Impact of Type 2 Myocardial Infarction (MI) on Hospital-Level MI Outcomes: Implications for Quality and Public Reporting

Prevalence, Predictors, and Outcomes of Type 2 NSTEMI in Hospitalized Patients With COVID-19

BACKGROUND

Data on the incidence of type 2 non-ST-segment-elevation myocardial infarction (T2MI) in hospitalized patients with COVID-19 has been limited to single-center studies. Given that certain characteristics, such as obesity and type 2 diabetes, have been associated with higher mortality in COVID-19 infections, we aimed to define the incidence of T2MI in a national cohort and identify pre-hospital patient characteristics associated with T2MI in hospitalized patients with COVID-19.

METHODS AND RESULTS

Using the national American Heart Association COVID-19 Cardiovascular Disease Quality Improvement Registry, we performed a retrospective 4:1 matched (age, sex, race, and body mass index) analysis of controls versus cases with T2MI. We performed (1) conditional multivariable logistic regression to identify predictive pre-hospital patient characteristics of T2MI for patients hospitalized with COVID-19 and (2) stratified proportional hazards regression to investigate the association of T2MI with morbidity and mortality. From January 2020 through May 2021, there were 709 (2.2%) out of 32 015 patients with T2MI. Five hundred seventy-nine cases with T2MI were matched to 2171 controls (mean age 70; 43% female). Known coronary artery disease, heart failure, chronic kidney disease, hypertension, payor source, and presenting heart rate were associated with higher odds of T2MI. Anti-hyperglycemic medication and anti-coagulation use before admission were associated with lower odds of T2MI. Those with T2MI had higher morbidity and mortality (hazard ratio, 1.40 [95% CI, 1.13-1.74]; P=0.002).

CONCLUSIONS

In hospitalized patients with COVID-19, those with a T2MI compared with those without had higher morbidity and mortality. Outpatient anti-hyperglycemic and anti-coagulation use were the only pre-admission factors associated with reduced odds of T2MI.

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.

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.

Potential Biomarkers to Distinguish Type 1 Myocardial Infarction in Troponin-Elevated Diseases

Classifying myocardial infarction by subtype is crucial for appropriate patient management. Although troponin is currently the most commonly used biomarker, it is not a specific marker for myocardial infarction and cannot distinguish subtypes. Furthermore, previous studies have confirmed that proteins known as myocardial infarction markers could function to distinguish the type of myocardial infarction. Therefore, we identify a marker that can distinguish type 1 myocardial infarction from other diseases with elevated troponin. We used mass spectrometry to compare type 1 myocardial infarction with other conditions characterized by troponin elevation and identified new candidate markers for disease classification. We then verified these markers, along with those already known to be associated with cardiovascular disease and plaque rupture. We identified α-1 acid glycoprotein 2, corticosteroid-binding globulin, and serotransferrin as potential distinguishing markers. The presence of these markers and other parameters, such as chest pain, electrocardiogram, and troponin levels from the complementary diagnostic processes, could provide valuable information to specifically diagnose type 1 myocardial infarction.

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.

Reproducing extracellular matrix adverse remodelling of non-ST myocardial infarction in a large animal model

The rising incidence of non-ST-segment elevation myocardial infarction (NSTEMI) and associated long-term high mortality constitutes an urgent clinical issue. Unfortunately, the study of possible interventions to treat this pathology lacks a reproducible pre-clinical model. Indeed, currently adopted small and large animal models of MI mimic only full-thickness, ST-segment-elevation (STEMI) infarcts, and hence cater only for an investigation into therapeutics and interventions directed at this subset of MI. Thus, we develop an ovine model of NSTEMI by ligating the myocardial muscle at precise intervals parallel to the left anterior descending coronary artery. Upon histological and functional investigation to validate the proposed model and comparison with STEMI full ligation model, RNA-seq and proteomics show the distinctive features of post-NSTEMI tissue remodelling. Transcriptome and proteome-derived pathway analyses at acute (7 days) and late (28 days) post-NSTEMI pinpoint specific alterations in cardiac post-ischaemic extracellular matrix. Together with the rise of well-known markers of inflammation and fibrosis, NSTEMI ischaemic regions show distinctive patterns of complex galactosylated and sialylated N-glycans in cellular membranes and extracellular matrix. Identifying such changes in molecular moieties accessible to infusible and intra-myocardial injectable drugs sheds light on developing targeted pharmacological solutions to contrast adverse fibrotic remodelling.

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.

Serial measurements of protein and microRNA biomarkers to specify myocardial infarction subtypes

Background

While cardiac-specific troponin (cTn) allows for rapid diagnosis of acute type 1 myocardial infarction (T1MI), its performance to differentiate acute myocardial injury (AI) or type 2 myocardial infarction (T2MI) is limited. The objective was to combine biomarkers to improve discrimination of different myocardial infarction (MI) aetiologies.

Methods

We determined levels of cardiac troponin T and I (cTnT, cTnI), cardiac myosin-binding protein C (cMyBP-C), NT-proBNP and ten miRNAs, known to be associated with cardiac pathology in a total of n = 495 serial plasma samples at three time points (on admission, after 1 h and 3 h) from 57 NSTEMI (non-ST-elevation myocardial infarction), 18 AI, and 31 STEMI patients, as defined by fourth universal definition of MI (UDMI4) and 59 control individuals. We then applied linear mixed effects model to compare the kinetics of all molecules in these MI sub-types.

Results

Established (cTnT, cTnI) and novel (cMyBP-C) cardiac necrosis markers failed in differentiating T1MI vs T2MI at early time points. All cardiac necrosis markers were higher in T1MI than in T2MI at 3 h after admission. Muscle-enriched miRNAs (miR-1 and miR-133a) were correlated with cardiac necrosis protein markers and did not offer better discrimination. Established cardiac strain marker NT-proBNP differentiated AI and T1MI at all time points but failed to discriminate T2MI from T1MI. However, the combination of NT-proBNP and cTnT along with age returned an overall AUC of 0.76 [95 % CI 0.67-0.84] for differentiating T1MI, T2MI and AI.

