Effect of early metoprolol on infarct size in ST-segment-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: the Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction (METOCARD-CNIC) trial

The role of β-adrenergic receptors in the regulation of cardiac tolerance to ischemia/reperfusion. Why do β-adrenergic receptor agonists and antagonists protect the heart?

BACKGROUND

Catecholamines and β-adrenergic receptors (β-ARs) play an important role in the regulation of cardiac tolerance to the impact of ischemia and reperfusion. This systematic review analyzed the molecular mechanisms of the cardioprotective activity of β-AR ligands.

METHODS

We performed an electronic search of topical articles using PubMed databases from 1966 to 2023. We cited original in vitro and in vivo studies and review articles that documented the cardioprotective properties of β-AR agonists and antagonists.

RESULTS

The infarct-reducing effect of β-AR antagonists did not depend on a decrease in the heart rate. The target for β-blockers is not only cardiomyocytes but also neutrophils. β1-blockers (metoprolol, propranolol, timolol) and the selective β2-AR agonist arformoterol have an infarct-reducing effect in coronary artery occlusion (CAO) in animals. Antagonists of β1- and β2-АR (metoprolol, propranolol, nadolol, carvedilol, bisoprolol, esmolol) are able to prevent reperfusion cardiac injury. All β-AR ligands that reduced infarct size are the selective or nonselective β1-blockers. It was hypothesized that β1-AR blocking promotes an increase in cardiac tolerance to I/R. The activation of β1-AR, β2-AR, and β3-AR can increase cardiac tolerance to I/R. The cardioprotective effect of β-AR agonists is mediated via the activation of kinases and reactive oxygen species production.

CONCLUSIONS

It is unclear why β-blockers with the similar receptor selectivity have the infarct-sparing effect while other β-blockers with the same selectivity do not affect infarct size. What is the molecular mechanism of the infarct-reducing effect of β-blockers in reperfusion? Why did in early studies β-blockers decrease the mortality rate in patients with acute myocardial infarction (AMI) and without reperfusion and in more recent studies β-blockers had no effect on the mortality rate in patients with AMI and reperfusion? The creation of more effective β-AR ligands depends on the answers to these questions.

Clinical Efficacy and Safety of Early Intravenous Administration of Beta-Blockers in Patients Suffering from Acute ST-Segment Elevation Myocardial Infarction Without Heart Failure Undergoing Primary Percutaneous Coronary Intervention: A Study-Level Meta-Analysis of Randomized Clinical Trials

BACKGROUND

Several clinical studies have produced diverse results regarding the efficacy and safety of early intravenous beta-blockers in patients with acute ST-segment elevation myocardial infarction (STEMI). A study-level meta-analysis of randomized clinical trials (RCTs) comparing early intravenous beta-blockers versus placebo or routine care in STEMI patients undergoing primary percutaneous coronary intervention (PCI) was performed.

METHODS

A database search was conducted using PubMed, EMBASE, the Cochrane Library, and Clinicaltrials.gov for randomized clinical trials (RCTs) that compared intravenous beta-blockers versus placebo or routine care in STEMI patients who underwent primary PCI. The efficacy outcomes were infarct size (IS, % of LV) and the myocardial salvage index (MSI) based on magnetic resonance imaging, electrocardiographic findings, heart rate, ST-segment reduction percent (STR%), and complete STR. Safety outcomes included arrhythmias in the first 24 h (ventricular tachycardia and fibrillation [VT/VF], atrial fibrillation [AF], bradycardia, and advanced atrioventricular [AV] block), cardiogenic shock and hypotension during hospitalization, left ventricular ejection fraction (LVEF), and major adverse cardiovascular events (cardiac death, stroke, reinfarction, and heart failure readmission) at follow-up.

RESULTS

Seven RCTs with 1428 patients were included in this study, with 709 patients in the intravenous beta-blockers and 719 in the control group. Intravenous beta-blockers improved MSI compared to the control group (weighted mean difference [WMD] 8.46, 95% confidence interval [CI] 3.12-13.80, P = 0.002, I2 = 0%), but no differences were observed in IS (% of LV) between groups. Compared to the control group, the intravenous beta-blockers group had a lower risk of VT/VF (relative risk [RR] 0.65, 95% CI 0.45-0.94, P = 0.02, I2 = 35%) without an increase of AF, bradycardia, and AV-block and significantly decreased HR, hypotension. LVEF at 1 week ± 7 days (WMD 2.06, 95% CI 0.25-3.88, P = 0.03, I2 = 12%) and 6 months ± 7 days (WMD 3.24, 95% CI 1.54-4.95, P = 0.0002, I2 = 0%) was improved in the intravenous beta-blockers group compared to the control group. Subgroup analysis showed that intravenous beta-blockers before PCI decreased the risk of VT/VF and improved LVEF compared to the control group. Furthermore, sensitivity analysis showed that patients with a left anterior descending (LAD) artery lesion had a smaller IS (% of LV) in the intravenous beta-blockers group compared to the control group.

CONCLUSION

Intravenous beta-blockers improved the MSI, decreased the risk of VT/VF in the first 24 h, and were associated with increased LVEF at 1 week and 6 months following PCI. In particular, intravenous beta-blockers started before PCI is beneficial for patients with LAD lesions.

Effect of the combined use of ivabradine and metoprolol in patients with acute myocardial infarction early after percutaneous coronary intervention: A randomized controlled study

Objective

To investigate the effect and safety of the combined use of ivabradine and metoprolol in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI).

Methods

Eighty patients with AMI were randomly divided into the ivabradine group and the control group. The ivabradine group was treated with ivabradine combined with metoprolol after PCI, while the control group was treated with metoprolol only. Both groups were treated continuously for 1 year. Echocardiography-derived parameters, heart rate, cardiopulmonary exercise testing (CPET) data, major adverse cardiac events (MACE) and myocardial markers were analyzed. The primary endpoint was the left ventricular ejection fraction (LVEF). The safety outcomes were blood pressure, liver and kidney function.

Results

The LVEF was significantly higher in the ivabradine group than in the control group at 1 week, 3 months and 1 year after PCI. The heart rate of the ivabradine group was significantly lower than that of the control group at 1 week and 1month after PCI. The VO2max, metabolic equivalents, anaerobic threshold heart rate, peak heart rate, and heart rate recovery at 8 min of the ivabradine group were significantly higher than those of the control group at 1 year after PCI. Kaplan-Meier analysis demonstrated the one-year total incidence of MACE in the ivabradine group was significantly lower than that in the control group. The B-type natriuretic peptide of the ivabradine group was significantly lower than that of the control group on Day 2 and Day 3 after PCI. The high-sensitivity cardiac troponin I level of the ivabradine group was significantly lower than that of the control group on Day 5 after PCI.

Conclusion

Early use of ivabradine in patients with AMI after PCI can achieve effective heart rate control, reduce myocardial injury, improve cardiac function and exercise tolerance, and may reduce the incidence of major adverse cardiac events. (Clinical research registration number: ChiCTR2000032731).

