Mortality rate in type 2 myocardial infarction: observations from an unselected hospital cohort

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

BACKGROUND

Myocardial 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.

METHODS

In 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.

RESULTS

31,383 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.

CONCLUSIONS

In 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.

Trends and Outcomes of Type 2 Myocardial Infarction During the COVID-19 Pandemic in the United States

BACKGROUND AND OBJECTIVES

There is limited data on the impact of type 2 myocardial infarction (T2MI) during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

The National Inpatient Sample (NIS) database from January 2019 to December 2020 was queried to identify T2MI hospitalizations based on the appropriate International Classification of Disease, Tenth Revision-Clinical Modification codes. Monthly trends of COVID-19 and T2MI hospitalizations were evaluated using Joinpoint regression analysis. In addition, the multivariate logistic and linear regression analysis was used to compare in-hospital mortality, coronary angiography use, and resource utilization between 2019 and 2020.

RESULTS

A total of 743,535 patients hospitalized with a diagnosis of T2MI were identified in the years 2019 (n=331,180) and 2020 (n=412,355). There was an increasing trend in T2MI hospitalizations throughout the study period corresponding to the increase in COVID-19 hospitalizations in 2020. The adjusted odds of in-hospital mortality associated with T2MI hospitalizations were significantly higher in 2020 compared with 2019 (11.1% vs. 8.1%: adjusted odds ratio, 1.19 [1.13-1.26]; p<0.01). In addition, T2MI hospitalizations were associated with lower odds of coronary angiography and higher total hospitalization charges, with no difference in the length of stay in 2020 compared with 2019.

CONCLUSIONS

We found a significant increase in T2MI hospitalizations with higher in-hospital mortality, total hospitalization costs, and lower coronary angiography use during the early COVID-19 pandemic corresponding to the trends in the rise of COVID-19 hospitalizations. Further research into the factors associated with increased mortality can increase our preparedness for future pandemics.

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.

Impact of clinical diagnosis of myocardial infarction in patients with elevated cardiac troponin

OBJECTIVE

Type 2 myocardial infarction (MI) and myocardial injury are common conditions associated with an adverse prognosis. Physicians experience uncertainty how to distinguish these conditions, as well as how to manage and treat them. Therefore, the objective of this study was to compare treatment and prognosis in patients with an adjudicated diagnosis of type 2 MI and myocardial injury, who were discharged with and without a clinical diagnosis of MI.

DESIGN

The study consisted of two cohorts, 964 and 281 consecutive patients with elevated cardiac troponin, discharged with and without a clinical diagnosis of MI, respectively. All cases were adjudicated into MI type 1-5 or myocardial injury and followed regarding all-cause death.

RESULTS

The adjudication identified 138 and 37 cases of type 2 MI, and 86 and 185 of myocardial injury, with and without a clinical MI diagnosis, respectively. In patients with type 2 MI, a clinical MI diagnosis was associated with more coronary angiography investigations (39.1% vs 5.4%, p<0.001) and an increased use of secondary prevention medications (all p<0.001). However, no difference was observed in adjusted 5-year mortality between patients with and without a clinical MI diagnosis (HR: 0.77 with 95% CI 0.43 to 1.38). The results were similar for adjudicated myocardial injury.

CONCLUSION

In both type 2 MI and myocardial injury, a clinical diagnosis of MI at discharge was associated with more investigations and treatments. However, no prognostic effect of receiving a clinical MI diagnosis was observed.

Stachydrine ameliorates hypoxia reoxygenation injury of cardiomyocyte via enhancing SIRT1-Nrf2 pathway

BACKGROUND

Hypoxia/reoxygenation (H/R)-induced cardiomyocyte cell apoptosis is critical in developing myocardial infarction. Stachydrine (STA), an active constituent of Leonurus heterophyllus sweet, could have a protective effect on myocardial H/R injury, which remains unexplored. Therefore, the study aimed to investigate the protective effects and mechanisms of STA on H/R injury of cardiomyocytes.

METHODS

Rat cardiomyocyte H9c2 cells underwent H/R (hypoxia for 4 h and reoxygenation for 12 h). Cells were pretreated with STA (50 µM) 2 h before H/R. Cardiomyocyte injury was evaluated by CCK-8 assay and lactate dehydrogenase (LDH) release. Apoptosis was assessed by TUNEL staining and caspase-3 activity. Oxidative stress was assessed by lipid oxidation product MDA and a ROS-scavenging enzyme SOD in culture media. Western blot was performed to measure the protein expressions of SIRT1, Nrf2, and heme oxygenase-1 (HO-1).

RESULTS

STA reversed the decrease in cell viability and increased LDH release in H9c2 cells with the H/R insult. STA significantly suppressed oxidative stress, reduced MDA content, and increased SOD activity in H9c2 cells exposed to H/R. STA reduced apoptosis in H9c2 cells exposed to H/R, as evidenced by the reduced TUNEL positive cells and caspase-3 activity. In addition, STA enhanced SIRT1, Nrf2, and HO-1 protein expression in H/R-stimulated H9c2 cells. SIRT1 and Nrf2 involved the protective effect of STA in H/R-exposed H9c2 cells, as the changes in cell viability and caspase-3 activity by STA can be reversed by SIRT1 inhibitor EX-527 or Nrf2 siRNA.

CONCLUSIONS

Our data speculated that STA protects H/R injury and inhibits oxidative stress and apoptosis in cardiomyocytes by activation of the SIRT1-Nrf2 pathway.

Antiplatelet therapy and long-term mortality in patients with myocardial injury after non-cardiac surgery

BACKGROUNDS

Myocardial injury after non-cardiac surgery (MINS) has recently been accepted as a common complication associated with increased mortality. However, little is known about the treatment of MINS. The aim of this study was to investigate an association between antiplatelet therapy and long-term mortality after MINS.

METHODS

From 2010 to 2019, patients with MINS, defined as having a peak high-sensitivity troponin I higher than 40 ng/L within 30 days after non-cardiac surgery, were screened at a tertiary centre. Patients were excluded if they had a history of coronary revascularisation before or during index hospitalisation. Clinical outcomes at 1 year were compared between patients with and without antiplatelet therapy at hospital discharge. The primary outcome was death, and the secondary outcome was major bleeding.

RESULTS

Of the 3818 eligible patients with MINS, 940 (24.6%) received antiplatelet therapy at hospital discharge. Patients with antiplatelet therapy had a significantly lower mortality at 1 year than those without antiplatelet therapy (7.5% vs 15.9%, adjusted HR 0.60, 95% CI 0.45 to 0.79, p<0.001). A risk of major bleeding at 1 year was not significantly different between the patients with and without antiplatelet therapy (6.6% vs 7.6%, adjusted HR 0.85, 95% CI 0.62 to 1.17, p=0.324). In propensity score-matched analysis of 886 pairs, patients with antiplatelet therapy had a significantly lower risk of 1-year mortality (adjusted HR 0.53, 95% CI 0.39 to 0.73, p<0.001) than those without antiplatelet therapy.

CONCLUSIONS

In patients with MINS, antiplatelet therapy at discharge was associated with decreased 1-year mortality.

L'infarctus du myocarde type 2

Type 2 MI is a category of myocardial infarction according to the UDMI, frequently encountered in routine practice but still poorly understood in terms of prevalence, diagnostic and therapeutic approach, it affects a heterogeneous population at high risk of major cardiovascular events and non-cardiac death. It is due to an inadequacy between oxygen supply and demand in the absence of a primary coronary event, e.g. coronary artery spasm, coronary embolism, anemia, arrhythmias, hypertension or hypotension. Diagnosis has traditionally required an integrated history assessment, with some combination of indirect evidence of myocardial necrosis based on biochemical, electrocardiographic, and imaging modalities. Differentiation between type 1 and type 2 MI is more complicated than it appears. Treatment of the underlying pathology is the primary goal of treatment.

Defining Myocardial Infarction in trials of people receiving hemodialysis: consensus report from the SONG-HD MI Expert Working group

Cardiovascular disease is the leading cause of death in patients receiving hemodialysis. Currently there is no standardized definition of myocardial infarction (MI) for patients receiving hemodialysis. Through an international consensus process MI was established as the core CVD measure for this population in clinical trials. The Standardised Outcomes in Nephrology Group - Hemodialysis (SONG-HD) initiative convened a multidisciplinary, international working group to address the definition of MI in this population.Based on current evidence, the working group recommends using the 4th Universal Definition of MI with specific caveats with regard to the interpretation of "ischemic symptoms" and performing a baseline 12-lead electrocardiogram to facilitate interpretation of acute changes on subsequent tracings. The working group does not recommend obtaining baseline cardiac troponin values, though does recommend obtaining serial cardiac biomarkers in settings where ischemia is suspected. Application of an evidence-based uniform definition should increase the reliability and accuracy of trial results.

