Type 2 Myocardial Infarction: JACC Review Topic of the Week

Diagnosis of acute myocardial infarction in patients with renal failure using high-sensitivity cardiac troponin T

AIMS

Diagnosing myocardial infarction (MI) in patients with chronic kidney disease (CKD) is difficult as they often have increased high-sensitivity cardiac troponin T (hs-cTnT) concentrations.

METHODS AND RESULTS

Observational US cohort study of emergency department patients undergoing hs-cTnT measurement. Cases with ≥1 hs-cTnT increase > 99th percentile were adjudicated following the Fourth Universal Definition of MI. Diagnostic performance of baseline and serial 2 h hs-cTnT thresholds for ruling-in acute MI was compared between those without and with CKD (estimated glomerular filtration rate < 60 mL/min/1.73 m2). The study cohort included 1992 patients, amongst whom 501 (25%) had CKD. There were 75 (15%) and 350 (70%) patients with CKD and 80 (5%) and 351 (24%) without CKD who had acute MI and myocardial injury. In CKD patients with baseline hs-cTnT thresholds of ≥52, >100, >200, or >300 ng/L, positive predictive values (PPVs) for MI were 36% (95% CI 28-45), 53% (95% CI 39-67), 73% (95% CI 50-89), and 80% (95% CI 44-98), and in those without CKD, 61% (95% CI 47-73), 69% (95% CI 49-85), 59% (95% CI 33-82), and 54% (95% CI 25-81). In CKD patients with a 2 h hs-cTnT delta of ≥10, >20, or >30 ng/L, PPVs were 66% (95% CI 51-79), 86% (95% CI 68-96), and 88% (95% CI 68-97), and in those without CKD, 64% (95% CI 50-76), 73% (95% CI 57-86), and 75% (95% CI 58-88).

CONCLUSION

Diagnostic performance of standard baseline and serial 2 h hs-cTnT thresholds to rule-in MI is suboptimal in CKD patients. It significantly improves when using higher baseline thresholds and delta values.

Type 2 Myocardial Infarction in a Sub-Saharan Africa Population: Challenging the Current Concepts-Data From REACTIV

BACKGROUND

From a large observational acute coronary syndrome registry in Côte d'Ivoire, we aimed to assess incidence, clinical presentation, management, and in-hospital outcomes for type 2 myocardial infarction (T2MI) compared with type 1 MI.

METHODS AND RESULTS

We conducted a cross-sectional monocentric study using data from REACTIV (Registre des Infarctus de Côte d'Ivoire) at the Abidjan Heart Institute. All patients hospitalized with MI between 2018 and 2022 who underwent coronary angiography were included. For each patient, sociodemographic data, cardiovascular risk factors and history, and clinical and paraclinical presentation were collected at admission. In-hospital outcomes, including major adverse cardiovascular events and mortality, were reported. Among 541 consecutive patients hospitalized with MI, 441 met the definition of type 1 MI or T2MI. T2MI accounted for 14.1% of cases. Patients with T2MI showed a trend toward slightly younger age (54 versus 58 years, P=0.09). Patients with T2MI seemed to have less severe coronary artery disease, with less frequent multivessel disease (P<0.001). Main triggering factors for T2MI were coronary embolism (24.2%), severe hypertension with or without left ventricular hypertrophy (22.6%), and tachyarrhythmia (16.1%). In-hospital event rates were low in both MI types. Although the difference was nonsignificant, death rates for patients with type 1 MI tended to be higher than for patients with T2MI, as well as occurrence of major adverse cardiovascular events.

CONCLUSIONS

Our study revealed disparities in clinical characteristics, angiographic features, cause, and in-hospital outcomes in T2MI in our population compared with Western populations. These results suggest the heterogeneity of T2MI and the potential causative and demographic variability depending on geographical area.

The cytoplasmic sensor, the AIM2 inflammasome: A precise therapeutic target in vascular and metabolic diseases

Cardio-cerebrovascular diseases encompass pathological changes in the heart, brain and vascular system, which pose a great threat to health and well-being worldwide. Moreover, metabolic diseases contribute to and exacerbate the impact of vascular diseases. Inflammation is a complex process that protects against noxious stimuli but is also dysregulated in numerous so-called inflammatory diseases, one of which is atherosclerosis. Inflammation involves multiple organ systems and a complex cascade of molecular and cellular events. Numerous studies have shown that inflammation plays a vital role in cardio-cerebrovascular diseases and metabolic diseases. The absent in melanoma 2 (AIM2) inflammasome detects and is subsequently activated by double-stranded DNA in damaged cells and pathogens. With the assistance of the mature effector molecule caspase-1, the AIM2 inflammasome performs crucial biological functions that underpin its involvement in cardio-cerebrovascular diseases and related metabolic diseases: The production of interleukin-1 beta (IL-1β), interleukin-18 (IL-18) and N-terminal pore-forming Gasdermin D fragment (GSDMD-N) mediates a series of inflammatory responses and programmed cell death (pyroptosis and PANoptosis). Currently, several agents have been reported to inhibit the activity of the AIM2 inflammasome and have the potential to be evaluated for use in clinical settings. In this review, we systemically elucidate the assembly, biological functions, regulation and mechanisms of the AIM2 inflammasome in cardio-cerebrovascular diseases and related metabolic diseases and outline the inhibitory agents of the AIM2 inflammasome as potential therapeutic drugs.

Copeptin for the differentiation of type 1 versus type 2 myocardial infarction or myocardial injury

BACKGROUND

The rapid and reliable differentiation of myocardial infarction (MI) due to atherothrombosis (T1MI) from MI due to supply-demand mismatch (T2MI) or acute myocardial injury is of major clinical relevance due to very different treatments, but still a major unmet clinical need. This study aimed to investigate whether copeptin, a stress hormone produced in the hypothalamus, helps to differentiate between T1MI versus T2MI or injury.

METHODS

In a retrospective analysis, 1271 unselected consecutive patients presenting with symptoms suggestive of MI to the emergency department were evaluated. Patients diagnosed with ST-elevation MI were excluded. All patients with elevated cardiac troponin I (cTnI) concentration possibly indicating MI were classified into T1MI, T2MI, or acute myocardial injury using detailed clinical assessment and coronary imaging. Copeptin plasma concentration was measured in a blinded fashion. A multicenter diagnostic study with central adjudication of the final diagnosis served as external validation cohort (n = 1390).

RESULTS

Among 1161 patients, 154 patients had increased cTnI concentration. Of these, 78 patients (51%) were classified as T1MI and 76 (49%) as T2MI or myocardial injury. Patients with T2MI or myocardial injury had significantly higher copeptin plasma concentration between patients versus T1MI (21,4 pmol/l versus 8,1 pmol/l, p = 0,001). A multivariable regression analysis revealed that higher concentrations of copeptin and C-reactive protein, higher heart rate at presentation and lower frequency of smoking remained significantly associated with T2MI and myocardial injury. Findings were largely confirmed in the external validation cohort.

CONCLUSION

In patients without ST-segment elevation, copeptin concentration was higher in T2MI and myocardial Injury versus T1MI and may help in their differential diagnosis.

Rate control or revascularisation in managing atrial fibrillation-induced myocardial infarction and heart failure?

Acute myocardial infarction (MI) is a common and severe cardiovascular emergency that requires immediate treatment. Angina pectoris, which typically signals myocardial ischaemia, can appear in MI cases with myriad causes aside from coronary artery disease. However, not all MI patients benefit from invasive revascularisation therapy. We herein report a case involving a 78-year-old female patient with a complex medical history, including non-ST-segment elevation MI and coronary artery bypass grafting, who experienced recurrent chest pain. Instead of a direct result of coronary artery disease, her chest pain was later found to be primarily induced by atrial fibrillation (AF). Consequently, we shifted the focus of management to effective rate control for the AF after careful evaluation and achieved a satisfactory result. This case highlights the successful identification and timely application of intensive heart rate control management in an MI case induced by AF.

Association between Myocardial Oxygen Supply and Demand and Myocardial Injury in Patients with End-Stage Kidney Disease

AIM

In patients with end-stage kidney disease (ESKD), it is unclear whether an imbalance between myocardial oxygen supply and demand leads to myocardial injury (MI). This study clarifies the association between the balance of the rate pressure product (RPP), consisting of the systolic blood pressure multiplied by the pulse rate (PR), a marker for myocardial oxygen demand, and hemoglobin (Hb), a marker for oxygen supply, with MI.

METHODS

A total of 283 consecutive unselected patients for hemodialysis were enrolled in this retrospective, cross-sectional study, and were divided into four groups according to Hb levels (high or low) and RPP. Potential imbalances between myocardial oxygen supply and demand were defined as patients with simultaneous high RPP and low Hb levels. The odds ratio (OR) for MI, defined as cardiac troponin T (cTnT) of ≥ 0.15 ng/mL was investigated using logistic regression analysis between the four patient groups.