Conclusions

Rather than using single biomarkers of myocardial necrosis, a combination of clinical biomarkers for cardiac necrosis (troponin) and cardiac strain (NT-proBNP) might aid in differentiating T1MI, T2MI and AI.

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.

Meta-Regression Analysis of the Impact of Medical Therapy on Long-Term Mortality in Type 2 Myocardial Infarction

The first approach for Type-2 myocardial infarction (T2MI) consists of the elimination of the condition determining the oxygen supply/demand mismatch. However, the long-term impact of medical therapy with beta blockers, statins, aspirin, and P2Y12 inhibitors, used in the case of Type-1 myocardial infarction has been poorly investigated and remains unclear. We, therefore, sought to assess the impact of medical therapy on 1-year mortality in patients with T2MI using a meta-regression analysis. A meta-regression analysis was performed with studies involving in patients with T2MI: 1-year all-cause mortality, rates of beta blockers, statins, aspirin, and P2Y12 inhibitors use were recorded and analyzed. After careful study selection, 8 observational studies were pooled in the analysis, including 3,756 in patients. During meta-regression analysis, a borderline correlation between rates of aspirin, P2Y12 inhibitors, and statins use and 1-year mortality (p = 0.087, p = 0.05, and p = 0.067, respectively) was found; no significant correlation was found at multivariable analysis. In conclusion, in a meta-regression analysis, no significant correlation was found between rates of use of usual drug therapy indicated for Type-1 myocardial infarction (statins, aspirin, P2Y12 inhibitors, β-blockers) and 1-year mortality in T2MI patients.

Long-term clinical outcomes of type 1 vs. type 2 myocardial infarction in patients who underwent angiography: data from the Korea acute myocardial infarction-national institute of health registry

BACKGROUND

In the cause of increase the clinical research observational evidence on type 2 myocardial infraction (T2MI), the study compared the characteristics of T2MI and T1MI with respect to major adverse cardiac events (MACE) and mortality as long-term outcomes from a large, nationwide, prospective Korean cohort registry.

METHODS

From 13,105 consecutively enrolled individuals in the Korea Acute Myocardial Infarction-National Institute of Health (KAMIR-NIH) registry between October 2011 and December 2015, 11,053 acute myocardial infarction (AMI) patients were divided into the T1MI (n=10,545) and T2MI (n=508) groups. All patients completed ≥3 years of follow-up.

RESULTS

The Kaplan-Meier curve analysis and Cox proportional hazard regression models showed that the cumulative rate of MACE was similar between the 2 groups (11.4% vs. 13.4%, log-rank P=0.185) at 3 years. However, the T2MI group showed higher rates of all-cause death [12.6% vs. 9.4%, log-rank P=0.019; hazard ratio (HR), 1.42; 95% CI: 1.08-1.85; P=0.012] and non-cardiac death (3.5% vs. 5.3%, log-rank P=0.043; HR, 1.55; 95% CI: 1.01-2.37; P=0.043) than the T1MI group. Male sex (HR 1.540; 95% CI: 1.218-1.947, P<0.001), old age (≥65 years; HR, 3.546; 95% CI: 2.645-4.753, P<0.001), low hemoglobin level (<12 g/dL; HR, 2.335; 95% CI: 1.841-2.961, P<0.001), high heart rate (>100 beats/min; HR, 1.852; 95% CI: 1.436-2.388, P<0.001), low glomerular filtration rate (GFR) (<60 mL/min/1.73 m2; HR, 2.373; 95% CI: 1.874-3.005, P<0.001), high body mass index (>25 kg/m2; HR, 0.644; 95% CI: 0.514-0.805, P<0.001), and low left ventricular ejection fraction (LVEF) (<40%; HR, 1.487; 95% CI: 1.095-2.020, P=0.011) were the independent predictors for 3-year non-cardiac mortality.

CONCLUSIONS

Although the 2 groups did not differ in MACE, the total mortality rate was higher in T2MI than in T1MI, especially non-cardiac mortality. The independent predictors for non-cardiac mortality were male sex, old age, anemia, low GFR, tachycardia, obesity, and low LVEF.

Outcomes of decreasing versus increasing cardiac troponin in patients admitted with non-ST-segment elevation myocardial infarction: the Atherosclerosis Risk in Communities Surveillance Study

BACKGROUND

The fourth universal definition of myocardial infarction requires an increase or decrease in cardiac troponin for the classification of non-ST-segment elevation myocardial infarction. We sought to determine whether the characteristics, management, and outcomes of patients admitted with non-ST-segment elevation myocardial infarction differ by the initial biomarker pattern.

METHODS

We identified patients in the Atherosclerosis Risk in Communities Surveillance Study admitted with chest pain and an initially elevated cardiac troponin I, who presented within 12 hours of symptom onset and were classified with non-ST-segment elevation myocardial infarction. A change in cardiac troponin I required an absolute difference of at least 0.02 ng/mL on the first day of hospitalization, prior to invasive cardiac procedures.

RESULTS

A total of 1926 hospitalizations met the inclusion criteria, with increasing cardiac troponin I more commonly observed (78%). Patients with decreasing cardiac troponin I were more often black (45% vs. 35%) and women (54% vs. 40%), and were less likely to receive non-aspirin antiplatelets (44% vs. 63%), lipid-lowering agents (62% vs. 80%), and invasive angiography (38% vs. 64%). Inhospital mortality was 3%, irrespective of the cardiac troponin I pattern. However, patients with decreasing cardiac troponin I had twice the 28-day mortality (12% vs. 5%; P=0.01). Fatalities within 28 days were more often attributable to non-cardiovascular causes in those with decreasing versus increasing cardiac troponin I (75% vs. 38%; P=0.01).

CONCLUSION

Patients presenting with chest pain and an initially elevated cardiac troponin I which subsequently decreases are less often managed by evidence-based therapies and have greater mortality, primarily driven by non-cardiovascular causes. Whether associations are attributable to type 2 myocardial infarction or a subacute presentation merits further investigation.