Comparison of outcome among type 2 vs type 1 myocardial infarction: a systematic review and meta-analysis

To date, there were limited studies available on myocardial infarction (MI), and consequently, the outcomes of patients with type 1 myocardial infarction (T1MI) compared to type 2 myocardial infarction (T2MI) remained inconclusive. We aimed to compare the outcomes of T1MI and T2MI patients in terms of mortality and adverse cardiovascular outcomes. We performed a systematic literature search on PubMed, Embase, and Scopus for relevant articles from inception until March 20, 2022. 341,049 patients had T1MI, while the remaining 67,537 patients had T2MI. Mean age was similar between both groups (T1MI: 67.3 years, T2MI: 71.03 years), while the proportion of females was lower in T1MI (37.81% vs 47.15%). Our analysis revealed that patients with T1MI had significantly lower odds of all-cause mortality (OR 0.45, 95% CI 0.36-0.56, p < 0.001), in-hospital mortality (OR 0.63, 95% CI 0.46-0.86, p < 0.001), 1-year mortality (OR 0.35, 95% CI 0.25-0.47, p < 0.001), and major adverse cardiovascular events (MACE) (OR 0.59, 95% CI 0.39-0.91, p = 0.02). There was no significant difference in terms of 30-day mortality (OR 0.58, 95% CI 0.25-1.36, p = 0.21), cardiovascular mortality (OR 0.95, 95% CI 0.68-1.32, p = 0.74), all-cause readmission (OR 0.84, 95% CI 0.62-1.14, p = 0.26), and readmission due to MI (OR 1.22, 95% CI 0.66-2.27, p = 0.53) between both groups. Patients with T1MI had favorable outcomes in terms of mortality and MACE compared to that of T2MI patients. Further studies should aim at determining the optimal management strategy for these high-risk patients for better patient outcomes.

Outcome of patients admitted with oxygen mismatch and myocardial injury or infarction in emergency departments

AIMS

To describe the outcomes and associated factors in a population of patients admitted to emergency departments with at least one condition of oxygen supply/demand imbalance, regardless of the troponin result or restrictive criteria for type 2 myocardial infarction.

METHODS

We constituted a retrospective cohort of 824 patients. Medical records of patients having undergone a troponin assay were reviewed for selection and classification, and data including in-hospital stay and readmissions were collected. The reported outcomes are in-hospital mortality, 3-year mortality, and major adverse cardiovascular events.

RESULTS

Patients with myocardial infarction or injury, either chronic or acute, were older, with more history of hypertension and chronic heart or renal failure but not for other cardiovascular risk factors and medical history. Acute myocardial injury and type 2 myocardial infarction were significantly associated with in-hospital mortality [odds ratio (OR) 3.71 95% confidence interval (CI) 1.90-7.33 and OR 3.15 95% CI 1.59-6.28, respectively]. However, the long-term mortality does not differ in comparison with patients presenting chronic myocardial injury or nonelevated troponin, ranging from 26.9 to 34.3%. Patients with chronic myocardial injury and type 2 myocardial infarction had more long-term major cardiovascular events (39.3 and 38.8%), but only for acute heart failure, and none was associated with this outcome after adjustment.

CONCLUSION

Among patients admitted to emergency departments with an oxygen supply/demand imbalance, acute myocardial injury and type 2 myocardial infarction are strongly associated with in-hospital mortality. However, they are not associated with higher long-term mortality or major cardiovascular events after discharge, which tend to occur in elderly people with comorbidities.

Management and outcome of patients with non-ST elevation myocardial infarction and intercurrent non-coronary precipitating events

AIMS

To evaluate the effect of an intercurrent non-coronary illness on the management and outcome of patients with non-ST-segment elevation myocardial infarction (NSTEMI).

METHODS AND RESULTS

Consecutive hospitalized patients with a primary diagnosis of NSTEMI between August 2008 and December 2019 at Sheba Medical Center. All patients' records were reviewed for the presence of a non-coronary precipitating event (NCPE): a major intercurrent acute non-coronary illness or condition, either cardiac or non-cardiac. The primary outcome was all-cause mortality. Cox regression with interaction analysis was applied. Final study population comprised 6491 patients, of whom 2621 (40%) had NCPEs. Patients with NCPEs were older (77 vs. 69 years) and more likely to have comorbidities. The most prevalent event was infection (35%, n = 922). During a median follow-up of 30 months, 2529 patients died. Patients with NCPEs were 43% more likely to die during follow-up in a multivariable model (95% CI: 1.31-1.55). Invasive strategy was associated with a 55% lower mortality among patients without NCPE and only 44% among patients with NCPE (P for interaction < 0.001). Dual antiplatelet therapy (DAPT) was associated with a 20% lower mortality in patients without NCEP and a non-significant mortality difference among patients with NCPE (P for interaction = 0.014). Sub-analysis by the specific NCPE showed the highest mortality risk among patients with infectious precipitant. The lower mortality associated with invasive strategy was not observed in this subgroup.

CONCLUSION

Among NSTEMI patients, the presence of an NCPE is associated with poor survival and modifies the effect of management strategies.

Transfusion in Older Anemic Patients: Should the Troponin Value Be Taken into Account?

BACKGROUND

Anemia is common in older individuals, but it is not known whether the prognostic impact of transfusion differs according to cardiac troponin concentration.

METHODS

During this 2-year retrospective study in an acute geriatric unit, 514 patients with hemoglobin <10 g/dL and troponin sampling were included. Thirty-day and 1-year mortality were compared according to transfusion status and troponin and hemoglobin levels.

RESULTS

Of the 514 anemic patients included (median age 88 years), 157 (31%) had elevated troponin concentrations. These patients were more likely to die at 30 days (49% vs 27%, P < .001) and 1 year (65% vs 51%, P = .004) than patients with normal values. Among patients with elevated troponin concentrations, 30-day mortality tended to be lower in transfused than in not-transfused patients (hazard ratio 0.48; 95% confidence interval, 0.21-1.08; P = .07). This association was not found in patients without troponin elevation (hazard ratio 1.09; 95% CI, 0.61-1.93; P = .8). Transfusion was associated with 30-day survival in patients with hemoglobin ≤8 g/dL. It was also associated with excess 1-year mortality in patients with hemoglobin >8 g/dL.

CONCLUSIONS

This pilot study suggests that transfusion could be associated with better 30-day outcomes in older anemic patients with anemia-related myocardial injury. Thus, troponin levels could be involved in decision-making relative to transfusion in anemic older patients. Clinical trials are needed to establish the benefit of transfusion in patients with elevated troponins.

Assessment of Oxygen Supply-Demand Imbalance and Outcomes Among Patients With Type 2 Myocardial Infarction: A Secondary Analysis of the High-STEACS Cluster Randomized Clinical Trial

Importance

Type 2 myocardial infarction occurs owing to multiple factors associated with myocardial oxygen supply-demand imbalance, which may confer different risks of adverse outcomes.

Objective

To evaluate the prevalence and outcomes of different factors associated with oxygen supply-demand imbalance among patients with type 2 myocardial infarction.

Design, Setting, and Participants

In this secondary analysis of a stepped-wedge, cluster randomized clinical trial conducted at 10 secondary and tertiary care hospitals in Scotland, 6096 patients with an adjudicated diagnosis of type 1 or type 2 myocardial infarction from June 10, 2013, to March 3, 2016, were identified, and the findings were reported on August 28, 2018. The trial enrolled consecutive patients with suspected acute coronary syndrome. The diagnosis of myocardial infarction was adjudicated according to the Fourth Universal Definition of Myocardial Infarction and the primary factor associated with oxygen supply-demand imbalance in type 2 myocardial infarction was defined. This secondary analysis was not prespecified. Statistical analysis was performed from July 7 to 30, 2020.

Intervention

Implementation of a high-sensitivity cardiac troponin I assay.

Main Outcomes and Measures

All-cause death at 1 year according to the factors associated with oxygen supply-demand imbalance among patients with type 2 myocardial infarction.

Results

Of 6096 patients (2602 women [43%]; median age, 70 years [IQR, 58-80 years]), 4981 patients had type 1 myocardial infarction, and 1115 patients had type 2 myocardial infarction. The most common factor associated with oxygen supply-demand imbalance was tachyarrhythmia (616 of 1115 [55%]), followed by hypoxemia (219 of 1115 [20%]), anemia (95 of 1115 [9%]), hypotension (89 of 1115 [8%]), severe hypertension (61 of 1115 [5%]), and coronary mechanisms (35 of 1115 [3%]). At 1 year, all-cause mortality occurred for 15% of patients (720 of 4981) with type 1 myocardial infarction and 23% of patients (285 of 1115) with type 2 myocardial infarction. Compared with patients with type 1 myocardial infarction, those with type 2 myocardial infarction owing to hypoxemia (adjusted odds ratio [aOR], 2.35; 95% CI, 1.72-3.18) and anemia (aOR, 1.83; 95% CI, 1.14-2.88) were at greatest risk of death, whereas those with type 2 myocardial infarction owing to tachyarrhythmia (aOR, 0.83; 95% CI, 0.65-1.06) or coronary mechanisms (aOR, 1.07; 95% CI, 0.17-3.86) were at similar risk of death as patients with type 1 myocardial infarction.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, mortality after type 2 myocardial infarction was associated with the underlying etiologic factor associated with oxygen supply-demand imbalance. Most type 2 myocardial infarctions were associated with tachyarrhythmia, with better prognosis, whereas hypoxemia and anemia accounted for one-third of cases, with double the mortality of type 1 myocardial infarction. These differential outcomes should be considered by clinicians when determining which cases need to be managed if patient outcomes are to improve.

Trial Registration

ClinicalTrials.gov Identifier: NCT01852123.

Demand Ischemia as a Predictor of Mortality in Older Patients With Delirium

Introduction

The impact of demand ischemia on clinical outcomes in patients with delirium remains largely unexplored. This study aims to evaluate the effects of demand ischemia in older patients with delirium on in-hospital mortality and length of stay (LOS) using the largest US inpatient care database, National Inpatient Sample (NIS).