RESULTS

The mean age was 68.7 years, 71.3% were men, and 52.6% had diabetes. The mean Hb level was 9.0 g/dL, and 20.5% of patients were latently diagnosed with MI. The median RPP and cTnT level was 12,144 and 0.083 ng/mL, respectively. When exposed to simultaneous high RPP with low Hb, OR significantly increased compared with that of the well-balanced group (RPP ＜12,500 and Hb ≥ 9.0 g/dL; OR 3.63, p＜0.05). Similar results were obtained in multivariate analysis after adjusting for confounding variables. These associations were enhanced or weakened when the Hb cut-off level became lower (Hb=8 g/dL) or higher (Hb=10 g/dL).

CONCLUSIONS

As the myocardial oxygen supply and demand balance in patients with ESKD is potentially associated with MI, appropriate management for blood pressure, PR, and anemia may prevent MI.

Type 2 Myocardial Infarction-Poorly Understood, Underevaluated, and Too Often Ignored

This Viewpoint discusses diagnosis of type 2 myocardial infarction.

Explore the effect of apparent temperature and air pollutants on the admission rate of acute myocardial infarction in Chongqing, China: a time-series study

OBJECTIVE

Limited research has been conducted on the correlation between apparent temperature and acute myocardial infarction (AMI), as well as the potential impact of air pollutants in modifying this relationship. The objective of this study is to investigate the lagged effect of apparent temperature on AMI and assess the effect modification of environmental pollutants on this association.

DESIGN

A time-series study.

SETTING AND PARTICIPANTS

The data for this study were obtained from the Academy of Medical Data Science at Chongqing Medical University, covering daily hospitalisations for AMI between 1 January 2015 and 31 December 2016. Meteorological and air pollutant data were provided by China's National Meteorological Information Centre.

OUTCOME MEASURES

We used a combined approach of quasi-Poisson generalised linear model and distributed lag non-linear model to thoroughly analyse the relationships. Additionally, we employed a generalised additive model to investigate the interaction between air pollutants and apparent temperature on the effect of AMI.

RESULT

A total of 872 patients admitted to hospital with AMI were studied based on the median apparent temperature (20.43°C) in Chongqing. Low apparent temperature (10th, 7.19℃) has obvious lagged effect on acute myocardial infarction, first appearing on the 8th day (risk ratio (RR) 1.081, 95% CI 1.010 to 1.158) and the greatest risk on the 11th day (RR 1.094, 95% CI 1.037 to 1.153). No lagged effect was observed at high apparent temperature. In subgroup analysis, women and individuals aged 75 and above were at high risk. The interaction analysis indicates that there exist significant interactions between PM2.5 and high apparent temperature, as well as nitrogen dioxide (NO2) and low apparent temperature.

CONCLUSION

The occurrence of decreased apparent temperature levels was discovered to be linked with a heightened relative risk of hospitalisations for AMI. PM2.5 and NO2 have an effect modification on the association between apparent temperature and admission rate of AMI.

Comparison between Invasive Intervention and Conservative Treatment in Patients with In-Hospital Myocardial Infarctions: Results from the Regional Myocardial Infarction Registry of Saxony-Anhalt (RHESA) Study

Background/Objectives: In-hospital myocardial infarctions (AMIs) are less often treated with invasive intervention, compared to out-of-hospital AMIs. We aimed to identify the determinants of invasive intervention in patients with in-hospital AMIs and assess its association with mortality, compared to conservative treatment. Methods: This was a cross-sectional study of in-hospital AMIs in The Regional Myocardial Infarction Registry of Saxony-Anhalt. Patients' characteristics and outcomes were compared based on the treatment strategy (invasive intervention vs. conservative treatment). Logistic regression was performed to assess the determinants of invasive intervention (vs. conservative treatment) and its association with 30-day mortality. Results: Nearly 67% of the patients (259/386) received invasive intervention, and the rest were treated conservatively. Those who were treated with an invasive intervention were younger and had a lower proportion of chronic heart failure than those treated conservatively. Age > 75 years compared to younger patients, pre-existing heart failure, and higher heart rate upon presentation were associated with lower odds of receiving invasive intervention. Hypertension (OR = 2.86, 95% CI [1.45-5.62]) and STEMI vs. NSTEMI (1.96, [1.10-3.68]) were associated with higher odds of invasive intervention. The adjusted odds of 30-day mortality were lower with invasive intervention compared to conservative treatment (0.25, [0.10-0.67]). Conclusions: One-third of the patients with in-hospital AMIs received conservative treatment. Younger age, absence of heart failure, lower heart rate, hypertension, and STEMI were determinants of invasive intervention usage. Invasive intervention had lower odds of 30-day mortality, but longitudinal studies are still needed to assess the efficacy of conservative vs. invasive strategies in in-hospital AMIs.

Application of the Universal Definition of Myocardial Infarction in Clinical Practice in Scotland and Sweden

Importance

Whether the diagnostic classifications proposed by the universal definition of myocardial infarction (MI) to identify type 1 MI due to atherothrombosis and type 2 MI due to myocardial oxygen supply-demand imbalance have been applied consistently in clinical practice is unknown.

Objective

To evaluate the application of the universal definition of MI in consecutive patients with possible MI across 2 health care systems.

Design, Setting, and Participants

This cohort study used data from 2 prospective cohorts enrolling consecutive patients with possible MI in Scotland (2013-2016) and Sweden (2011-2014) to assess accuracy of clinical diagnosis of MI recorded in hospital records for patients with an adjudicated diagnosis of type 1 or type 2 MI. Data were analyzed from August 2022 to February 2023.

Main Outcomes and Measures

The main outcome was the proportion of patients with a clinical diagnosis of MI recorded in the hospital records who had type 1 or type 2 MI, adjudicated by an independent panel according to the universal definition. Characteristics and risk of subsequent MI or cardiovascular death at 1 year were compared.

Results

A total of 50 356 patients were assessed. The cohort from Scotland included 28 783 (15 562 men [54%]; mean [SD] age, 60 [17] years), and the cohort from Sweden included 21 573 (11 110 men [51%]; mean [SD] age, 56 [17] years) patients. In Scotland, a clinical diagnosis of MI was recorded in 2506 of 3187 patients with an adjudicated diagnosis of type 1 MI (79%) and 122 of 716 patients with an adjudicated diagnosis of type 2 MI (17%). Similar findings were observed in Sweden, with 970 of 1111 patients with adjudicated diagnosis of type 1 MI (87%) and 57 of 251 patients with adjudicated diagnosis of type 2 MI (23%) receiving a clinical diagnosis of MI. Patients with an adjudicated diagnosis of type 1 MI without a clinical diagnosis were more likely to be women (eg, 336 women [49%] vs 909 women [36%] in Scotland; P < .001) and older (mean [SD] age, 71 [14] v 67 [14] years in Scotland, P < .001) and, when adjusting for competing risk from noncardiovascular death, were at similar or increased risk of subsequent MI or cardiovascular death compared with patients with a clinical diagnosis of MI (eg, 29% vs 18% in Scotland; P < .001).

Conclusions and Relevance

In this cohort study, the universal definition of MI was not consistently applied in clinical practice, with a minority of patients with type 2 MI identified, and type 1 MI underrecognized in women and older persons, suggesting uncertainty remains regarding the diagnostic criteria or value of the classification.

Characteristics and Prognosis of Type 2 Myocardial Infarction Through Worsening Renal Function and NT-proBNP in Older Adults with Pneumonia

Background

Type 2 myocardial infarction (MI) is becoming more recognized. This study aimed to assess the factors linked to type 2 MI in older adults with pneumonia and further determine the predictive factors of 90-day adverse events (refractory heart failure, cardiogenic shock, and all-cause mortality).

Methods

A single-center retrospective analysis was conducted among older adults with pneumonia. The primary outcome was the prevalence of type 2 MI. The secondary objective was to assess the adverse events in these patients with type 2 MI within 90 days.

Results

A total of 2618 patients were included. Of these, 361 patients (13.8%) suffered from type 2 MI. Multivariable predictors of type 2 MI were chronic kidney disease (CKD), age-adjusted Charlson comorbidity index (ACCI) score, and NT-proBNP > 4165pg/mL. Moreover, the independent predictive factors of 90-day adverse events included NT-proBNP > 4165pg/mL, age, ACCI score, and CKD. The Kaplan-Meier adverse events curves revealed that the type 2 MI patients with CKD and NT-proBNP > 4165pg/mL had a higher risk than CKD or NT-proBNP > 4165pg/mL alone.

Conclusion

Type 2 MI in older pneumonia hospitalization represents a heterogeneous population. Elevated NT-proBNP level and prevalence of CKD are important predictors of type 2 MI and 90-day adverse events in type 2 MI patients.

High Baseline High-Sensitivity Cardiac Troponin T Concentrations and Risk of Index Acute Myocardial Infarction

OBJECTIVE

To evaluate the diagnostic performance of the previously recommended baseline high-sensitivity cardiac troponin T (hs-cTnT) thresholds of 52 and 100 ng/L in identifying patients at high risk of acute myocardial infarction (AMI).