Outcomes of decreasing versus increasing cardiac troponin in patients admitted with non-ST-segment elevation myocardial infarction: the Atherosclerosis Risk in Communities Surveillance Study

BACKGROUND

The fourth universal definition of myocardial infarction requires an increase or decrease in cardiac troponin for the classification of non-ST-segment elevation myocardial infarction. We sought to determine whether the characteristics, management, and outcomes of patients admitted with non-ST-segment elevation myocardial infarction differ by the initial biomarker pattern.

METHODS

We identified patients in the Atherosclerosis Risk in Communities Surveillance Study admitted with chest pain and an initially elevated cardiac troponin I, who presented within 12 hours of symptom onset and were classified with non-ST-segment elevation myocardial infarction. A change in cardiac troponin I required an absolute difference of at least 0.02 ng/mL on the first day of hospitalization, prior to invasive cardiac procedures.

RESULTS

A total of 1926 hospitalizations met the inclusion criteria, with increasing cardiac troponin I more commonly observed (78%). Patients with decreasing cardiac troponin I were more often black (45% vs. 35%) and women (54% vs. 40%), and were less likely to receive non-aspirin antiplatelets (44% vs. 63%), lipid-lowering agents (62% vs. 80%), and invasive angiography (38% vs. 64%). Inhospital mortality was 3%, irrespective of the cardiac troponin I pattern. However, patients with decreasing cardiac troponin I had twice the 28-day mortality (12% vs. 5%; P=0.01). Fatalities within 28 days were more often attributable to non-cardiovascular causes in those with decreasing versus increasing cardiac troponin I (75% vs. 38%; P=0.01).

CONCLUSION

Patients presenting with chest pain and an initially elevated cardiac troponin I which subsequently decreases are less often managed by evidence-based therapies and have greater mortality, primarily driven by non-cardiovascular causes. Whether associations are attributable to type 2 myocardial infarction or a subacute presentation merits further investigation.

Patient Characteristics and Outcomes of Type 2 Myocardial Infarction During Heart Failure Hospitalizations in the United States

BACKGROUND

Type 2 myocardial infarction (MI) is increasingly diagnosed in patients with heart failure (HF). A paucity of data exists pertinent to the contemporary prevalence and impact of type 2 MI in patients with HF. We studied the patient profiles and the prognostic impact of type 2 MI on outcomes of HF hospitalizations.

METHODS

The Nationwide Readmission Database 2018 was queried for patients with HF hospitalizations with and without type 2 MI. Baseline characteristics, inpatient outcomes, and 30-day all-cause readmissions between both cohorts were compared.

RESULTS

Of 1,072,674 primary HF hospitalizations included in the study, 28,813 (2.7%) had type 2 MI. Patients with type 2 MI were more likely to be males (56.5% vs 51.6%; P < .001) and had a higher prevalence of hypertension (94% vs 92.2%; P < .001), prior myocardial infarction (17.1% vs 14.9%; P < .001), anemia (9.1% vs 8.1%; P < .001), chronic kidney disease (55.7% vs 49.4%; P < .001), neurological disorders (9.4% vs 7.3%; P < .001), and weight loss (7.3% vs 5.6%; P < .001). Compared with their counterparts without type 2 MI, patients with HF with type 2 MI had significantly higher in-hospital mortality (adjusted odds ratio [aOR], 1.53; 95% confidence interval [CI], 1.37-1.72), hospital costs (adjusted parameter estimate, $1785; 95% CI, 1388-2182), discharge to nursing facility (aOR, 1.22; 95% CI, 1.15-1.29), longer length of stay (adjusted parameter estimate, 0.53; 95% CI, 0.42-0.64), and rate of 30-day all-cause readmissions (aOR, 1.06; 95% CI, 1.01-1.12).

CONCLUSION

Type 2 MI in patients hospitalized with HF is associated with higher mortality and resource utilization in the United States.

Characteristics and Outcomes of Patients Admitted With Type 2 Myocardial Infarction

Type 2 myocardial infarction (Type 2 MI) is a common problem and carries a high diagnostic uncertainty. Large studies exploring outcomes in type 2 MI are lacking. Nationwide Readmission Database (2017) was queried using the International Classification of Diseases codes (ICD-10-CM) to identify type 2 MI patients. Characteristics, in-hospital outcomes, 30-day readmissions, and predictors of in-hospital mortality as well as 30-day readmissions were explored. We identified 21,738 patients with a diagnosis of type 2 MI. Most common primary diagnosis at presentation included infection/sepsis (27.5%), hypertensive heart disease (15.3%) and pulmonary diseases (8.5%). Overall, in-hospital mortality and 30-day readmission for patients with type 2 MI were 9.0% and 19.1% respectively. On multivariable analysis, significant predictors of increased in-hospital mortality included male gender, coexisting atrial fibrillation/flutter, peripheral vascular disease, coagulopathy, malignancy, and fluid/electrolyte abnormalities. Significant predictors of 30-day readmission were coexisting diabetes mellitus, atrial fibrillation/ flutter, carotid artery stenosis, anemia, COPD, CKD and prior history of myocardial infarction, A primary diagnosis of sepsis, pulmonary issues including respiratory failure, neurological conditions including stroke carried highest risk of mortality however readmission risk was not influenced by primary diagnosis at presentation. In conclusion, approximately 1 in 10 patients admitted for type 2 MI died during admission, and nearly 1 in 5 patients were readmitted at 30 days after discharge. In-hospital mortality varied based on associated primary diagnosis at presentation. Proposed predictive model for mortality and 30-day readmission in our study can help to target high risk patients for post-Type 2 MI care.