Methods

We obtained data from the year 2010 to 2014 National Inpatient Sample (NIS). We used the International Classification of Diseases-Ninth Edition-Clinical Modification (ICD-9-CM) diagnosis codes to identify all the records with a primary or secondary diagnosis of delirium with or without demand ischemia and other clinical characteristics. We then compared in-hospital mortality and length of stay (LOS) in patients with and without demand ischemia.

Results

We analyzed 232,137 records. Patients with demand ischemia had higher overall in-hospital mortality than those without demand ischemia (28 vs. 12%, p &lt; 0.001). After adjusting for clinical comorbidities and complications, demand ischemia was no longer associated with increased in-hospital mortality (OR: 1.14; 95% CI: 0.96–1.35; p = 0.141). However, further analysis with the exclusion of critically ill patients with non-cardiogenic shock or mechanical ventilation showed a significant association of demand ischemia with increased in-hospital mortality (adjusted OR: 1.39; 95% CI: 1.13–1.71; p = 0.002). Among non-critically ill survivors, patients with demand ischemia had a longer median LOS [4, (3–7) days] than those without demand ischemia [4, (2–6) days] (p &lt; 0.001). However, the difference was not statistically significant after adjustment for covariates.

Conclusion/Relevance

Demand ischemia did not affect mortality in critically sick patients. In non-critically ill patients, however, demand ischemia was significantly associated with increased in-hospital mortality, likely due to the severity of the underlying acute illness. Measures aimed at mitigating risk factors that contribute to delirium and/or demand ischemia need to be explored.

Coronary Artery and Cardiac Disease in Patients With Type 2 Myocardial Infarction: A Prospective Cohort Study

BACKGROUND

Type 2 myocardial infarction is caused by myocardial oxygen supply-demand imbalance, and its diagnosis is increasingly common with the advent of high-sensitivity cardiac troponin assays. Although this diagnosis is associated with poor outcomes, widespread uncertainty and confusion remain among clinicians as to how to investigate and manage this heterogeneous group of patients with type 2 myocardial infarction.

METHODS

In a prospective cohort study, 8064 consecutive patients with increased cardiac troponin concentrations were screened to identify patients with type 2 myocardial infarction. We excluded patients with frailty or renal or hepatic failure. All study participants underwent coronary (invasive or computed tomography angiography) and cardiac (magnetic resonance or echocardiography) imaging, and the underlying causes of infarction were independently adjudicated. The primary outcome was the prevalence of coronary artery disease.

RESULTS

In 100 patients with a provisional diagnosis of type 2 myocardial infarction (median age, 65 years [interquartile range, 55-74 years]; 43% women), coronary and cardiac imaging reclassified the diagnosis in 7 patients: type 1 or 4b myocardial infarction in 5 and acute myocardial injury in 2 patients. In those with type 2 myocardial infarction, median cardiac troponin I concentrations were 195 ng/L (interquartile range, 62-760 ng/L) at presentation and 1165 ng/L (interquartile range, 277-3782 ng/L) on repeat testing. The prevalence of coronary artery disease was 68% (63 of 93), which was obstructive in 30% (28 of 93). Infarct-pattern late gadolinium enhancement or regional wall motion abnormalities were observed in 42% (39 of 93), and left ventricular systolic dysfunction was seen in 34% (32 of 93). Only 10 patients had both normal coronary and normal cardiac imaging. Coronary artery disease and left ventricular systolic dysfunction were previously unrecognized in 60% (38 of 63) and 84% (27 of 32), respectively, with only 33% (21 of 63) and 19% (6 of 32) on evidence-based treatments.

CONCLUSIONS

Systematic coronary and cardiac imaging of patients with type 2 myocardial infarction identified coronary artery disease in two-thirds and left ventricular systolic dysfunction in one-third of patients. Unrecognized and untreated coronary or cardiac disease is seen in most patients with type 2 myocardial infarction, presenting opportunities for initiation of evidence-based treatments with major potential to improve clinical outcomes.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03338504.

Correlation between Traditional Chinese Medicine Syndromes and Type 2 Myocardial Infarction in Critically Ill Patients with Pulmonary Disease

Background

Treatment based on syndrome differentiation under the traditional Chinese medicine (TCM) framework has been shown to be helpful in patients with coronary artery disease. We hypothesized that syndrome types could predict the risk of type 2 myocardial infarction (T2MI) caused by imbalance between myocardial oxygen supply and demand in critically ill patients with pulmonary disease.

Methods

This retrospective study included consecutive critically ill patients with pulmonary disease admitted to the ICU at Jiading District Central Hospital Affiliated Shanghai University of Medicine & Health Sciences from January 1, 2017, to July 1, 2019. Diagnosis of T2MI was based on the fourth universal definition of myocardial infarction. Risk factors associated with T2MI were identified using multivariate regression analysis.

Results

A total of 244 patients were included in the study: 78 who developed T2MI and the remaining 166 who did not develop T2MI during hospitalization. The incidence of phlegm syndrome and deficiency syndrome was 61.9% and 38.1%, respectively. In comparison with the patients with phlegm syndrome, the incidence of T2MI in patients with deficiency syndrome is significantly higher (40.9% vs. 26.5%, P=0.019). In multivariate logistic regression, T2MI was independently associated with the baseline troponin level (OR 12.682, 95% CI 1.397∼115.121; P=0.024), hemoglobin < 55 g/L (OR 12.76, 95% CI 2.359∼69.021; P=0.003), mechanical ventilation (OR 2.244, 95% CI 1.029∼4.892; P=0.042), and TCM deficiency syndrome (OR 2.214, 95% CI 1.032∼4.749; P=0.041). After adjusting for confounding factors in Cox regression models, the hazard ratio (95% confidence interval) of qi deficiency syndrome groups was 1.183 (95% CI 1.053∼3.123, P=0.032).

Conclusions

Patients with deficiency syndrome are at high risk of T2MI, especially those combined with qi deficiency syndrome.

Type 2 myocardial infarction: a diagnostic and therapeutic challenge in contemporary cardiology

In the expanding world of cardiovascular diseases, rapidly reaching pandemic proportions, the main focus is still on coronary atherosclerosis and its clinical consequences. However, at least in the Western world, middle-aged male patients with acute myocardial infarction are no more the rule. Due to a higher life expectancy and major medical advances, physicians are to treat older and frailer individuals, usually with multiple comorbidities. In this context, myocardial ischaemia and infarction frequently result from an imbalance between myocardial oxygen supply and demand-i.e., type 2 myocardial infarction (T2MI), according to the current universal definition-rather than coronary atherothrombosis. Moreover, the increasing use of high-sensitivity cardiac troponin assays has led to a heightened detection of T2MI-often causing relatively little myocardial injury-, which seems to have doubled its numbers in recent years. Nevertheless, owing to its multifaceted pathophysiology and clinical presentation, T2MI is still underdiagnosed. Perhaps more importantly, T2MI is also victim of undertreatment, as drugs that constitute the cornerstone of therapy in most cardiovascular diseases are much more unlikely to be prescribed in T2MI than in coronary atherothrombosis. In this paper, we review the recent literature on the classification, pathophysiology, epidemiology, and management of T2MI, trying to summarise the state-of-the-art knowledge about this increasingly important pathologic condition. Finally, based on the current scientific evidence, we also propose an algorithm that may be easily utilised in clinical practice, in order to improve T2MI diagnosis and risk stratification.

Diagnostic features, management and prognosis of type 2 myocardial infarction compared to type 1 myocardial infarction: a systematic review and meta-analysis

IMPORTANCE

Distinguishing type 2 (T2MI) from type 1 myocardial infarction (T1MI) in clinical practice can be difficult, and the management and prognosis for T2MI remain uncertain.

OBJECTIVE

To compare precipitating factors, risk factors, investigations, management and outcomes for T2MI and T1MI.

DATA SOURCES

Medline and Embase databases as well as reference list of recent articles were searched January 2009 to December 2020 for term 'type 2 myocardial infarction'.

STUDY SELECTION

Studies were included if they used a universal definition of MI and reported quantitative data on at least one variable of interest.

DATA EXTRACTION AND SYNTHESIS

Data were pooled using random-effect meta-analysis. Risk of bias was assessed using Newcastle-Ottawa quality assessment tool. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. All review stages were conducted by two reviewers.

MAIN OUTCOMES AND MEASURES

Risk factors, presenting symptoms, cardiac investigations such as troponin and angiogram, management and outcomes such as mortality.

RESULTS

40 cohort studies comprising 98 930 patients with T1MI and 13 803 patients with T2MI were included. Compared with T1MI, patients with T2MI were: more likely to have pre-existing chronic kidney disease (OR 1.87; 95% CI 1.53 to 2.28) and chronic heart failure (OR 2.35; 95% CI 1.82 to 3.03), less likely to present with typical cardiac symptoms of chest pain (OR 0.19; 95% CI 0.13 to 0.26) and more likely to present with dyspnoea (OR 2.64; 95% CI 1.86 to 3.74); more likely to demonstrate non-specific ST-T wave changes on ECG (OR 2.62; 95% CI 1.81 to 3.79) and less likely to show ST elevation (OR 0.22; 95% CI 0.17 to 0.28); less likely to undergo coronary angiography (OR 0.09; 95% CI 0.06 to 0.12) and percutaneous coronary intervention (OR 0.06; 95% CI 0.04 to 0.10) or receive cardioprotective medications, such as statins (OR 0.25; 95% CI 0.16 to 0.38) and beta-blockers (OR 0.45; 95% CI 0.33 to 0.63). T2MI had greater risk of all cause 1-year mortality (OR 3.11; 95% CI 1.91 to 5.08), with no differences in short-term mortality (OR 1.34; 95% CI 0.63 to 2.85).