From Atherosclerotic Plaque to Myocardial Infarction-The Leading Cause of Coronary Artery Occlusion

Cardiovascular disease (CVD) constitutes the most common cause of death worldwide. In Europe alone, approximately 4 million people die annually due to CVD. The leading component of CVD leading to mortality is myocardial infarction (MI). MI is classified into several types. Type 1 is associated with atherosclerosis, type 2 results from inadequate oxygen supply to cardiomyocytes, type 3 is defined as sudden cardiac death, while types 4 and 5 are associated with procedures such as percutaneous coronary intervention and coronary artery bypass grafting, respectively. Of particular note is type 1, which is also the most frequently occurring form of MI. Factors predisposing to its occurrence include, among others, high levels of low-density lipoprotein cholesterol (LDL-C) in the blood, cigarette smoking, chronic kidney disease (CKD), diabetes mellitus (DM), hypertension, and familial hypercholesterolaemia (FH). The primary objective of this review is to elucidate the issues with regard to type 1 MI. Our paper delves into, amidst other aspects, its pathogenesis, risk assessment, diagnosis, pharmacotherapy, and interventional treatment options in both acute and long-term conditions.

Reperfusion Injury in Patients With Acute Myocardial Infarction: JACC Scientific Statement

Despite impressive improvements in the care of patients with ST-segment elevation myocardial infarction, mortality remains high. Reperfusion is necessary for myocardial salvage, but the abrupt return of flow sets off a cascade of injurious processes that can lead to further necrosis. This has been termed myocardial ischemia-reperfusion injury and is the subject of this review. The pathologic and molecular bases for myocardial ischemia-reperfusion injury are increasingly understood and include injury from reactive oxygen species, inflammation, calcium overload, endothelial dysfunction, and impaired microvascular flow. A variety of pharmacologic strategies have been developed that have worked well in preclinical models and some have shown promise in the clinical setting. In addition, there are newer mechanical approaches including mechanical unloading of the heart prior to reperfusion that are in current clinical trials.

Coronary microvascular obstruction and dysfunction in patients with acute myocardial infarction

Despite prompt epicardial recanalization in patients presenting with ST-segment elevation myocardial infarction (STEMI), coronary microvascular obstruction and dysfunction (CMVO) is still fairly common and is associated with poor prognosis. Various pharmacological and mechanical strategies to treat CMVO have been proposed, but the positive results reported in preclinical and small proof-of-concept studies have not translated into benefits in large clinical trials conducted in the modern treatment setting of patients with STEMI. Therefore, the optimal management of these patients remains a topic of debate. In this Review, we appraise the pathophysiological mechanisms of CMVO, explore the evidence and provide future perspectives on strategies to be implemented to reduce the incidence of CMVO and improve prognosis in patients with STEMI.

Stroke Related Brain-Heart Crosstalk: Pathophysiology, Clinical Implications, and Underlying Mechanisms

The emergence of acute ischemic stroke (AIS) induced cardiovascular dysfunctions as a bidirectional interaction has gained paramount importance in understanding the intricate relationship between the brain and heart. Post AIS, the ensuing cardiovascular dysfunctions encompass a spectrum of complications, including heart attack, congestive heart failure, systolic or diastolic dysfunction, arrhythmias, electrocardiographic anomalies, hemodynamic instability, cardiac arrest, among others, all of which are correlated with adverse outcomes and mortality. Mounting evidence underscores the intimate crosstalk between the heart and the brain, facilitated by intricate physiological and neurohumoral complex networks. The primary pathophysiological mechanisms contributing to these severe cardiac complications involve the hypothalamic-pituitary-adrenal (HPA) axis, sympathetic and parasympathetic hyperactivity, immune and inflammatory responses, and gut dysbiosis, collectively shaping the stroke-related brain-heart axis. Ongoing research endeavors are concentrated on devising strategies to prevent AIS-induced cardiovascular dysfunctions. Notably, labetalol, nicardipine, and nitroprusside are recommended for hypertension control, while β-blockers are employed to avert chronic remodeling and address arrhythmias. However, despite these therapeutic interventions, therapeutic targets remain elusive, necessitating further investigations into this complex challenge. This review aims to delineate the state-of-the-art pathophysiological mechanisms in AIS through preclinical and clinical research, unraveling their intricate interplay within the brain-heart axis, and offering pragmatic suggestions for managing AIS-induced cardiovascular dysfunctions.

Prognostic Impact of Early Administration of β-Blockers in Critically Ill Patients with Acute Myocardial Infarction

In critically ill patients with acute myocardial infarction (AMI), the relationship between the early administration of β-blockers and the risks of in-hospital and long-term mortality remains controversial. Furthermore, there are conflicting evidences for the efficacy of the early administration of intravenous followed by oral β-blockers in AMI. We conducted a retrospective analysis of critically ill patients with AMI who received the early administration of β-blockers within 24 hours of admission. The data were extracted from the Medical Information Mart for Intensive Care IV database. We enrolled 2467 critically ill patients with AMI in the study, with 1355 patients who received the early administration of β-blockers and 1112 patients who were non-users. Kaplan-Meier survival analysis and Cox proportional hazards models showed that the early administration of β-blockers was associated with a lower risk of in-hospital mortality (adjusted hazard ratio [aHR] 0.52; 95% confidence interval [95%CI] 0.42-0.64), 1-year mortality (aHR 0.54, 95%CI 0.47-0.63), and 5-year mortality (aHR 0.60, 95%CI 0.52-0.69). Furthermore, the early administration of both oral β-blockers and intravenous β-blockers followed by oral β-blockers may reduce the mortality risk, compared with non-users. The risks of in-hospital and long-term mortality were significantly decreased in patients who underwent revascularization with the early administration of β-blockers. We found that the early administration of β-blockers could lower the risks of in-hospital and long-term mortality. Furthermore, the early administration of both oral β-blockers and intravenous β-blockers followed by oral β-blockers may reduce the mortality risk, compared with non-users. Notably, patients who underwent revascularization with the early administration of β-blockers showed the lowest risks of in-hospital and long-term mortality.

The Clinical Characteristics of Heart Rate Variability After Stroke: A Systematic Review

The autonomic nervous system dysfunction has been reported in up to 76% of stroke patients 7 days after an acute stroke. Heart rate variability (HRV) is one of the important indicators reflecting the balance of sympathetic and parasympathetic nerves. Therefore, we performed a systematic literature review of existing literature on the association between heart rate variability and the different types of stroke. We included studies published in the last 32 years (1990 to 2022). The electronic databases MEDLINE and PubMed were searched. We selected the research that met the inclusion or exclusion criteria. A narrative synthesis was performed. This review aimed to summarize evidence regarding the potential mechanism of heart rate variability among patients after stroke. In addition, the association of clinical characteristics of heart rate variability and stroke has been depicted. The review further discussed the relationship between post-stroke infection and heart rate variability, which could assist in curbing clinical infection in patients with stroke. HRVas a noninvasive clinical monitoring tool can quantitatively assess the changes in autonomic nervous system activity and further predict the outcome of stroke. HRV could play an important role in guiding the clinical practice for autonomic nervous system disorder after stroke.

KATP channels are regulators of programmed cell death and targets for the creation of novel drugs against ischemia/reperfusion cardiac injury

BACKGROUND

The use of percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is associated with a mortality rate of 5%-7%. It is clear that there is an urgent need to develop new drugs that can effectively prevent cardiac reperfusion injury. ATP-sensitive K+ (KATP ) channel openers (KCOs) can be classified as such drugs.