PATIENTS AND METHODS

This study compared the positive predictive value (PPV) for index AMI of these high-risk hs-cTnT thresholds in adult patients in the emergency department undergoing hs-cTnT measurement.

RESULTS

The adjudicated MAyo Southwest Wisconsin 5th Gen Troponin T ImplementatiON cohort included 2053 patients, with 157 (7.6%) who received a diagnosis of AMI. The hs-cTnT concentrations of greater than 52 and greater than 100 ng/L resulted in PPVs of 41% (95% CI, 35%-48%) and 57% (95% CI, 48%-66%). In patients with chest discomfort, hs-cTnT concentrations greater than 52 ng/L resulted in a PPV of 66% (95% CI, 56%-76%) and hs-cTnT concentrations greater than 100 ng/L resulted in a PPV of 77% (95% CI, 65%-87%). The CV Data Mart Biomarker cohort included 143,709 patients, and 3003 (2.1%) received a diagnosis of AMI. Baseline hs-cTnT concentrations greater than 52 and greater than 100 ng/L resulted in PPVs of 12% (95% CI, 11%-12%) and 17% (95% CI, 17%-19%), respectively. In patients with chest pain and hs-cTnT concentrations greater than 52 ng/L, the PPV for MI was 17% (95% CI, 15%-18%) and in those with concentrations greater than 100 ng/L, only 22% (95% CI, 19%-25%).

CONCLUSION

In unselected patients undergoing hs-cTnT measurement, the hs-cTnT thresholds of greater than 52 and greater than 100 ng/L provide suboptimal performance for identifying high-risk patients. In patients with chest discomfort, an hs-cTnT concentration of greater than 100 ng/L, but not the European Society of Cardiology-recommended threshold of greater than 52 ng/L, provides an acceptable performance but should be used only with other clinical features.

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

Post translational modifications of connexin 43 in ventricular arrhythmias after myocardial infarction

Ventricular arrhythmias are the leading cause of sudden cardiac death in patients after myocardial infarction (MI). Connexin43 (Cx43) is the most important gap junction channel-forming protein in cardiomyocytes. Dysfunction of Cx43 contributes to impaired myocardial conduction and the development of ventricular arrhythmias. Following an MI, Cx43 undergoes structural remodeling, including expression abnormalities, and redistribution. These alterations detrimentally affect intercellular communication and electrical conduction within the myocardium, thereby increasing the susceptibility to post-infarction ventricular arrhythmias. Emerging evidence suggests that post-translational modifications play essential roles in Cx43 regulation after MI. Therefore, Cx43-targeted management has the potential to be a promising protective strategy for the prevention and treatment of post infarction ventricular arrhythmias. In this article, we primarily reviewed the regulatory mechanisms of Cx43 mediated post-translational modifications on post-infarction ventricular arrhythmias. Furthermore, Cx43-targeted therapy have also been discussed, providing insights into an innovative treatment strategy for ventricular arrhythmias after MI.

Pseudo-targeted metabolic profile differences between emergency patients with type 1 and type 2 myocardial infarction diagnosed by optical coherence tomography

BACKGROUND

It is difficult to distinguish type 2 myocardial infarction (T2MI) from type 1 myocardial infarction (T1MI), although their management varies.

OBJECTIVES

Using optical coherence tomography (OCT) and pseudo-targeted metabolomics to identify biomarkers, investigate metabolic differences, and establish a T2MI subclassification.

METHODS

Among 1519 patients with MI, 97 T2MI patients are identified who are 1:1 matched with 97 T1MI patients after considering age, gender, ST-segment elevation, time from onset to coronary angiography, and hs-cTnI on admission by propensity score matching. Plasma pseudo-targeted metabolomics at baseline was determined.

RESULTS

The clinical characteristics of the two groups were comparable, while the T1MI showed more severe coronary lesions than T2MI according to OCT imaging. 90 differential metabolites were identified between the two groups, among 1027 endogenous metabolites in 20 classes. N-Acetyl-L-Leucine, free fatty acid (15:1), Thymidine-5'-triphosphate, Mevalonic acid 5-pyrophosphate, and five oligopeptides were candidate biomarkers (AUC ≥ 0.85) distinguishing T2MI from T1MI. 12 KEGG pathways showed significant differences, mainly involving amino acid, nucleotide, and their derivatives metabolism, and signaling pathways such as mTOR, cGMP-PKG, and cAMP. Other differences were observed in TCA cycle (P = 0.08) and ROS (P = 0.05). Proteolysis and coronary heart disease risk lipid level were lower in T2MI. T2MI had a decrease of differential abundance score in almost all the KEGG enrichment pathways. Furthermore, T2MI can be subdivided into three subtypes by hierarchical cluster analysis of AUCs with causes/triggers of T2MI.

CONCLUSIONS

There are significant metabolic profile differences between T1MI and T2MI. Several candidate metabolic biomarkers can effectively distinguish the two groups.

CLINICAL TRIAL REGISTRATION

ClinicalTrials. gov NCT03297164.

Sex Differences in Coronary Artery Disease Characteristics Among Patients With Type 2 Myocardial Infarction

Background

Type 2 myocardial infarction (MI) results from coronary supply and demand imbalance and has a poor prognosis. It is crucial to identify potential sex-based differences in the prevalence and nature of coronary artery disease (CAD) within this population.

Objectives

The purpose of this study was to evaluate sex-based disease differences in type 2 MI among patients evaluated with coronary computed tomography angiography and fractional flow reserve.

Methods

In a single-center, prospective study, patients with strictly adjudicated type 2 MI underwent coronary computed tomography angiography with fractional flow reserve.

Results

Among 50 study participants enrolled, 50% were women. A similar mix of MI precipitants was present in both sexes. ST-segment depression was more common in women (64% vs 32%), while men were more likely to have T wave inversion (68% vs 36%). Women and men had comparable coronary artery calcium scores (median: 152 [Q1, Q3: 45, 762] vs 234 [Q1, Q3: 56, 422]). Prevalence of any CAD (84% vs 100%), obstructive CAD (24% vs 28%), and hemodynamically significant focal stenosis (20% vs 32%) were similar between sexes. Total plaque volume was similar between sexes, but women had significantly lower levels of low-attenuation plaque (median: 3 [Q1, Q3: 1, 7] vs 9 [Q1, Q3: 3, 14]).

Conclusions

Among patients with type 2 MI, prevalence of any CAD and obstructive CAD did not differ according to sex. Total plaque volume was similar between sexes, but women had a lower volume of low-attenuation plaque (DEFINing the PrEvalence and Characteristics of Coronary Artery Disease Among Patients With TYPE 2 Myocardial Infarction Using CT-FFR [DEFINE TYPE2MI]; NCT04864119).

Aerobic exercise protects MI heart through miR-133a-3p downregulation of connective tissue growth factor

OBJECTIVE

To investigate the effect of aerobic exercise intervention to inhibit cardiomyocyte apoptosis and thus improve cardiac function in myocardial infarction (MI) mice by regulating CTGF expression through miR-133a-3p.

METHODS

Male C57/BL6 mice, 7-8 weeks old, were randomly divided into sham-operated group (S group), sham-operated +aerobic exercise group (SE group), myocardial infarction group (MI group) and MI + aerobic exercise group (ME group). The mice were anesthetized the day after training and cardiac function was assessed by cardiac echocardiography. Myocardial collagen volume fraction (CVF%) was analyzed by Masson staining. Myocardial CTGF, Bax and Bcl-2 were detected by Western blotting, and myocardial miR-133a-3p was measured by RT-qPCR.

RESULTS

Compared with the S group, miR-133a-3p, Bcl-2 and EF were significantly decreased and CTGF, Bax, Bax/ Bcl-2, Caspase 3, Cleaved Caspase-3, LVIDd, LVIDs and CVF were significantly increased in the MI group. Compared with the MI group, miR-133a-3p, Bcl-2 and EF were significantly increased, cardiac function was significantly improved, and CTGF, Bax, Bax/ Bcl-2, Caspase 3, Cleaved Caspase-3, LVIDd, LVIDs and CVF were significantly decreased in ME group. The miR-133a-3p was significantly lower and CTGF was significantly higher in the H2O2 intervention group compared with the control group of H9C2 rat cardiomyocytes. miR-133a-3p was significantly higher and CTGF was significantly lower in the AICAR intervention group compared to the H2O2 intervention group. Compared with the control group of H9C2 rat cardiomyocytes, CTGF, Bax and Bax/Bcl-2 were significantly increased and Bcl-2 was significantly decreased in the miR-133a-3p inhibitor intervention group; CTGF, Bax and Bax/Bcl-2 were significantly decreased and Bcl-2 was significantly upregulated in the miR-133a-3p mimics intervention group.

CONCLUSION

Aerobic exercise down-regulated CTGF expression in MI mouse myocardium through miR-133a-3p, thereby inhibiting cardiomyocyte apoptosis and improving cardiac function.

Possibilities of predicting adverse cardiovascular events based on the analysis of clinical and instrumental research methods, as well as sST2 in patients after myocardial infarction

OBJECTIVE

Aim: To determine the possibility of predicting adverse cardiovascular events based on the analysis of clinical and instrumental research methods, as well as sST2 in patients after myocardial infarction.