CONCLUSION AND RELEVANCE

This review has identified clinical, management and survival differences between T2MI and T1MI with greater precision and scope than previously reported. Differential use of coronary revascularisation and cardioprotective medications highlight ongoing uncertainty of their utility in T2MI compared with T1MI.

Type 2 MI and Myocardial Injury in the Era of High-sensitivity Troponin

Troponin has been the cornerstone of the definition of MI since its introduction to clinical practice. High-sensitivity troponin has allowed clinicians to detect degrees of myocardial damage at orders of magnitude smaller than previously and is challenging the definitions of MI, with implications for patient management and prognosis. Detection and diagnosis are no doubt enhanced by the greater sensitivity afforded by these markers, but perhaps at the expense of specificity and clarity. This review focuses on the definitions, pathophysiology, prognosis, prevention and management of type 2 MI and myocardial injury. The five types of MI were first defined in 2007 and were recently updated in 2018 in the fourth universal definition of MI. The authors explore how this pathophysiological classification is used in clinical practice, and discuss some of the unanswered questions in this era of availability of high-sensitivity troponin.

Risk factors for type 1 and type 2 myocardial infarction

AIMS

Whilst the risk factors for type 1 myocardial infarction due to atherosclerotic plaque rupture and thrombosis are established, our understanding of the factors that predispose to type 2 myocardial infarction during acute illness is still emerging. Our aim was to evaluate and compare the risk factors for type 1 and type 2 myocardial infarction.

METHODS AND RESULTS

We conducted a secondary analysis of a multi-centre randomized trial population of 48 282 consecutive patients attending hospital with suspected acute coronary syndrome. The diagnosis of myocardial infarction during the index presentation and all subsequent reattendances was adjudicated according to the Universal Definition of Myocardial Infarction. Cox regression was used to identify predictors of future type 1 and type 2 myocardial infarction during a 1-year follow-up period. Within 1 year, 1331 patients had a subsequent myocardial infarction, with 924 and 407 adjudicated as type 1 and type 2 myocardial infarction, respectively. Risk factors for type 1 and type 2 myocardial infarction were similar, with age, hyperlipidaemia, diabetes, abnormal renal function, and known coronary disease predictors for both (P < 0.05 for all). Whilst women accounted for a greater proportion of patients with type 2 as compared to type 1 myocardial infarction, after adjustment for other risk factors, sex was not a predictor of type 2 myocardial events [adjusted hazard ratio (aHR) 0.82, 95% confidence interval (CI) 0.66-1.01]. The strongest predictor of type 2 myocardial infarction was a prior history of type 2 events (aHR 6.18, 95% CI 4.70-8.12).

CONCLUSIONS

Risk factors for coronary disease that are associated with type 1 myocardial infarction are also important predictors of type 2 events during acute illness. Treatment of these risk factors may reduce future risk of both type 1 and type 2 myocardial infarction.

Circular RNA ciRs-126 promotes hypoxia/reoxygenation cardiac injury possibly through miR-21

Background

This study aimed to analyze the role of circular RNA ciRs-126 in hypoxia/reoxygenation cardiac injury (H/R).

Methods

Expression of ciRs-126 and miR-21 in plasma samples from patients with H/R and healthy controls was determined by RT-qPCR. Correlations were analyzed by linear regression. Overexpression of ciRs-126 and miR-21 was achieved in cardiomyocytes to explore their crosstalk. The roles of ciRs-126 and miR-21 in H/R-induced apoptosis of cardiomyocytes were analyzed using cell apoptosis assay.

Results

CiRs-126 was upregulated and miR-21 was downregulated in H/R patients. They were inversely correlated across plasma samples from H/R patients. In H/R cardiomyocytes, ciRs-126 was upregulated and miR-21 was downregulated. In cardiomyocytes, ciRs-126 overexpression decreased miR-21 level and reduced the inhibitory effects of miR-21 overexpression on H/R-induced cell apoptosis.

Conclusions

Circular RNA ciRs-126 may suppress miR-21 expression to promote H/R cardiac injury.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00355-x.

Clinical characteristics and prognostic implications of diabetes and myocardial injury in patients admitted to the emergency room

BACKGROUND

This study aimed to investigate the clinical features and prognosis of diabetes and myocardial injury in patients admitted to the emergency department.

METHODS

We analyzed the clinical data of all consecutive patients admitted to the emergency department during the years 2012 and 2013 with at least 1 cardiac Troponin I (cTnI Ultra Siemens, Advia Centaur) determination, and were classified according to the status of diabetes mellitus (DM) and myocardial injury (MI). Clinical events were evaluated in a 4-year follow-up.

RESULTS

A total of 3622 patients were classified according to the presence of DM (n = 924 (25.55%)) and MI (n = 1049 (28.96%)). The proportion of MI in patients with DM was 40% and 25% in patients without DM. Mortality during follow-up was 10.9% in non-DM patients without MI, 21.3% in DM patients without MI, 40.1% in non-DM patients with MI, and 52.8% in DM patients with MI. A competitive risk model was used to obtain the Hazard Ratio (HR) for readmission for myocardial infarction or heart failure. There was a similar proportion of readmission for myocardial infarction and heart failure at a four-year follow-up in patients with DM or MI, which was much higher when DM was associated with MI, with respect to patients without DM or MI. The HR (95% Coefficient Interval) for myocardial infarction in the DM without MI, non-DM with MI, and DM with MI groups with respect to the non-DM without MI group was 2511 (1592-3960), 2682 (1739-4138), and 5036 (3221-7876), respectively. The HR (95% CI) for the risk of readmission for heart failure in the DM without MI, non-DM with MI, and DM with MI groups with respect to the non-DM without MI group was 2663 (1825-3886), 2562 (1753-3744) and 4292 (2936-6274), respectively.

CONCLUSIONS

The association of DM and MI in patients treated in an Emergency Service identifies patients at very high risk of mortality and cardiovascular events.

The prognostic value of myocardial perfusion imaging in patients with type 2 myocardial infarction

OBJECTIVES

The aim of this retrospective study is to evaluate the prognostic role of myocardial perfusion imaging (MPI) in patients with type 2 myocardial infarction (T2MI).

BACKGROUND

T2MI is an increasingly common diagnosis in clinical practice. The management of this condition is controversial and the prognostic value of MPI has not been established in this setting.

METHODS

We retrospectively studied T2MI patients who underwent vasodilator gated MPI within 90 days of T2MI at a single tertiary care institution in 2013. Abnormal myocardial perfusion was defined as the perfusion defect involving ≥ 5% of left ventricular (LV) myocardium. Abnormal LV ejection fraction (EF) was defined as < 50% by gated images. The primary outcome was a composite of death, myocardial infarction (other than index event) or coronary revascularization (CR).

RESULTS

There were 234 patients (62 ± 14 years, 57% men) with T2MI (peak troponin 0.2 ng/ml, interquartile 0.1-1.4), of whom 136 (58%) had an abnormal MPI. During a median follow-up of 20 months, 155 patients (66%) had the primary outcome (39% death, 42% MI, 5% CR). An abnormal MPI was associated with an increased risk of the primary outcome with a hazard ratio of 1.56, 95%CI (1.12-2.18, P = .008) that remained statistically significant after multivariate adjustment (1.45, 95%CI (1.02-2.06, P = .04))).

CONCLUSIONS

Patients with T2MI are at high risk for death or cardiac events in the intermediate term. More than one-half of patients with T2MI have an abnormal MPI and this is associated with the increased risk of cardiac events during follow-up. Risk stratification with MPI after T2MI may identify patients who would benefit from aggressive risk reduction.

Development and validation of a model for predicting 18-month mortality in type 2 myocardial infarction

BACKGROUND

Despite the poor prognosis in patients with type 2 myocardial infarction (MI), no prospective data on risk stratification exists. The aim of this study was to develop and validate a model for prediction of 18-month mortality of among patients with type 2 MI (T2MI) and compare its performance with GRACE and TARRACO scores.

METHODS

The prospective observational study included 712 consecutive patients diagnosed with MI undergoing coronary angiography <24 h between January 2017 and December 2018. Diagnosis of T2MI was adjusted according to Third universal definition. A prognostic model was developed by using Bayesian approach and logistic regression analysis with identifying predictors for mortality. The model was validated by bootstrap validation. Comparison performance between scores using Delong test.

RESULTS

T2MI was identified in 174 (24.4%) patients. The median age of patients was 69 years, 52% were female. The mortality rate was 20.1% at 18 months. Prior MI, presence of ST elevation, hemoglobin level at admission, Charlson comorbidity index and were independently associated with 18-month mortality. The model to predict 18-month mortality showed excellent discrimination (optimism corrected c-statistic = 0.822) and calibration (corrected slope = 0.893). GRACE and TARRACO scores had moderate discrimination [c-statistic = 0.748 (95% CI 0.652-0.843) and 0.741, 95% CI 0.669-0.805), respectively] and inferior compared with model (p = 0.043 and 0.037, respectively).