RESULTS

KCOs prevent irreversible ischemia and reperfusion injury of the heart. KATP channel opening promotes inhibition of apoptosis, necroptosis, pyroptosis, and stimulation of autophagy. KCOs prevent the development of cardiac adverse remodeling and improve cardiac contractility in reperfusion. KCOs exhibit antiarrhythmic properties and prevent the appearance of the no-reflow phenomenon in animals with coronary artery occlusion and reperfusion. Diabetes mellitus and a cholesterol-enriched diet abolish the cardioprotective effect of KCOs. Nicorandil, a KCO, attenuates major adverse cardiovascular event and the no-reflow phenomenon, reduces infarct size, and decreases the incidence of ventricular arrhythmias in patients with acute myocardial infarction.

CONCLUSION

The cardioprotective effect of KCOs is mediated by the opening of mitochondrial KATP (mitoKATP ) and sarcolemmal KATP (sarcKATP ) channels, triggered free radicals' production, and kinase activation.

Updating a Healthcare System-wide Clinical Pathway for Managing Chest Pain and Acute Coronary Syndromes

Clinical pathways are useful tools for conveying and reinforcing best practices to standardize care and optimize patient outcomes across myriad conditions. The NewYork-Presbyterian Healthcare System has utilized a clinical chest pain pathway for more than 20 years to facilitate the timely recognition and management of patients presenting with chest pain syndromes and acute coronary syndromes. This chest pain pathway is regularly updated by an expanding group of key stakeholders, which has extended from the Columbia University Irving Medical Center to encompass the entire regional healthcare system, which includes 8 hospitals. In this 2023 update of the NewYork-Presbyterian clinical chest pain pathway, we present the key changes to the healthcare system-wide clinical chest pain pathway.

Health position paper and redox perspectives on reactive oxygen species as signals and targets of cardioprotection

The present review summarizes the beneficial and detrimental roles of reactive oxygen species in myocardial ischemia/reperfusion injury and cardioprotection. In the first part, the continued need for cardioprotection beyond that by rapid reperfusion of acute myocardial infarction is emphasized. Then, pathomechanisms of myocardial ischemia/reperfusion to the myocardium and the coronary circulation and the different modes of cell death in myocardial infarction are characterized. Different mechanical and pharmacological interventions to protect the ischemic/reperfused myocardium in elective percutaneous coronary interventions and coronary artery bypass grafting, in acute myocardial infarction and in cardiotoxicity from cancer therapy are detailed. The second part keeps the focus on ROS providing a comprehensive overview of molecular and cellular mechanisms involved in ischemia/reperfusion injury. Starting from mitochondria as the main sources and targets of ROS in ischemic/reperfused myocardium, a complex network of cellular and extracellular processes is discussed, including relationships with Ca2+ homeostasis, thiol group redox balance, hydrogen sulfide modulation, cross-talk with NAPDH oxidases, exosomes, cytokines and growth factors. While mechanistic insights are needed to improve our current therapeutic approaches, advancements in knowledge of ROS-mediated processes indicate that detrimental facets of oxidative stress are opposed by ROS requirement for physiological and protective reactions. This inevitable contrast is likely to underlie unsuccessful clinical trials and limits the development of novel cardioprotective interventions simply based upon ROS removal.

Early beta-blocker therapy improves in-hospital mortality of patients with non-ST-segment elevation myocardial infarction - a meta-analysis

BACKGROUND

Although current guidelines endorse early beta-blocker therapy in stable patients with STEMI, there is no clear recommendation on the early use of these drugs in patients with NSTEMI.

METHODS

Literature search was conducted by 3 independent researchers using PubMed/MEDLINE, CDSR, CENTRAL, CCAs, EBM Reviews, Web of Science and LILACS. Studies were eligible if (P) patients included were ≥ 18 years of age and had non-ST-segment elevation myocardial infarction (NSTEMI), (I) early (<24 h) treatment with intravenous or oral beta-blockers was compared to (C) no treatment with beta-blockers and data on (O) in-hospital mortality and/or in-hospital cardiogenic shock were depicted. Odds ratios and 95% confidence intervals were calculated using random effects models with the Mantel-Haenszel method. The Hartung-Knapp-Sidik-Jonkman method was used as estimator for τ2.

RESULTS

977 records were screened for eligibility, which led to the inclusion of 4 retrospective, nonrandomized, observational cohort studies comprising a total of N = 184,951 patients. After pooling of the effect sizes, early therapy with beta-blockers resulted in a reduction of in-hospital mortality (OR 0.43 [0.36-0.51], p = 0.0022) despite no significant effect on the prevalence of cardiogenic shock (OR 0.36 [0.07-1.91], p = 0.1196).

CONCLUSION

Early treatment with beta-blockers was associated with an attenuation of in-hospital mortality despite no increase in cardiogenic shock. Thus, early therapy with these drugs could elicit beneficial effects on top of reperfusion therapy, similar to the effects seen in STEMI-patients. The low number of studies (k = 4) has to be considered when interpreting the findings of this analysis.

The effect of nicorandil on cardiac function and clinical outcomes in ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: a randomised trial

BACKGROUND

We investigated the effect of nicorandil on infarct size, cardiac function assessed by cardiac magnetic resonance imaging (CMR) and outcomes in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI).

METHODS

In a prospective, randomised, controlled trial, 83 patients with STEMI receiving primary PCI were randomised into the nicorandil (n =  40) or placebo (n  =  43) groups. Nicorandil was administered in the emergency room before primary PCI as an intravenous bolus of 4 mg followed by a continuous infusion of 6 mg/h for 24 h and as 2-mg intracoronary injections prior to balloon dilatation and coronary stenting. Nicorandil was continued orally at 10-20 mg/d for 6 months. Infarct size and cardiac function were measured by CMR at 5 d and 6 months after primary PCI. Furthermore, major adverse cardiac events (MACEs) including all-cause death, nonfatal myocardial infarction (MI), any revascularisation, stroke, and definite/probable stent thrombosis (ST) were compared.

RESULTS

There were no significant differences in baseline clinical characteristics between the groups. Infarct size at baseline and 6 months as well as infarct size changes during 6 months as measured by CMR were similar between the groups. Similarly, other CMR parameters were comparable at baseline and 6 months between the groups. MACEs occurred in four patients (4.8%) during 6 months. No significant difference in the risk of MACEs was observed between the groups.

CONCLUSIONS

Treatment with nicorandil for 6 months after primary PCI was not associated with any improvement in infarct size, CMR-determined cardiac function, and outcomes in STEMI patients.

Timing of SGLT2i initiation after acute myocardial infarction

BACKGROUND

Pharmacological post-MI treatment is routinely initiated at intensive/cardiac care units. However, solid evidence for an early start of these therapies is only available for dual platelet therapy and statins, whereas data on beta blockers and RAAS inhibitors are heterogenous and mainly limited to STEMI and heart failure patients. Recently, the EMMY trial provided the first evidence on the beneficial effects of SGLT2 inhibitors (SGLT2i) when initiated early after PCI. In patients with type 2 diabetes mellitus, SGLT2i are considered "sick days drugs" and it, therefore, remains unclear if very early SGLT2i initiation following MI is as safe and effective as delayed initiation.