Outcomes and Resource Utilization of Atrial Fibrillation Hospitalizations With Type 2 Myocardial Infarction

Scarce data exist on the prognostic impact of type 2 myocardial infarction (MI) in patients with AF. The Nationwide Readmission Database 2018 was queried for primary AF hospitalizations with and without type 2 MI. Complex samples multivariable logistic and linear regression models were used to determine the association between type 2 MI and outcomes (in-hospital mortality, index length of stay [LOS], hospital costs, discharge to nursing facility, and 30-day all-cause readmissions). Of 382,896 weighted primary AF hospitalizations included in this study, 7,375 (1.9%) had type 2 MI. AF with type 2 MI is associated with significantly higher in-hospital mortality (adjusted OR [aOR] 1.76; 95% CI 1.30 to 2.38), LOS (adjusted parameter estimate [aPE] 0.48; 95% CI 0.35 to 0.62), hospital costs (aPE 1307.75; 95% CI 986.05 to 1647.44), discharges to nursing facility (aOR 1.38; 95% CI 1.24 to 1.54), and 30-day all-cause readmissions (adjusted hazard ratio 1.17; 95% CI 1.07 to 1.27) compared to AF without type 2 MI. Heart failure, chronic kidney disease, neurologic disorders, and age (per year) were identified as independent predictors of mortality among AF patients with type 2 MI. In conclusion, type 2 MI in the setting of AF hospitalization is associated with high in-hospital mortality and increased resource utilization.

Revascularization rates with coronary angioplasty and mortality in type 2 myocardial infarction: A meta-regression analysis

BACKGROUND

Percutaneous coronary intervention (PCI) represents the best therapeutic option for type-1 myocardial infarction (T1MI) in the majority of clinical settings; its role in the treatment of type-2 myocardial infarction (T2MI), however, remains unclear. We therefore sought to assess in a meta-regression analysis the impact of PCI rates on mortality in patients with T2MI according to available observational studies.

METHODS

We performed a meta-regression analysis including all the studies involving in-patients affected by T2MI. We excluded studies not reporting the rate of T2MI patients undergoing PCI and not specifying absolute in-hospital or 1-year all-cause mortality. In the meta-regression analysis we used the in-hospital mortality and 1-year mortality as dependent variables and the rate of PCI as independent; regression was weighted for studies' size.

RESULTS

After careful examination, 8 studies were selected for the assessment of in-hospital mortality and 8 for 1-year-mortality. We included 3155 and 3756 in-patients for in-hospital and 1-year mortality respectively. At meta-regression analysis, a borderline correlation between PCI rate and in-hospital mortality (p 0.05) and a statistically significant correlation with 1-year mortality (p < 0.01) in T2MI patients were found.

CONCLUSIONS

In a meta-regression analysis higher rates of PCI on T2MI in-patients were associated with lower mortality rates both in-hospital and at 1 year. Whether this association is related to the direct effect of PCI or better general conditions of T2MI patients undergoing a PCI still remains unclear.

Acute Myocardial Infarction Cohorts Defined by International Classification of Diseases, Tenth Revision Versus Diagnosis-Related Groups: Analysis of Diagnostic Agreement and Quality Measures in an Integrated Health System

BACKGROUND

Among Medicare value-based payment programs for acute myocardial infarction (AMI), the Hospital Readmissions Reduction Program uses International Classification of Diseases, Tenth Revision (ICD-10) codes to identify the program denominator, while the Bundled Payments for Care Improvement Advanced program uses diagnosis-related groups (DRGs). The extent to which these programs target similar patients, whether they target the intended population (type 1 myocardial infarction), and whether outcomes are comparable between cohorts is not known.

METHODS

In a retrospective study of 2176 patients hospitalized in an integrated health system, a cohort of patients assigned a principal ICD-10 diagnosis of AMI and a cohort of patients assigned an AMI DRG were compared according to patient-level agreement and outcomes such as mortality and readmission.

RESULTS

One thousand nine hundred thirty-five patients were included in the ICD-10 cohort compared with 662 patients in the DRG cohort. Only 421 patients were included in both AMI cohorts (19.3% agreement). DRG cohort patients were older (70 versus 65 years, P<0.001), more often female (48% versus 30%, P<0.001), and had higher rates of heart failure (52% versus 33%, P<0.001) and kidney disease (42% versus 25%, P<0.001). Comparing outcomes, the DRG cohort had significantly higher unadjusted rates of 30-day mortality (6.6% versus 2.5%, P<0.001), 1-year mortality (21% versus 8%, P<0.001), and 90-day readmission (26% versus 19%, P=0.006) than the ICD-10 cohort. Two observations help explain these differences: 61% of ICD-10 cohort patients were assigned procedural DRGs for revascularization instead of an AMI DRG, and type 1 myocardial infarction patients made up a smaller proportion of the DRG cohort (34%) than the ICD-10 cohort (78%).

CONCLUSIONS

The method used to identify denominators for value-based payment programs has important implications for the patient characteristics and outcomes of the populations. As national and local quality initiatives mature, an emphasis on ICD-10 codes to define AMI cohorts would better represent type 1 myocardial infarction patients.

Brief Report: Differences in Types of Myocardial Infarctions Among People Aging With HIV

BACKGROUND

Type 1 myocardial infarctions (T1MIs) result from atherosclerotic plaque instability, rupture, and/or erosion. Type 2 MIs (T2MIs) are secondary to causes such as sepsis and cocaine-induced vasospasm resulting in an oxygen demand-supply mismatch and are associated with higher mortality than T1MIs. T2MIs account for a higher proportion of MIs among people living with HIV (PLWH) compared with the general population. We compared MI rates by type among aging PLWH. We hypothesized that increases in MI rates with older age would differ by MI types, and T2MIs would be more common than T1MIs in younger individuals.

METHODS

Potential MIs from 6 sites were centrally adjudicated using physician notes, electrocardiograms, procedure results, and laboratory results. Reviewers categorized MIs by type and identified causes of T2MIs. We calculated T1MI and T2MI incidence rates. Incidence rate ratios were calculated for T2MI vs. T1MI rates per decade of age.

RESULTS

We included 462 T1MIs (52%) and 413 T2MIs (48%). T1MI rates increased with older age, although T1MIs occurred in all age decades including young adults. T2MI rates were significantly higher than T1MI rates for PLWH younger than 40 years. T1MI rates were similar or higher than T2MI rates among those older than 40 years (significantly higher for those aged 50-59 and 60-69 years).