CONCLUSIONS

The risk of mortality among T2MI patients could be accurately predicted by using common clinical characteristics and laboratory tests. Further studies are required with external validation of nomogram prior to clinical implementation.

Type-II myocardial infarction and chronic myocardial injury rates, invasive management, and 4-year mortality among consecutive patients undergoing high-sensitivity troponin T testing in the emergency department

AIMS

As assessment of patients with suspected acute coronary syndromes (ACS) in emergency departments (EDs) represents a major workload because high-sensitivity troponin (HsTn) T and I levels are frequently measured, and a minority of patients have final diagnosis of myocardial infarction (MI). We determined the relative frequencies of three patients groups: Type-I MI, Type-II MI (including acute myocardial injury).

METHODS AND RESULTS

Among 2738 consecutive patients with suspected ACS presenting to ED at Liverpool Hospital, Australia, between March and June 2014. We studied the use of invasive and pharmacological therapies, and 4-year outcomes. Adjudication of MI was according to the 4th universal definition as follows: (i) Type-I MI; (ii) Type-II MI (including acute myocardial injury), and (iii) chronic myocardial injury. Of 995 patients (36%) [median age 76 years (interquartile range 65-83)] with ≥2 HsTnT measurements and one >14 ng/L, 727 (73%) had chronic myocardial injury, 171 (17%) had Type-II MI, and 97 (9.7%) had Type-I MI; respective late mortality rates to 48 months were 33%, 43%, and 14% (P < 0.001). In-hospital angiography rates were 95% for patients with Type-I MI, [62% had percutaneous coronary intervention (PCI)] 24% (7% PCI) for those with Type-II MI, and 3.4% for chronic myocardial injury. On Cox modelling for mortality relative to Type 1 MI, adjusted hazard ratios were 1.94 [95% confidence intervals (CIs) 1.06-3.57]; P = 0.032 for Type 2 MI, and for chronic myocardial injury 1.14 (95% CIs 0.64-2.02); P = 0.66.

CONCLUSION

Among unselected patients undergoing HsTnT testing in EDs, Type-II MI including acute myocardial injury was more common than Type-I MI. Chronic myocardial injury, which occurred in three of four patients. Whereas patients with Type-II MI had higher late mortality than those with Type-I MI, after multivariable analyses mortality rates were marginally different.

Concordance and Prognostic Relevance of Angiographic and Clinical Definitions of Myocardial Infarction Type

BACKGROUND

Atherothrombosis is the principal mechanism of type 1 (T1) myocardial infarction (MI), while type 2 (T2) MI is typically diagnosed in the presence of triggers (anemia, arrhythmia, etc.). We aimed to evaluate the proportions of T1 vs. T2 MI based on angiographic and clinical definitions, their concordance and prognosis.

METHODS

Consecutive MI patients [n = 712, 61% male; age 64.6 ± 12.3 years] undergoing coronary angiography were classified according to the presence of atherothrombosis and identifiable triggers. Association of angiographic and clinical MI type criteria with adverse outcomes (Time follow-up was 1.5 years) was evaluated. Predictive ability of GRACE risk score for all-cause mortality was then assessed.

RESULTS

Atherothrombosis and clinical triggers were identified in 397 (55.6%) and 324 (45.5%) subjects, respectively. Only 247 (34.7%) patients had "true" T1MI (atherothrombosis+ / triggers-); 174 (24.4%) were diagnosed with "true" T2MI (atherothrombosis- / triggers+), while 291 (40.9%) had discordant clinical and angiographic characteristics. All-cause mortality in T2MI (20.1%) patients was higher than in T1MI (9.3%), P = 0.002. Presence of triggers [odds ratio (OR) 2.4, 95% CI 1.5-3.6, P < 0.0001] but not atherothrombosis [OR 0.8, 95% confidence interval (CI) 0.5-1.3, P = 0.26] was associated with worse prognosis. GRACE score is a better predictor of death in T1MI vs. T2MI: area under curve 0.893 (95% CI 0.830-0.956) vs 0.748 (95% CI 0.652-0.843), P = 0.013.

CONCLUSION

Angiographic and clinical definitions of MI type are discordant in a substantial proportion of patients. Clinical triggers are associated with all-cause mortality. Predictive performance of GRACE score is worse in T2MI patients.

High sensitivity troponin, analytical advantages, clinical benefits and clinical challenges - An update

The measurement of cardiac troponin (cTn) by a high sensitivity method now represents the standard method for cTn measurement in the laboratory. High sensitivity method are not measuring a novel form of troponin but have undergone methodological improvement in assay sensitivity to allow both very low level detection and repeat measurements at low levels with very low degrees of analytical imprecision. The methods identify additional patients with myocardial injury who would benefit from evidence-based interventions. Rapid predictive algorithms utilising measurement on admission as well as short sampling periods (1-2 h) allow much more rapid categorisation of patients to appropriate clinical pathways. The shift in the diagnosis from traditional "cardiac enzymes" to troponin based on the 99th percentile has accounted for the majority of the detection of myocardial injury in patients without acute coronary syndromes. These patients have a worse prognosis irrespective of the underlying cause of their hospital admission. The appropriate management strategy in this group, beyond managing the underlying problem, remains to be defined. Measurement of cTn in otherwise asymptomatic individuals may have a role for patient selection for preventive treatment or for patients monitoring. Clinical trials in this area are awaited.

Demographic description and outcomes of a metropolitan network for myocardial infarction treatment

OBJECTIVE

The objective of the study was to describe the myocardial infarction treatment network and compare in-hospital mortality in patients undergoing either primary angioplasty or pharmacoinvasive strategy in Mexico City and a broad metropolitan area.

METHODS

Cohort study including patients with ST-elevation myocardial infarction. We recorded demographic and clinical data, laboratory tests and in-hospital mortality in patients that underwent primary angioplasty and pharmacoinvasive strategy. Kaplan-Meier analysis was used to assess mortality and Cox-regression assessed mortality risk factors.

RESULTS

Three hundred forty patients from a network of 60 hospitals and 9 states were analyzed. Of the total population, 166 were treated with pharmacoinvasive strategy and 174 with primary angioplasty. Door to thrombolytic time was 54 min and door to wire crossing time was 72.5 min; no differences in total ischemia time were demonstrated. No differences for in-hospital mortality (6.3% vs. 5.4%, p = 0.49) were found when comparing pharmacoinvasive and primary angioplasty groups. The main predictors for in-hospital mortality were: glucose > 180 mg/dl (HR 3.73), total ischemia time > 420 min (HR 3.18), heart rate > 90 bpm (HR 5.46), Killip and Kimball > II (HR 11.03), and left ventricle ejection fraction < 40% (HR 3.21).

CONCLUSIONS

This myocardial infarction network covers a large area and constitutes one of the biggest in the world. There were no differences regarding in-hospital mortality between pharmacoinvasive strategy and primary angioplasty. Pharmacoinvasive strategy is an effective and safe option for prompt reperfusion in Mexico.

Type 2 Myocardial Infarction: CURRENT CONCEPTS AND OUR EXPERIENCE WITH CARDIAC REHABILITATION

BACKGROUND

Type 2 myocardial infarction (T2MI) is commonly encountered in clinical practice, yet little is known about this challenging condition. Outpatient cardiac rehabilitation (CR) is an integral component in the care of patients with MI. However, specific recommendations for CR, information on the feasibility of participation, and outcome measures for patients with T2MI are lacking.

CLINICAL CONSIDERATIONS

The frequency of T2MI is markedly variable and depends on the studied population, disease definition, adjudication process, cardiac troponin assays, and cutoff values used to make the diagnosis of T2MI. Clinically, it is difficult to distinguish T2MI from type 1 MI or myocardial injury. Type 2 myocardial infarction occurs due to myocardial oxygen supply-demand mismatch without acute atherothrombotic plaque disruption and is associated with adverse short- and long-term prognoses. Currently, there are substantial gaps in knowledge regarding T2MI and there are no clear guidelines for the optimal management of these patients.

SUMMARY

In this article, we present important current concepts surrounding T2MI including the definition, pathophysiology, epidemiology, diagnosis, prognosis, and management. We also discuss referral patterns to CR and participation rates and provide our experience with a case series of 17 patients. Very few patients with T2MI are referred to and participate in CR. Our small case series indicated that patients with T2MI respond favorably to CR and that exercise training following standard guidelines appears safe and is well tolerated.

Cardiovascular Mortality After Type 1 and Type 2 Myocardial Infarction in Young Adults

BACKGROUND

Type 2 myocardial infarction (MI) and myocardial injury are associated with increased short-term mortality. However, data regarding long-term mortality are lacking.

OBJECTIVES

This study compared long-term mortality among young adults with type 1 MI, type 2 MI, or myocardial injury.

METHODS

Adults age 50 years or younger who presented with troponin >99th percentile or the International Classification of Diseases code for MI over a 17-year period were identified. All cases were adjudicated as type 1 MI, type 2 MI, or myocardial injury based on the Fourth Universal Definition of MI. Cox proportional hazards models were constructed for survival free from all-cause and cardiovascular death.