METHODS AND RESULTS

The EMMY trial evaluated the effect of empagliflozin on NT-proBNP and functional and structural measurements. Within the Empagliflozin group, 22 (9.5%) received early treatment (< 24 h after PCI), 98 (42.2%) within a 24 to < 48 h window (intermediate), and 111 (48.1%) between 48 and 72 h (late). NT-proBNP levels declined by 63.5% (95%CI: - 69.1; - 48.1) in the early group compared to 61.0% (- 76.0; - 41.4) in the intermediate and 61.9% (- 70.8; - 45.7) in the late group (n.s.) within the Empagliflozin group with no significant treatment groups-initiation time interaction (pint = 0.96). Secondary endpoints of left ventricular function (LV-EF, e/e`) as well as structure (LVESD and LVEDD) were also comparable between the groups. No significant difference in severe adverse event rate between the initiation time groups was detected.

CONCLUSION

Very early administration of SGLT2i after acute myocardial infarction does not show disadvantageous signals with respect to safety and appears to be as effective in reducing NT-proBNP as well as improving structural and functional LV markers as initiation after 2-3 days.

Coronary No-Reflow after Primary Percutaneous Coronary Intervention-Current Knowledge on Pathophysiology, Diagnosis, Clinical Impact and Therapy

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research.

No robust reduction of infarct size and no-reflow by metoprolol pretreatment in adult Göttingen minipigs

Whereas prior experiments in juvenile pigs had reported infarct size reduction by intravenous metoprolol early during myocardial ischaemia, two major clinical trials in patients with reperfused acute myocardial infarction were equivocal. We, therefore, went back and tested the translational robustness of infarct size reduction by metoprolol in minipigs. Using a power analysis-based prospective design, we pretreated 20 anaesthetised adult Göttingen minipigs with 1 mg kg-1 metoprolol or placebo and subjected them to 60-min coronary occlusion and 180-min reperfusion. Primary endpoint was infarct size (triphenyl tetrazolium chloride staining) as a fraction of area at risk; no-reflow area (thioflavin-S staining) was a secondary endpoint. There was no significant reduction in infarct size (46 ± 8% of area at risk with metoprolol vs. 42 ± 8% with placebo) or area of no-reflow (19 ± 21% of infarct size with metoprolol vs. 15 ± 23% with placebo). However, the inverse relationship between infarct size and ischaemic regional myocardial blood flow was modestly, but significantly shifted downwards with metoprolol, whereas ischaemic blood flow tended to be reduced by metoprolol. With an additional dose of 1 mg kg-1 metoprolol after 30-min ischaemia in 4 additional pigs, infarct size was also not reduced (54 ± 9% vs. 46 ± 8% in 3 contemporary placebo, n.s.), and area of no-reflow tended to be increased (59 ± 20% vs. 29 ± 12%, n.s.).Infarct size reduction by metoprolol in pigs is not robust, and this result reflects the equivocal clinical trials. The lack of infarct size reduction may be the result of opposite effects of reduced infarct size at any given blood flow and reduced blood flow, possibly through unopposed alpha-adrenergic coronary vasoconstriction.

Rationale and design of the RESTORE trial: A multicenter, randomized, double-blinded, parallel-group, placebo-controlled trial to evaluate the effect of Shenfu injection on myocardial injury in STEMI patients after primary PCI

BACKGROUND

The mortality following ST-segment elevation myocardial infarction (STEMI) remains substantial in the reperfusion era. Shenfu injection, as a traditional Chinese herbal formula, can alleviate ischemia-reperfusion injury through multiple pharmacologic effects. However, no robust data are available regarding the role of Shenfu injection in reducing infarct size for patients with STEMI undergoing primary percutaneous coronary intervention (PPCI).

METHODS/DESIGN

This RESTORE trial is a multicenter, randomized, double-blind, parallel-group, placebo-controlled trial (NCT04493840). A total of 326 eligible patients with first-time anterior STEMI undergoing PPCI within 12 h of symptom onset will be enrolled from 10 centers in mainland China. Patients are randomized in a 1:1 fashion to receive either intravenous Shenfu injection (80mL Shenfu injection + 70mL 5% glucose injection) or placebo group (150mL 5% glucose injection) before reperfusion and followed by once a day until 5 days after PPCI. The primary end point is infarct size assessed by cardiac magnetic resonance (CMR) imaging 5±2 days after PPCI. The major secondary end points include enzymatic infarct size, microvascular obstruction, intramyocardial hemorrhage, left ventricular volume and ejection fraction assessed by CMR, as well as cardiovascular events at 30 days.

CONCLUSIONS

The RESTORE trial is sufficiently powered to demonstrate the clinical effects of Shenfu injection on myocardial injury in STEMI patients undergoing PPCI in the contemporary era.

Research progress on the effects of novel hypoglycemic drugs in diabetes combined with myocardial ischemia/reperfusion injury

Acute myocardial infarction (AMI) reperfusion is associated with ischemia/reperfusion (I/R) injury, which leads to enlarged myocardial infarction size, poor healing of the infarcted myocardium, and poor left ventricular remodeling, thus increasing the risk of major adverse cardiovascular events (MACEs). Diabetes increases myocardial susceptibility to I/R injury, decreases myocardial responsiveness to cardioprotective strategies, exacerbates myocardial I/R injury, and expands the infarct size of AMI, thereby increasing the incidence of malignant arrhythmias and heart failure. Currently, evidence regarding pharmacological interventions for diabetes combined with AMI and I/R injury is lacking. Traditional hypoglycemic drugs have a limited role in the prevention and treatment of diabetes combined with I/R injury. Current evidence suggests that novel hypoglycemic drugs may exert a preventive effect on diabetes combined with myocardial I/R injury, especially glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-dependent glucose transporter protein 2 inhibitors (SGLT2i), which may increase coronary blood flow, reduce acute thrombosis, attenuate I/R injury, decrease myocardial infarction size, inhibit structural and functional remodeling of the ischemic heart, improve cardiac function, and reduce the occurrence of MACEs of diabetes patients combined with AMI via mechanisms such as reduction of inflammatory response, inhibition of oxidative stress, and improvement of vascular endothelial function. This paper will systematically elaborate the protective role and molecular mechanisms of GLP-1 RA and SGLT2i in diabetes combined with myocardial I/R injury, aiming to provide clinical assistance.

Impact of Reperfusion on Temporal Immune Cell Dynamics After Myocardial Infarction

Excessive inflammation and impaired healing of cardiac tissue following a myocardial infarction (MI) can drive the development of heart failure. Cardiac repair begins immediately after the onset of MI and continues for months. The repair process can be divided into the following 3 overlapping phases, each having distinct functions and sequelae: the inflammatory phase, the proliferative phase, and the maturation phase. Macrophages, neutrophils, and lymphocytes are present in the myocardium throughout the repair process and govern the duration and function of each of these phases. However, changes in the functions of these cell types across each phase are poorly characterized. Numerous immunomodulatory therapies that specifically target inflammation have been developed for promoting cardiac repair and preventing heart failure after MI. However, these treatments have been largely unsuccessful in large-scale clinical randomized controlled trials. A potential explanation for this failure is the lack of a thorough understanding of the time-dependent evolution of the functions of immune cells after a major cardiovascular event. Failure to account for this temporal plasticity in cell function may reduce the efficacy of immunomodulatory approaches that target cardiac repair. This review is concerned with how the functions of different immune cells change with time following an MI. Improved understanding of the temporal changes in immune cell function is important for the future development of effective and targeted treatments for preventing heart failure after MI.