CONCLUSIONS

Rates of T2MIs were higher than T1MIs until age 40 years among PLWH, differing from the general population, but rates of both were high among older PLWH. Given prognostic differences between MI types, these results highlight the importance of differentiating MI types among PLWH.

Effect of Evolocumab on Type and Size of Subsequent Myocardial Infarction: A Prespecified Analysis of the FOURIER Randomized Clinical Trial

Importance

The PCSK9 inhibitor evolocumab reduced major vascular events in the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) trial, yet the types and sizes of myocardial outcomes in FOURIER have not been previously explored.

Objective

To assess the types and sizes of myocardial infarction (MI) and the effect of evolocumab on MI by subtype.

Design, Setting, and Participants

A prespecified analysis of a multicenter double-blind randomized clinical trial. Patients were randomized to evolocumab or placebo and followed up for a median of 2.2 years. The study included 27 564 patients with stable atherosclerotic disease receiving statin therapy. Clinical end points were evaluated by the Thrombolysis in Myocardial Infarction clinical events committee. Rates presented are 3-year Kaplan-Meier estimates. Data were collected from 2013 to 2016 and analyzed from June 2017 to December 2019.

Main Outcomes and Measures

Myocardial infarction was defined based on the third universal MI definition, and further classified according to MI type (universal MI subclass, ST-segment elevation myocardial infarction [STEMI] vs non-STEMI) and by MI size (determined by peak troponin level).

Results

A total of 27 564 patients were randomized, with a mean (SD) age of 62.5 (9.0) years, and 20 795 (75%) were male. Of these, 1107 patients experienced a total of 1288 MIs. Most MIs (68%) were atherothrombotic (type 1), with 15% from myocardial oxygen supply-demand mismatch (type 2) and 15% percutaneous coronary intervention-related (type 4). Sudden death (type 3) and coronary artery bypass grafting-related (type 5) accounted for a total of 21 MIs (<2%). Evolocumab significantly reduced the risk of first MI by 27% (4.4% vs 6.3%; hazard ratio [HR], 0.73; 95% CI, 0.65-0.82; P < .001), type 1 by 32% (2.9% vs 4.5%; HR, 0.68; 95% CI, 0.59-0.79; P < .001), and type 4 by 35% (0.8% vs 1.1%; HR, 0.65; 95% CI, 0.48-0.87; P = .004), with no effect on type 2 (0.9% vs 0.8%; HR, 1.09; 95% CI, 0.82-1.45; P = .56). Most MIs (688 [59.8%]) had troponin levels greater than or equal to 10 times the upper limit of normal. The benefit was highly significant and consistent regardless of the size of MI with a 34% reduction in MIs with troponin level greater than or equal to 10 times the upper limit of normal (2.6% vs 3.7%; HR, 0.66; 95% CI, 0.56-0.77; P < .001) and a 36% reduction in the risk of STEMI (1.0% vs 1.5%; HR, 0.64; 95% CI, 0.49-0.84; P < .001).

Conclusions and Relevance

Low-density lipoprotein cholesterol lowering with evolocumab was highly effective in reducing the risk of MI. This reduction with evolocumab included benefit across multiple subtypes of MI related to plaque rupture, smaller and larger MIs, and both STEMI and non-STEMI. These data are consistent with the known benefit of low-density lipoprotein cholesterol lowering and underscore the reduction in clinically meaningful events.

Trial Registration

ClinicalTrials.gov Identifier: NCT01764633.

Trends, Management, and Outcomes of Acute Myocardial Infarction Hospitalizations With In-Hospital-Onset Versus Out-of-Hospital Onset: The ARIC Study

Background Acute myocardial infarction (AMI) with in-hospital onset (AMI-IHO) has poor prognosis but is clinically underappreciated. Whether its occurrence has changed over time is uncertain. Methods and Results Since 1987, the ARIC (Atherosclerosis Risk in Communities) study has conducted adjudicated surveillance of AMI hospitalizations in 4 US communities. Our analysis was limited to patients aged 35 to 74 years with symptomatic AMI. Patients with symptoms initiating after hospital arrival were considered AMI-IHO. A total of 26 678 weighted hospitalizations (14 276 unweighted hospitalizations) for symptomatic AMI were identified from 1995 to 2014, with 1137 (4%) classified as in-hospital onset. The population incidence rate of AMI-IHO increased in the 4 ARIC communities from 1995 through 2004 to 2005 through 2014 (12.7-16.9 events per 100 000 people; P for 20-year trend <0.0001), as did the proportion of AMI hospitalizations with in-hospital onset (3.7%-6.1%; P for 20-year trend =0.03). The 10-year proportions were stable for patients aged 35 to 64 years (3.0%-3.4%; P for 20-year trend =0.3) but increased for patients aged ≥65 years (4.6%-7.8%; P for 20-year trend =0.008; P for interaction by age group =0.04). AMI-IHO had a more severe clinical course with lower use of AMI therapies or invasive strategies and higher in-hospital (7% versus 3%), 28-day (19% versus 5%), and 1-year (29% versus 12%) mortality (P<0.0001 for all). Conclusions In this population-based community surveillance, AMI-IHO increased from 2005 to 2014, particularly among older patients. Quality initiatives to improve recognition and management of AMI-IHO should be especially focused on hospitalized patients aged >65.

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.

The Multifaceted Interplay between Atrial Fibrillation and Myocardial Infarction: A Review

This review was conducted to emphasize the complex interplay between atrial fibrillation (AF) and myocardial infraction (MI). In type 1 (T1) MI, AF is frequent and associated with excess mortality. Moreover, AF after hospital discharge for T1MI is not rare, suggesting the need to improve AF screening and to develop therapeutic strategies for AF recurrence. Additionally, AF is a common trigger for type 2 MI (T2MI), and recent data have shown that tachyarrhythmia or bradyarrhythmia could be a causal factor in, respectively, 13-47% or 2-7% of T2MI. In addition, AF is involved in T2MI pathogenesis as a result of severe anemia related to anticoagulants. AF is also an underestimated and frequent cause of coronary artery embolism (CE), as a situation at risk of myocardial infarction with non-obstructive coronary arteries. AF-causing CE is difficult to diagnose and requires specific management. Moreover, patients with both AF and chronic coronary syndromes represent a therapeutic challenge because the treatment of AF include anticoagulation, depending on the embolic risk, and ischemic heart disease management paradoxically includes antiplatelet therapy.

