiology, diagnosis, treatment and prognosis

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for 10% of myocardial infarctions. Previously, patients were thought to have good prognosis, but evidence-based management and treatment strategies were scarce. Today, researchers and physicians recognize MINOCA as a condition with non-trivial mortality and morbidity. Therapeutic strategies are highly dependent on the underlying disease mechanism in each patient. However, to reach a diagnosis of MINOCA, a multimodal approach is required and, even with an optimal work-up, the cause remains unknown in 8-25% of patients. Research has been growing and position papers from the European Society of Cardiology (ESC) and the American Heart Association/American College of Cardiology have been published, and MINOCA has been included in the more recent ESC guidelines on myocardial infarction. Nonetheless, some clinicians still assume that the absence of coronary obstruction excludes the possibility of acute myocardial infarction. Therefore, in the present paper, we aim to compile and present the available data on the etiology, diagnosis, treatment, and prognosis of MINOCA.

Role of Cardiac Magnetic Resonance Imaging in the Evaluation of MINOCA

Myocardial infarction with Non Obstructive Coronary Arteries (MINOCA) is defined by patients presenting with signs and symptoms similar to acute myocardial infarction, but are found to have non-obstructive coronary arteries angiography. What was once considered a benign phenomenon, MINOCA has been proven to carry with it significant morbidity and worse mortality when compared to the general population. As the awareness for MINOCA has increased, guidelines have focused on this unique situation. Cardiac magnetic resonance (CMR) has proven to be an essential first step in the diagnosis of patients with suspected MINOCA. CMR has also been shown to be crucial when differentiating between MINOCA like presentations such as myocarditis, takotsubo and other forms of cardiomyopathy. The following review focuses on demographics of patients with MINOCA, their unique clinical presentation as well as the role of CMR in the evaluation of MINOCA.

Nonobstructive coronary atherosclerosis is associated with adverse prognosis among patients diagnosed with myocardial infarction without obstructive coronary arteries

BACKGROUND AND AIMS

The prognostic impact of nonobstructive coronary artery disease (CAD), as opposed to normal coronary arteries, on long-term outcomes of patients with myocardial infarction with no obstructive coronary arteries (MINOCA) is unclear. We aimed to address the association between nonobstructive-CAD and major adverse events (MAE) following MINOCA.

METHODS

We conducted a retrospective cohort study of consecutive MINOCA patients admitted to a large referral medical center between 2005 and 2018. Patients were classified according to coronary angiography as having either normal-coronaries or nonobstructive-CAD. The primary outcome was MAE, defined as the composite of all-cause mortality and recurrent acute coronary syndrome (ACS).

RESULTS

Of the 1544 MINOCA patients, 651 (42%) had normal coronaries, and 893 (58%) had CAD. The mean age was 61.2 ± 12.6 years, and 710 (46%) were females. Nonobstructive-CAD patients were older and less likely to be females, with higher rates of diabetes, hypertension, dyslipidemia, atrial fibrillation, and chronic renal-failure (p < 0.05). At a median follow-up of 7 years, MAE occurred in 203 (23%) patients and 67 (10%) patients in the nonobstructive-CAD and normal-coronaries groups, respectively (p < 0.01). In multivariable models, nonobstructive -CAD was significantly associated with long-term MAE [adjusted-hazard-ratio (aHR):1.67, 95% confidence-interval (95%CI):1.25-2.23; p < 0.001]. Other factors associated with a higher MAE-risk were older-age (aHR:1.05,95%CI:1.03-1.06; p < 0.001) and left ventricular ejection-fraction<40% (aHR:3.04,95%CI:2.03-4.57; p < 0.001), while female-sex (aHR:0.72, 95%CI: 0.56-0.94; p=0.014) and sinus rhythm at presentation (aHR:0.66, 95%CI: 0.44-0.98; p=0.041) were associated with lower MAE-risk.

CONCLUSIONS

In MINOCA, nonobstructive-CAD is independently associated with a higher MAE-risk than normal-coronaries. This finding may promote risk-stratification of patients with nonobstructive-CAD-MINOCA who require tighter medical follow-up and treatment optimization.