Interaction of Cardiovascular Nonmodifiable Risk Factors, Comorbidities and Comedications With Ischemia/Reperfusion Injury and Cardioprotection by Pharmacological Treatments and Ischemic Conditioning

Preconditioning, postconditioning, and remote conditioning of the myocardium enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and the potential to provide novel therapeutic paradigms for cardioprotection. While many signaling pathways leading to endogenous cardioprotection have been elucidated in experimental studies over the past 30 years, no cardioprotective drug is on the market yet for that indication. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic preclinical evaluation of promising cardioprotective therapies prior to their clinical evaluation, since ischemic heart disease in humans is a complex disorder caused by or associated with cardiovascular risk factors and comorbidities. These risk factors and comorbidities induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury and responses to cardioprotective interventions. Moreover, some of the medications used to treat these comorbidities may impact on cardioprotection by again modifying cellular signaling pathways. The aim of this article is to review the recent evidence that cardiovascular risk factors as well as comorbidities and their medications may modify the response to cardioprotective interventions. We emphasize the critical need for taking into account the presence of cardiovascular risk factors as well as comorbidities and their concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple comorbidities. SIGNIFICANCE STATEMENT: Ischemic heart disease is a major cause of mortality; however, there are still no cardioprotective drugs on the market. Most studies on cardioprotection have been undertaken in animal models of ischemia/reperfusion in the absence of comorbidities; however, ischemic heart disease develops with other systemic disorders (e.g., hypertension, hyperlipidemia, diabetes, atherosclerosis). Here we focus on the preclinical and clinical evidence showing how these comorbidities and their routine medications affect ischemia/reperfusion injury and interfere with cardioprotective strategies.

Role of β-blockers in Preventing Heart Failure and Major Adverse Cardiac Events Post Myocardial Infarction

β-blockers have been widely utilized as a part of acute myocardial infarction (AMI) treatment for the past 40 years. Patients receiving β-adrenergic blockers for an extended period following myocardial infarction have a higher chance of surviving. Although many patients benefited from β-blockers, many do not, including those with myocardial infarction, left ventricle dysfunction, chronic pulmonary disease, and elderly people. In individuals with the post-acute coronary syndrome and normal left ventricular ejection fraction (LVEF), the appropriate duration of betablocker therapy is still unknown. There is also no time limit for those without angina and those who do not need β-blockers for arrhythmia or hypertension. Interestingly, β-blockers have been prescribed for more than four decades. The novel mechanism of action on cellular compartments has been found continually, which opens a new way for their potential application in cardiac failure and other cardiac events like post-myocardial infarction. Here, in this review, we studied β-blocker usage in these circumstances and the current recommendations for β-blocker use from clinical practice guidelines.

Beta-Blockers in the Prevention and Treatment of Ischemic Heart Disease: Evidence and Clinical Practice

Coronary artery disease (CAD) is the most prevalent cardiovascular disease characterized by atherosclerotic plaque buildup that can lead to partial or full obstruction of blood flow in the coronary arteries. Treatment for CAD involves a combination of lifestyle changes, pharmacologic therapy, and modern revascularization procedures. Beta-adrenoceptor antagonists (or beta-blockers) have been widely used for decades as a key therapy for CAD. In this review, prior studies are examined to better understand beta-adrenoceptor antagonist use in patients with acute coronary syndrome, stable coronary heart disease, and in the perioperative setting. The evidence for the benefit of beta-blocker therapy is well established for patients with acute myocardial infarction, but it diminishes as the time from the index cardiac event elapses. The evidence for benefit in the perioperative setting is not strong.

Neutrophils in aging and aging‐related pathologies

Over the past millennia, life expectancy has drastically increased. While a mere 25 years during Bronze and Iron ages, life expectancy in many European countries and in Japan is currently above 80 years. Such an increase in life expectancy is a result of improved diet, life style, and medical care. Yet, increased life span and aging also represent the most important non-modifiable risk factors for several pathologies including cardiovascular disease, neurodegenerative diseases, and cancer. In recent years, neutrophils have been implicated in all of these pathologies. Hence, this review provides an overview of how aging impacts neutrophil production and function and conversely how neutrophils drive aging-associated pathologies. Finally, we provide a perspective on how processes of neutrophil-driven pathologies in the context of aging can be targeted therapeutically.

The multiple value characteristics of fly ash from Indian coal thermal power plants: a review

Coal-powered thermal plants are the primary source of energy production around the globe. More than half (56.89%) of the Indian power plants use coal for power production. Coal burning in power plants results in coal combustion residuals, which contain coal fly ash (CFA) that is recognized as principle by-product. CFA is difficult to characterize due to its broad compositional variation. Hence, the present article summarizes the various physical, chemical, mineralogical, and petrological characterizations of CFA to its use in different applications. Indian coal thermal power plants are found to release two types of CFA: F (fine) and C (coarse). CFA particles are identified as unburned carbon particles with a large fraction of silica oxides, alumina oxides, and iron oxides with a small fraction of calcium oxide (CaO). Morphologically, CFA particles are spherical, with large carbon molecules and a smooth texture surface. In terms of mineralogy; quartz, mullite, magnetite, and hematite are the dominant mineral phases of CFA and tend to be non-plastic, with permeability levels ranging from 8 × 10^-6 to 1.87 × 10^-4 cms^-1. Petrographically, CFA is enriched in inertinite and liptinites as well as collotelinite, collodetrinite, and vitrodetrinite particles. Moreover, CFA is found to be composed of various organic and inorganic particles. By virtue of multiple characterizations, it has been utilized in several applications for decades, which is still quite limited. Therefore, current study aim to provide helpful insights into the potential use of CFA-derived products in different ways to increase sustainability.

Effects of Nicorandil Administration on Infarct Size in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: The CHANGE Trial

Background Nicorandil was reported to improve microvascular dysfunction and reduce reperfusion injury when administered before primary percutaneous coronary intervention. In this multicenter, prospective, randomized, double-blind clinical trial (CHANGE [Effects of Nicorandil Administration on Infarct Size in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention]), we investigated the effects of nicorandil administration on infarct size in patients with ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention. Methods and Results A total of 238 patients with ST-segment-elevation myocardial infarction were randomized to receive intravenous nicorandil (n=120) or placebo (n=118) before reperfusion. Patients in the nicorandil group received a 6-mg intravenous bolus of nicorandil followed by continuous infusion at a rate of 6 mg/h. Patients in the placebo group received the same dose of placebo. The predefined primary end point was infarct size on cardiac magnetic resonance (CMR) imaging performed at 5 to 7 days and 6 months after reperfusion. CMR imaging was performed in 201 patients (84%). Infarct size on CMR imaging at 5 to 7 days after reperfusion was significantly smaller in the nicorandil group compared with the placebo (control) group (26.5±17.1 g versus 32.4±19.3 g; P=0.022), and the effect remained significant on long-term CMR imaging at 6 months after reperfusion (19.5±14.4 g versus 25.7±15.4 g; P=0.008). The incidence of no-reflow/slow-flow phenomenon during primary percutaneous coronary intervention was much lower in the nicorandil group (9.2% [11/120] versus 26.3% [31/118]; P=0.001), and thus, complete ST-segment resolution was more frequently observed in the nicorandil group (90.8% [109/120] versus 78.0% [92/118]; P=0.006). Left ventricular ejection fraction on CMR imaging was significantly higher in the nicorandil group than in the placebo group at both 5 to 7 days (47.0±10.2% versus 43.3±10.0%; P=0.011) and 6 months (50.1±9.7% versus 46.4±8.5%; P=0.009) after reperfusion. Conclusions In the present trial, administration of nicorandil before primary percutaneous coronary intervention led to improved myocardial perfusion grade, increased left ventricular ejection fraction, and reduced myocardial infarct size in patients with ST-segment-elevation myocardial infarction. Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT03445728.