PATIENTS AND METHODS

Materials and Methods: The study included 64 patients who suffered an acute myocardial infarction and underwent PCI with balloon angioplasty and stenting of the infarct-related vessel in the acute period. The predictors of adverse cardiovascular events were assessed events during 1 year of observation. Indicators of echocardiography and coronary angiography were assessed and concentrations sST2.

RESULTS

Results: A worse prognosis was associated with intermediate ejection fraction (EF) (odds ratio (OR)=3.981, p<0.05), left aneurysm ventricle (LV) (OR=29.5, p<0.05), high concentrations of sST2 (OR=1.017, p<0.05) and scores on the Syntax scale (OR=1.001, p<0.05).

CONCLUSION

Conclusions: In patients who underwent percutaneous coronary intervention for myocardial infarction, adverse outcome during the next 2 years is associated with coronary and echocardiographic parameters, as well as biochemical indicators of myocardial stress and fibrosis. HF patients with intermediate EF, LV aneurysm, high sST2 concentrations, and high Syntax scores have the worst prognosis.

Scorpion-Induced Acute Coronary Syndrome: A Stinging Complication

The Tityus trinitatis, a black scorpion species endemic to the fauna of Trinidad, has been implicated in envenomation with devastating clinical sequelae such as acute pancreatitis and major adverse cardiovascular events. We present the first in-Caribbean case of a 59-year-old Caribbean South Asian male with human immunodeficiency virus who presented with a non-ST-segment-elevation acute coronary syndrome after being stung, which was managed with comprehensive, guideline-directed medical therapy. The clinician should be cognizant of scorpion-induced acute coronary syndrome (ACS) as a potential sequela of envenomation and its clinical management.

Diagnostic and prognostic impact of new pathophysiology-based categorization of type 1 and type 2 myocardial infarction: data from the French RICO survey

BACKGROUND

A new classification of type 1 and 2 myocardial infarction (MI) derived from the fourth universal definition of MI (UDMI) has been recently proposed, based on pathophysiology of coronary artery disease (CAD). We assessed the impact of this new MI categorization on epidemiology and outcomes, considering type 1 MI (T1MI) and type 2 MI (T2MI), with and without CAD.

METHODS

Retrospective study including all consecutive patients hospitalized for an acute MI in a multicenter database (RICO). MI was defined according to current UDMI. Rates and outcomes of T1MI and T2MI were addressed according to the new classification.

RESULTS

Among the 4,573 patients included in our study, 3,710 patients (81.1%) were initially diagnosed with T1M1 and 863 (18.9%) with T2MI. After reclassification, 96 T2MI patients were moved into the T1MI category. Out of the remaining 767 patients with T2MI, 567 underwent coronary angiography, and were adjudicated as type 2A MI (68.6%) with obstructive CAD, and type 2B MI (31.4%) without obstructive CAD. When compared with T1MI and T2BMI, T2AMI patients had worse in-hospital outcomes, including severe heart failure (P < .001), atrial fibrillation or flutter (P < .001) and severe bleeding (P < .001). Kaplan-Meier 1-year survival curves showed higher all-cause and CV causes mortality in T2AMI patients compared to T1MI and T2BMI (P < .001). In multivariate Cox regression analysis, type of MI was independent predictor of death.

CONCLUSION

Our large observational multicenter study shows major disparities in mortality according to type of MI and support the relevance of the new MI classification to improve risk classification, taking into account CAD in T2MI. Our findings may help identifying specific phenotypes and considering personalized diagnostic and management strategies.

Ivabradine in the Prevention, and Reduction in Size, of Perioperative Myocardial Injury in Patients Undergoing Orthopedic Surgery for Acute Fracture

BACKGROUND

Perioperative myocardial injury is common after major noncardiac surgery and is associated with adverse outcomes. This study investigated the use of ivabradine in patients undergoing urgent surgery for fracture.

METHODS AND RESULTS

This was a prospective, double-blind, placebo-controlled, randomized clinical trial. Participants were enrolled 1:1 into ivabradine or placebo arm, and study drug was commenced before operation and continued for 7 days or until discharge. High-sensitivity troponin I was measured daily using Abbott Alinity analyzer and assay, and heart rate data were obtained using continuous Holter monitoring. A total of 199 patients underwent acute orthopedic surgery, 98 in the ivabradine group and 101 in the placebo group. The mean age was 78.7 years (range, 77.5-79.9 years), with 68% women. The average heart rate was 5 to 11 beats per minute lower in the ivabradine group compared with the placebo group at all time points (P<0.001 for all). There was no statistically significant difference between the ivabradine and placebo groups in the number of patients who had perioperative myocardial injury: 28.6% versus 31.6% (P=0.71). In patients with perioperative myocardial injury, average peak troponin was 168.8 ng/L (±431.2 ng/L) in the ivabradine group and 2094.5 ng/L (±7201.9 ng/L) in the placebo group (P=0.16). There was no statistically significant difference between groups in 30-day mortality, blood pressure, stroke, or major adverse cardiovascular event.

CONCLUSIONS

Starting ivabradine preoperatively in elderly patients requiring acute surgery for fracture did not result in a statistically significant difference in the incidence of perioperative myocardial injury. There was no statistically significant difference in morbidity, mortality, or adverse events between treatment groups.

REGISTRATION

URL: https://www.anzctr.org.au/; Unique identifier: ACTRN12616001634460p.

Coronary Computed Tomographic Angiography With Fractional Flow Reserve in Patients With Type 2 Myocardial Infarction

BACKGROUND

Type 2 myocardial infarction (T2MI) related to a supply/demand imbalance of coronary blood flow is common and associated with poor prognosis. Coronary artery disease (CAD) may predispose some individuals to T2MI and contribute to its high rate of recurrent cardiovascular events. Little is known about the presence and extent of CAD in this population.

OBJECTIVES

The goal of this study was to evaluate the presence and characteristics of CAD among patients with T2MI.

METHODS

In this prospective study, consecutive eligible individuals with Fourth Universal Definition of Myocardial Infarction criteria for T2MI were enrolled. Participants underwent coronary computed tomography angiography (CTA), fractional flow reserve derived with coronary CTA (FFRCT), and plaque volume analyses.

RESULTS

Among 50 participants, 25 (50%) were female, and the mean age was 68.0 ± 11.4 years. Atherosclerotic risk factors were common. Coronary CTA revealed coronary plaque in 46 participants (92%). A moderate or greater stenosis (≥50%) was identified in 42% of participants, and obstructive disease (≥50% left main stenosis or ≥70% stenosis in any other epicardial coronary artery) was present in 26%. Prevalence of obstructive CAD did not differ according to T2MI cause (P = 0.54). A hemodynamically significant focal stenosis identified by FFRCT was present in 13 participants (26%). Among participants with a stenosis ≥50% (n = 21), FFRCT excluded lesion-specific hemodynamically significant stenosis in 8 cases (38%).

CONCLUSIONS

Among individuals with adjudicated T2MI, CAD was prevalent, but the majority of patients had nonobstructive CAD. Mediators of ischemia are likely multifactorial in this population. (Defining the Prevalence and Characteristics of Coronary Artery Disease Among Patients with Type 2 Myocardial Infarction using CT-FFR [DEFINE TYPE 2 MI]; NCT04864119).

Prevalence and outcomes of type 2 myocardial infarction in patients with cancer: A retrospective analysis from the National Inpatient Sample dataset

BACKGROUND

This study aimed to investigate the prevalence, clinical characteristics and outcomes of type 2 myocardial infarction (T2AMI) in patients with versus without cancer.

METHODS

All hospitalizations with a primary discharge diagnosis of T2AMI were stratified according to cancer status (secondary diagnosis of any-cancer vs cancer-free) using data from the US National Inpatient Sample (2016-2019). The primary outcome was in-hospital all-cause mortality while secondary outcomes were in-hospital major adverse cardiovascular and cerebrovascular events (MACCE).

RESULTS

Among 61,305 included hospitalizations with primary diagnosis of T2AMI, 3745 (6.1%) were associated with a diagnosis of cancer. Patients with T2AMI and cancer presented more frequently with acute respiratory failure (23.2% vs 18.1%), acute pulmonary embolism (3.7% v 1.3%), major bleeding (6.8% vs 4.1%) and renal failure (51.0% vs 46.8%), compared to patients without. On adjusted analysis, diagnosis of cancer was associated with lower odds of invasive coronary angiography (aOR 0.75, 95% CI 0.60 to 0.93, p = 0.009) but greater odds of mortality (aOR 1.95, 95% C.I. 1.26-2.99 p = 0.002). Among the different types of cancer, adjusted risk of all-cause mortality was higher in patients with colorectal (aOR 4.17 95% CI 1.68-10.32, p = 0.002), lung (aOR 3.63, 95% CI 1.83-7.18, p < 0.001) and haematologic (aOR 2.48, 95% CI 1.22-5.05, p = 0.001) cancer.

