Risk factors for type 1 and type 2 myocardial infarction

APOB and CCL17 as mediators in the protective effect of SGLT2 inhibition against myocardial infarction: Insights from proteome-wide mendelian randomization

AIMS

Sodium-glucose cotransporter 2 (SGLT2) inhibitors offer a novel therapeutic avenue for myocardial infarction (MI). However, the exact nature of this relationship and the underlying mechanisms are not fully understood.

METHODS

Utilizing a two-sample Mendelian Randomization (MR) analysis, we elucidated the causal effects stemming from the inhibition of SGLT2 on MI. Then, The pool of 4907 circulating proteins within the plasma proteome were utilized to explore the mediators of SGLT2 inhibitors on MI. Protein-protein network and enrichment analysis were conducted to clarify the potential mechanism. Finally, employing MR analysis and meta-analysis techniques, we systematically assessed the causal associations between SGLT2 inhibition and coronary heart diseases (CHD).

RESULTS

SGLT2 inhibition (per 1 SD decrement in HbA1c) was associated with reduced risk of MI (odds ratio [OR] = 0.462, [95% CI 0.222, 0.958], P = 0.038). Among 4907 circulating proteins, we identified APOB and CCL17 which were related to both SGLT2 inhibition and MI. Mediation analysis showed evidence of the indirect effect of SGLT2 inhibition on MI through APOB (β = -0.557, 95%CI [-1.098, -0.155]) with a mediated proportion of 72%, and CCL17 (β = -0.176, 95%CI [-0.332, -0.056]) with a mediated proportion of 17%. The meta-analysis result showed that SGLT2 inhibition was associated with a lower risk of CHD.

CONCLUSION

Based on proteome-wide mendelian randomization, APOB and CCL17 were seen as mediators in the protective effect of SGLT2 inhibition against myocardial infarction.

Current US prevalence of myocardial injury patterns and clinical outcomes among hospitalised patients with familial hypercholesterolaemia: insight from the National Inpatient Sample-a retrospective cohort study

BACKGROUND

Familial hypercholesterolaemia (FH) increases propensity for premature atherosclerotic disease. Knowledge of inpatient outcomes among patients with FH admitted with acute myocardial injury (AMI) is limited.

OBJECTIVES

Our study aimed to identify myocardial injury types, including type 1 myocardial infarction (MI), type 2 MI and takotsubo cardiomyopathy, assess lesion severity and study adverse short-term inpatient outcomes among patients with FH admitted with AMI.

SETTING

Our study retrospectively queried the US National Inpatient Sample from 2018 to 2020.

POPULATION

Adults admitted with AMI and dichotomised based on the presence of FH.

STUDY OUTCOMES

We evaluated myocardial injury types and complexity of coronary revascularisation. Primary outcome of all-cause mortality and other clinical secondary outcomes were studied.

RESULTS

There were 3 711 765 admissions with AMI including 2360 (0.06%) with FH. FH was associated with higher odds of ST-elevation MI (STEMI) (adjusted OR (aOR): 1.62, p<0.001) and non-ST-elevation MI (NSTEMI) (aOR: 1.29, p<0.001) but lower type 2 MI (aOR: 0.39, p<0.001) and takotsubo cardiomyopathy (aOR: 0.36, p=0.004). FH was associated with higher multistent percutaneous coronary interventions (aOR: 2.36, p<0.001), multivessel coronary artery bypass (aOR: 2.65, p<0.001), higher odds of intracardiac thrombus (aOR: 3.28, p=0.038) and mechanical circulatory support (aOR: 1.79, p<0.001). There was 50% reduction in odds of all-cause mortality (aOR: 0.50, p=0.006) and lower odds of mechanical ventilation (aOR: 0.37, p<0.001). There was no difference in rate of ventricular tachycardia, cardioversion, new implantable cardioverter defibrillator implantation, cardiogenic shock and cardiac arrest.

CONCLUSION

Among patients hospitalised with AMI, FH was associated with higher STEMI and NSTEMI, lower type 2 MI and takotsubo cardiomyopathy, higher number of multiple stents and coronary bypasses, and mechanical circulatory support device but was associated with lower all-cause mortality and rate of mechanical ventilation.