Effect of early metoprolol before PCI in ST-segment elevation myocardial infarction on infarct size and left ventricular ejection fraction. A systematic review and meta-analysis of clinical trials

Aim

This meta‐analysis aims to look at the impact of early intravenous Metoprolol in ST‐segment elevation myocardial infarction (STEMI) before percutaneous coronary intervention (PCI) on infarct size, as measured by cardio magnetic resonance (CMR) and left ventricular ejection fraction.

Methods

We searched the following databases: PubMed, Scopus, Cochrane library, and Web of Science. We included only randomized control trials that reported the use of early intravenous Metoprolol in STEMI before PCI on infarct size, as measured by CMR and left ventricular ejection fraction. RevMan software 5.4 was used for performing the analysis.

Results

Following a literature search, 340 publications were found. Finally, 18 studies were included for the systematic review, and 8 clinical trials were included in the meta‐analysis after the full‐text screening. At 6 months, the pooled effect revealed a statistically significant association between Metoprolol and increased left ventricular ejection fraction (LVEF) (%) compared to controls (mean difference [MD] = 3.57, [95% confidence interval [CI] = 2.22–4.92], p < .00001), as well as decreased infarcted myocardium(g) compared to controls (MD = −3.84, [95% [CI] = −5.75 to −1.93], p < .0001). At 1 week, the pooled effect revealed a statistically significant association between Metoprolol and increased LVEF (%) compared to controls (MD = 2.98, [95% CI = 1.26−4.69], p = .0007), as well as decreased infarcted myocardium(%) compared to controls (MD = −3.21, [95% CI = −5.24 to −1.18], p = .002).

Conclusion

A significant decrease in myocardial infarction and increase in LVEF (%) was linked to receiving Metoprolol at 1 week and 6‐month follow‐up.

The Roles of Neutrophils Linking Periodontitis and Atherosclerotic Cardiovascular Diseases

Inflammation plays a crucial role in the onset and development of atherosclerosis. Periodontitis is a common chronic disease linked to other chronic inflammatory diseases such as atherosclerotic cardiovascular disease (ASCVD). The mechanistic pathways underlying this association are yet to be fully understood. This critical review aims at discuss the role of neutrophils in mediating the relationship between periodontitis and ASCVD. Systemic inflammation triggered by periodontitis could lead to adaptations in hematopoietic stem and progenitor cells (HSPCs) resulting in trained granulopoiesis in the bone marrow, thereby increasing the production of neutrophils and driving the hyper-responsiveness of these abundant innate-immune cells. These alterations may contribute to the onset, progression, and complications of atherosclerosis. Despite the emerging evidence suggesting that the treatment of periodontitis improves surrogate markers of cardiovascular disease, the resolution of periodontitis may not necessarily reverse neutrophil hyper-responsiveness since the hyper-inflammatory re-programming of granulopoiesis can persist long after the inflammatory inducers are removed. Novel and targeted approaches to manipulate neutrophil numbers and functions are warranted within the context of the treatment of periodontitis and also to mitigate its potential impact on ASCVD.

Early donepezil monotherapy or combination with metoprolol significantly prevents subsequent chronic heart failure in rats with reperfused myocardial infarction

Despite the presence of clinical guidelines recommending that β-blocker treatment be initiated early after reperfused myocardial infarction (RMI), acute myocardial infarction remains a leading cause of chronic heart failure (CHF). In this study, we compared the effects of donepezil, metoprolol, and their combination on the progression of cardiac remodeling in rats with RMI. The animals were randomly assigned to untreated (UT), donepezil-treated (DT), metoprolol-treated (MT), and a combination of donepezil and metoprolol (DMT) groups. On day 8 after surgery, compared to the UT, the DT and DMT significantly improved myocardial salvage, owing to the suppression of macrophage infiltration and apoptosis. After the 10-week treatment, the DT and DMT exhibited decreased heart rate, reduced myocardial infarct size, attenuated cardiac dysfunction, and decreased plasma levels of brain natriuretic peptide and catecholamine, thereby preventing subsequent CHF. These results suggest that donepezil monotherapy or combined therapy with β-blocker may be an alternative pharmacotherapy post-RMI.

"No-Reflow" Phenomenon: A Contemporary Review

Primary percutaneous angioplasty (pPCI), represents the reperfusion strategy of choice for patients with STEMI according to current international guidelines of the European Society of Cardiology. Coronary no-reflow is characterized by angiographic evidence of slow or no anterograde epicardial flow, resulting in inadequate myocardial perfusion in the absence of evidence of mechanical vessel obstruction. No reflow (NR) is related to a functional and structural alteration of the coronary microcirculation and we can list four main pathophysiological mechanisms: distal atherothrombotic embolization, ischemic damage, reperfusion injury, and individual susceptibility to microvascular damage. This review will provide a contemporary overview of the pathogenesis, diagnosis, and treatment of NR.

Therapeutic Targets for Regulating Oxidative Damage Induced by Ischemia-Reperfusion Injury: A Study from a Pharmacological Perspective

Ischemia-reperfusion (I-R) injury is damage caused by restoring blood flow into ischemic tissues or organs. This complex and characteristic lesion accelerates cell death induced by signaling pathways such as apoptosis, necrosis, and even ferroptosis. In addition to the direct association between I-R and the release of reactive oxygen species and reactive nitrogen species, it is involved in developing mitochondrial oxidative damage. Thus, its mechanism plays a critical role via reactive species scavenging, calcium overload modulation, electron transport chain blocking, mitochondrial permeability transition pore activation, or noncoding RNA transcription. Other receptors and molecules reduce tissue and organ damage caused by this pathology and other related diseases. These molecular targets have been gradually discovered and have essential roles in I-R resolution. Therefore, the current study is aimed at highlighting the importance of these discoveries. In this review, we inquire about the oxidative damage receptors that are relevant to reducing the damage induced by oxidative stress associated with I-R. Several complications on surgical techniques and pathology interventions do not mitigate the damage caused by I-R. Nevertheless, these therapies developed using alternative targets could work as coadjuvants in tissue transplants or I-R-related pathologies

Complementary Pharmacotherapy for STEMI Undergoing Primary PCI: An Evidence-Based Clinical Approach

Antithrombotic therapy is the cornerstone of pharmacological treatment in patients undergoing primary percutaneous coronary intervention (PCI). However, the acute management of ST elevation myocardial infarction (STEMI) patients includes therapy for pain relief and potential additional strategies for cardioprotection. The safety and efficacy of some commonly used treatments have been questioned by recent evidence. Indeed a concern about morphine use is the interaction between opioids and oral P2Y₁₂ inhibitors; early beta-blocker treatment has shown conflicting results for the improvement of clinical outcomes; and supplemental oxygen therapy lacks benefit in patients without hypoxia and may be of potential harm. Other additional strategies remain disappointing; however, some treatments may be selectively used. Therefore, we intend to present a critical updated review of complementary pharmacotherapy for a modern treatment approach for STEMI patients undergoing primary PCI.