CONCLUSIONS

Patients with cancer presenting with T2AMI have lower odds of management with invasive diagnostic coronary angiography and have higher rates of in-hospital all-cause death. Further studies are warranted to improve overall care and outcomes of cancer patients and cardiovascular diseases.

Identifying and Treating Vulnerable Atherosclerotic Plaques

Acute coronary syndromes and, in particular, ST-elevation myocardial infarction are usually caused by coronary thrombosis in which the thrombus develops either on a disrupted plaque (usually a thin-capped fibroatheroma) or an eroded atherosclerotic plaque. These thrombus-prone plaques are vulnerable or high-risk. Although, traditionally, cardiologists have concentrated on treating significant coronary obstruction, there has been great interest over the last 2 decades in possibly preventing the thrombotic causes of myocardial infarction/sudden coronary death by mostly identifying and stabilizing these asymptomatic vulnerable or high-risk plaques, which, at least on invasive angiography, are mostly nonobstructive. Computed tomographic angiography and intravascular imaging during invasive coronary angiography have now been shown to identify a majority of these vulnerable or high-risk plaques before symptoms, thus opening up new preventive strategies. In conclusion, this article discusses the identification and management of these thrombus-prone lesions and patients with these lesions either with noninvasive techniques and systemic therapies or possibly through a new and bold interventional paradigm.

Coronary Artery Disease: A Key Issue in Type 2 Myocardial Infarction: Systematic Review and Recent Findings

Underlying coronary artery disease (CAD) is increasingly considered to be a key issue in the pathophysiology of type 2 myocardial infarction (T2MI). In T2MI, which is attributable to a mismatch between oxygen supply/demand, CAD is common and appears to be more severe than in type 1 myocardial infarction (T1MI). Little is known about the heterogeneous mechanisms that cause supply/demand imbalance and non-coronary triggers leading to myocardial ischemia or about how they are potentially modulated by the presence and severity of CAD. CAD seems to be underrecognized and undertreated in T2MI, even though previous studies have demonstrated both the short and long-term prognostic value of CAD in T2MI. In this literature review, we attempt to address the prevalence and severity of CAD, challenges in the discrimination between T2MI and T1MI in the presence of CAD, and the prognostic value of CAD among patients with T2MI.

A Convergent fabrication of silk fibroin nanoparticles on quercetin loaded metal-organic frameworks for promising nanocarrier of myocardial infraction

The biomacromolecule silk fibroin (SF) may be constructed to promote biomimetic nucleation and nanostructures of inorganic nanomaterials, offering it a promising candidate for use in various biomimetic applications. We combined SF-NPs and ZIF-8-NPs to fabricate new drug vehicles that effectively release the drug. SF nanoparticles (SF-NPs) were assembled into quercetin (QCT), a myocardial drug added to fabricate QSF-NPs. By acting as a template for the ZIF-8 nucleation onto the surface, the QSF-NPs fabricated core-shell-structured nanocomposites (named QSF@Z-NCs) with ZIF-8 as the core-shell and the QSF-NPs. The biocompatibility analysis using the MTT assay revealed that the developed QCT, SF-NPs, and QSF@Z-NCs are not harmful to cardiac myoblast (H9C2) cells. The in vivo model demonstrated that H9C2 cells encouraged cardiomyocyte fibre regeneration in myocardial infarction rats. We fabricated a brand-new technique using H9C2 cells and QSF@Z-NCs that might encourage the healing processes in myocardial ischemia cells. This study's results demonstrate that it successfully treats myocardial injury.

Outcomes of Patients With Takotsubo Syndrome Compared With Type 1 and Type 2 Myocardial Infarction

Background Takotsubo syndrome (TS) and myocardial infarction (MI) share similar clinical and laboratory characteristics but have important differences in causes, demographics, management, and outcomes. Methods and Results In this observational study, the National Inpatient Sample and National Readmission Database were used to identify patients admitted with TS, type 1 MI, or type 2 MI in the United States between October 1, 2017, and December 31, 2019. We compared patients hospitalized with TS, type 1 MI, and type 2 MI with respect to key features and outcomes. Over the 27-month study period, 2 035 055 patients with type 1 MI, 639 075 patients with type 2 MI, and 43 335 patients with TS were identified. Cardiac arrest, ventricular fibrillation, and ventricular tachycardia were more prevalent in type 1 MI (4.02%, 3.2%, and 7.2%, respectively) compared with both type 2 MI (2.8%, 0.8%, and 5.4% respectively) and TS (2.7%, 1.8%, and 5.3%, respectively). Risk of mortality was lower in TS compared with both type 1 MI (3.3% versus 7.9%; adjusted odds ratio [OR], 0.3; P<0.001) and type 2 MI (3.3% versus 8.2%; adjusted OR, 0.3; P<0.001). Mortality rate (OR, 1.2; P<0.001) and cardiac-cause 30-day readmission rate (adjusted OR, 1.7; P<0.001) were higher in type 1 MI than in type 2 MI. Conclusions Patients with type 1 MI had the highest rates of in-hospital mortality and cardiac-cause 30-day readmission. Risk of all-cause 30-day readmission was highest in patients with type 2 MI. The risk of ventricular arrhythmias in patients with TS is lower than in patients with type 1 MI but higher than in patients with type 2 MI.

The bidirectional association between atrial fibrillation and myocardial infarction

Atrial fibrillation (AF) is associated with an increased risk of myocardial infarction (MI) and vice versa. This bidirectional association relies on shared risk factors as well as on several direct and indirect mechanisms, including inflammation, atrial ischaemia, left ventricular remodelling, myocardial oxygen supply-demand mismatch and coronary artery embolism, through which one condition can predispose to the other. Patients with both AF and MI are at greater risk of stroke, heart failure and death than patients with only one of the conditions. In this Review, we describe the bidirectional association between AF and MI. We discuss the pathogenic basis of this bidirectional relationship, describe the risk of adverse outcomes when the two conditions coexist, and review current data and guidelines on the prevention and management of both conditions. We also identify important gaps in the literature and propose directions for future research on the bidirectional association between AF and MI. The Review also features a summary of methodological approaches for the study of bidirectional associations in population-based studies.

Prediction of Outcomes Through Cystatin C and cTnI in Elderly Type 2 Myocardial Infarction Patients

Background

Chronic kidney disease (CKD) and coronary artery disease (CAD) are strongly associated. Cystatin C (Cys C) is a more sensitive marker of early renal insufficiency. This study aimed to evaluate the prognostic implications of combined of Cys C and cardiac troponin I (cTnI) on 90-day outcomes in elderly patients with type 2 myocardial infarction (MI).

Methods

The data of consecutive type 2 MI patients aged 80 years and older who received Cys C and cTnI measurements within 24 h of admission were retrospectively reviewed. The endpoint was a 90-day all-cause and cardiac mortality.

Results

A total of 4326 patients were included. During the 90-day follow-up period, a higher all-cause and cardiac mortality was observed in patients with Cys C ≥ 1.49mg/L than in patients with Cys C < 1.49 mg/L (P <0.001). After the multivariate logistic regression adjustments, the higher CysC and cTnI levels remained independent predictors of the 90-day all-cause mortality and cardiac mortality. Moreover, the Kaplan-Meier all-cause and cardiac mortality event-free survival curves showed that the patients with the presence of elevated levels of both Cys C and cTnI had a significantly increased risk than those with Cys C or cTnI alone.

Conclusion

Elevated Cys C level is an independent risk factor for all-cause and cardiac mortality in the elderly type 2 MI population. The predictive ability of the combined use of Cys C and cTnI in elderly type 2 MI patients is stronger than that of Cys C or cTnI alone.

The Impact of Type 2 Myocardial Infarction in Acute Pancreatitis: Analysis of 1.1 Million Hospitalizations and Review of the Literature

Introduction  Acute pancreatitis (AP) is a common inflammatory disorder with acute onset and rapid progression. Studies have reported cardiac injury in patients with AP. It is often thought that stress cardiomyopathy can induce these changes leading to type 2 myocardial infarction (type 2 MI) in AP. Our study aims to assess the prevalence as well as the impact of type 2 MI on outcomes in patients with AP.  Methods National Inpatient Sample (NIS) 2016-2020 was used to identify adult patients (age>18) with acute pancreatitis. We excluded patients with STEMI, NSTEMI, pancreatic cancer, or chronic pancreatitis. Patients with missing demographics and mortality were also excluded. Patients were stratified into two groups, based on the presence of type 2 MI. Multivariate logistic regression analysis was performed to assess the impact of concomitant type 2 MI on mortality, sepsis, acute kidney injury (AKI), ICU admission, deep venous thrombosis (DVT), and pulmonary embolism (PE) after adjusting for patient demographics, hospital characteristics, etiology of AP and the Elixhauser comorbidities.  Results Of the 1.1 million patients in the study population, only 2315 patients had type 2 MI. The majority of the patients in the type 2 MI group were aged >65 years (49.2%, p<0.001), males (54.6%, p=0.63), White (67.6%, p=0.19), had Medicare insurance (55.5%, p<0.001), and were in the lowest income quartile (34.8%, p=0.12). Patients in the type 2 MI group had a higher incidence of mortality (5.4% vs 0.6%, p<0.001), sepsis (7.1% vs 3.7%, p<0.001), shock (9.3% vs 0.9%, p<0.001), AKI (42.9% vs. 11.8%, p<0.001) and ICU admission (12.1% vs 1.4%, p<0.001). After adjusting for confounding factors, patients in the type 2 MI group were noted to be at higher odds of mortality (aOR=2.4; 95% CI 1.5-3.8, p<0.001). Patients in the type 2 MI group had a longer length of stay (adjusted coefficient=2.1 days; 95% CI 1.4-2.8; p<0.001) and higher total hospitalization charges (adjusted coefficient=$45,088; 95% CI $30,224-$59,952; p<0.001).  Conclusion Although the prevalence of type 2 MI in AP is low, the presence of type 2 MI is associated with increased mortality and worse outcomes. Physicians should be aware of this association and these patients should be monitored carefully to prevent worse outcomes.