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.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

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

Background

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

Methods

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

Results

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

Conclusion

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

Lipid regulation of protocatechualdehyde and hydroxysafflor yellow A via AMPK/SREBP2/PCSK9/LDLR signaling pathway in hyperlipidemic zebrafish

The consumption of a high-cholesterol diet is known to cause hyperlipidemia, which is one of the main risk factors for cardiovascular disease. Protocatechualdehyde (PCA) and hydroxysafflor yellow A (HSYA) are the active components of Salvia miltiorrhiza and safflower, respectively. However, their exact mechanism is still unclear. The aim of this study is to investigate its effects on lipid deposition and liver damage in hyperlipidemic zebrafish and its mechanism of anti-hyperlipidemia. The results showed that the use of PCA and HSYA alone and in combination can improve lipid deposition, slow behavior, abnormal blood flow and liver tissue damage, and the combined use is more effective. Further RT-qPCR results showed that PCA + HSYA can regulate the mRNA levels of PPAR-γ, SREBP2, SREBP1, HMGCR, PCSK9, mTOR, C/EBPα, LDLR, AMPK, HNF-1α and FoxO3a. The PCA + HSYA significantly improves lipid deposition and abnormal liver function in hyperlipidemic zebrafish larvae, which may be related to the AMPK/SREBP2/PCSK9/LDLR signaling pathway.

Classification Algorithm to Distinguish Between Type 1 and Type 2 Myocardial Infarction in Administrative Claims Data

BACKGROUND

Type 2 myocardial infarction (T2MI) and type 1 myocardial infarction (T1MI) differ with respect to demographics, comorbidities, treatments, and clinical outcomes. Reliable quality and outcomes assessment depends on the ability to distinguish between T1MI and T2MI in administrative claims data. As such, we aimed to develop a classification algorithm to distinguish between T1MI and T2MI that could be applied to claims data.

METHODS

Using data for beneficiaries in a Medicare accountable care organization contract in a large health care system in New England, we examined the distribution of MI diagnosis codes between 2018 to 2021 and the patterns of care and coding for beneficiaries with a hospital discharge diagnosis International Classification of Diseases, Tenth Revision code for T2MI, compared with those for T1MI. We then assessed the probability that each hospitalization was for a T2MI versus T1MI and examined care occurring in 2017 before the introduction of the T2MI code.

RESULTS

After application of inclusion and exclusion criteria, 7759 hospitalizations for myocardial infarction remained (46.5% T1MI and 53.5% T2MI; mean age, 79±10.3 years; 47% female). In the classification algorithm, female gender (odds ratio, 1.26 [95% CI, 1.11-1.44]), Black race relative to White race (odds ratio, 2.48 [95% CI, 1.76-3.48]), and diagnoses of COVID-19 (odds ratio, 1.74 [95% CI, 1.11-2.71]) or hypertensive emergency (odds ratio, 1.46 [95% CI, 1.00-2.14]) were associated with higher odds of the hospitalization being for T2MI versus T1MI. When applied to the testing sample, the C-statistic of the full model was 0.83. Comparison of classified T2MI and observed T2MI suggest the possibility of substantial misclassification both before and after the T2MI code.

CONCLUSIONS

A simple classification algorithm appears to be able to differentiate between hospitalizations for T1MI and T2MI before and after the T2MI code was introduced. This could facilitate more accurate longitudinal assessments of acute myocardial infarction quality and outcomes.

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

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

Six-month cardiovascular prognostic impact of type 1 And type 2 myocardial infarction in patients hospitalized for gastrointestinal bleeding

BACKGROUND

Patients with gastrointestinal bleeding (GIB) are at an increased risk of cardiovascular events and myocardial infarction (MI). Myocardial supply-demand mismatch results in type 2 MI(T2MI) and atherosclerotic plaque rupture leads to type 1 MI(T1MI). Data comparing the prognostic impact of these MI types in GIB are sparse.

METHODS

Patients hospitalized for GIB were identified in the 2019 US Nationwide Readmissions Sample. In this population, we studied the differences in management of T1MI and T2MI, and the association of these MI types with in-hospital mortality and risk for 6-month MI and MI-related mortality.