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.

Why We Fail at Heart Failure: Lymphatic Insufficiency Is Disregarded

Is the definition of heart failure too narrow, not allowing research into compensatory mechanisms, comorbidities, right heart function, and lymphatic function?

A review of the absolute mortality of heart failure drugs and devices suggests a modest improvement in outcomes. Absolute mortality from common comorbidities, including renal insufficiency, arrhythmia, conduction deficits, pulmonary hypertension, anemia, obstructive sleep apnea, infection, inflammation, edema, ischemic heart disease, and diabetes II, is significant. The lymphatic function is involved in short, intermediate, and long-term compensation for a failing heart and plays a role in most of the comorbidities.

A better definition of heart failure is: Heart failure is a complex clinical syndrome that results from any structural or functional impairment of right or left ventricular filling or ejection of blood and failure of peripheral compensatory mechanisms. Lymphatic function from the anatomic, fluid management, immune modification standpoints requires study. New therapies from this analysis will improve patients with congestive heart failure.

Acute Myocardial Infarction among Hospitalizations for Heat Stroke in the United States

Background: This study aimed to assess the risk factors and impact of acute myocardial infarction on in-hospital treatments, complications, outcomes, and resource utilization in hospitalized patients for heat stroke in the United States. Methods: Hospitalized patients with a principal diagnosis of heat stroke were identified in the National Inpatient Sample dataset from the years 2003 to 2014. Acute myocardial infarction was identified using the hospital International Classification of Diseases, Ninth Revision (ICD-9), diagnosis of 410.xx. Clinical characteristics, in-hospital treatment, complications, outcomes, and resource utilization between patients with and without acute myocardial infarction were compared. Results: A total of 3372 heat stroke patients were included in the analysis. Of these, acute myocardial infarction occurred in 225 (7%) admissions. Acute myocardial infarction occurred more commonly in obese female patients with a history of chronic kidney disease, but less often in male patients aged <20 years with a history of hypothyroidism. The need for mechanical ventilation, blood transfusion, and renal replacement therapy were higher in patients with acute myocardial infarction. Acute myocardial infarction was associated with rhabdomyolysis, metabolic acidosis, sepsis, gastrointestinal bleeding, ventricular arrhythmia or cardiac arrest, renal failure, respiratory failure, circulatory failure, liver failure, neurological failure, and hematologic failure. Patients with acute myocardial infarction had 5.2-times greater odds of in-hospital mortality than those without myocardial infarction. The length of hospital stay and hospitalization cost were also higher when an acute myocardial infarction occurred while hospitalized. Conclusion: Acute myocardial infarction was associated with worse outcomes and higher economic burden among patients hospitalized for heat stroke. Obesity and chronic kidney disease were associated with increased risk of acute myocardial infarction, while young male patients and hypothyroidism were associated with decreased risk.

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.

Defining and managing patients with non-ST-elevation myocardial infarction: Sorting through type 1 vs other types

Advances in cardiovascular (CV) imaging, redefined electrocardiogram criteria, and high-sensitivity CV biomarker assays have enabled more differentiated etiological classification of myocardial infarction (MI). Type 1 MI has a different underlying pathophysiology than type 2 through type 5 MI; type 1 MI is characterized primarily by intracoronary atherothrombosis and the other types by a variety of mechanisms, which can occur with or without an atherosclerotic component. In type 2 MI, there is evidence of myocardial oxygen supply-demand imbalance unrelated to acute coronary atherothrombosis. Types 1 and 2 MI are spontaneous events, while type 4 and type 5 are procedure-related; type 3 MI is identified only after death. Most type 1 and type 2 MI present as non-ST-elevation MI (NSTEMI), although both types can also present as ST-elevation MI. Because of their different underlying etiologies, type 1 and type 2 NSTEMI have different presentation and prognosis and should be managed differently. In this article, we discuss the epidemiology, prognosis, and management of NSTEMI occurring in the setting of underlying type 1 or type 2 pathophysiology. Most NSTEMI (65%-90%) are type 1 MI. Patients with type 2 MI have multiple comorbidities and causes of in-hospital mortality among these patients are not always CV-related. It is important to distinguish between type 1 and type 2 NSTEMI early in the clinical course to allow for the use of the most appropriate treatments that will provide the greatest benefit for these patients.

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.

Type 1 or Type 2 Myocardial Infarction in Patients with a History of Coronary Artery Disease: Data from the Emergency Department

A type 2 myocardial infarction (T2MI) is the result of an imbalance between oxygen supply and demand, without acute atherothrombosis. T2MI is frequent in emergency departments (ED), but has not been extensively evaluated in patients with previously known coronary artery disease (CAD). Our study assessed the incidence and characteristics of T2MI compared to type 1 (T1MI) in CAD patients admitted to an ED. Among 33,669 consecutive patients admitted to the ED, 2830 patients with T1MI or T2MI were systematically included after prospective adjudication by the attending clinician according to the universal definition. Among them, 619 (22%) patients had a history of CAD. Using multivariable analysis, CAD history was found to be an independent predictive factor of T2MI versus T1MI (odds ratio (95% confidence interval) = 1.38 (1.08-1.77), p = 0.01). Among CAD patients, those with T2MI (n = 254) were older (median age: 82 vs. 72 years, p < 0.001), and had more frequent comorbidities and more frequent three-vessel disease at the coronary angiography (56% vs. 43%, p = 0.015). Percutaneous coronary intervention was by far less frequent after T2MI than after T1MI (28% vs. 67%, p < 0.001), and in-hospital mortality was twice as high in T2MI (15% vs. 7% for T1MI, p < 0.001). Among biomarkers, the C reactive protein (CRP)/troponin Ic ratio predicted T2MI remarkably well (C-statistic (95% confidence interval) = 0.84 (0.81-0.87, p < 0.001). In a large unselected cohort of MI patients in the ED, a quarter of patients had previous CAD, which was associated with a 40% higher risk of T2MI. CRP/troponin ratios could be used to help distinguish T2MI from T1MI.