Role of cardiac magnetic resonance in MINOCA of unclear etiology: a case report of a suspicious paradoxical coronary embolism

The acronym MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) refers to myocardial infarction with normal or near-normal coronary arteries on invasive angiography. The broad spectrum of pathological mechanisms responsible for myocardial injury in MINOCA makes defining the exact underlying etiology challenging. We report the uncommon case of an acute myocardial infarction with normal coronary arteries suggestive of MINOCA caused by paradoxical coronary embolism due to a wide right-to-left shunting through a patent fossa ovalis. Integrated multimodality imaging diagnostic work-up, including cardiac magnetic resonance, transesophageal contrast echocardiography, and transcranial contrast Doppler, has been crucial for identifying the most likely mechanism underlying MINOCA.

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.

Acute clinical presentation of nonischemic cardiomyopathies: early detection by cardiovascular magnetic resonance

Nonischemic cardiomyopathies include a wide range of dilated, hypertrophic and arrhythmogenic heart muscle disorders, not explained by coronary artery disease, hypertension, valvular or congenital heart disease. Advances in medical treatments and the availability of implantable cardioverter defibrillators to prevent sudden cardiac death have allowed a substantial increase in the survival of affected individuals, thus making early diagnosis and tailored treatment mandatory. The characterization of cardiomyopathies has received a great boost from the recent advances in cardiovascular magnetic resonance (CMR) imaging, which, to date, represents the gold standard for noninvasive assessment of cardiac morphology, function and myocardial tissue changes. An acute clinical presentation has been reported in a nonnegligible proportion of patients with nonischemic cardiomyopathies, usually complaining of acute chest pain, worsening dyspnoea or palpitations; 'hot phases' of cardiomyopathies are characterized by a dynamic rise in high-sensitivity troponin, myocardial oedema on CMR, arrhythmic instability, and by an increased long-term risk of adverse remodelling, progression of myocardial fibrosis, heart failure and malignant ventricular arrhythmias. Prompt recognition of 'hot phases' of nonischemic cardiomyopathies is of utmost importance to start an early, individualized treatment in these high-risk patients. On the one hand, CMR represents the gold standard imaging technique to detect early and typical signs of ongoing myocardial remodelling in patients presenting with a 'hot phase' nonischemic cardiomyopathy, including myocardial oedema, perfusion abnormalities and pathological mapping values. On the other hand, CMR allows the differential diagnosis of other acute heart conditions, such as acute coronary syndromes, takotsubo syndrome, myocarditis, pericarditis and sarcoidosis. This review provides a deep overview of standard and novel CMR techniques to detect 'hot phases' of cardiomyopathies, as well as their clinical and prognostic utility.

Imaging of heart disease in women: review and case presentation

Cardiovascular diseases (CVD) remain the leading cause of mortality worldwide. Although major diagnostic and therapeutic advances have significantly improved the prognosis of patients with CVD in the past decades, these advances have less benefited women than age-matched men. Noninvasive cardiac imaging plays a key role in the diagnosis of CVD. Despite shared imaging features and strategies between both sexes, there are critical sex disparities that warrant careful consideration, related to the selection of the most suited imaging techniques, to technical limitations, and to specific diseases that are overrepresented in the female population. Taking these sex disparities into consideration holds promise to improve management and alleviate the burden of CVD in women. In this review, we summarize the specific features of cardiac imaging in four of the most common presentations of CVD in the female population including coronary artery disease, heart failure, pregnancy complications, and heart disease in oncology, thereby highlighting contemporary strengths and limitations. We further propose diagnostic algorithms tailored to women that might help in selecting the most appropriate imaging modality.

Desmoplakin cardiomyopathy—an inherited cardiomyopathy presenting with recurrent episodes of acute myocardial injury

We present two female patients with recurrent episodes of myocardial injury, consisting of acute chest pain and elevated cardiac markers without coronary artery disease. Cardiovascular magnetic resonance imaging identified extensive late gadolinium enhancement suggestive of an inherited cardiomyopathy. Genetic testing showed heterozygous pathogenic variants in the desmoplakin (DSP) gene, the gene coding for the desmoplakin protein, a structural protein found in the cardiac desmosome. Pathogenic variants in the DSP gene are associated with dilated and arrhythmogenic cardiomyopathy. DSP cardiomyopathies may cause recurring myocardial injury mimicking an acute coronary syndrome or myocarditis. Cardiac magnetic resonance imaging is key in its diagnosis due to its specifying imaging features. Genetic testing is essential for the evaluation and confirmation of the diagnosis.