RESULTS

Of 444,475 patients admitted for a GIB, 12,860 (2.9%) had an MI (1.7% T2MI, 1.2% T1MI). Patients with T1MI were more likely to receive coronary angiography and revascularization than patients with T2MI. In-hospital mortality occurred in 2.0% patients, at a significantly higher rate in patients with an MI (7.9% vs 1.8%; P < 0.001), and higher with T1MI (11.9%) than T2MI (5.3%; P < 0.001). Among the survivors, 2.2% patient had an MI within 6 months, at a significantly higher rate in patients with index MI (13.1% vs 2.0%, adjusted OR 4.3 95% CI 3.83-4.90; P < 0.001). Mortality during the subsequent MI occurred in 0.3% of all patients (12% with an MI), at a 6-fold higher rate in patients with index MI (1.7% vs 0.3%; adjusted OR 3.69 95% CI 2.75-4.95; P < 0.001). The elevated risks were associated with both MI types. The risks for 6-month MI and related mortality were similar between T1MI and T2MI (6-month AMI: adjusted OR for T2MI = 1.03, 95% 0.83-1.29; fatal MI: adjusted OR for T2MI = 1.5, 95% CI 0.85-2.7).

CONCLUSION

The occurrence of an MI is associated with a substantially elevated risk for subsequent AMI and related mortality in patients hospitalized for a GIB. This future prognostic impact was similar between T1MI and T2MI.

Comparison between In-Hospital and Out-of-Hospital Acute Myocardial Infarctions: Results from the Regional Myocardial Infarction Registry of Saxony-Anhalt (RHESA) Study

AIMS

Risk factors and outcomes of in-hospital ST elevation myocardial infraction (STEMI) are well explored. Recent findings show that non-ST elevation myocardial infarction (NSTEMI) accounts for the majority of in-hospital infarctions (IHMIs). Our aim was to identify differences between IHMI and out-of-hospital myocardial infraction (OHMI) in terms of risk factors, treatment and outcomes, including both STEMI and NSTEMI.

METHODS

We analyzed the Regional Myocardial Infarction Registry of Saxony-Anhalt dataset. Patient characteristics, treatments and outcomes were compared between IHMI and OHMI. The association between clinical outcomes and myocardial infarction type was assessed using generalized additive models.

RESULTS

Overall, 11.4% of the included myocardial infractions were IHMI, and the majority were NSTEMI. Patients with IHMI were older and had more comorbidities than those with OHMI. Compared to OHMI, in-hospital myocardial infarction was associated with higher odds of 30-day mortality (OR = 1.85, 95% CI 1.32-2.59) and complications (OR = 2.36, 95 % CI 1.84-3.01).

CONCLUSIONS

We provided insights on the full spectrum of IHMI, in both of its classifications. The proportion of IHMI was one ninth of all AMI cases treated in the hospital. Previously reported differences in the baseline characteristics and treatments, as well as worse clinical outcomes, in in-hospital STEMI compared to out-of-hospital STEMI persist even when including NSTEMI cases.

High-Sensitivity Cardiac Troponin for Risk Assessment in Patients With Chronic Coronary Artery Disease

BACKGROUND

Cardiac troponin is used for risk stratification of patients with acute coronary syndromes; however, the role of testing in other settings remains unclear.

OBJECTIVES

The aim of this study was to evaluate whether cardiac troponin testing could enhance risk stratification in patients with chronic coronary artery disease independent of disease severity and conventional risk measures.

METHODS

In a prospective cohort of consecutive patients with symptoms suggestive of stable angina attending for outpatient coronary angiography, high-sensitivity cardiac troponin I was measured before angiography, and clinicians were blinded to the results. The primary outcome was myocardial infarction or cardiovascular death during follow-up.

RESULTS

In 4,240 patients (age 66 years [IQR: 59-73 years], 33% female), coronary artery disease was identified in 3,888 (92%) who had 255 (6%) primary outcome events during a median follow-up of 2.4 years (IQR: 1.3-3.6 years). In patients with coronary artery disease, troponin concentrations were 2-fold higher in those with an event compared with those without (6.7 ng/L [IQR: 3.2-14.2 ng/L] vs 3.3 ng/L [IQR: 1.7-6.6 ng/L]; P < 0.001). Troponin concentrations were associated with the primary outcome after adjusting for cardiovascular risk factors and coronary artery disease severity (adjusted HR: 2.3; 95% CI: 1.7-3.0, log10 troponin; P < 0.001). A troponin concentration >10 ng/L identified patients with a 50% increase in the risk of myocardial infarction or cardiovascular death.