Incidence, Clinical Characteristics, and Impact of Acute Coronary Syndrome Following Transcatheter Aortic Valve Replacement

OBJECTIVES

The authors sought to assess the incidence, predictors, management, and prognosis of acute coronary syndrome (ACS) following TAVR.

BACKGROUND

About one-half of the patients undergoing transcatheter aortic valve replacement (TAVR) have concurrent coronary artery disease (CAD). However, the occurrence and clinical impact of coronary events following TAVR remain largely unknown.

METHODS

Consecutive patients undergoing TAVR in our institution between May 2007 and November 2017 were included. Patients were followed at 1, 6, and 12 months, and yearly thereafter. ACS was diagnosed and classified according to the Third Universal Definition of Myocardial Infarction.

RESULTS

A total of 779 patients (mean age 79 ± 9 years, 52% male, mean STS: 6.8 ± 5.1%) were included, 68% of which had a history of CAD. At a median follow-up of 25 (interquartile range: 10 to 44) months, 78 patients (10%) presented at least 1 episode of ACS, with one-half of the events occurring within the year following TAVR. Clinical presentation was type 2 non-ST-segment elevation myocardial infarction (35.9%), unstable angina (34.6%), type 1 non-ST-segment elevation myocardial infarction (28.2%), and ST-segment elevation myocardial infarction (1.3%). Male sex (hazard ratio [HR]: 2.19; 95% confidence interval [CI]: 1.36 to 3.54; p = 0.001), prior CAD (HR: 2.78; 95% CI: 1.50 to 5.18; p = 0.001), and nontransfemoral approach (HR: 1.71; 95% CI: 1.04 to 2.75; p = 0.035) were independently associated with ACS. Coronary angiography was performed in 53 (67.9%) patients with ACS, and 30 of them (56.6%) underwent percutaneous coronary intervention. In-hospital death rate at the time of the ACS episode was 3.8%. At a median follow-up of 21 (interquartile range: 8 to 34) months post-ACS, all-cause and cardiovascular death rates were 37.3% and 25.3%, respectively.

CONCLUSIONS

Approximately one-tenth of patients undergoing TAVR were readmitted for an ACS after a median follow-up of 25 months. Male sex, prior CAD, and nontransfemoral approach were independent predictors of ACS. ACS was associated with high midterm mortality.

Mortality following myocardial infarction among HIV-infected persons: the Center for AIDS Research Network Of Integrated Clinical Systems (CNICS)

BACKGROUND

Persons with human immunodeficiency virus (HIV) have higher risks for myocardial infarction (MI) than the general population. This is driven in part by higher type 2 MI (T2MI, due to coronary supply-demand mismatch) rates among persons with HIV (PWH). In the general population, T2MI has higher mortality than type 1 MI (T1MI, spontaneous and generally due to plaque rupture and thrombosis). PWH have a greater burden of comorbidities and may therefore have an even greater excess risk for complication and death in the setting of T2MI. However, mortality patterns after T1MI and T2MI in HIV are unknown.

METHODS

We analyzed mortality after MI among PWH enrolled in the multicenter, US-based Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort (N = 28,186). Incident MIs occurring between January 1, 1996, and December 31, 2014, were centrally adjudicated and classified as T1MI or T2MI. We first compared mortality following T1MI vs. T2MI among PWH. Cox survival analyses and Bayesian model averaging were then used to evaluate pre-MI covariates associated with mortality following T1MI and T2MI.

RESULTS

Among the 596 out of 28,186 PWH who experienced MI (2.1%; 293 T1MI and 303 T2MI), mortality rates were significantly greater after T2MI (22.2/100 person-years; 1-, 3-, and 5-year mortality 39%, 52%, and 62%) than T1MI (8.2/100 person-years; 1-, 3-, and 5-year mortality 15%, 22%, and 30%). Significant mortality predictors after T1MI were higher HIV viral load, renal dysfunction, and older age. Significant predictors of mortality after T2MI were low body-mass index (BMI) and detectable HIV viral load.

CONCLUSIONS

Mortality is high following MI for PWH and substantially greater after T2MI than T1MI. Predictors of death after MI differed by type of MI, reinforcing the different clinical scenarios associated with each MI type and the importance of considering MI types separately.

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.

Mechanisms of ST Elevation Myocardial Infarction in Patients Hospitalized for Noncardiac Conditions

ST elevation myocardial infarction (STEMI) occurring in patients hospitalized for a noncardiac condition is associated with a high mortality rate and thus we sought to determine the mechanisms underlying STEMI in this patient population. This is a single center retrospective study of 70 patients who had STEMI while hospitalized on a noncardiac service and underwent coronary angiography. Thrombotic in-hospital STEMI was defined by angiographic or intravascular imaging evidence of intracoronary thrombus, plaque rupture, or stent thrombosis. Thirty-six (51%) inpatient STEMIs developed in the operating room or various postoperative stages and 6 (9%) after endoscopy or a percutaneous procedure. Thrombotic etiologies were found in 39 (56%) patients. Nonthrombotic etiologies included vasospasm, supply-demand mismatch, and takotsubo cardiomyopathy. Patients in the thrombotic group were more likely to have antiplatelet medications discontinued on admission, had higher peak troponin levels and were more likely to undergo percutaneous coronary intervention than patients in the nonthrombotic group. Exposure to vasopressors, time from ECG to angiography, post-STEMI ejection fraction, length of stay, and in-hospital mortality were similar in both groups. There was no difference in the use of percutaneous coronary intervention in patients but longer ECG to coronary angiography times and fivefold higher in-hospital mortality in thrombotic inpatient STEMI compared with 643 patients who presented with an out-of-hospital STEMI during the same time period. In conclusion, thrombotic and nonthrombotic mechanisms cause STEMI in hospitalized patients and are associated with a high mortality.