Diagnosis and Prognosis of Type 2 Myocardial Infarction Using Objective Evidence of Acute Myocardial Ischemia: A Validation Study

BACKGROUND

Differentiating type 2 myocardial infarction from myocardial injury can be difficult. In addition, the presence of objective evidence of myocardial ischemia may facilitate identification of high-risk type 2 myocardial infarction patients.

METHODS

This was an observational cohort study of adult emergency department patients undergoing high-sensitivity cardiac troponin T (hs-cTnT) measurement. Patients with ≥1 hs-cTnT >99th percentile were adjudicated following the Fourth Universal Definition of Myocardial Infarction. Patients were categorized as "subjective type 2 myocardial infarction" when ischemic symptoms were the lone criteria supporting type 2 myocardial infarction, or "objective type 2 myocardial infarction" when there was ≥1 objective clinical feature (electrocardiography, imaging, angiography) of acute myocardial ischemia. The primary outcome was mortality.

RESULTS

A total of 857 patients were included, among which 55 (6.4%) were classified as subjective type 2 myocardial infarction, 36 (4.2%) as objective type 2 myocardial infarction, and 702 (82%) as myocardial injury. Those with objective type 2 myocardial infarction had a higher risk of mortality during the index presentation (17% vs 1.7%, P < .0001; hazard ratio 11.1; 95% confidence interval, 3.7-33.4) and at 2-year follow-up (47% vs 31%, P = .04; hazard ratio 1.92; 95% confidence interval, 1.17-3.14) than those with myocardial injury. Objective type 2 myocardial infarction had a higher mortality than subjective type 2 myocardial infarction at index presentation (17% vs 2.0%, P = .01) and at 1 (25% vs 9.1%, P = .04) and 3 months (31% vs 13%, P = .04) follow-up. There were no mortality differences between subjective type 2 myocardial infarction and myocardial injury.

CONCLUSION

In patients diagnosed with type 2 myocardial infarction, those with objective evidence of myocardial ischemia have significantly worse outcomes compared with those with myocardial injury and subjective type 2 myocardial infarction. A more rigorous type 2 myocardial infarction definition that emphasizes these criteria may facilitate diagnosis and risk-stratification.

Associations between alcohol and cigarette use and type 1 and 2 myocardial infarction among people with HIV

OBJECTIVES

People with HIV have a higher risk of myocardial infarction (MI) than the general population, with a greater proportion of type 2 MI (T2MI) due to oxygen demand-supply mismatch compared with type 1 (T1MI) resulting from atherothrombotic plaque disruption. People living with HIV report a greater prevalence of cigarette and alcohol use than do the general population. Alcohol use and smoking as risk factors for MI by type are not well studied among people living with HIV. We examined longitudinal associations between smoking and alcohol use patterns and MI by type among people living with HIV.

DESIGN AND METHODS

Using longitudinal data from the Centers for AIDS Research Network of Integrated Clinical Systems cohort, we conducted time-updated Cox proportional hazards models to determine the impact of smoking and alcohol consumption on adjudicated T1MI and T2MI.

RESULTS

Among 13 506 people living with HIV, with a median 4 years of follow-up, we observed 177 T1MI and 141 T2MI. Current smoking was associated with a 60% increase in risk of both T1MI and T2MI. In addition, every cigarette smoked per day was associated with a 4% increase in risk of T1MI, with a suggestive, but not significant, 2% increase for T2MI. Cigarette use had a greater impact on T1MI for men than for women and on T2MI for women than for men. Increasing alcohol use was associated with a lower risk of T1MI but not T2MI. Frequency of heavy episodic alcohol use was not associated with MI.

CONCLUSIONS

Our findings reinforce the prioritization of smoking reduction, even without cessation, and cessation among people living with HIV for MI prevention and highlight the different impacts on MI type by gender.

Management and outcome trends in type 2 myocardial infarction: an investigation from the SWEDEHEART registry

Despite poor prognosis, patients with type 2 myocardial infarction (MI) tend to be underdiagnosed and undertreated compared to those with type 1 MI. Whether this discrepancy has improved over time is uncertain. We conducted a registry-based cohort study investigating type 2 MI patients managed at Swedish coronary care units (n = 14,833) during 2010-2022. Multivariable-adjusted changes (first three vs last three calendar years of the observation period) were assessed regarding diagnostic examinations (echocardiography, coronary assessment), provision of cardioprotective medications (betablockers, renin-angiotensin-aldosterone-system inhibitors, statins) and 1-year all-cause mortality. Compared to type 1 MI patients (n = 184,329), those with type 2 MI less often had diagnostic examinations and cardioprotective medications. Increases in the use of echocardiography (OR 1.08 [95% confidence interval 1.06-1.09]) and coronary assessment (OR 1.06 [95% confidence interval 1.04-1.08]) were smaller compared to type 1 MI (p_interaction < 0.001). The provision of medications did not increase in type 2 MI. All-cause mortality rate in type 2 MI was 25.4% without temporal change (OR 1.03 [95% confidence interval 0.98-1.07]). Taken together, the provision of medications and all-cause mortality did ot improve in type 2 MI despite modest increases in diagnostic procedures. This emphasizes the need of defining optimal care pathways in these patients.

Elevated Cardiac Troponin Is Most Often Associated With Type 2 Myocardial Infarction in Trauma Patients

Introduction Cardiac troponin (cTn) forms an essential part of the diagnostic criteria for myocardial infarction (MI). Type 1 MI is a primary coronary arterial event, whereas type 2 MI is due to coronary oxygen supply/demand mismatch, which is common in trauma patients. In addition, cTn may be elevated for many reasons other than MI. cTn elevations in trauma may not be specific for MI amenable to revascularization. The aim of this study is to determine which subset of trauma patients benefits from measuring cTn, and which patients with elevated cTn benefit from ischemic workup. Methods This is a retrospective cohort study. All patients on the trauma service of a level 1 trauma center with cTn elevated above the upper reference value of 0.032 ng/ml from July 2017 through December 2020 were selected. Baseline characteristics were recorded. The main outcomes were cardiology determination of the etiology of elevated cTn and patient survival. Logistic regression was used for multivariate analysis. Results One hundred forty-seven (147; 1.1%) of 13746 trauma patients had maximum cTn over the 99th percentile. Forty-one (27.5%) of the 147 had ischemic changes on electrocardiogram (ECG). Sixty-four (43.0%) had chest pain. In 81 (55.1%) cases, cTn was ordered without a clearly justified indication. One hundred thirty-seven patients (93.3%) received a cardiology consult. Two (1.5%) of 137 patients had a type 1 MI, which was diagnosed by ECG and clinical symptoms before cTn results were available. One hundred thirty-five patients were evaluated for cardiac ischemia based on elevated cTn. In 91 (66.4%) cases, the elevated cTn was attributed to a cardiac oxygen supply/demand mismatch. The etiology was cardiac contusion for 26 (19.0%), with the rest attributed to various other trauma-related causes. The cardiology consult changed management for 90 (65.7%) patients, mainly consisting of further evaluation by echocardiogram for 78 (57.0%) patients. Elevated cTn was a significant independent predictor of death with an adjusted odds ratio of 2.6 (p=0.002). Conclusion Isolated cTn values in trauma are most often due to type 2 MI resulting from trauma-related issues, such as tachycardia and anemia, which affect myocardial oxygen supply and demand. Changes in management generally consisted of further workup and interventions such as monitoring and pharmacologic treatment. Elevated cTn in this cohort never led to revascularization but was valuable to identify patients who required more intensive monitoring, longer-term follow-up, and supportive cardiac care. More selective ordering of cTn would improve specificity for patients requiring specialized cardiac care.

Type 2 Myocardial Infarction and Long-Term Mortality Risk Factors: A Retrospective Cohort Study

INTRODUCTION

In-hospital risk factors for type 1 myocardial infarction (MI) have been extensively investigated, but risk factors for type 2 MI are still emerging. Moreover, type 2 MI remains an underdiagnosed and under-researched condition. Our aim was to assess survival rates after type 2 MI and to analyze the risk factors for patient prognosis after hospitalization.