CONCLUSIONS

In patients with chronic coronary artery disease, cardiac troponin predicts risk of myocardial infarction or cardiovascular death independent of cardiovascular risk factors and disease severity. Further studies are required to evaluate whether routine testing could inform the selection of high-risk patients for treatment intensification. (Myocardial Injury in Patients Referred for Coronary Angiography [MICA]; ISRCTN15620297).

Clinical risk factors and outcomes of young patients with acute ST segment elevation myocardial infarction: a retrospective study

BACKGROUND

This study aimed to analysis the clinical characteristics and prognosis of acute STEMI in patients aged ≤ 45 years.

METHODS

Seven hundred and one patients with STEMI from Liaocheng People's Hospital from January 2018 to March 2021 were included in this study. Clinical characteristics, management, and outcomes (average follow-up: 11.5 months) were compared between patients aged ≤ 45 years and those aged > 45 years.

RESULTS

Of the patients with STEMI who underwent primary percutaneous coronary intervention, 108 (15.4%) were aged ≤ 45 years. Compared to the older group, the younger patient group included more males, current smokers, and those with alcohol use disorder (AUD) or a family history of ischaemic heart disease (IHD). The culprit vessel in young patients was the left anterior descending (LAD) artery (60% vs. 45.9%, P = 0.031), which may have been due to smoking (odds ratio, 3.5; 95% confidence interval: 1.12-10.98, P = 0.042). Additionally, young patients presented with higher low-density lipoprotein and lower high-density lipoprotein levels than older patients; uric acid levels were also significantly higher in younger patients than that in the older group. Diabetes showed a trend toward major adverse cardiovascular events (MACE) in both groups; age and sex were both independent predictors of MACE in older patients.

CONCLUSION

More patients who were smokers, had AUD, or a family history of IHD were present in the young patient group. Hyperuricaemia (but not dyslipidaemia) was a prevalent risk factor in patients aged ≤ 45 years. Diabetes should be controlled to reduce cardiovascular events in young patients.

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

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

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Circular RNAs: Biogenesis, Biological Functions, and Roles in Myocardial Infarction

Non-coding RNAs have been excavated as important cardiac function modulators and linked to heart diseases. Significant advances have been obtained in illuminating the effects of microRNAs and long non-coding RNAs. Nevertheless, the characteristics of circular RNAs are rarely mined. Circular RNAs (circRNAs) are widely believed to participate in cardiac pathologic processes, especially in myocardial infarction. In this review, we round up the biogenesis of circRNAs, briefly describe their biological functions, and summarize the latest literature on multifarious circRNAs related to new therapies and biomarkers for myocardial infarction.

Treatment strategies of acute myocardial infarction: updates on revascularization, pharmacological therapy, and beyond

Owing to recent advances in early reperfusion strategies, pharmacological therapy, standardized care, and the identification of vulnerable patient subsets, the prognosis of acute myocardial infarction has improved. However, there is still considerable room for improvement. This review article summarizes the latest evidence concerning clinical diagnosis and treatment of acute myocardial infarction.

Improving Risk Stratification for Patients With Type 2 Myocardial Infarction

BACKGROUND

Despite poor cardiovascular outcomes, there are no dedicated, validated risk stratification tools to guide investigation or treatment in type 2 myocardial infarction.

OBJECTIVES

The goal of this study was to derive and validate a risk stratification tool for the prediction of death or future myocardial infarction in patients with type 2 myocardial infarction.

METHODS

The T2-risk score was developed in a prospective multicenter cohort of consecutive patients with type 2 myocardial infarction. Cox proportional hazards models were constructed for the primary outcome of myocardial infarction or death at 1 year using variables selected a priori based on clinical importance. Discrimination was assessed by area under the receiving-operating characteristic curve (AUC). Calibration was investigated graphically. The tool was validated in a single-center cohort of consecutive patients and in a multicenter cohort study from sites across Europe.

