Non-ischemic Myocardial Injury Research Articles

Management of Acute Coronary Syndrome in Elderly Patients: A Narrative Review through Decisional Crossroads.

Diagnosis and treatment of acute coronary syndrome (ACS) pose particular challenges in elderly patients. When high troponin levels are detected, the distinction between non-ischemic myocardial injury (NIMI), type 1, and type 2 myocardial infarction (MI) is the necessary first step to guide further care. However, the assessment of signs of ischemia is hindered in older patients, and no simple clinical or laboratory tool proved useful in this discrimination task. Current evidence suggests a benefit of an invasive vs. conservative approach in terms of recurrence of MI, with no significant impact on mortality. In patients with multivessel disease in which the culprit lesion has been treated, a physiology-guided complete percutaneous revascularization significantly reduced major events. The management of ACS in elderly patients is an example of the actual need for a multimodal, thorough clinical approach, coupled with shared decision-making, in order to ensure the best treatment and avoid futility. Such a need will likely grow throughout the next decades, with the aging of the world population. In this narrative review, we address pivotal yet common questions arising in clinical practice while caring for elderly patients with ACS.

The Correlation between Cardiac Magnetic Resonance Findings and Post-COVID-19: The Impact of Myocardial Injury on Quality of Life.

In the post-COVID-19 era, there is growing concern regarding its impact on cardiovascular health and the following effects on the overall quality of life of affected individuals. This research seeks to investigate cardiac magnetic resonance (CMR) findings following COVID-19 and their impact on the quality of life of affected individuals. An observational, cross-sectional study was conducted in consecutive patients with persistent cardiovascular symptoms after COVID-19 who were referred to CMR due to suspected myocardial injury. In addition, patients completed a questionnaire about symptoms and the quality of life during the post-COVID-19 period. In this study, 85 patients were included. The study population consisted of patients with a mean age of 42.5 ± 13.4 years, predominantly women, who made up 69.4% of the study population, while men made up 30.6%. CMR findings showed non-ischemic myocardial injury in 78.8% of patients and myocardial edema in 14.1% of patients. Late pericardial enhancement was present in 40% of patients and pericardial effusion in 51.8% of patients. Pericardial effusion (p = 0.001) was more prevalent in patients who reported more pronounced symptoms in the post-COVID-19 period compared to the acute infection phase. Predictors of lower quality of life in the post-COVID-19 period were the presence of irregular heartbeat (p = 0.039), cardiovascular problems that last longer than 12 weeks (p = 0.018), and the presence of pericardial effusion (p = 0.037). Acute myocarditis was observed in a minority of patients after COVID-19, while non-ischemic LGE pattern and pericardial effusion were observed in the majority. Quality of life was worse during the post-COVID-19 period in patients with CMR abnormalities, primarily in patients with pericardial effusion. Also, irregular heartbeat, cardiovascular symptoms that last longer than 12 weeks, as well as pericardial effusion were independent predictors of lower quality of life during the post-COVID-19 period.

Machine-Learning for Phenotyping and Prognostication of Myocardial Infarction and Injury in Suspected Acute Coronary Syndrome

BackgroundClinical work-up for suspected acute coronary syndrome (ACS) is resource intensive. ObjectivesThis study aimed to develop a machine learning model for digitally phenotyping myocardial injury and infarction and predict 30-day events in suspected ACS patients. MethodsTraining and testing data sets, predominantly derived from electronic health records, included suspected ACS patients presenting to 6 and 26 South Australian hospitals, respectively. All index presentations and 30-day death and myocardial infarction (MI) were adjudicated using the Fourth Universal Definition of MI. We developed 2 diagnostic prediction models which phenotype myocardial injury and infarction according to the Fourth UDMI (chronic myocardial injury vs acute myocardial injury patterns, the latter further differentiated into acute non-ischaemic myocardial injury, Types 1 and 2 MI) using eXtreme Gradient Boosting (XGB) and deep-learning (DL). We also developed an event prediction model for risk prediction of 30-day death or MI using XGB. Analyses were performed in Python 3.6. ResultsThe training and testing data sets had 6,722 and 8,869 participants, respectively. The diagnostic prediction XGB and deep learning models achieved an area under the curve of 99.2% ± 0.1% and 98.8% ± 0.2%, respectively, for differentiating an acute myocardial injury pattern from no injury or chronic myocardial injury pattern and achieved 95.5% ± 0.2% and 94.6% ± 0.9%, respectively, for differentiating type 1 MI from type 2 MI or acute nonischemic myocardial injury. The 30-day death/MI event prediction model achieved an area under the curve of 88.5% ± 0.5%. ConclusionsMachine learning models can digitally phenotype suspected ACS patients at index presentation and predict subsequent events within 30 days. These models require external validation in a randomized clinical trial to evaluate their impact in clinical practice.