RESULTS

The cohort consisted of 3,829 patients (median age 44 years; 30% women); 55% had type 1 MI, 32% had type 2 MI, and 13% had myocardial injury. Over a median follow-up of 10.2 years, mortality was highest for myocardial injury (45.6%), followed by type 2 MI (34.2%) and type 1 MI (12%) (p < 0.001). In an adjusted model, type 2 MI was associated with higher all-cause (hazard ratio: 1.8; 95% confidence interval: 1.2 to 2.7; p = 0.004) and cardiovascular mortality (hazard ratio: 2.7; 95% confidence interval: 1.4 to 5.1; p = 0.003) compared with type 1 MI. Those with type 2 MI or myocardial injury were younger and had fewer cardiovascular risk factors but had more noncardiovascular comorbidities. They were significantly less likely to be prescribed cardiovascular medications at discharge.

CONCLUSIONS

Young patients who experience a type 2 MI have higher long-term all-cause and cardiovascular mortality than those who experience type 1 MI, with nearly one-half of patients with myocardial injury and more than one-third of patients with type 2 MI dying within 10 years. These findings emphasize the need to provide more aggressive secondary prevention for patients who experience type 2 MI and myocardial injury.

Upregulated lncRNA Pvt1 may be important for cardiac remodeling at the infarct border zone

Myocardial infarction (MI) is a leading cause of mortality due to progression to ventricular arrhythmias (VAs) or heart failure (HF). Cardiac remodeling at the infarct border zone (IBZ) is the primary contributor for VAs or HF. Therefore, genes involved in IBZ remodeling may be potential targets for the treatment of MI, but the mechanism remains unclear. The present study aimed to explain the molecular mechanisms of IBZ remodeling based on the roles of long non-coding RNAs (lncRNAs). After downloading miRNA (GSE76592) and mRNA/lncRNA (GSE52313) datasets from the Gene Expression Omnibus database, 23 differentially expressed miRNAs (DEMs), 2,563 genes (DEGs) and 168 lncRNAs (DELs) were identified between IBZ samples of MI mice and sham controls. A total of 483 DEGs were predicted to be regulated by 23 DEMs, among which Itgam, Met and TNF belonged to hub genes after five topological parameters were calculated for genes in the protein-protein interaction network. These hub genes-associated DEMs (mmu-miR-181a, mmu-miR-762) can also interact with six DELs (Gm15832, Gas5, Gm6634, Pvt1, Gm14636 and A330023F24Rik) to constitute the competing endogenous RNA (ceRNA) axes. Furthermore, a co-expression network was constructed based on the co-expression pairs between 44 DELs and 297 DEGs, in which Pvt1 and Bst1 were overlapped with the ceRNA network. Thus, Bst1-associated ceRNA (Pvt1-mmu-miR-181a-Bst1) and co-expression (Pvt-Bst1) axes were also pivotal for MI. Accordingly, Pvt1 may be a crucial lncRNA for modification of cardiac remodeling in the IBZ after MI and may function by acting as a ceRNA for miR-181a to regulate TNF/Met/Itgam/Bst1 or by co-expressing with Bst1.

Type 2 myocardial infarction among critically ill elderly patients in the Intensive Care Unit: the clinical features and in-hospital prognosis

BACKGROUND

Type 2 myocardial infarction (T2MI) refers to myocardial ischemic necrosis as a result of myocardial oxygen supply/demand mismatch, which are common comorbidities of critically ill patients. The purpose of this study was to investigate the incidence rate and risks of T2MI in critically ill elderly patients and further elucidate in-hospital prognostic factors.

METHODS

A total of 223 critically ill elderly patients admitted to our hospital from October 2016 to September 2018 were recruited. The clinical data and the in-hospital mortality rate were compared between the T2MI and non-T2MI groups. Multivariate linear regression analysis was used to identify independent factors related to T2MI. The clinical data and incidence of T2MI were also compared between patients who survived and those who died; multivariate regression analysis was used to identify independent risk factors for in-hospital death and survival analysis was conducted.

RESULTS

In this study, the incidence of T2MI was 24.2% (54/223), and the mortality rate of critically ill elderly patients was 39.0% (87/223). Multivariate linear regression analysis showed that severe hypoxemia, arrhythmia, shock, and multiple organ dysfunction syndrome (MODS) were independent risk factors of T2MI. Compared to the survival patients, the use of mechanical ventilation, the incidence of T2MI, APACHE II score, troponin T, high-sensitivity C-reactive protein, and procalcitonin levels were significantly higher in patients who died, while the estimated glomerular filtration rate (eGFR) was significantly decreased (all P < 0.05). In-hospital mortality was significantly increased in patients with T2MI (59.3% vs. 32.5%, P < 0.001). After adjustment for relevant factors, the incidence of T2MI, mechanical ventilation required, and eGFR reduction were independent and significant predictors of in-hospital death.

CONCLUSIONS

Critically, ill elderly patients have a high incidence of T2MI. In addition to severe hypoxia, shock, and arrhythmia, MODS is also associated with T2MI. At the same time, the risk of in-hospital death is increased in patients with type 2 MI.

[The Frequency of Type 2 Myocardial Infarction in the Structure of Hospital Mortality According to 7-Years Data of a State University Clinic]

 Aim      To evaluate the proportion of type 2 myocardial infarction (MI) in the structure of mortality at a multidisciplinary hospital; to describe major causes for MI development, and characteristics of patients with a verified diagnosis of type 2 MI by data of postmortem examination.Material and methods  1574 protocols of the autopsies performed at the Central Pathology Department of the I.I. Mechnikov North-West State Medical University from 01.01.10 through 31.12.16 were studied retrospectively by the continuous sampling method. A group with verified diagnosis of type 2 MI was isolated from the total sample of autopsies. Major causes for and the proportion of type 2 MI among the causes of death were studied. Also, major demographic parameters, hospitalization profile, and condition of coronary arteries (CA) were compared in patients with fatal type 2 MI and those who died from atherothrombotic type 1 MI.Results Analysis of 1574 fatal cases among patients of the multidisciplinary hospital showed that in 360 cases (22.87 %), the cause of death was MI, including 137 cases of fatal type 2 MI. Proportions of men and women among the patients with postmortem verification of type 2 MI were comparable. Analysis of the age structure showed the highest incidence of type 2 MI in elderly (48.2 %) and senile (34.3 %) age. Mean age of patients with type 2 MI was 71.7 years (68.2 years for men and 75.3 years for women), which was comparable with the age range of patients with fatal type 1 MI. In both groups, men with fatal MI were significantly younger than women. Analysis of causes for type 2 MI demonstrated that the most frequent ones were tachysystolic arrhythmias (59.12 %) and severe hypoxia of different origin (35.04 %). Analysis of the type of CA lesions showed that significant lesions were significantly more frequently absent in type 2 MI (32.85 %) while in type 1 MI, the proportion of patients with unchanged CA was 1.84 %. In the group of patients with fatal type 1 MI, 67.29 % had multivascular lesions, and one in two patients had an occlusive lesion. In the group with type 2 MI, multivascular lesions were half as frequent (31.38 %), and only 4.38 % of patients had a complete occlusion of a coronary vessel. Comparison of death rate in different departments of the multidisciplinary hospital showed that only 29.2 % of patients with type 2 MI originally were managed at a specialized cardiological department; 45.3 % of patients were admitted to an internal medicine department for different conditions often not related with ischemic heart disease. Furthermore, 25.5 % of patients with subsequently developed type 2 MI originally even received scheduled or emergency medical care for a leading surgical condition.Conclusion      Cardiovascular diseases predominate among causes of mortality in a multidisciplinary hospital. This study showed that almost one in four patients dies from MI, and type 2 MI accounts for more than one third of fatal MIs. Among major causes for type 2 MI, tachysystolic arrhythmias (59.12 %) and pronounced hypoxia associated with anemia and severe respiratory failure (35.04 %) should be noted. Gender and age characteristics of patients with type 2 MI were comparable with those of patients with fatal type 1 MI. Furthermore, surgical patients accounted for 25.5 % of fatal cases of type 2 MI.

Long-Term Prognosis of Patients with Myocardial Infarction Type 1 and Type 2 with and without Involvement of Coronary Vasospasm

While prognoses in relation to myocardial infarction (MI) type have been elucidated in past reports, the results were not consistent, perhaps due to occurrence of Type 2 MI with CVS and its mortality. The Japanese registry of acute Myocardial Infarction diagnosed by Universal Definition (J-MINUET) is a prospective multicenter registry in Japan. In contrast to thromboembolic event-related Type 1 myocardial infarction (MI), clinical features of Type 2 MI, including coronary vasospasm (CVS), are varied due to the heterogeneous nature of its development. To elucidate the MI type-related all-cause mortality, 2989 consecutive patients with AMI were stratified as Type 1 MI, Type 2 MI with CVS, and Type 2 MI with non-CVS. Most patients (n = 2834; 94.8%) were classified as Type 1 MI and 155 patients (5.2%) were classified as Type 2 MI. Of the Type 2 MI patients, 87 (56% of Type 2 MI) were diagnosed as MI with CVS. Although the 3-year mortality was comparable between Type 1 and Type 2 MI patients, significant differences were observed between Type 2 MI with CVS and with non-CVS (3.4% and 22.1%, p < 0.001). Among Japanese patients with AMI, mortality rates between Type 1 MI and Type 2 MI are comparable, but further stratification of Type 2 MI (with or without CVS) may be useful in predicting the prognosis of patients with Type 2 MI.