METHODS

We conducted a retrospective database analysis of patients with MI diagnosis who were treated in Vilnius University Hospital Santaros Klinikos. A total of 6495 patients with the diagnosis of MI were screened. The primary study endpoint was long-term all-cause mortality. The predictive value of laboratory tests was estimated including blood hemoglobin, D dimer, creatinine, brain natriuretic peptide (BNP), C-reactive protein (CRP), and troponin levels.

RESULTS

Out of all the patients diagnosed with MI there were 129 cases of type 2 MI (1.98%). Death rate almost doubled from 19.4% at 6 months to 36.4% after 2 years of follow-up. Higher age and impaired kidney function were risk factors for death both during hospitalization and after 2 years of follow-up. Lower hemoglobin (116.6 vs. 98.9 g/L), higher creatinine (90 vs. 161.9 μmol/L), higher CRP (31.4 vs. 63.3 mg/l), BNP (707.9 vs. 2999.3 ng/L), and lower left ventricle ejection fraction were all predictors of worse survival after 2 years of follow-up. Preventive medication during hospitalization can decrease the mortality risk: angiotensin-converting enzyme inhibitor (ACEi) (HR 0.485, 95% CI 0.286-0.820) and statins (HR 0.549, 95% CI 0.335-0.900). No significant influence was found for beta blockers (HR 0.662, 95% CI 0.371-1.181) or aspirin (HR 0.901, 95% CI 0.527-1.539).

CONCLUSIONS

There is significant underdiagnosis of type 2 MI (1.98% out of all MIs). If the patient is prescribed a preventive medication like ACEi or statins, the mortality risk is lower. Increased awareness of elevation of laboratory results could help to improve the treatment of these patients and identify the most vulnerable groups.

Microbiome-metabolome reveals that the Suxiao Jiuxin pill attenuates acute myocardial infarction associated with fatty acid metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

The Suxiao Jiuxin pill (SJP) is a Chinese medical patent drug on the national essential drug list of China, with well-established cardiovascular protective effects in the clinic. However, the mechanisms underlying the protective effects of SJP on cardiovascular disease have not yet been elucidated clearly, especially its relationship with the gut microbiota.

AIM OF THE STUDY

This study aimed to investigate the cardioprotective effect of SJP against isoproterenol-induced acute myocardial infarction (AMI) by integrating the gut microbiome and metabolome.

METHODS

A rat model of AMI was generated using isoproterenol. Firstly, the effect of antibiotic (ABX) treatment on the blood absorption and excretion of the main components of SJP were studied. Secondly, 16S rRNA sequencing and untargeted metabolomics were used to discover the improvement of SJP treatment on gut microbiota and host metabolism in AMI rats. Finally, targeted metabolomics was used to verify the effects of SJP treatment on host metabolism in AMI rats.

RESULT

The results showed that ABX treatment could affect the blood absorption and fecal excretion of the main active components of SJP. At the same time, SJP can restore the richness and diversity of gut microbiota, and multiple gut microbiota (including Jeotgalicoccus, Lachnospiraceae, and Blautia) are significantly associated with fatty acids. Untargeted metabolomics also found that SJP could restore the levels of various fatty acid metabolites in serum and cecal contents (p < 0.01, FC > 1.5 and VIP >1). Targeted metabolomics further confirmed that 41, 21, and 39 fatty acids were significantly altered in serum, cecal contents, and heart samples, respectively. Interestingly, these fatty acids belong to the class of eicosanoids, and SJP can significantly downregulate these eicosanoids in AMI rats.

CONCLUSION

The results of this study suggest that SJP may exert its cardioprotective effects by remodeling the gut microbiota and host fatty acid metabolism.

Cardiovascular outcomes of type 2 myocardial infarction among COVID-19 patients: a propensity matched national study

BACKGROUND

Myocardial infarction Type II (T2MI) is a prevalent cause of troponin elevation secondary to a variety of conditions causing stress/demand mismatch. The impact of T2MI on outcomes in patients hospitalized with COVID-19 is not well studied.

METHODS

The Nationwide Inpatient Sample database from the year 2020 was queried to identify COVID-19 patients with T2MI during the index hospitalization. Clinical Modification (ICD-10-CM) codes "U07.1" and "I21.A1" were used as disease identifiers for COVID-19 and T2MI respectively. Multivariate adjusted Odds ratio (aOR) and propensity score matching (PSM) was done to compare outcomes among COVID patients with and without T2MI. The primary outcome was in-hospital mortality.

RESULTS

A total of 1,678,995 COVID-19-weighted hospitalizations were identified in the year 2020, of which 41,755 (2.48%) patients had T2MI compared to 1,637,165 (97.5%) without T2MI. Patients with T2MI had higher adjusted odds of in-hospital mortality (aOR 1.44, PSM 32.27%, 95% CI 1.34-1.54) sudden cardiac arrest (aOR 1.29, PSM 6.6 %, 95% CI 1.17-1.43) and CS (aOR 2.16, PSM 2.73%, 95% CI 1.85-2.53) compared to patients without T2MI. The rate of coronary angiography (CA) in T2MI with COVID was 1.19 %, with significant use of CA among patients with T2MI complicated by CS compared to those without CS (4% vs 1.1%, p<0.001). Additionally, COVID-19 patients with T2MI had an increased prevalence of sepsis compared to COVID-19 without T2MI (48% vs 24.1%, p<0.001).

CONCLUSION

COVID-19 patients with T2MI had worse cardiovascular outcomes with significantly higher in-hospital mortality, SCA, and CS compared to those without T2MI. Long-term mortality and morbidity among COVID-19 patients who had T2MI will need to be clarified in future studies.

HOTAIR regulates SIRT3-mediated cardiomyocyte survival after myocardial ischemia/reperfusion by interacting with FUS

BACKGROUND

Myocardial ischemia/reperfusion (I/R) contributes to serious myocardial injury and even death. Therefore, prevention and mitigation of myocardial I/R is particularly important. LncRNA HOTAIR has been reported to be implicated in myocardial I/R progression. However, the detailed molecular mechanism of HOTAIR in cardiomyocyte was explored in myocardial I/R.

METHODS

Firstly, cell model of myocardial I/R was established through hypoxia/reoxygenation (H/R). Apoptosis and cell cycle were evaluated utilizing flow cytometry. The corresponding test kits were conducted to monitor the levels of LDH, Caspase3 and Caspase9. The gene expression and protein levels were detected by qPCR and western blot, respectively. RNA pull-down and RIP were performed to verify the interaction between FUS and lncRNA HOTAIR.

RESULTS

In AC16 cardiomyocytes treated with H/R, lncRNA HOTAIR and SIRT3 expression were obviously decreased. Overexpression of HOTAIR or SIRT3 could ameliorate H/R-induced cardiomyocyte injury by promoting cell viability, lowering LDH levels, and suppressing cell apoptosis. Further, lncRNA HOTAIR upregulated the expression of SIRT3 via interacting with FUS, thereby promoting the survival of H/R-injured cardiomyocytes.

CONCLUSION

LncRNA HOTAIR can improve myocardial I/R by affecting cardiomyocyte survival through regulation of SIRT3 by binding to the RNA binding protein FUS.

The potential role of SARS‐CoV‐2 infection in acute coronary syndrome and type 2 myocardial infarction (T2MI): Intertwining spread

Coronavirus disease 2019 (COVID‐19) is a novel pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). It has been shown that SARS‐CoV‐2 infection‐induced inflammatory and oxidative stress and associated endothelial dysfunction may lead to the development of acute coronary syndrome (ACS). Therefore, this review aimed to ascertain the link between severe SARS‐CoV‐2 infection and ACS. ACS is a spectrum of acute myocardial ischemia due to a sudden decrease in coronary blood flow, ranging from unstable angina to myocardial infarction (MI). Primary or type 1 MI (T1MI) is mainly caused by coronary plaque rupture and/or erosion with subsequent occlusive thrombosis. Secondary or type 2 MI (T2MI) is due to cardiac and systemic disorders without acute coronary atherothrombotic disruption. Acute SARS‐CoV‐2 infection is linked with the development of nonobstructive coronary disorders such as coronary vasospasm, dilated cardiomyopathy, myocardial fibrosis, and myocarditis. Furthermore, SARS‐CoV‐2 infection is associated with systemic inflammation that might affect coronary atherosclerotic plaque stability through augmentation of cardiac preload and afterload. Nevertheless, major coronary vessels with atherosclerotic plaques develop minor inflammation during COVID‐19 since coronary arteries are not initially and primarily targeted by SARS‐CoV‐2 due to low expression of angiotensin‐converting enzyme 2 in coronary vessels. In conclusion, SARS‐CoV‐2 infection through hypercytokinemia, direct cardiomyocyte injury, and dysregulation of the renin‐angiotensin system may aggravate underlying ACS or cause new‐onset T2MI. As well, arrhythmias induced by anti‐COVID‐19 medications could worsen underlying ACS.