Importance of T1-Mapping Sequence in Patients with Hypertrophic Cardiomyopathy without Foci of Non-Ischemic Myocardial Injury in Late Gadolinium Enhancement Sequence.

The aim of this study was to assess the importance of T1-mapping sequences in the diagnosis of hypertrophic cardiomyopathy (HCM) in patients without foci of non-ischemic myocardial injury in classic cardiac magnetic resonance (CMR) sequences. Two groups were compared: 28 patients with HCM, without any foci of myocardial injury in the late gadolinium enhancement (LGE) sequence (HCM group), and 28 patients without cardiomyopathy (CON group). Classic CMR sequences and T1-mapping sequences were performed. The following parameters were assessed: T1 time of the whole left ventricular myocardium, T1 time of myocardium in the basal, middle and apical layers of the left ventricle, and T1 time in individual segments of the left ventricular myocardium. Myocardial extracellular volume (ECV) was assessed similarly. ECV was significantly higher in the HCM group than in the CON group, for the whole left ventricular myocardium, for the basal and apical layers of the left ventricle, and for segments 1-3, 8, and 13-16 of the left ventricle. Regression analysis showed that a higher left-ventricular mass index (LVMI), a higher body mass index and older age are factors independently associated with a higher ECV of the whole myocardium but only in the group with LVMI ≥ 131.84 g/m2. In patients with HCM without foci of non-ischemic myocardial injury, higher ECV values of the left ventricular myocardium are observed.

Acute ischemic stroke and troponin elevation: update of the Mannheim clinical algorithm

Elevated high-sensitivity cardiac troponin (hs-cTn) levels should be expected in about half of all patients with acute ischemic stroke (AIS). Since those patients are at risk of increased morbidity and mortality, often attributable to cardiac causes, an adequate work-up of the underlying etiology is required. This can only be achieved by ateam of cardiologists and neurologists. Since underlying causes of hs-cTn elevation in AIS patients are diverse, often atypical or silent in their clinical presentation and some, such as an accompanying myocardial infarction, can be acutely life-threatening, the work-up should follow astandardized clinical algorithm. The vast majority of hs-cTn elevations are caused by non-ischemic myocardial injury associated with AIS. This work presents apractice-oriented approach to differential diagnosis with the update of the Mannheim clinical algorithm for acute ischemic stroke and troponin elevation.

Evaluating a novel accelerated free-breathing late gadolinium enhancement imaging sequence for assessment of myocardial injury

IntroductionCardiac magnetic resonance imaging (MRI), including late gadolinium enhancement (LGE), plays an important role in the diagnosis and prognostication of ischemic and non-ischemic myocardial injury. Conventional LGE sequences require patients to perform multiple breath-holds and require long acquisition times. In this study, we compare image quality and assessment of myocardial LGE using an accelerated free-breathing sequence to the conventional standard-of-care sequence. MethodsIn this prospective cohort study, a total of 41 patients post Coronavirus 2019 (COVID-19) infection were included. Studies were performed on a 1.5 Tesla scanner with LGE imaging acquired using a conventional inversion recovery rapid gradient echo (conventional LGE) sequence followed by the novel accelerated free-breathing (FB-LGE) sequence. Image quality was visually scored (ordinal scale from 1 to 5) and compared between conventional and free-breathing sequences using the Wilcoxon rank sum test. Presence of per-segment LGE was identified according to the American Heart Association 16-segment myocardial model and compared across both conventional LGE and FB-LGE sequences using a two-sided chi-square test. The perpatient LGE extent was also evaluated using both sequences and compared using the Wilcoxon rank sum test. Interobserver variability in detection of per-segment LGE and per-patient LGE extent was evaluated using Cohen's kappa statistic and interclass correlation (ICC), respectively. ResultsThe mean acquisition time for the FB-LGE sequence was 17 s compared to 413 s for the conventional LGE sequence (P < 0.001). Assessment of image quality was similar between both sequences (P = 0.19). There were no statistically significant differences in LGE assessed using the FB-LGE versus conventional LGE on a per-segment (P = 0.42) and per-patient (P = 0.06) basis. Interobserver variability in LGE assessment for FB-LGE was good for per-segment (= 0.71) and per-patient extent (ICC = 0.92) analyses. ConclusionsThe accelerated FB-LGE sequence performed comparably to the conventional standard-of-care LGE sequence in a cohort of patients post COVID-19 infection in a fraction of the time and without the need for breath-holding. Such a sequence could impact clinical practice by increasing cardiac MRI throughput and accessibility for frail or acutely ill patients unable to perform breath-holding.