RESULTS

There were 1,121, 250, and 253 patients in the derivation, single-center, and multicenter validation cohorts, with the primary outcome occurring in 27% (297 of 1,121), 26% (66 of 250), and 14% (35 of 253) of patients, respectively. The T2-risk score incorporating age, ischemic heart disease, heart failure, diabetes mellitus, myocardial ischemia on electrocardiogram, heart rate, anemia, estimated glomerular filtration rate, and maximal cardiac troponin concentration had good discrimination (AUC: 0.76; 95% CI: 0.73-0.79) for the primary outcome and was well calibrated. Discrimination was similar in the consecutive patient (AUC: 0.83; 95% CI: 0.77-0.88) and multicenter (AUC: 0.74; 95% CI: 0.64-0.83) cohorts. T2-risk provided improved discrimination over the Global Registry of Acute Coronary Events 2.0 risk score in all cohorts.

CONCLUSIONS

The T2-risk score performed well in different health care settings and could help clinicians to prognosticate, as well as target investigation and preventative therapies more effectively. (High-Sensitivity Troponin in the Evaluation of Patients With Suspected Acute Coronary Syndrome [High-STEACS]; NCT01852123).

Management and outcomes of patients admitted with type 2 myocardial infarction with and without standard modifiable risk factors

BACKGROUND

Whilst it is known patients without standard modifiable cardiovascular risk factors (SMuRF; hypertension, diabetes, hypercholesterolaemia, smoking) have worse outcomes in Type 1 acute myocardial infarction (AMI), the relationship between type 2 AMI (T2AMI) and outcomes in patients with and without SMuRF is unknown. This study aimed to determine the prevalence, characteristics and clinical outcomes of patients hospitalised with T2AMI based on the presence of SMuRF.

METHODS

Using the National Inpatient Sample, all hospitalizations with a primary discharge diagnosis of T2AMI were stratified according to SMuRF status (SMuRF and SMURF-less). Primary outcome was all-cause mortality while secondary outcomes were major adverse cardiovascular and cerebrovascular events (MACCE), major bleeding and ischemic stroke. Multivariable logistic regression was used to determine adjusted odds ratios (aOR) with 95% confidence intervals (95% CI).

RESULTS

Among 17,595 included hospitalizations, 1345 (7.6%) were SMuRF-less and 16,250 (92.4%) were SMuRF. On adjusted analysis, SMuRF-less patients had increased odds of all-cause mortality (aOR 2.43, 95% CI 1.83 to 3.23), MACCE (aOR 2.32, 95% CI 1.79 to 2.90) and ischaemic stroke (aOR 2.57, 95% CI 1.56 to 4.24) compared to their SMuRF counterparts. Secondary diagnoses among both cohorts were similar, with respiratory disorders most prevalent followed by cardiovascular and renal disorders.

CONCLUSIONS

T2AMI in the absence of SMuRF was associated with worse in-hospital outcomes compared to SMuRF-less patients. There was no SMuRF-based difference in the secondary diagnoses with the most common being respiratory, cardiovascular, and renal disorders. Further studies are warranted to improve overall care and outcomes of SMuRF-less patients.

Cardiovascular safety of COVID-19 vaccines in real-world studies: a systematic review and meta-analysis

OBJECTIVES

To evaluate the cardiovascular safety of COVID-19 vaccines in the real world.

METHODS

Studies reported on any COVID-19 vaccine-related cardiovascular events in the population aged ≥12 years between 1 January 2020 and 15 June 2022 were included.

RESULTS

A total of 42 studies were included in this meta-analysis. Myocarditis risk was mainly seen after the second (risk ratio [RR], 2.09; 95% confidence interval [CI]: 1.59-2.58) and third (RR, 2.02; 95% CI: 1.04-2.91) dose. A total of 5 vaccines were analyzed, among which mRNA-1273 (RR, 3.13; 95% CI: 2.11-4.14) and BNT162b2 (RR, 1.57; 95% CI: 1.30-1.85) vaccines were associated with myocarditis risk. No significant increase in risk of myocardial infarction (RR, 0.96) or arrhythmia (RR, 0.98) events was observed following vaccination. The risk of cardiovascular events (myocarditis, RR, 8.53; myocardial infarction, RR, 2.59; arrhythmia, RR, 4.47) after SARS-CoV-2 infection was much higher than after vaccination.