Meta-analysis Comparing Outcomes of Type 2 Myocardial Infarction and Type 1 Myocardial Infarction With a Focus on Dual Antiplatelet Therapy

BACKGROUND

There are important knowledge gaps in type 2 myocardial infarction (T2MI). Our primary objective was to compare the outcomes of patients with T2MI with those of patients with type 1 myocardial infarction (T1MI). Our secondary objective was to determine whether randomized controlled trials (RCTs) evaluating dual antiplatelets (DAPTs) have explicitly included patients with T2MI.

METHODS

We performed a meta-analysis comparing outcomes of patients with T2MI with patients with T1MI and a separate systematic review to evaluate the inclusion of T2MI in RCTs evaluating DAPT. There were 19 cohorts enrolling 48,829 patients (40,604 with T1MI and 5361 with T2MI) and 51 RCTs enrolling 188,132 patients with acute coronary syndrome.

RESULTS

Patients with T2MI had approximately 2-fold increases in unadjusted odds of long-term mortality compared with patients with T1MI (odds ratio, 2.47; 95% confidence interval, 2.06-2.96; P < 0.0001) and a 45% increase in adjusted odds of long-term mortality (odds ratio, 1.45; 95% confidence interval, 1.25-1.69; P < 0.0001, respectively). There was no published evaluation of efficacy, effectiveness, and safety of DAPT in patients with T2MI.

CONCLUSION

Patients with T2MI are at increased risk of adjusted all-cause long-term mortality compared with patients with T1MI. The role of DAPT remains unclear in T2MI.

Type 2 myocardial infarction: is it a geriatric syndrome?

Type 2 myocardial infarctions (T2-MI) is a type of necrosis that results from reduced oxygen supply and/or increased demand secondary to other causes unrelated to acute coronary atherothrombosis. The development and implementation of sensitive and high-sensitivity cardiac necrosis marker and the age-related increase of comorbidity lead to a boost of the frequency of T2-MI. T2-MI is often a complication of a high degree of clinical frailty in older adults, emerging as a "geriatric syndrome". Age-related non-cardiovascular causes may be the triggering factors and are strongly associated with the diagnosis, treatment, and prognosis of T2-MI. To date, there are no guidelines on management of this pathology in advancing age. Patient-centered approach and comprehensive geriatric assessment play a key role in the diagnosis, therapy and prognosis of geriatric patients with T2-MI.

Type 2 Myocardial Infarction: JACC Review Topic of the Week

Acute myocardial infarction (MI) can occur from increased myocardial oxygen demand and/or reduced supply in the absence of acute atherothrombotic plaque disruption; a condition called type 2 myocardial infarction (T2MI). As with any MI subtype, there must be clinical evidence of myocardial ischemia to make the diagnosis. This condition is increasingly diagnosed due to the increasing sensitivity of cardiac troponin assays and is associated with adverse short-term and long-term prognoses. Limited data exist defining optimal management strategies because T2MI is a heterogeneous entity with varying etiologies and triggers. Thus, these patients require individualized care. A major barrier is the absence of a uniform definition that can be operationalized with high reproducibility. This document provides a synthesis of the data about T2MI to assist clinicians' understanding of its pathobiology, when to deploy the diagnosis, and its associated treatments. It also clarifies prognosis, identifies gaps in knowledge, and provides recommendations for moving forward.

Incidence, Trends, and Outcomes of Type 2 Myocardial Infarction in a Community Cohort

BACKGROUND

Type 2 myocardial infarction (T2MI) occurs because of an acute imbalance in myocardial oxygen supply and demand in the absence of atherothrombosis. Despite being frequently encountered in clinical practice, the population-based incidence and trends remain unknown, and the long-term outcomes are incompletely characterized.

METHODS

We prospectively recruited residents of Olmsted County, Minnesota, who experienced an event associated with a cardiac troponin T >99th percentile of a normal reference population (≥0.01 ng/mL) between January 1, 2003, and December 31, 2012. Events were retrospectively classified into type 1 myocardial infarction (T1MI, atherothombotic event), T2MI, or myocardial injury (troponin rise not meeting criteria for myocardial infarction [MI]) using the universal definition. Outcomes were long-term all-cause and cardiovascular mortality and recurrent MI. T2MI was further subclassified by the inciting event for supply/demand mismatch.

RESULTS

A total of 5460 patients had at least one cardiac troponin T ≥0.01 ng/mL; 1365 of these patients were classified as index T1MI (age, 68.5±14.8 years; 63% male) and 1054 were classified as T2MI (age, 73.7±15.8 years; 46% male). The annual incidence of T1MI decreased markedly from 202 to 84 per 100 000 persons between 2003 and 2012 (P<0.001), whereas the incidence of T2MI declined from 130 to 78 per 100 000 persons (P=0.02). In comparison with patients with T1MI, patients with T2MI had higher long-term all-cause mortality after adjustment for age and sex, driven by early and noncardiovascular death. Rates of cardiovascular death were similar after either type of MI (hazard ratio, 0.8 [95% CI, 0.7-1.0], P=0.11). Subclassification of T2MI by cause demonstrated a more favorable prognosis when the principal provoking mechanism was arrhythmia, in comparison with postoperative status, hypotension, anemia, and hypoxia. After index T2MI, the most common MI during follow-up was a recurrent T2MI, whereas the occurrence of a new T1MI was relatively rare (estimated rates at 5 years, 9.7% and 1.7%).

CONCLUSIONS

There has been an evolution in the type of MI occurring in the community over a decade, with the incidence of T2MI now being similar to T1MI. Mortality after T2MI is higher and driven by early and noncardiovascular death. The provoking mechanism of supply/demand mismatch affects long-term survival. These findings underscore the healthcare burden of T2MI and provide benchmarks for clinical trial design.

Incidence, Characteristics, and Outcomes of Myocardial Infarction in Patients With Peripheral Artery Disease: Insights From the EUCLID Trial

Importance

Patients with peripheral artery disease (PAD) are at high risk for myocardial infarction (MI).

Objective

To characterize the incidence and types of MI in a PAD population, identify factors associated with MI, and determine the association of MI with cardiovascular mortality and acute limb ischemia.

Design, Setting, and Participants

The Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease (EUCLID) was a double-blind randomized clinical trial conducted at 811 sites in 28 countries that randomized 13 885 patients with symptomatic PAD to monotherapy with ticagrelor or clopidogrel. Participants had an ankle-brachial index (ABI) of 0.80 or less or previous lower extremity revascularization. Median follow-up was 30 months. For these analyses, patients were evaluated for MI occurrence during follow-up irrespective of treatment. Data were analyzed from June 2017 to September 2018.

Main Outcomes and Measures

An adjudication clinical events committee classified MI as type 1 (spontaneous), type 2 (secondary), type 3 (sudden cardiac death), type 4a (less than 48 hours after percutaneous coronary intervention), type 4b (definite stent thrombosis), or type 5 (less than 72 hours after coronary artery bypass graft). A multivariate regression model was developed by stepwise selection to identify factors associated with MI, and a time-dependent multivariate Cox regression analysis was performed to determine the association of MI with cardiovascular death and acute limb ischemia requiring hospitalization.

Results

Of the 13 885 patients included in this analysis, 9997 (72.0%) were male, and the median (interquartile range) age was 66 (60-73) years. Myocardial infarction occurred in 683 patients (4.9%; 2.4 events per 100 patient-years) during a median follow-up of 30 months. Patients experiencing MI were older (median [interquartile range] age, 69 [62-75] vs 66 [60-72] years), more likely to have diabetes (349 of 683 [51.1%] vs 4996 of 13 202 [37.8%]) or a previous lower extremity revascularization (466 of 683 [68.2%] vs 7409 of 13 202 [56.1%]), and had a lower ABI (if included by ABI) compared with censored patients. Of the 683 patients with MI during follow-up, the most common MI type was type 1 (405 [59.3%]), followed by type 2 (236 [34.6%]), type 4a (14 [2.0%]), type 3 (12 [1.8%]), type 4b (11 [1.6%]), and type 5 (5 [0.7%]). Postrandomization MI was independently associated with cardiovascular death (adjusted hazard ratio, 9.0; 95% CI, 7.3-11.2; P < .001) and acute limb ischemia requiring hospitalization (adjusted hazard ratio, 2.5; 95% CI, 1.3-5.0; P = .008).

Conclusions and Relevance

Approximately 5% of patients with symptomatic PAD had an MI during a median follow-up of 30 months. Type 1 MI (spontaneous) was the most common MI type; however, one-third of MIs were type 2 MI (secondary). More research is needed to identify therapies to reduce the risk of MI in patients with PAD and to improve management of type 2 MI.

Trial Registration

ClinicalTrials.gov Identifier: NCT01732822.