Abstract 16188: Fibrosis-4 Index in the Evaluation of Non-Ischemic Myocardial Injury in the Emergency Department

Introduction: Fibrosis-4 (FIB-4) is a recognized score of liver fibrosis that is associated with ischemic heart disease and cardiac death. The relationship between FIB-4 index and non-ischemic myocardial injury (ni-MI) has not yet been investigated. Hypothesis: There is an association between FIB-4 index and ni-MI in patients admitted to an emergency department (ED). Methods: This retrospective study included consecutive patients presenting at the ED within a six months’ timeframe, with at least one high-sensitivity cardiac troponin T (hs-cTnT) value and without acute coronary syndromes diagnosis. The cohort with ni-MI was compared with the group with normal hs-cTnT values (control group, CG). FIB-4 index was calculated by: {age [years]хAST [U/L]/ [platelet count (10 9 /L)хALT (U/L) 1/2 ]}. Results: A total of 3,853 patients were enrolled, 1,950 (51%) males, 64 [48-78] years, 1,372 (35.6%) with ni-MI. FIB-4 index was higher in the cohort with ni-MI compared to the CG (1.90 [1.28-2.78] vs. 1.01 [0.64-1.49]; p&lt;0.001), with no sex differences (see Figure 1) . After adjustment for other covariates, FIB-4 index was independently associated with ni-MI in overall population (OR 1.468, 95% CI:1.195-1.803; p&lt;0.001), and separately in both males and females (OR 1.385, 95% CI:1.054-1.822; p=0.02 and OR 1.407, 95% CI:1.017-1.946; p=0.039, respectively). FIB-4 index was positively correlated with hs-cTnT (Rho= +0.536, p&lt;0.001), NT-proB-type Natriuretic Peptide (Rho= +0.280, p&lt;0.001) and negatively with estimated glomerular filtration rate (Rho= -0.510, p&lt;0.001). AUC of FIB-4 index for predicting ni-MI in the overall population was 0.790 (optimal cutoff: ≥1.46, sensitivity: 71.9%, specificity: 73.2%). Conclusions: FIB-4 index is independently associated with ni-MI in ED, without sex differences, and positively correlated with the grade of cardiac injury, volume overload and renal dysfunction.

Abstract 11836: A Rare Cause of Recurrent Myocardial Infarction: Genetic Testing Cracks the Case

A 29-year-old man presented to our institution with acute, severe substernal chest pain. An ECG on arrival revealed 3mm ST-elevations in the lateral leads with reciprocal depressions in the inferior leads. Troponin-I was above assay (&gt;50 ng/mL). Emergent coronary angiography showed normal coronary arteries, and left ventriculogram showed no wall motion abnormalities. A transthoracic echocardiogram showed normal biventricular size, wall thickness, and ejection fraction (EF). This was his fifth episode of chest pain over the past 10 years, consistent with prior presentations of ST-elevation myocardial infarction and angiographically normal coronary arteries. A prior cardiac magnetic resonance imaging (MRI, 6 years before the current presentation) revealed increased T2 signal intensity and subepicardial late gadolinium enhancement (LGE) in the septum, inferior, and inferolateral walls, suggestive of nonischemic acute myocardial injury. A repeat cardiac MRI during the current presentation showed mildly reduced biventricular systolic function (LVEF 52%, RVEF 36%), and again showed increased T2 signal intensity and subepicardial LGE involving the septum, inferior and inferolateral walls. The anterior and anterolateral walls were also now involved. Endomyocardial biopsy (EMB) showed focal interstitial fibrosis with no evidence of active myocarditis. On telemetry he was noted to have runs of non-sustained ventricular tachycardia (NSVT). Serologic evaluation was negative for parvovirus, cytomegalovirus, and Chagas disease. Erythrocyte sedimentation rate and C-reactive protein levels were normal. Genetic testing was performed at our newly established cardiovascular genetics program, which showed a pathogenic truncating mutation in the desmoplakin gene (DSP). DSP cardiomyopathy (CM) is an LV-predominant arrhythmogenic CM, which can present with episodic myocardial injury, and has a high disposition for ventricular arrhythmias with subepicardial LGE pattern often proceeding LV systolic dysfunction. A primary prevention implantable cardioverter-defibrillator was placed given extent of LGE and NSVT burden in the context of DSP variant. This case illustrates the importance of genetic testing in identifying rare CM phenotypes.