CONCLUSIONS

The risk of myocarditis was observed after COVID-19 vaccination, but it was much lower than that following the SARS-CoV-2 infection. No significant increased risk of myocardial infarction or arrhythmia was found after COVID-19 vaccination.

Mitigating Cardiotoxicity of Dendrimers: Angiotensin-(1-7) via Its Mas Receptor Ameliorates PAMAM-Induced Cardiac Dysfunction in the Isolated Mammalian Heart

AIM

The influence of the physiochemical properties of dendrimer nanoparticles on cardiac contractility and hemodynamics are not known. Herein, we investigated (a) the effect of polyamidoamine (PAMAM) dendrimer generation (G7, G6, G5, G4 and G3) and surface chemistry (-NH₂, -COOH and -OH) on cardiac function in mammalian hearts following ischemia-reperfusion (I/R) injury, and (b) determined if any PAMAM-induced cardiotoxicity could be mitigated by Angiotensin-(1-7) (Ang-(1-7), a cardioprotective agent.

METHODS

Hearts isolated from male Wistar rats underwent regional I/R and/or treatment with different PAMAM dendrimers, Ang-(1-7) or its MAS receptors antagonists. Thirty minutes of regional ischemia through ligation of the left anterior descending coronary artery was followed by 30 min of reperfusion. All treatments were initiated 5 min prior to reperfusion and maintained during the first 10 min of reperfusion. Cardiac function parameters for left ventricular contractility, hemodynamics and vascular dynamics data were acquired digitally, whereas cardiac enzymes and infarct size were used as measures of cardiac injury.

RESULTS

Treatment of isolated hearts with increasing doses of G7 PAMAM dendrimer progressively exacerbated recovery of cardiac contractility and hemodynamic parameters post-I/R injury. Impairment of cardiac function was progressively less on decreasing dendrimer generation with G3 exhibiting little or no cardiotoxicity. Cationic PAMAMs (-NH₂) were more toxic than anionic (-COOH), with neutral PAMAMs (-OH) exhibiting the least cardiotoxicity. Cationic G7 PAMAM-induced cardiac dysfunction was significantly reversed by Ang-(1-7) administration. These cardioprotective effects of Ang-(1-7) were significantly revoked by administration of the MAS receptor antagonists, A779 and D-Pro⁷-Ang-(1-7).

CONCLUSIONS

PAMAM dendrimers can impair the recovery of hearts from I/R injury in a dose-, dendrimer-generation-(size) and surface-charge dependent manner. Importantly, PAMAM-induced cardiotoxicity could be mitigated by Ang-(1-7) acting through its MAS receptor. Thus, this study highlights the activation of Ang-(1-7)/Mas receptor axis as a novel strategy to overcome dendrimer-induced cardiotoxicity.

Computed tomography coronary angiography in non-ST-segment elevation myocardial infarction

Electrocardiography and high-sensitivity cardiac troponin testing are routinely applied as the initial step for clinical evaluation of patients with suspected non-ST-segment elevation myocardial infarction. Once diagnosed, patients with non-ST-segment elevation myocardial infarction are commenced on antithrombotic and secondary preventative therapies before undergoing invasive coronary angiography to determine the strategy of coronary revascularisation. However, this clinical pathway is imperfect and can lead to challenges in the diagnosis, management, and clinical outcomes of these patients. Computed tomography coronary angiography (CTCA) has increasingly been utilised in the setting of patients with suspected non-ST-segment elevation myocardial infarction, where it has an important role in avoiding unnecessary invasive coronary angiography and reducing downstream non-invasive functional testing for myocardial ischaemia. CTCA is an excellent gatekeeper for the cardiac catheterisation laboratory. In addition, CTCA provides complementary information for patients with myocardial infarction in the absence of obstructive coronary artery disease and highlights alternative or incidental diagnoses for those with cardiac troponin elevation. However, the routine application of CTCA has yet to demonstrate an impact on subsequent major adverse cardiovascular events. There are several ongoing studies evaluating CTCA and its associated technologies that will define and potentially expand its application in patients with suspected or diagnosed non-ST-segment elevation myocardial infarction. We here review the current evidence relating to the clinical application of CTCA in patients with non-ST-segment elevation myocardial infarction and highlight the areas where CTCA is likely to have an increasing important role and impact for our patients.

