Clinical features of myocardial infarction and myocarditis in young adults: a retrospective study

Automatic classification of patients with myocardial infarction or myocarditis based only on clinical data: A quick response

BACKGROUND

In acute cardiovascular disease management, the delay between the admission in a hospital emergency department and the assessment of the disease from a Delayed Enhancement cardiac MRI (DE-MRI) scan is one of the barriers for an immediate management of patients with suspected myocardial infarction or myocarditis.

OBJECTIVES

This work targets patients who arrive at the hospital with chest pain and are suspected of having a myocardial infarction or a myocarditis. The main objective is to classify these patients based solely on clinical data in order to provide an early accurate diagnosis.

METHODS

Machine learning (ML) and ensemble approaches have been used to construct a framework to automatically classify the patients according to their clinical conditions. 10-fold cross-validation is used during the model's training to avoid overfitting. Approaches such as Stratified, Over-sampling, Under-sampling, NearMiss, and SMOTE were tested in order to address the imbalance of the data (i.e. proportion of cases per pathology). The ground truth is provided by a DE-MRI exam (normal exam, myocarditis or myocardial infarction).

RESULTS

The stacked generalization technique with Over-sampling seems to be the best one providing more than 97% of accuracy corresponding to 11 wrong classifications among 537 cases. Generally speaking, ensemble classifiers such as Stacking provided the best prediction. The five most important features are troponin, age, tobacco, sex and FEVG calculated from echocardiography.

CONCLUSION

Our study provides a reliable approach to classify the patients in emergency department between myocarditis, myocardial infarction or other patient condition from only clinical information, considering DE-MRI as ground-truth. Among the different machine learning and ensemble techniques tested, the stacked generalization technique is the best one providing an accuracy of 97.4%. This automatic classification could provide a quick answer before imaging exam such as cardiovascular MRI depending on the patient's condition.

Acute coronary syndrome versus acute myocarditis in young adults–value of speckle tracking echocardiography

Purpose

Comparing myocarditis with an acute coronary syndrome (ACS)-like presentation and acute myocardial infarction (AMI) poses an important clinical challenge. The purpose of the study was to investigate the diagnostic value of the clinical, laboratory and especially echocardiographic characteristics including speckle tracking echocardiography (STE) of patients with ACS-like myocarditis and AMI.

Methods

We conducted a retrospective analysis comparing 69 symptomatic patients (≤ 45 years old), hospitalized at the Department of Interventional Cardiology (Medical University of Lodz, Poland) between April 2014 and June 2021 with an initial diagnosis of ST-segment elevation myocardial infarction.

Results

37 patients with the cardiac magnetic resonance–confirmed acute myocarditis and 32 patients diagnosed with AMI based on the clinical presentation, electrocardiogram and the presence of a culprit lesion on the coronary angiography were analysed including echocardiography parameters. On STE analysis an average global longitudinal (GLS), radial and circumferential strain including three—layers observation were significantly lower (absolute value) in patients with AMI versus acute myocarditis (p<0.05). There was no significant difference in Endo/Epi ratio (p = 0.144) between the groups. An average GLS < (-17.5) represented the optimal cut-off value for the myocarditis diagnosis.

Conclusion

In patients with AMI a significant reduction of global and three-layers strains compared to patients with myocarditis was detected. Furthermore, our analysis also confirmed the discriminative pattern of myocardial injury between the groups.

Symptomatic Young Adults with ST-Segment Elevation-Acute Coronary Syndrome or Myocarditis: The Three-Factor Diagnostic Model

Myocarditis may mimic myocardial infarction (MI) due to a similar clinical presentation, including chest pain, electrocardiography changes, and laboratory findings. The purpose of the study was to investigate the diagnostic value of clinical, laboratory, and electrocardiography characteristics of patients with acute coronary syndrome - like myocarditis and MI. We analysed 90 patients (≤45 years old) with an initial diagnosis of ST-segment elevation myocardial infarction; 40 patients (44.4%), through the use of cardiac magnetic resonance, were confirmed to have myocarditis, and 50 patients (55.6%) were diagnosed with MI. Patients with myocarditis were younger and had fewer cardiovascular risk factors than those with MI. The cutoff value distinguishing between myocarditis and MI was defined as the age of 36 years. The history of recent infections (82.5% vs. 6%) and C-reactive protein (CRP) levels on admission (Me 45.9 vs. 3.4) was more associated with myocarditis. Further, the QTc interval was inversely correlated with the echocardiographic ejection fraction in both groups but was significantly longer in patients with MI. Non-invasive diagnostics based on clinical features and laboratory findings are basic but still essential tools for differentiation between MI and myocarditis. The three-factor model including the criteria of age, abnormal CRP, and history of recent infections might become a valuable clinical indication.