Sex–related differences in non-ischemic myocardial injury in the emergency department: A real-world perspective

BackgroundMyocardial injury is associated with adverse outcomes. No data are reported about sex differences in incidence and factors associated with myocardial injury in an emergency department (ED) setting from a real-world perspective. We aimed to assess whether sex plays a major role in the diagnosis of myocardial injury in the ED. MethodsIn this subanalysis of a retrospective study, patients presenting at the ED with at least one high-sensitivity cardiac troponin T (hs-cTnT) value and without acute coronary syndromes diagnosis were compared. Results31,383 patients were admitted to the ED, 4660 had one hs-cTnT value, and 3937 were enrolled: 1943 females (49.4%) and 1994 males (50.6%). The diagnosis of myocardial injury was higher among men (36.8% vs. 32.9%, p < 0.01). Male sex was independently associated with myocardial injury. An older age, an elevated NT-proB-type Natriuretic Peptide and a lower estimated glomerular filtrate rate were independently associated with myocardial injury in both sexes. ConclusionsIn the ED, from a real-world perspective, myocardial injury occurred more frequently in males, and it was associated with older age and the presence of cardiac, lung, and kidney disease but not higher hs-cTnT values.

Differentiation of acute non-ST elevation myocardial infarction and acute infarct-like myocarditis by visual pattern analysis: a head-to-head comparison of different cardiac MR techniques

ObjectivesParametric cardiac magnetic resonance (CMR) techniques have improved the diagnosis of pathologies. However, the primary tool for differentiating non-ST elevation myocardial infarction (NSTEMI) from myocarditis is still a visual assessment of conventional signal-intensity-based images. This study aimed at analyzing the ability of parametric compared to conventional techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns.MethodsTwenty NSTEMI patients, twenty infarct-like myocarditis patients, and twenty controls were examined using cine, T2-weighted CMR (T2w) and late gadolinium enhancement (LGE) imaging and T1/T2 mapping on a 1.5 T scanner. CMR images were presented in random order to two experienced fully blinded observers, who had to assign them to three categories by a visual analysis: NSTEMI, myocarditis, or healthy.ResultsThe conventional approach (cine, T2w and LGE combined) had the best diagnostic accuracy with 92% (95%CI: 81–97) for NSTEMI and 86% (95%CI: 71–94) for myocarditis. The diagnostic accuracies using T1 maps were 88% (95%CI: 74–95) and 80% (95%CI: 62–91), 84% (95%CI: 67–93) and 74% (95%CI: 54–87) for LGE, and 83% (95%CI: 66–92) and 73% (95%CI: 53–87) for T2w. The accuracies for cine (72% (95%CI: 52–86) and 60% (95%CI: 38–78)) and T2 maps (62% (95%CI: 40–79) and 47% (95%CI: 28–68)) were significantly lower compared to the conventional approach (p < 0.001 and p < 0.0001).ConclusionsThe conventional approach provided a reliable visual discrimination between NSTEMI, myocarditis, and controls. The diagnostic accuracy of a visual pattern analysis of T1 maps was not significantly inferior, whereas the diagnostic accuracy of T2 maps was not sufficient in this context.Clinical relevance statementThe ability of parametric compared to conventional CMR techniques to visually differentiate ischemic from non-ischemic myocardial injury patterns can avoid potentially unnecessary invasive coronary angiography and help to shorten CMR protocols and to reduce the need of gadolinium contrast agents.Key Points•A visual differentiation of ischemic from non-ischemic patterns of myocardial injury is reliably achieved by a combination of conventional CMR techniques (cine, T2-weighted and LGE imaging).•There is no significant difference in accuracies between visual pattern analysis on native T1 maps without providing quantitative values and a conventional combined approach for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls.•T2 maps do not provide a sufficient diagnostic accuracy for visual pattern analysis for differentiating non-ST elevation myocardial infarction, infarct-like myocarditis, and controls.