Distinguishing Type 1 from Type 2 Myocardial Infarction by Using CT Coronary Angiography

Purpose

To determine whether quantitative plaque characterization by using CT coronary angiography (CTCA) can discriminate between type 1 and type 2 myocardial infarction.

Materials and Methods

This was a secondary analysis of two prospective studies (ClinicalTrials.gov registration nos. NCT03338504 [2014-2019] and NCT02284191 [2018-2020]) that performed blinded quantitative plaque analysis on findings from CTCA in participants with type 1 myocardial infarction, type 2 myocardial infarction, and chest pain without myocardial infarction. Logistic regression analyses were performed to identify predictors of type 1 myocardial infarction.

Results

Overall, 155 participants (mean age, 64 years ± 12 [SD]; 114 men) and 36 participants (mean age, 67 years ± 12; 19 men) had type 1 and type 2 myocardial infarction, respectively, and 136 participants (62 years ± 12; 78 men) had chest pain without myocardial infarction. Participants with type 1 myocardial infarction had greater total (median, 44% [IQR: 35%-50%] vs 35% [IQR: 29%-46%]), noncalcified (39% [IQR: 31%-46%] vs 34% [IQR: 29%-40%]), and low-attenuation (4.15% [IQR: 1.88%-5.79%] vs 1.64% [IQR: 0.89%-2.28%]) plaque burdens (P < .05 for all) than those with type 2. Participants with type 2 myocardial infarction had similar low-attenuation plaque burden to those with chest pain without myocardial infarction (P = .4). Low-attenuation plaque was an independent predictor of type 1 myocardial infarction (adjusted odds ratio, 3.44 [95% CI: 1.84, 6.96]; P < .001), with better discrimination than noncalcified plaque burden and maximal area of coronary stenosis (C statistic, 0.75 [95% CI: 0.67, 0.83] vs 0.62 [95% CI: 0.53, 0.71] and 0.61 [95% CI: 0.51, 0.70] respectively; P ≤ .001 for both).

Conclusion

Higher low-attenuation coronary plaque burden in patients with type 1 myocardial infarction may help distinguish these patients from those with type 2 myocardial infarction.Keywords: Ischemia/Infarction, CT Angiography, Quantitative CTClinical trial registration nos. NCT03338504 and NCT02284191 Supplemental material is available for this article. © RSNA, 2022.

Platelet Redox Imbalance in Hypercholesterolemia: A Big Problem for a Small Cell

The imbalance between reactive oxygen species (ROS) synthesis and their scavenging by anti-oxidant defences is the common soil of many disorders, including hypercholesterolemia. Platelets, the smallest blood cells, are deeply involved in the pathophysiology of occlusive arterial thrombi associated with myocardial infarction and stroke. A great deal of evidence shows that both increased intraplatelet ROS synthesis and impaired ROS neutralization are implicated in the thrombotic process. Hypercholesterolemia is recognized as cause of atherosclerosis, cerebro- and cardiovascular disease, and, closely related to this, is the widespread acceptance that it strongly contributes to platelet hyperreactivity via direct oxidized LDL (oxLDL)-platelet membrane interaction via scavenger receptors such as CD36 and signaling pathways including Src family kinases (SFK), mitogen-activated protein kinases (MAPK), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In turn, activated platelets contribute to oxLDL generation, which ends up propagating platelet activation and thrombus formation through a mechanism mediated by oxidative stress. When evaluating the effect of lipid-lowering therapies on thrombogenesis, a large body of evidence shows that the effects of statins and proprotein convertase subtilisin/kexin type 9 inhibitors are not limited to the reduction of LDL-C but also to the down-regulation of platelet reactivity mainly by mechanisms sensitive to intracellular redox balance. In this review, we will focus on the role of oxidative stress-related mechanisms as a cause of platelet hyperreactivity and the pathophysiological link of the pleiotropism of lipid-lowering agents to the beneficial effects on platelet function.