The Hypertension Paradox: Survival Benefit After ST-Elevation Myocardial Infarction in Patients With History of Hypertension. A Prospective Cohort- and Risk-Analysis

Background

Mortality after ST-elevation myocardial infarction (STEMI) is dependent from best-medical treatment after initial event.

Objectives

Determining the impact of prescription of guideline-recommended therapy after STEMI in two cohorts, patients with and without history of arterial hypertension, on survival.

Methods

1,025 patients of the Cologne Infarction Model registry with invasively adjudicated STEMI were dichotomized according to their history of arterial hypertension. We recorded prescription rates and dosing of RAS-inhibitors, β-blockers and statins in all patients. The primary outcome was all-cause death. Mean follow-up was 2.5 years.

Results

Mean age was 64 ± 13 years, 246 (25%) were women. 749 (76%) patients had a history of hypertension. All-cause mortality was 24.2%, 30-day and 1-year mortality was 11.3% and 16.6%, respectively. History of hypertension correlated with lower mortality (hazard ratio [HR], @30 days: 0.41 [0.27-0.62], @1 year: 0.37 [0.26-0.53]). After adjusting for age, sex, Killip-class, diabetes mellitus, body-mass index, kidney function and statin prescription at discharge 1-year mortality HR was 0.24 (0.12-0.48). At discharge, prescription rates for RAS-inhibitors, β-blockers and statins, as well as individual dosing and long-term persistence of RAS-inhibitors were higher in patients with history of hypertension. On the same lines, prescription rates for RAS-inhibitors, β-blockers and statins at discharge correlated significantly with lower mortality regardless of history of hypertension.

Conclusion

Patients with history of hypertension show higher penetration of guideline recommended drug therapy after STEMI, which may contribute to better survival. Better tolerance of β-blockers and RAS-inhibitors in patients with history of hypertension, not hypertension itself, likely explains these differences in prescription and dosing.

Astragaloside IV Alleviates Infarction Induced Cardiomyocyte Injury by Improving Mitochondrial Morphology and Function

The protective effect of astragaloside IV (AS-IV) on myocardial injury after myocardial infarction has been reported. However, the underlying mechanism is still largely unknown. We established a myocardial infarction model in C57BL/6 mice and injected intraperitoneally with 10 mg/kg/d AS-IV for 4 weeks. The cardiac function, myocardial fibrosis, and angiogenesis were investigated by echocardiography, Masson's trichrome staining, and CD31 and smooth muscle actin staining, respectively. Cardiac mitochondrial morphology was visualized by transmission electron microscopy. Cardiac function, infarct size, vascular distribution, and mitochondrial morphology were significantly better in AS-IV-treated mice than in the myocardial infarction model mice. In vitro, a hypoxia-induced H9c2 cell model was established to observe cellular apoptosis and mitochondrial function. H9c2 cells transfected with silent information regulator 3 (Sirt3) targeting siRNA were assayed for Sirt3 expression and activity. Sirt3 silencing eliminated the beneficial effects of AS-IV and abrogated the inhibitory effect of AS-IV on mitochondrial division. These results suggest that AS-IV protects cardiomyocytes from hypoxic injury by maintaining mitochondrial homeostasis in a Sirt3-dependent manner.

Knockdown of hypoxia-inducible factor 1-alpha (HIF1α) interferes with angiopoietin-like protein 2 (ANGPTL2) to attenuate high glucose-triggered hypoxia/reoxygenation injury in cardiomyocytes

To investigate the role of hypoxia-inducible factor 1-alpha (HIF1A) in hypoxia/reoxygenation (H/R) injury of cardiomyocytes induced by high glucose (HG). The in vitro model of coronary heart disease with diabetes was that H9c2 cells were stimulated by H/R and HG. Quantitative reverse transcription PCR (RT-qPCR) and Western blot analysis were used to detect the expression of HIF1A and angiopoietin-like protein 2 (ANGPTL2) in H9c2 cells. Cell viability and apoptosis were, respectively, estimated by Cell Counting Kit 8 (CCK-8) and TUNEL assays. Lactate dehydrogenase (LDH) activity, inflammation and oxidative stress were in turn detected by their commercial assay kits. Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were used to confirm the association between HIF1A and ANGPTL2 promoter. The expression of nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway-related proteins and apoptosis-related proteins were also detected by Western blot analysis. As a result, ANGPTL2 expression was upregulated in H9c2 cells induced by HG or/and H/R. ANGPTL2 positively modulated HIF1A expression in H9c2 cells. HG or/and H/R suppressed the cell viability and promoted apoptosis, inflammatory response and oxidative stress levels in H9c2 cells. However, the knockdown of ANGPTL2 could reverse the above phenomena in H/R-stimulated-H9c2 cells through activation of Nrf2/HO-1 pathway. HIF1A transcriptionally activated ANGPTL2 expression. The effect of knockdown of ANGPTL2 on H/R triggered-H9c2 cells was weakened by HIF1A overexpression. In conclusion, knockdown of HIF1A downregulated ANGPTL2 to alleviate H/R injury in HG-induced H9c2 cells by activating the Nrf2/HO-1 pathway.

Intramyocardial Hemorrhage and the "Wave Front" of Reperfusion Injury Compromising Myocardial Salvage

BACKGROUND

Reperfusion therapy for acute myocardial infarction (MI) is lifesaving. However, the benefit of reperfusion therapy can be paradoxically diminished by reperfusion injury, which can increase MI size.

OBJECTIVES

Hemorrhage is known to occur in reperfused MIs, but whether hemorrhage plays a role in reperfusion-mediated MI expansion is not known.

METHODS

We studied cardiac troponin kinetics (cTn) of ST-segment elevation MI patients (n = 70) classified by cardiovascular magnetic resonance to be hemorrhagic (70%) or nonhemorrhagic following primary percutaneous coronary intervention. To isolate the effects of hemorrhage from ischemic burden, we performed controlled canine studies (n = 25), and serially followed both cTn and MI size with time-lapse imaging.

RESULTS

CTn was not different before reperfusion; however, an increase in cTn following primary percutaneous coronary intervention peaked earlier (12 hours vs 24 hours; P < 0.05) and was significantly higher in patients with hemorrhage (P < 0.01). In hemorrhagic animals, reperfusion led to rapid expansion of myocardial necrosis culminating in epicardial involvement, which was not present in nonhemorrhagic cases (P < 0.001). MI size and salvage were not different at 1 hour postreperfusion in animals with and without hemorrhage (P = 0.65). However, within 72 hours of reperfusion, a 4-fold greater loss in salvageable myocardium was evident in hemorrhagic MIs (P < 0.001). This paralleled observations in patients with larger MIs occurring in hemorrhagic cases (P < 0.01).

CONCLUSIONS

Myocardial hemorrhage is a determinant of MI size. It drives MI expansion after reperfusion and compromises myocardial salvage. This introduces a clinical role of hemorrhage in acute care management, risk assessment, and future therapeutics.