Risk factor associations with individual myocardial infarction subtypes and acute non-ischemic myocardial injury in the Multi-Ethnic Study of Atherosclerosis (MESA): Design and rationale

Despite different prevalence, pathobiology, and prognosis between etiologically distinct myocardial infarction (MI) subtypes, prospective study of risk factor for MI in large NHLBI-sponsored cardiovascular cohorts is limited to acute MI as a singular entity. Therefore, we sought to utilize the Multi-Ethnic Study of Atherosclerosis (MESA), a large prospective primary prevention cardiovascular study, to define the incidence and risk factor profile of individual myocardial injury subtypes. We describe the rationale and design of re-adjudicating 4,080 events that occurred over the first 14 years of follow-up in MESA for the presence and subtype of myocardial injury as defined by the Fourth Universal Definition of MI: MI type 1 to 5, acute non-ischemic myocardial injury, and chronic myocardial injury. The project utilizes a 2-physician adjudication process via examination of medical records, abstracted data collection forms, cardiac biomarker results, and electrocardiograms of all relevant clinical events. Comparison of the magnitude and direction of associations between baseline traditional and novel cardiovascular risk factors with incident and recurrent acute MI subtypes and acute non-ischemic myocardial injury events will be made. This project will result in one of the first large prospective cardiovascular cohort with modern classification of acute MI subtypes, as well as a full accounting of non-ischemic myocardial injury events, with implications for numerous ongoing and future studies in MESA. By creating precise MI phenotypes, and defining their epidemiology, this project will allow for discovery of novel pathobiology-specific risk factors, allow for development of more accurate risk prediction, and suggest more targeted preventive strategies.

Toxic myocarditis presenting as an acute coronary syndrome

BackgroundAcute myocarditis is one of the causes of acute non-ischemic myocardial injury mimicking acute coronary syndrome (ACS) on presentation. It is usually underdiagnosed due to the non-specificity of presenting symptoms, elevated troponin levels, and abnormal ECG (electrocardiogram) findings. Delayed contrast-enhanced cardiac MRI (CMR) is known as the gold standard imaging modality for differentiating acute non-ischemic myocardial injury from infarcted myocardium. The most frequent cause of myocarditis is viral infections, but further infrequent causes include other infectious pathogens, toxins, hypersensitivity drug reactions, and autoimmune diseases. Cannabis is one of the most abused illicit and recreational drugs in the world among adolescents and adults. Also, many reports of marijuana-associated cardiovascular risks have been established previously, mainly presenting as arrhythmias, myocardial infarction, and myocarditis.Case presentationA 19-year-old female, complaining of radiating chest pain to the left arm and jaw, along with associated sweating for 1 day. Initial work-up showed elevated troponin levels with ST segment elevation on ECG. On further investigation, CMR showed findings of myocarditis and negative virology work-up led to a work-up of proper history, which revealed marijuana abuse, with a history of consumption 3 days before presentation. Hence, it was diagnosed as toxic myocarditis secondary to presumed cannabis abuse and treated for same.ConclusionsNon-ischemic myocardial injury causes like myocarditis should be considered in young patients especially, who are presenting to emergency with ACS. CMR should be used as a first line diagnostic imaging modality (based on its availability) in cases mimicking an ACS or suspected myocarditis, especially in young patients. Though viral etiology is considered the most common cause of myocarditis, less common causes such as toxic myocarditis must be considered in cases of young individuals presenting with ACS in an emergency.

Perioperative infarction and myocardial injury: risk factors, mechanisms of development and clinical and epidemiological features

Тhe concept, risk factors, mechanisms, clinical and epidemiological, and angiographic features of perioperative ischemic injury and myocardial infarction were considered. Perioperative myocardial infarction is one of the most common complications (up to 3.6%) in non-cardiac surgical interventions and is characterized by high in-hospital mortality, reaching 25%. Most patients with this pathology (up to 65%) do not have typical symptoms of myocardial ischemia due to anesthesia and sedation. Pathogenetic mechanisms of perioperative myocardial infarction development continues to be actively studied. A critical increase in myocardial oxygen demand is indicated as the leading cause in some studies. Angiography reveals rupture of the coronary plaque and atherothrombosis in more than half of patients, according to other data. These contradictions point to the need for further epidemiological studies using coronary angiography with a focus on risk factors and triggers of this complication. In addition, the concept of perioperative myocardial injury in recent years has been formulated in the scientific literature. This is understood as ischemic damage that occurs in the first 30 days after surgery. Recent studies have shown that it can occur in 16% of surgical patients and is associated with a 6-fold increase in mortality within 1 month after surgery and a 2.5-fold increase within a year. It is important that perioperative myocardial injury does not include cases of non-ischemic etiology myocardial injury, for example, due to pulmonary embolism, sepsis, or electrical cardioversion. Thus, the assessment and understanding of risk factors for the development of perioperative myocardial ischemia is of great practical importance in optimizing the patient selection and preparation for surgical treatment.