Myocardial infarction with non-obstructive coronary arteries (MINOCA)

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is evident in up to 15% of all acute myocardial infarctions (AMI) and disproportionally affects females. Despite younger age, female predominance, and fewer cardiovascular risk factors, MINOCA patients have a worse prognosis than patients without cardiovascular disease and a similar prognosis compared to patients with MI and obstructive coronary artery disease (CAD). MINOCA is a syndrome with a broad differential diagnosis that includes both ischemic [coronary artery plaque disruption, coronary vasospasm, coronary microvascular dysfunction, spontaneous coronary artery dissection (SCAD), and coronary embolism/thrombosis] and non-ischemic mechanisms (Takotsubo cardiomyopathy, myocarditis, and non-ischemic cardiomyopathy)-the latter called MINOCA mimickers. Therefore, a standardized approach that includes multimodality imaging, such as coronary intravascular imaging, cardiac magnetic resonance, and in selected cases, coronary reactivity testing, including provocation testing for coronary vasospasm, is necessary to determine underlying etiology and direct treatment. Herein, we review the prevalence, characteristics, prognosis, diagnosis, and treatment of MINOCA -a syndrome often overlooked.

Detection of myocardial fibrosis: Where we stand

Myocardial fibrosis, resulting from the disturbance of extracellular matrix homeostasis in response to different insults, is a common and important pathological remodeling process that is associated with adverse clinical outcomes, including arrhythmia, heart failure, or even sudden cardiac death. Over the past decades, multiple non-invasive detection methods have been developed. Laboratory biomarkers can aid in both detection and risk stratification by reflecting cellular and even molecular changes in fibrotic processes, yet more evidence that validates their detection accuracy is still warranted. Different non-invasive imaging techniques have been demonstrated to not only detect myocardial fibrosis but also provide information on prognosis and management. Cardiovascular magnetic resonance (CMR) is considered as the gold standard imaging technique to non-invasively identify and quantify myocardial fibrosis with its natural ability for tissue characterization. This review summarizes the current understanding of the non-invasive detection methods of myocardial fibrosis, with the focus on different techniques and clinical applications of CMR.

MINOCA: One Size Fits All? Probably Not—A Review of Etiology, Investigation, and Treatment

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of conditions that include both atherosclerotic (coronary plaque disruption) and non-atherosclerotic (spontaneous coronary artery dissection, coronary artery spasm, coronary artery embolism, coronary microvascular dysfunction, and supply–demand mismatch) causes resulting in myocardial damage that is not due to obstructive coronary artery disease. Failure to identify the underlying cause may result in inadequate and inappropriate therapy in these patients. The cornerstone of managing MINOCA patients is to identify the underlying mechanism to achieve the target treatment. Intravascular imaging is able to identify different morphologic features of coronary plaques, while cardiac magnetic resonance is the gold standard for detection of myocardial infarction in the setting of MINOCA. In this review, we summarize the relevant clinical issues, contemporary diagnosis, and treatment options of MINOCA.

Stroke-Heart Syndrome: Recent Advances and Challenges

After ischemic stroke, there is a significant burden of cardiovascular complications, both in the acute and chronic phase. Severe adverse cardiac events occur in 10% to 20% of patients within the first few days after stroke and comprise a continuum of cardiac changes ranging from acute myocardial injury and coronary syndromes to heart failure or arrhythmia. Recently, the term stroke–heart syndrome was introduced to provide an integrated conceptual framework that summarizes neurocardiogenic mechanisms that lead to these cardiac events after stroke. New findings from experimental and clinical studies have further refined our understanding of the clinical manifestations, pathophysiology, and potential long‐term consequences of the stroke–heart syndrome. Local cerebral and systemic mediators, which mainly involve autonomic dysfunction and increased inflammation, may lead to altered cardiomyocyte metabolism, dysregulation of (tissue‐resident) leukocyte populations, and (micro‐) vascular changes. However, at the individual patient level, it remains challenging to differentiate between comorbid cardiovascular conditions and stroke‐induced heart injury. Therefore, further research activities led by joint teams of basic and clinical researchers with backgrounds in both cardiology and neurology are needed to identify the most relevant therapeutic targets that can be tested in clinical trials.