Wake Forest University long-term follow-up of type 2 myocardial infarction: The Wake-Up T2MI Registry

Background

The Wake‐Up T2MI Registry is a retrospective cohort study investigating patients with type 2 myocardial infarction (T2MI), acute myocardial injury, and chronic myocardial injury. We aim to explore risk stratification strategies and investigate clinical characteristics, management, and short‐ and long‐term outcomes in this high‐risk, understudied population.

Methods

From 1 January 2009 to 31 December 2010, 2846 patients were identified with T2MI or myocardial injury defined as elevated cardiac troponin I with at least one value above the 99th percentile upper reference limit and coefficient of variation of 10% (>40 ng/L) and meeting our inclusion criteria. Data of at least two serial troponin values will be collected from the electronic health records to differentiate between acute and chronic myocardial injury. The Fourth Universal Definition will be used to classify patients as having (a) T2MI, (b) acute myocardial injury, or (c) chronic myocardial injury during the index hospitalization. Long‐term mortality data will be collected through data linkage with the National Death Index and North Carolina State Vital Statistics.

Results

We have collected data for a total of 2205 patients as of November 2018. The mean age of the population was 65.6 ± 16.9 years, 48% were men, and 64% were white. Common comorbidities included hypertension (71%), hyperlipidemia (35%), and diabetes mellitus (30%). At presentation, 40% were on aspirin, 38% on β‐blockers, and 30% on statins.

Conclusion

Improved characterization and profiling of this cohort may further efforts to identify evidence‐based strategies to improve cardiovascular outcomes among patients with T2MI and myocardial injury.

Implications of Misclassification of Type 2 Myocardial Infarction on Clinical Outcomes

BACKGROUND

Patients with type 2 myocardial infarction (MI) are often classified under the diagnosis of non-ST-segment-elevation MI (NSTEMI) despite the significant differences in clinical characteristics, management, and outcomes between type 2 MI and type 1 NSTEMI. This may have significant implications that can lead to inaccurate assessment of quality measures by MI quality review programs.

METHODS

A single-center retrospective study of 1224 patients discharged with the diagnosis of type 1 NSTEMI between January 2015 and September 2017. Based on the third universal definition of MI, we stratified patients into type 2 MI or type 1 NSTEMI. Patient's characteristics, comorbidities, medications prescribed during hospitalization and at discharge, readmissions within 30 days after discharge, and diagnostic and therapeutic interventions data was collected. The primary goal of this study was to identify how often type 2 MI patients were misclassified as type 1 NSTEMI, we also assessed the differences in treatment and outcomes between type 2 MI and type 1 NSTEMI.

RESULTS

1224 patients assigned the ICD-9 and ICD-10 codes of type 1 NSTEMI at discharge were evaluated for study inclusion. After application of the inclusion criteria, 945 patients were included in the final analysis. Of these 945 patients, 281 (29.7%) patients were classified as type 2 MI and 664 (70.3%) patients were classified as type 1 NSTEMI. Patients with type 2 MI were older, more likely to have systolic heart failure, had lower peak troponin levels, were less likely to receive aspirin, P2Y12 inhibitors and statin at discharge, and had longer length of stay. Compared with type 1 NSTEMI patients, those with type 2 MI had higher all cause 30-day mortality (13.5% versus 2.9%, P < 0.0001) (RR: 4.65; 95% CI, 2.85-9.65). After adjusting for patient demographics, comorbidities, and medications, patients with type 2 MI were still more likely to die within 30 days after discharge (RR: 2.89; 95% CI, 1.58-7.46). In addition, patients with type 2 MI were more likely to be readmitted within 30 days after discharge than patients with type 1 NSTEMI (17.7% versus 13.9%, P < 0.01) (RR: 1.27; 95% CI, 1.08-2.5).

CONCLUSIONS

Close to one third of patients given the diagnosis of type 1 NSTEMI at discharge at our institution were type 2 MI patients. Patients with type 2 MI are managed differently from type 1 NSTEMI patients and have higher 30-day mortality and readmission rate. Misclassification of type 2 MI as type 1 NSTEMI can have a significant impact on hospitals MI clinical performance and quality measures.

Patterns of Acute Myocardial Infarction in Taiwan from 2009 to 2015

Most studies about the trends of acute myocardial infarction (AMI) were based on the data from Western countries. In recent years, little information is available from Asia since 2010. This study assessed the nationwide trends of AMI in Taiwan from 2009 to 2015. Using data from the Taiwan National Health Insurance Research Database, we identified 100,570 adult patients hospitalized for AMI from 2009 to 2015 and examined the temporal trends in the incidence of AMI. Overall, the age- and gender-adjusted incidence of AMI (per 100,000 persons) remained constant from 49.8 in 2009 to 50.7 in 2015. The incidence of AMI increased 30.3% and 29.4% in the young male and female populations (<55 years), whereas in other age groups, the incidence decreased or remained unchanged. The ratio of non-ST-segment elevation MI (NSTEMI) to STEMI incidence increased from 1.93 in 2009 to 2.47 in 2015. In young men (<55 years), a 49.8% increase in NSTEMI was observed. The prevalence of dyslipidemia increased significantly and it was the most common risk factor of AMI in young patients. Despite being increasingly used, percutaneous coronary intervention and secondary preventive medications, including dual antiplatelet therapy, angiotensin converting enzyme inhibitor/angiotensin receptor blocker, β blocker and statin, were less prescribed for NSTEMI compared with STEMI. The in-hospital mortality of STEMI continued to decrease from 2013 to 2015 (8.8% to 7.6%), but not in NSTEMI (13.3% to 13.5%). In conclusion, our study revealed a marked increase of NSTEMI in young Taiwanese male population in recent years. Despite the increased utilization of percutaneous coronary intervention and guideline-recommended medications, the overall in-hospital mortality of NSTEMI remained stagnating in Taiwan.