Implementation of high-sensitivity cardiac troponin and risk of myocardial infarction or death at 5 years: a stepped-wedge cluster-randomised controlled trial

Abstract Background Implementation of a high-sensitivity cardiac troponin I assay with the sex-specific 99th centile as the diagnostic threshold identifies more patients with myocardial injury and infarction, but whether this impacts on long-term clinical outcomes is unknown. Purpose In a prespecified analysis of a stepped-wedge cluster-randomised controlled trial performed across ten hospitals in Scotland, we evaluated the impact of implementing a high-sensitivity cardiac troponin I assay on outcomes at 5 years in consecutive patients with suspected acute coronary syndrome. Methods Throughout the trial, all 48,282 patients had cardiac troponin I concentrations measured using both a contemporary (standard care) and high-sensitivity (implementation) assay. During standard care, results from the high-sensitivity assay were concealed and the contemporary assay was used to guide care. Hospitals were randomly allocated to early (n=5) or late (n=5) implementation of the high-sensitivity assay using the sex-specific 99th centile to guide care and results from the contemporary assay were concealed. Patients reclassified by the high-sensitivity assay were defined as those with cardiac troponin concentrations above the sex-specific 99th centile but below the contemporary assay diagnostic threshold. Subsequent myocardial infarction or all-cause death at 5 years was compared before and after implementation using an adjusted Cox proportional hazards model in those reclassified by the high-sensitivity assay and stratified by index diagnosis. Results Overall, 10,360 patients had cardiac troponin concentrations greater than the sex-specific 99th centile of whom 1,771 (17%) were reclassified by the high-sensitivity assay. Compared to those identified as having elevated cardiac troponin by the contemporary assay, patients reclassified by the high-sensitivity assay were more likely to have non-ischemic myocardial injury (54% versus 28%) and less likely to have type 1 myocardial infarction (33% versus 59%; P&amp;lt;0.001 for both). In those reclassified, the 5-year incidence of subsequent myocardial infarction or all-cause death was 63% (456/720) before and 54% (567/1051) after implementation of the high-sensitivity assay (adjusted hazard ratio [aHR] 0.75 [95% CI 0.57–0.98]) (Figure 1). Following implementation, subsequent myocardial infarction or all-cause death at 5 years was reduced in patients with non-ischemic myocardial injury (aHR 0.66 [0.51–0.86]) but not type 1 or type 2 myocardial infarction (aHR 0.90 [0.78–1.03] and 0.81 [0.55–1.20], respectively). Conclusions In patients with suspected acute coronary syndrome, implementation of a high-sensitivity cardiac troponin assay was associated with a lower risk of subsequent myocardial infarction or death at 5 years. Improvements in outcome were greater in those with a diagnosis of non-ischemic myocardial injury rather than infarction. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Structural Cardiac Abnormalities in Patients with Atrial Fibrillation/Flutter and Myocardial Injury

BackgroundHigh-sensitivity cardiac troponin (hs-cTnT) is often increased in patients with atrial fibrillation/flutter, portending a poor prognosis. The etiologies for these increases have not been systematically investigated. Our aim was to define prevalence/significance of structural cardiac abnormalities in patients with atrial fibrillation/flutter and high-sensitivity cardiac troponin T (hs-cTnT) increases. MethodsThis is a retrospective observational cohort study of patients with atrial fibrillation/flutter diagnosis with hs-cTnT measurements, echocardiograms, and coronary angiograms. Myocardial injury was defined as hs-cTnT >10 ng/L for women and >15 ng/L for men. Cases with myocardial injury were adjudicated according to the Fourth Universal Definition of Myocardial Infarction. ResultsPatients with definite causes for increased hs-cTnT (n = 875) were tabulated but not evaluated further; common diagnoses were type 1 myocardial infarction, critical illness, and known heart failure. Of the remaining 401, increased hs-cTnT was present in 336 (84%) patients. Of those, 78% had nonischemic myocardial injury, the remaining (n = 75, 22%) had type 2 myocardial infarction. Patients with elevated hs-cTnT had greater left ventricular mass index, left ventricular filling pressures, and right ventricular systolic pressure. They more frequently had significant coronary artery disease (47% vs 31%, P = .016), especially in type 2 myocardial infarction. With logistic regression, age, sex (F), diabetes, left ventricular mass index, e′ medial velocity, and right ventricular systolic pressure were independent determinants of myocardial injury. One-year mortality was higher in patients with myocardial injury. ConclusionsStructural heart abnormalities are common in patients with atrial fibrillation/flutter and increased hs-cTnT. Causes of myocardial injury should be elucidated in each patient to craft appropriate therapies.