Role of thrombin generation assays in the diagnosis of acute myocarditis and non-ST myocardial infarction

Myocarditis and myocardial infarction share a common clinical characteristics despite significant differences in etiology and pathogenesis. Current guidelines recommend using cardiac magnetic resonance imaging (MRI) or endocardial biopsy for a definite diagnosis; however, these guidelines are not fully implemented due to the high cost and low availability. We used a thrombin generation assay and simple blood test to characterize both diseases. We conducted a cross-sectional study from April to December 2018. Patients with initial clinical suspicions of non-ST elevation myocardial infarction (NSTEMI) or myocarditis were eligible. All patients were recruited prior to anticoagulant treatment. Patients in both groups underwent acceptable standard clinical evaluation. Twenty-eight patients were enrolled; 12 patients in the NSTEMI group and 16 in the myocarditis group. Patients in the NSTEMI group were significantly older than those in the myocarditis group (64.25 ± 9.67 vs. 37.94 ± 19.66 years, p < 0.01, respectively) with a higher prevalence of hyperlipidemia, diabetes mellitus, and ischemic heart disease (p < 0.01 for all). There was no difference between the groups regarding INR, PT, aPTT, and serum levels of creatinine, urea, CPK, troponin, and fibrinogen. Endogenous thrombin potential (ETP), which represents the total thrombin concentration in the plasma, was significantly higher in the myocarditis group than in the NSTEMI group (2091.88 ± 336.41 vs. 1860.75 ± 438.02 nM × min, p < 0.03). Myocarditis and myocardial infarction have a different pattern of thrombin generation Thrombogram. The myocarditis group had significantly higher plasma ETP than the NSTEMI group. This finding requires further evaluation to define a numerical threshold, thus avoiding invasive or expensive assessment of myocarditis.

Acute myocardial infarction or acute myocarditis? Discharge registry-based study of likelihood and associated features in hospitalised patients

OBJECTIVE

To evaluate the likelihood of and patient features associated with acute myocardial infarction (AMI) versus acute myocarditis in different population segments.

DESIGN

Nationwide, multihospital observational retrospective registry study of 9.6 years in Finland.

PARTICIPANTS

All consecutive patients aged ≥18 years hospitalised with a primary diagnosis of AMI (n=89 399) or acute myocarditis (n=2131) in 22 hospitals with a coronary catheterisation laboratory.

PRIMARY OUTCOME MEASURES

Likelihood of AMI versus acute myocarditis and associated patient features.

RESULTS

Men were over-represented in patients with AMI (59.8%) and in patients with acute myocarditis (76.1%). Age distributions of AMI and acute myocarditis were opposite as a majority of patients with myocarditis were aged 18-29 years, while the number of patients with AMI increased gradually up to 80 years of age. Patients aged 18-29 years were more likely to have acute myocarditis as the cause of hospitalisation (relative risk (RR)=11.4; 95% CI 7.6 to 16.1 for myocarditis, p<0.0001), but after 30 years of age the likelihood of infarction was higher with exponentially increasing RR for AMI. In youngest patients (18-29 years), the likelihood of AMI was higher in women, but men had higher odds for AMI after 40 years of age. Overall, men had OR of 1.97 (95% CI 1.74 to 2.23, p<0.0001) for AMI versus myocarditis when compared with women. Hypercholesterolaemia, chronic coronary artery disease, diabetes and hypertension predicted AMI in multivariate analysis. Odds for myocarditis were significantly higher if the patient had an otolaryngeal infection (OR 18.13; 95% CI 8.96 to 36.67, p<0.0001).

CONCLUSIONS

Acute myocarditis is more common than AMI in hospitalised patients aged 18-29 years, but the risk of AMI increases exponentially thereafter. Hypercholesterolaemia, diabetes and hypertension predict AMI regardless of age and gender.

Diagnostic contribution of cardiac magnetic resonance in patients with acute coronary syndrome and culprit-free angiograms

BACKGROUND

In spite of robust knowledge about underlying ischemic myocardial damage, acute coronary syndromes (ACS) with culprit-free angiograms raise diagnostic concerns. The present study aimed to evaluate the additional value of cardiac magnetic resonance (CMR) over commonly available non-CMR standard tests, for the differentiation of myocardial injury in patients with ACS and non-obstructed coronary arteries.

MATERIAL/METHODS

Patients with ACS, elevated hs-TnT, and a culprit-free angiogram were prospectively enrolled into the study between January 2009 and July 2013. After initial evaluation with standard tests (ECG, echocardiography, hs-TnT) and provisional exclusion of acute myocardial infarction (AMI) in coronary angiogram, patients were referred for CMR with the suspicion of myocarditis or Takotsubo cardiomyopathy (TTC). According to the result of CMR, patients were reclassified as having myocarditis, AMI, TTC, or non-injured myocardium as assessed by late gadolinium enhancement.

RESULTS

Out of 5110 patients admitted with ACS, 75 had normal coronary angiograms and entered the study; 69 of them (92%) were suspected for myocarditis and 6 (8%) for TTC. After CMR, 49 patients were finally diagnosed with myocarditis (65%), 3 with TTC (4%), 7 with AMI (9%), and 16 (21%) with non-injured myocardium. The provisional diagnosis was changed or excluded in 23 patients (31%), with a 9% rate of unrecognized AMI.

CONCLUSIONS

The study results suggest that the evaluation of patients with ACS and culprit-free angiogram should be complemented by a CMR examination, if available, because the initial work-up with non-CMR tests leads to a significant proportion of misdiagnosed AMI.