Type 2 Myocardial Infarction: A Geriatric Population-based Model of Pathogenesis

Distinction between type 2 myocardial infarction (T2MI), defined as an imbalance between oxygen supply and demand without atherothrombosis, and type 1 myocardial infarction (T1MI), due to plaque disruption, is often a clinical challenge in frail elderly patients. We aimed to identify the characteristics and underlying causes of T2MI using a comprehensive geriatric approach. From a multicentre population-based prospective study in coronary care units, we adjudicated 4572 consecutive patients hospitalized for an acute T1MI or T2MI, according to the 3^rd universal definition and a prespecified geriatric model of T2MI pathogenesis. In total, 3710 (81%) had T1MI and 862 (19%) T2MI. Patients with T2MI were 10 y older (77 vs 67 y, p<0.001), more frequently female (44 vs 26%, p<0.001) and had more frequent comorbidities. In multivariate analysis, acute heart failure, tachycardia and C-reactive protein elevation at admission were associated with a higher risk of T2MI vs T1MI, whereas chest pain, troponin I peak > 10 µg/L and ST-segment elevation were associated with a lower risk. Underlying mechanisms leading to T2MI highlighted 3 main patterns: 1) Age-related physiological cardiovascular decline 2) chronic predisposing factors including chronic anaemia (10%) and severe aortic stenosis (7%), 3) acute triggering factors, the most common being acute infection (39%), mainly respiratory tract infection, followed by tachyarrhythmia (13%) and acute heart failure (10%). 122 (14%) patients had combined predisposing and triggering conditions for T2MI. In our large population-based survey of T2MI, chronic anaemia and severe aortic stenosis increased predisposition to T2MI and acute respiratory infection was by far the most frequent trigger. Our data shed new light on the age-related pathophysiological basis for discrepancies in oxygen supply and demand leading to MI.

High-Sensitivity Cardiac Troponin and the Universal Definition of Myocardial Infarction

BACKGROUND

The introduction of more sensitive cardiac troponin assays has led to increased recognition of myocardial injury in acute illnesses other than acute coronary syndrome. The Universal Definition of Myocardial Infarction recommends high-sensitivity cardiac troponin testing and classification of patients with myocardial injury based on pathogenesis, but the clinical implications of implementing this guideline are not well understood.

METHODS

In a stepped-wedge cluster randomized, controlled trial, we implemented a high-sensitivity cardiac troponin assay and the recommendations of the Universal Definition in 48 282 consecutive patients with suspected acute coronary syndrome. In a prespecified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death and secondary outcome of noncardiovascular death at 1 year across diagnostic categories.

RESULTS

Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4471), type 2 myocardial infarction by 22% (205/916), and acute and chronic myocardial injury by 36% (443/1233) and 43% (389/898), respectively. Compared with those without myocardial injury, the rate of the primary outcome was highest in those with type 1 myocardial infarction (cause-specific hazard ratio [HR] 5.64 [95% CI, 5.12-6.22]), but was similar across diagnostic categories, whereas noncardiovascular deaths were highest in those with acute myocardial injury (cause specific HR 2.65 [95% CI, 2.33-3.01]). Despite modest increases in antiplatelet therapy and coronary revascularization after implementation in patients with type 1 myocardial infarction, the primary outcome was unchanged (cause specific HR 1.00 [95% CI, 0.82-1.21]). Increased recognition of type 2 myocardial infarction and myocardial injury did not lead to changes in investigation, treatment or outcomes.

CONCLUSIONS

Implementation of high-sensitivity cardiac troponin assays and the recommendations of the Universal Definition of Myocardial Infarction identified patients at high-risk of cardiovascular and noncardiovascular events but was not associated with consistent increases in treatment or improved outcomes. Trials of secondary prevention are urgently required to determine whether this risk is modifiable in patients without type 1 myocardial infarction.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov. Unique identifier: NCT01852123.

Type 2 myocardial infarction in general medical wards: Clinical features, treatment, and prognosis in comparison with type 1 myocardial infarction

Type 2 myocardial infarction (MI) is defined as myocardial necrosis due to imbalance between myocardial oxygen supply and demand. The objective of this study was to assess the features, treatments, and outcomes of patients with type 2 MI in comparison with patients with type 1 MI hospitalized in general medical wards. A retrospective review was performed on patients admitted to general medicine wards diagnosed with MI in Sheba Medical Center between January 1, 2016 and December 31, 2016. Comparative analysis between patients with type 1 and type 2 MI was performed. The study included 349 patients with type 1 MI and 206 patients with type 2 MI. The main provoking factors for type 2 MI were sepsis (38.1%), anemia (29.1%), and hypoxia (23.8%). Patients with type 2 MI were older (79.1 ± 11.9 vs 75.2 ± 11.7, P < .001) and had a lower rate of prior MI (23.3% vs 38.1%, P < .001) and percutaneous coronary intervention (PCI) (34% vs 48.7%, P = .023) compared with patients with type 1 MI. Patients with type 2 MI were significantly less prescribed antiplatelet therapy (79.1% vs 96%, P < .001) and statins (60.7% vs 80.2%, P < .001), and were less referred to coronary angiography (10.7% vs 54.4%, P < .001). Type 2 MI was associated with a significantly higher 1-year mortality rate compared with type 1 MI (38.8% vs 26.6%, P = .004), but after accounting for age and sex differences, this association lacked statistical significance. In conclusion, type 2 MI patients were older and had similar comorbidities compared with those with type 1 MI. These patients were less prescribed medical therapy and coronary intervention, and had a higher 1-year mortality rate. Establishing a clear therapeutic approach for type 2 MI is required.

Effects of alirocumab on types of myocardial infarction: insights from the ODYSSEY OUTCOMES trial

AIMS

The third Universal Definition of Myocardial Infarction (MI) Task Force classified MIs into five types: Type 1, spontaneous; Type 2, related to oxygen supply/demand imbalance; Type 3, fatal without ascertainment of cardiac biomarkers; Type 4, related to percutaneous coronary intervention; and Type 5, related to coronary artery bypass surgery. Low-density lipoprotein cholesterol (LDL-C) reduction with statins and proprotein convertase subtilisin-kexin Type 9 (PCSK9) inhibitors reduces risk of MI, but less is known about effects on types of MI. ODYSSEY OUTCOMES compared the PCSK9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome (ACS) and elevated LDL-C (≥1.8 mmol/L) despite intensive statin therapy. In a pre-specified analysis, we assessed the effects of alirocumab on types of MI.

METHODS AND RESULTS

Median follow-up was 2.8 years. Myocardial infarction types were prospectively adjudicated and classified. Of 1860 total MIs, 1223 (65.8%) were adjudicated as Type 1, 386 (20.8%) as Type 2, and 244 (13.1%) as Type 4. Few events were Type 3 (n = 2) or Type 5 (n = 5). Alirocumab reduced first MIs [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77-0.95; P = 0.003], with reductions in both Type 1 (HR 0.87, 95% CI 0.77-0.99; P = 0.032) and Type 2 (0.77, 0.61-0.97; P = 0.025), but not Type 4 MI.

CONCLUSION

After ACS, alirocumab added to intensive statin therapy favourably impacted on Type 1 and 2 MIs. The data indicate for the first time that a lipid-lowering therapy can attenuate the risk of Type 2 MI. Low-density lipoprotein cholesterol reduction below levels achievable with statins is an effective preventive strategy for both MI types.

Assessment and Treatment of Patients With Type 2 Myocardial Infarction and Acute Nonischemic Myocardial Injury

Although coronary thrombus overlying a disrupted atherosclerotic plaque has long been considered the hallmark and the primary therapeutic target for acute myocardial infarction (MI), multiple other mechanisms are now known to cause or contribute to MI. It is further recognized that an MI is just one of many types of acute myocardial injury. The Fourth Universal Definition of Myocardial Infarction provides a taxonomy for acute myocardial injury, including 5 subtypes of MI and nonischemic myocardial injury. The diagnosis of MI is reserved for patients with myocardial ischemia as the cause of myocardial injury, whether attributable to acute atherothrombosis (type 1 MI) or supply/demand mismatch without acute atherothrombosis (type 2 MI). Myocardial injury in the absence of ischemia is categorized as acute or chronic nonischemic myocardial injury. However, optimal evaluation and treatment strategies for these etiologically distinct diagnoses have yet to be defined. Herein, we review the epidemiology, risk factor associations, and diagnostic tools that may assist in differentiating between nonischemic myocardial injury, type 1 MI, and type 2 MI. We identify limitations, review new research, and propose a framework for the diagnostic and therapeutic approach for patients who have suspected MI or other causes of myocardial injury.

A systematic review on the triggers and clinical features of type 2 myocardial infarction

Little is known about the correlation between triggering factors, clinical characteristics, diagnosis, and prognosis of patients with type 2 myocardial infarction (T2MI). The triggers and features of T2MI are linked to its diagnosis and prognosis. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. A structured search of three databases (PubMed, Embase, and Medline) was undertaken to identify peer-reviewed articles related to the triggers and clinical features of T2MI published between January 2012 and August 2018. Seven retrospective cohort studies and seven prospective cohort studies involving 3867 patients with T2MI were included. All selected studies were rated as being of high or acceptable quality. Nine studies revealed that the leading trigger of T2MI was arrhythmia, especially tachyarrhythmia. Six studies revealed that the proportion of single-trigger T2MIs was higher than that of multiple triggers and two studies showed that two-trigger cases formed the majority of multiple trigger cases. All included studies found that a greater prevalence of T2MI in the older population. Thirteen studies revealed that the patients with T2MI often had a previous relevant medical history. The leading trigger of T2MI is arrhythmia, especially tachyarrhythmia, and the majority of cases arise from a single trigger. Two-trigger is the most common form of multiple-trigger T2MI, which often occurs in older patients with cardiovascular risk factors or comorbidities. Non-cardiovascular causes may be the triggering factors and are strongly associated with the diagnosis, treatment, and prognosis of T2MI.