Use and Prognostic Implications of Cardiac Troponin in COVID-19.

Myocardial injury is common in patients with COVID-19 and is associated with an adverse prognosis. Cardiac troponin (cTn) is used to detect myocardial injury and assist with risk stratification in this population. SARS-CoV-2 infection can play a role in the pathogenesis of acute myocardial injury due to both direct and indirect damage to the cardiovascular system. Despite the initial concerns about an increased incidence of acute myocardial infarction (MI), most cTn increases are related to chronic myocardial injury due to comorbidities and/or acute nonischemic myocardial injury. This review will discuss the latest findings on this topic.

Cardiovascular Sequelae of Covid-19 Infection in Post-Acute Phase

The wide array of clinical manifestations of the ongoing COVID-19 pandemic due to the SARS-CoV-2 infection continues to be a big puzzle to the healthcare professionals. The picture is becoming complex with appearance of new strains and widespread vaccination against the viral infection. The acute cardiovascular manifestations are diverse; but have been fairly well-documented. But the mechanism behind the persistent symptoms like dyspnea, fatigue, chest pain and other symptoms in some of the survivors, weeks and months after the onset of initial infection are poorly understood. The post-acute and long-term cardiovascular impact of COVID-19 affection on heart and other systems is not fully clear. As the survivors after an acute episode are fast growing in number, managing them is emerging as a new public health concern. A recent study on cardiovascular outcomes of COVID-19 in post-acute phase by Xie et al in a cohort of 153,760 survivors of COVID showed that these individuals are at substantial risk of CV disorders like thromboembolic problems, arrhythmias, ischemic and non-ischemic myocardial injury, pericarditis, myocarditis and heart failure irrespective of the intensity of the initial infection. Currently, defining cardiovascular risk and predicting the long-term consequences in COVID survivors are issues of priority for the researchers and clinicians alike. The cardiac MRI is emerging as a useful tool to evaluate the myocardial damage in post-acute phase of COVID infection. This review is an attempt to analyze the existing knowledge and bring out the potential gaps in the understanding of these challenging issues after acute phase of COVID is over.

Use of cardiac troponin I (cTnI) levels to diagnose severe hypoxia and myocardial injury induced by perinatal asphyxia in neonatal dogs

Prolonged perinatal asphyxia and subsequent severe hypoxia are the main causes of mortality in neonatal dogs in the first days of life. In medicine, specific cardiac biochemical markers, such as troponin I, are used to diagnose ischemic and nonischemic myocardial injury in asphyxiated newborns after birth. Thus, the objectives of this study were to compare the levels of cardiac troponin I (cTnI) between asphyxiated and nonasphyxiated newborn dogs and evaluate the correlations of cTnI levels with the modified Apgar score, the levels of oxygen saturation, blood glucose, and lactatemia, and blood gas parameters. This study aimed to determine the possible use of cTnI as a marker of severe hypoxia and myocardial ischemic injury in neonatal dogs. Fifteen animals in a eutocic vaginal delivery group (VG), 15 animals in a cesarean section group (CG), and 13 animals in a hypoxia (asphyxiated) group (HG) were evaluated. The animals in the asphyxiated group were from dystocic deliveries and born by vaginal delivery or cesarean section. All groups were evaluated at birth and after 60 min. The newborns in the VG and CG exhibited mixed acidosis (respiratory acidosis due to increased partial pressure of CO2 (pCO2) and metabolic acidosis due to reduced pH and bicarbonate (HCO3) levels, base excess/deficit in the extracellular fluid compartment (BEecf), and increased lactate levels) due to transient physiological hypoxemia at birth. The cTnI levels in the VG and CG were within the reference standards for healthy dogs. No correlations between cTnI level and the other parameters were observed in the VG and CG. Newborns in the HG exhibited prominent mixed acidosis (p < 0.05) due to severe hypoxemia. The Apgar score and blood gas parameters showed that these dogs were born asphyxiated, and they presented low vitality and the need for resuscitation maneuvers. The cTnI levels in the HG were significantly higher than those in the VG and CG (p < 0.05) and above the reference standards for healthy dogs, which indicated ischemic myocardial injury. The cTnI level was negatively correlated (p < 0.05) with the parameters Apgar score, heart rate, peripheral oxygen saturation (sO2) level, reflex score, and total carbon dioxide (TCO2) level and positively correlated (p < 0.01) with lactate level. This study showed that asphyxiated newborn dogs have higher serum cTnI levels than nonasphyxiated newborn dogs; thus, the cTnI can be used as a marker of severe hypoxia and ischemic myocardial damage in newborn dogs.