Acute Coronary Syndrome during the Pandemic New Coronavirus Infection

The experience of managing patients with COVID-19 around the world has shown that, although  respiratory symptoms predominate  during the manifestation of infection, then many patients can develop serious damage  to the cardiovascular system. However, coronary artery disease (CHD) remains the leading cause of death worldwide. The purpose of the review is to clarify the possible pathogenetic links between COVID-19 and acute coronary syndrome (ACS), taking into account which will help to optimize the management of patients with comorbid  pathology. Among the body's responses to SARS-CoV-2 infection, which increase the likelihood of developing  ACS,  the role of systemic inflammation, the quintessence  of which is a "cytokine storm" that can destabilize  an atherosclerotic  plaque is discussed.  Coagulopathy, typical for patients with Covid-19, is based on immunothrombosis, caused by a complex  interaction between neutrophilic  extracellular  traps and von Willebrandt  factor in conditions  of systemic inflammation. The implementation  of a modern strategy  for managing patients with ACS,  focused on the priority of percutaneous interventions (PCI), during  a pandemic is experiencing great  difficulties  due to the formation  of time delays  before  the start of invasive  procedures  due to the epidemiological situation. Despite this, the current European,  American and Russian recommendations for the management of infected patients with ACS confirm the inviolability of the position of PCI as the first choice for treating patients with ACS and the undesirability  of replacing  invasive treatment with thrombolysis.

Evaluating the role of intravenous pentoxifylline administration on primary percutaneous coronary intervention success rate in patients with ST-elevation myocardial infarction (PENTOS-PCI)

Ischemia reperfusion injury can lead to further myocardiocyte damage in patients with ST-elevation myocardial infarction (STEMI). Pentoxifylline is a methylxanthine derivative with known anti-inflammatory, antioxidant, vasodilator, and rheological properties which can be a promising agent in preventing reperfusion injury. PENTOS-PCI is a single-center, randomized, double-blind, placebo-controlled trial which evaluated the efficacy and safety of preprocedural administration of intravenous pentoxifylline in patients undergoing primary percutaneous coronary intervention (PCI). Patients with acute STEMI who were eligible for PCI were randomized to receive either 100-mg intravenous infusion of pentoxifylline or placebo, prior to transferring to catheterization laboratory. Overall, 161 patients were included in our study of whom 80 patients were assigned to pentoxifylline and 81 to the control groups. Per-protocol analysis of primary endpoint indexing PCI's success rate as measured by thrombolysis in myocardial infarction (TIMI) flow grade 3 was not significantly different between pentoxifylline and placebo (71.3% and 66.3% respectively, P = 0.40). In addition, pentoxifylline could not improve secondary angiographic endpoints including myocardial blush grade 3 (87.5% and 85.2%, P = 0.79) and corrected TIMI frame count (22.8 [± 9.0] and 24.0 [± 5.1], P = 0.33) in the intervention and placebo groups respectively. The rates of major adverse cardiac and treatment emergent adverse effects were not significantly different between the two groups. Administration of intravenous pentoxifylline before primary PCI did not improve the success rate of the procedure in patients with STEMI. Intravenous administration of pentoxifylline was well tolerated, and there were no significant differences regarding adverse drug reactions in the two groups. Panel A, background: pentoxifylline is a methylxanthine derivative with known anti-inflammatory, antioxidant, vasodilator, and rheological properties which can be a promising agent in preventing reperfusion injury. Panel B: study design and main results of the PENTOS-PCI trial. cTFC corrected TIMI frame count, ED emergency department, IRI ischemia reperfusion injury, MBG myocardial blush grade, PCI percutaneous coronary intervention, PPCI primary PCI, PTX pentoxifylline, ROS reactive oxygen species, SD standard deviation, STEMI ST-elevation myocardial infarction, TIMI thrombolysis in myocardial infarction.

An update on the molecular mechanism and pharmacological interventions for Ischemia-reperfusion injury by regulating AMPK/mTOR signaling pathway in autophagy

AMP-activated protein kinase (5'-adenosine monophosphate-activated protein kinase, AMPK)/mammalian target of rapamycin (mTOR) is an important signaling pathway maintaining normal cell function and homeostasis in vivo. The AMPK/mTOR pathway regulates cellular proliferation, autophagy, and apoptosis. Ischemia-reperfusion injury (IRI) is secondary damage that frequently occurs clinically in various disease processes and treatments, and the exacerbated injury during tissue reperfusion increases disease-associated morbidity and mortality. IRI arises from multiple complex pathological mechanisms, among which cell autophagy is a focus of recent research and a new therapeutic target. The activation of AMPK/mTOR signaling in IRI can modulate cellular metabolism and regulate cell proliferation and immune cell differentiation by adjusting gene transcription and protein synthesis. Thus, the AMPK/mTOR signaling pathway has been intensively investigated in studies focused on IRI prevention and treatment. In recent years, AMPK/mTOR pathway-mediated autophagy has been found to play a crucial role in IRI treatment. This article aims to elaborate the action mechanisms of AMPK/mTOR signaling pathway activation in IRI and summarize the progress of AMPK/mTOR-mediated autophagy research in the field of IRI therapy.

Myocardial infarction and viral triggers: what do we know by now?

Myocardial infarction (MI) is an acute clinical manifestation ischaemic heart disease, which is the leading cause of death worldwide. Infections also have an important burden worldwide, with lower respiratory infections being the worldwide leading cause of death due to communicable diseases. The relationship of MI with viral respiratory infections (including influenza and SARS-CoV-2) as a trigger has been well documented with significant associations. These infections can lead to Type 1 MI, where inflammation and vascular dysfunction, as well as the increased prothrombotic environment lead to atherothrombosis. Type 2 MI may also occur due to an imbalance of oxygen/blood supply and myocardial demand (hypoxaemia, fever, and tachycardia). The data from randomized controlled trials showing a potential benefit of influenza vaccination in coronary artery disease patients should not be ignored. This can be considered a further argument for the association of viral infections (influenza in particular) and MI.

Machine learning-based integration develops biomarkers initial the crosstalk between inflammation and immune in acute myocardial infarction patients

Great strides have been made in past years toward revealing the pathogenesis of acute myocardial infarction (AMI). However, the prognosis did not meet satisfactory expectations. Considering the importance of early diagnosis in AMI, biomarkers with high sensitivity and accuracy are urgently needed. On the other hand, the prevalence of AMI worldwide has rapidly increased over the last few years, especially after the outbreak of COVID-19. Thus, in addition to the classical risk factors for AMI, such as overwork, agitation, overeating, cold irritation, constipation, smoking, and alcohol addiction, viral infections triggers have been considered. Immune cells play pivotal roles in the innate immunosurveillance of viral infections. So, immunotherapies might serve as a potential preventive or therapeutic approach, sparking new hope for patients with AMI. An era of artificial intelligence has led to the development of numerous machine learning algorithms. In this study, we integrated multiple machine learning algorithms for the identification of novel diagnostic biomarkers for AMI. Then, the possible association between critical genes and immune cell infiltration status was characterized for improving the diagnosis and treatment of AMI patients.

Eugenol attenuates ischemia-mediated oxidative stress in cardiomyocytes via acetylation of histone at H3K27

Despite clinical advances, ischemia-induced cardiac diseases remain an underlying cause of death worldwide. Epigenetic modifications, especially alterations in the acetylation of histone proteins play a pivotal role in counteracting stressful conditions, including ischemia. In our study, we found that histone active mark H3K27ac was significantly reduced and histone repressive mark H3K27me3 was significantly upregulated in the cardiomyocytes exposed to the ischemic condition. Then, we performed a high throughput drug screening assay using rat ventricular cardiomyocytes during the ischemic condition and screened an antioxidant compound library comprising of 84 drugs for H3K27ac by fluorescence microscopy. Our data revealed that most of the phenolic compounds like eugenol, apigenin, resveratrol, bis-demethoxy curcumin, D-gamma-tocopherol, ambroxol, and non-phenolic compounds like l-Ergothioneine, ciclopirox ethanolamine, and Tanshinone IIA have a crucial role in maintaining the cellular H3K27ac histone marks during the ischemic condition. Further, we tested the role of eugenol on cellular protection during ischemia. Our study shows that ischemia significantly reduces cellular viability and increases total reactive oxygen species (ROS), and mitochondrial ROS in the cells. Interestingly, eugenol treatment significantly restores the cellular acetylation at H3K27, decreases cellular ROS, and improves cellular viability. To explore the mechanism of eugenol-medicated inhibition of deacetylation, we performed a RNAseq experiment. Analysis of transcriptome data using IPA indicated that eugenol regulates several cellular functions associated with cardiovascular diseases, and metabolic processes. Further, we found that eugenol regulates the expression of HMGN1, CD151 and Ppp2ca genes during ischemia. Furthermore, we found that eugenol might protect the cells from ischemia through modulation of HMGN1 protein expression, which plays an active role in regulation of histone acetylation and cellular protection during stress. Thus, our study indicated that eugenol can be exploited as an agent to protect the ischemic cells and also could be used to develop a novel drug for treating cardiac disease.