Vascular Repair by Grafting Based on Magnetic Nanoparticles

Magnetic nanoparticles (MNPs) have attracted much attention in the past few decades because of their unique magnetic responsiveness. Especially in the diagnosis and treatment of diseases, they are mostly involved in non-invasive ways and have achieved good results. The magnetic responsiveness of MNPs is strictly controlled by the size, crystallinity, uniformity, and surface properties of the synthesized particles. In this review, we summarized the classification of MNPs and their application in vascular repair. MNPs mainly use their unique magnetic properties to participate in vascular repair, including magnetic stimulation, magnetic drive, magnetic resonance imaging, magnetic hyperthermia, magnetic assembly scaffolds, and magnetic targeted drug delivery, which can significantly affect scaffold performance, cell behavior, factor secretion, drug release, etc. Although there are still challenges in the large-scale clinical application of MNPs, its good non-invasive way to participate in vascular repair and the establishment of a continuous detection process is still the future development direction.

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.

New horizons in Type 2 myocardial infarction: pathogenesis, assessment and management of an emerging geriatric disease

Type 2 myocardial infarction (MI) is characterised by a functional imbalance between myocardial oxygen supply and demand in the absence of a thrombotic process, leading to myocardial necrosis. This type of MI was relatively unknown among clinicians until the third universal definition of MI was published in 2017, differentiating Type 2 from Type 1 MI, which follows an acute atherothrombotic event. The pathogenesis, diagnostic and therapeutic aspects of Type 2 MI are described in the present review. Type 2 MI is a condition that is strongly linked to age because of vascular ageing concerning both epicardic vessels and microcirculation, age-related atherosclerosis and stress maladaptation. This condition predominantly affects multimorbid individuals with a history of cardiovascular disease. However, the conditions that lead to the functional imbalance between oxygen supply and demand are frequently extra-cardiac (e.g. pneumonia or anaemia). The great heterogeneity of the underlying etiological factors requires a comprehensive approach that is tailored to each case. In the absence of evidence for the benefit of invasive reperfusion strategies, the treatment of Type 2 MI remains to date essentially based on the restoration of the balance between oxygen supply and demand. For older co-morbid patients with Type 2 MI, geriatricians and cardiologists need to work together to optimise etiological investigations, treatment and prevention of predisposing conditions and precipitating factors.

Coronary Artery Disease in Patients Presenting With Acute Ischemic Stroke or Transient Ischemic Attack and Elevated Troponin Levels

Background: There is little information concerning the invasive coronary angiography (ICA) findings of patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) with elevated troponin levels and suspected myocardial infarction (MI). This study analyzed patient characteristics associated with ICA outcomes.

Methods: A total of 8,322 patients with AIS or TIA, treated between March 2010 and May 2020, were retrospectively screened for elevated serum troponin I at hospital admission. Patients in whom ICA was performed, due to suspected type 1 MI based on symptoms, echocardiography, and ECG, were categorized according to ICA results (non-obstructive coronary artery disease (CAD): ≥1 stenosis ≥50% but no stenosis ≥80%; obstructive CAD: any stenosis ≥80% or hemodynamically relevant stenosis assessed by FFR/iwFR).

Results: Elevated troponin levels were detected in 2,205 (22.5%) patients, of whom 123 (5.6%) underwent ICA (mean age 71 ± 12 years; 67% male). CAD was present in 98 (80%) patients, of whom 51 (41%) were diagnosed with obstructive CAD. Thus, ICA findings of obstructive CAD accounted for 2.3% of patients with troponin elevation and 0.6% of all stroke patients. The clinical hallmarks of myocardial ischemia, including angina pectoris (31 vs. 15%, p < 0.05) and regional wall motion abnormalities (49 vs. 32%, p = 0.07), and increased cardiovascular risk indicated obstructive CAD. While there was no association between lesion site or stroke severity and ICA findings, causal large-artery atherosclerosis was significantly more common in patients with obstructive coronary disease (p < 0.05).

Conclusion: The rate of obstructive CAD in patients with stroke or TIA and elevated troponin levels with suspected concomitant type I MI is low. The cumulation of several cardiovascular risk factors and clinical signs of MI were predictive. AIS patients with large-artery atherosclerosis and elevated troponin may represent an especially vulnerable subgroup of stroke patients with risk for obstructive CAD.