Effects of Metoprolol on Periprocedural Myocardial Infarction After Percutaneous Coronary Intervention (Type 4a MI): An Inverse Probability of Treatment Weighting Analysis

Background: Metoprolol is the most used cardiac selective β-blocker and has been recommended as a mainstay drug in the management of acute myocardial infarction (AMI). However, the evidence supporting this regimen in periprocedural myocardial infarction (PMI) is limited.

Methods: This study identified 860 individuals who suffered PMI following percutaneous coronary intervention (PCI) procedure and median followed up for 3.2 years. Subjects were dichotomized according to whether they received chronic oral sustained-release metoprolol succinate following PMI. After inverse probability of treatment weighting (IPTW) adjustment, logistic regression analysis, Kaplan-Meier curve, and Cox regression analysis were performed to estimate the effects of metoprolol on major adverse cardiovascular events (MACEs) which composed of cardiac death, myocardial infarction (MI), stroke, and revascularization. Moreover, an exploratory analysis was performed according to hypertension, cardiac troponin I (cTnI) elevation, and cardiac function. A double robust adjustment was used for sensitivity analysis.

Results: Among enrolled PMI subjects, 456 (53%) patients received metoprolol treatment and 404 (47%) patients received observation. After IPTW adjustment, receiving metoprolol was found to reduce the subsequent 3-year risk of MACEs by nearly 7.1% [15 vs. 22.1%, absolute risk difference (ARD) = 0.07, number needed to treat (NNT) = 14, relative risk (RR) = 0.682]. In IPTW-adjusted Cox regression analyses, receiving metoprolol was related to a reduced risk of MACEs (hazard ratio [HR] = 0.588, 95%CI [0.385–0.898], P = 0.014) and revascularization (HR = 0.538, 95%CI [0.326–0.89], P = 0.016). Additionally, IPTW-adjusted logistic regression analysis showed that receiving metoprolol reduced the risk of MI at the third year (odds ratio [OR] = 0.972, 95% CI [0.948–997], P = 0.029). Exploratory analysis showed that the protective effect of metoprolol was more pronounced in subgroups of hypertension and cTnI elevation ≥1,000%, and was remained in patients without cardiac dysfunction. The benefits above were consistent when double robust adjustments were performed.

Conclusion: In the real-world setting, receiving metoprolol treatment following PCI-related PMI has decreased the subsequent risk of MACEs, particularly the risk of recurrent MI and revascularization.

Early Trimetazidine Therapy in Patients Undergoing Primary Percutaneous Coronary Intervention for ST Segment Elevation Myocardial Infarction Reduces Myocardial Infarction Size

PURPOSE

Trimetazidine, a metabolic agent with anti-ischemic effects, was reported to reduce reperfusion injury in animal models. In this randomized double-blind placebo-controlled trial, we investigated the effects of trimetazidine on the reduction of infarction size in patients undergoing revascularization for ST segment elevation myocardial infarction (STEMI).

METHODS

Patients with STEMI randomly received trimetazidine (n = 87) or placebo (n = 86) before primary percutaneous coronary intervention (PCI), and subsequently received oral trimetazidine or placebo for 12 months after reperfusion. The predefined primary endpoint was infarction size on cardiac magnetic resonance (CMR) performed at 7 days after primary PCI. The trial was registered on www.clinicaltrials.gov (registration number: NCT02826616).

RESULTS

The clinical characteristics of the patients in both groups were well-matched at baseline. At 7 days after primary PCI, the percentage and absolute infarction size in the trimetazidine group were significantly smaller than those in the control group (22% ± 12% [n = 74] vs. 27% ± 13% [n = 74], p = 0.011 and 28 ± 18 g [n = 74] vs. 35 ± 19 g [n = 74], p = 0.022, respectively), and the incidence of myocardial microvascular obstruction (MVO) measured by CMR was significantly reduced in the trimetazidine group (29.7% [22/74] vs. 52.7% [39/74], p = 0.005). The myocardial salvage index (MSI) measured by CMR was significantly higher in the trimetazidine group (48% ± 20% vs. 39% ± 20%, p = 0.008). The incidence of readmission due to aggravated heart failure did not differ significantly between the trimetazidine group and the control group (8.0% vs. 14.0%, p = 0.234).

CONCLUSIONS

In patients with STEMI undergoing primary PCI, early trimetazidine before reperfusion reduced myocardial infarction size and MVO, and improved MSI.

Protective Effect of Shexiang Baoxin Pill on Myocardial Ischemia/Reperfusion Injury in Patients With STEMI

Background: There is no definite effect in the treatment of myocardial ischemia/reperfusion (I/R) injury in patients with acute ST-segment elevation myocardial infarction (STEMI). We evaluated the protective effect of Shexiang Baoxin Pill (SBP) on I/R injury in STEMI patients.

Methods: STEMI patients were randomly divided into a primary percutaneous coronary intervention (PPCI) group (n = 52) and a PPCI + SBP group (n = 51). The area at risk of infarction (AAR) and final infarct size (FIS) were examined by single-photon emission computed tomography (SPECT). I/R injury was assessed using myocardial salvage (MS) and salvage index (SI) calculated from AAR and FIS.

Results: The ST-segment resolution (STR) in the PPCI + SBP group was significantly higher than that in the PPCI group (p = 0.036), and the peak value of high-sensitivity troponin T (hsTNT) was lower than that in the PPCI group (p = 0.048). FIS in the PPCI + SBP group was smaller than that in the PPCI group (p = 0.047). MS (p = 0.023) and SI (p = 0.006) in the PPCI + SBP group were larger than those in the PPCI group. The left ventricular ejection fraction (LVEF) in the PPCI + SBP group was higher than that in the PPCI group (p = 0.049), and N-terminal pro-B type natriuretic peptide (NT-proBNP) level in the PPCI + SBP group was lower than that in the PPCI group (p = 0.048).

Conclusions: SBP can alleviate I/R injury (MS and SI), decrease myocardial infarction area (peak value of hsTNT and FIS), and improve myocardial reperfusion (MBG and STR) and cardiac function (LVEF and NT-proBNP).

Neutrophils in cardiovascular disease: warmongers, peacemakers, or both?

Neutrophils, the most abundant of all leucocytes and the first cells to arrive at the sites of sterile inflammation/injury act as a double-edged sword. On one hand, they inflict a significant collateral damage to the tissues and on the other hand, they help facilitate wound healing by a number of mechanisms. Recent studies have drastically changed the perception of neutrophils from being simple one-dimensional cells with an unrestrained mode of action to a cell type that display maturity and complex behaviour. It is now recognized that neutrophils are transcriptionally active and respond to plethora of signals by deploying a wide variety of cargo to influence the activity of other cells in the vicinity. Neutrophils can regulate macrophage behaviour, display innate immune memory, and play a major role in the resolution of inflammation in a context-dependent manner. In this review, we provide an update on the factors that regulate neutrophil production and the emerging dichotomous role of neutrophils in the context of cardiovascular diseases, particularly in atherosclerosis and the ensuing complications, myocardial infarction, and heart failure. Deciphering the complex behaviour of neutrophils during inflammation and resolution may provide novel insights and in turn facilitate the development of potential therapeutic strategies to manage cardiovascular disease.