Elevated circulating high-sensitivity cardiac troponin t and cardiac remodeling in obesity

BackgroundIt is well established that body mass index (BMI) and troponins are independently associated. However, whether the obesity could cause myocardial injury independent of coronary heart disease (CHD) remains unclear. This study focuses on the relationship between BMI and troponins, and whether this relationship is being attenuated when CHD is accounted for.MethodsIn populations without acute ischemic events, 383 patients with coronary artery stenosis less than 75% were included, that is, people who have not yet reached the indications for coronary intervention, and of them 70 patients being obese according to BMI ≥ 28 kg/m2. Continuous variables were represented as mean ± SD or median(inter quartile range[IQR]). Chi-square test was adopted for categorical data. Correlations between variables were evaluated by Spearman analysis, multiple regression or logistic regression.ResultsThe circulating hs-cTnT level was higher in the obese group [8(6,11) ng/L vs. 6(4,9) ng/L; p < 0.001). In subgroup analysis based on the presence or absence of coronary heart disease(CHD), the adjusted β(95%CI) for circulating hs-cTnT exhibited a proportional relationship with BMI when the non-obesity were defined as the reference[β; 2.22(95%CI, 0.73 to 3.71) in non-CHD, 5.58(95%CI, 0.70 to 10.46) in CHD, p < 0.05]. Additionally, the degree of coronary stenosis has shown a positive correlation with circulating hs-cTnT (rho = 0.1162; p < 0.05).ConclusionWhen CHD is taken into account, obesity is independently associated to the elevation of circulating hs-cTnT, a biomarker of myocardial injury, potentially indicating the impact of obesity on non-ischemic subclinical myocardial injury.

Abstract 14145: The Ratio Of Hs-ctni/hs-ctnt In Patients With Myocardial Injury Is Associated With Different Clinical Phenotypes

Introduction: Hs-cTnI and hs-cTnT concentrations are poorly correlated with a non-linear relationship. The purpose of this study is to determine whether patients with different ratios of hs-cTnI and hs-cTnT are phenotypically distinct. Methods: The study included a consecutive patient cohort that presented to a single academic institution between June and July 2020. Only the first admission and the first corresponding pair of troponin values obtained was analyzed. Patients with both hs-cTnI and hs-cTnT &gt; 99 th percentile URL (≥ 28 ng/L for hs-cTnI and ≥19 ng/L for hs-cTnT) were categorized based on their hs-cTnT to hs-cTnT ratio (I/T ratio). Patient demographic, clinical characteristics, and adjudicated final diagnoses were compared among tertiles of I/T ratio. Results: Of the 809 unique patient encounters, 137 patients had both hs-cTnI and hs-cTnT &gt; 99% URL. Patients in the lowest I/T tertile were more likely to be male, Black, and have diabetes, hypertension, CKD and CAD. The prevalence of myocardial infarction was 5% with the remaining elevated values secondary to acute or chronic non-ischemic myocardial injury. The adjudicated final diagnosis was more likely to be chronic non-ischemic myocardial injury in the lowest I/T tertile and more likely to be acute non-ischemic myocardial injury in the middle and highest tertiles. Conclusions: In this small, single center study, patients with myocardial injury and lower I/T ratio were more likely to have medical comorbidities and chronic myocardial injury as compared to the highest I/T tertile. This suggests that important phenotypic differences exist among patients with abnormal hs-cTnI and T levels. Table 1. Demographics and clinical characteristics of patient cohort with Hs-cTnI and Hs-cTnT values over 99 th percentile categorized by tertile of I/T ratio #Final adjudicated diagnoses defined as per the Fourth Universal Definition of Myocardial Infarction