Myocardial infarction: cardioprotection by erythropoietin

Are There Any Cardioprotective Effects or Safety Concerns of Erythropoietin in Patients With Myocardial Infarction? A Systematic Review

Myocardial infarction (MI) is a global cause of morbidity and mortality. MI is the outcome of a chronic process termed atherosclerosis, a buildup of fatty and other substances called plaques inside the coronary vessels, causing hardening and thickening of the arterial wall. Erythropoietin (EPO) is a pleiotropic cytokine released mainly by the kidneys in adults. Besides its well-known erythropoietic functions, EPO possesses anti-apoptotic, mitogenic, and angiogenic effects. This review aims to analyze the strength of any therapeutic or protective value of EPO on the heart and safety concerns regarding its administration in MI individuals.

This systematic review was performed based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Four databases (PubMed, PubMed Central, Google Scholar, and Sciences Direct) were employed to search for articles published in the last 10 years. Focused studies were relevant articles in the English language, trials, reviews, meta-analyses, and studies with a control group. Following the quality assessment process, nine studies were eligible and hence were included in the review consisting of six randomized controlled trials and three systematic reviews and meta-analyses. Contrary to preclinical studies, EPO administration did not significantly have notable effects on mortality, major adverse cardiovascular events, or infarction size reduction. Significant left ventricle ejection fraction amelioration was not appreciated either. However, EPO seems to reduce the incidence of post-MI arrhythmias.

Lack of association between erythropoietin treatment and risk of depression in patients with end-stage kidney disease on maintenance dialysis: a nationwide database study in Taiwan

Background

Patients with end-stage kidney disease (ESKD), have been associated with higher risk of developing depression. Erythropoietin (EPO), frequently used for the treatment of anemia in ESKD patients, has been shown to have neuroprotective and antidepressant effects. In this study, we examined whether EPO treatment changed the risk of depression in ESKD patients.

Methods

In a nationwide population-based cohort in Taiwan from 1998 to 2013, patients with a diagnosis of ESKD on maintenance dialysis and aged greater than 18 years were classified into EPO treatment group or non-EPO treatment group. All patients were followed up until the diagnosis of depressive disorder or the end of the study period.

Results

In this cohort (13,067 patients in the EPO and 67,258 patients in the non-EPO group), 5569 patients were diagnosed as depressive disorder in the follow-up period. We found the risk of depression in EPO group was not significantly different from that in non-EPO group (adjusted hazard ratio = 0.98, 95% confidence interval 0.92-1.04, p = 0.499) after adjusting for sex, age, certification year of catastrophic illness for ESKD, physical co-morbidities, and use of benzodiazepines.

Conclusion

In summary, using the nationwide reimbursement data in Taiwan, we found that EPO treatment in ESKD patients was not associated with their general risk of developing depression.

Getting an Early Start in Understanding Perinatal Asphyxia Impact on the Cardiovascular System

Perinatal asphyxia (PA) is a burdening pathology with high short-term mortality and severe long-term consequences. Its incidence, reaching as high as 10 cases per 1000 live births in the less developed countries, prompts the need for better awareness and prevention of cases at risk, together with management by easily applicable protocols. PA acts first and foremost on the nervous tissue, but also on the heart, by hypoxia and subsequent ischemia-reperfusion injury. Myocardial development at birth is still incomplete and cannot adequately respond to this aggression. Cardiac dysfunction, including low ventricular output, bradycardia, and pulmonary hypertension, complicates the already compromised circulatory status of the newborn with PA. Multiorgan and especially cardiovascular failure seem to play a crucial role in the secondary phase of hypoxic-ischemic encephalopathy (HIE) and its high mortality rate. Hypothermia is an acceptable solution for HIE, but there is a fragile equilibrium between therapeutic gain and cardiovascular instability. A profound understanding of the underlying mechanisms of the nervous and cardiovascular systems and a close collaboration between the bench and bedside specialists in these domains is compulsory. More resources need to be directed toward the prevention of PA and the consecutive decrease of cardiovascular dysfunction. Not much can be done in case of an unexpected acute event that produces PA, where recognition and prompt delivery are the key factors for a positive clinical result. However, the situation is different for high-risk pregnancies or circumstances that make the fetus more vulnerable to asphyxia. Improving the outcome in these cases is possible through careful monitoring, identifying the high-risk pregnancies, and the implementation of novel prenatal strategies. Also, apart from adequately supporting the heart through the acute episode, there is a need for protocols for long-term cardiovascular follow-up. This will increase our recognition of any lasting myocardial damage and will enhance our perspective on the real impact of PA. The goal of this article is to review data on the cardiovascular consequences of PA, in the context of an immature cardiovascular system, discuss the potential contribution of cardiovascular impairment on short and long-term outcomes, and propose further directions of research in this field.

Possible involvement of alpha B-crystallin in the cardioprotective effect of n-butanol extract of Potentilla anserina L. on myocardial ischemia/reperfusion injury in rat

BACKGROUND

It has been reported that n-butanol extract of Potentilla anserina L (NP) had protective effect against acute myocardial ischemia/reperfusion (I/R) injury in mice. Because of limited phytochemical study on NP, its bioactive compounds and underlying protective mechanisms are largely unclear.

PURPOSE

The purpose of this study was to investigate the major bioactive compounds and possible mechanism for the cardioprotective effect of NP on rat with I/R injury.

METHODS

We analyzed the phytochemical isolation of NP and identified the structure of compounds, which was elucidated by a combination of spectroscopic analyses. An I/R model was established by I-30 min/R-2 h in Sprage-Dawley rats. The rats were given intragastric administration of NP (49.3, 98.6, and 197.2 mg•kg^-1) continuously for 10 days before I/R operation. The morphological changes and apoptosis of cardiomyocytes were observed by H&E staining, Transmission electron microscope and TUNEL staining respectively. The activities or contents of catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH) in plasma were detected. Apoptosis related factors were also measured by RT-PCR and western blot. In order to discover the underlying mechanism of NP on I/R, we performed proteomic analysis using two-dimensional gel electrophoresis (2D-DIGE) and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) to describe differential proteins expression. Potential target protein resulted from 2D-DIGE coupled to MALDI-TOF/MS analysis were further confirmed by immunohistochemical staining, RT-PCR, and western blot.

RESULTS

We isolated and identified 14 compounds, of which 7 compounds belong to triterpenes. Rats pretreated with NP showed a significant increase on the activities of GSH, SOD and CAT, and remarkable decrease on the content of MDA. NP significantly inhibited the apoptosis of cardiomyocyte and decreased the expression of Cyt C and cleaved-caspase-3. Proteomic analysis revealed that alpha B-crystallin (CryAB) might participate in the NP protective effect against I/R. NP enhanced the level of pCryAB Ser59, whereas the expression of CryAB was decreased.

CONCLUSION

NP was showed to alleviate I/R injury and inhibit myocardial apoptosis, which might be associated with reduction on oxidative stress and apoptosis. CryAB as a possible target involved in the NP protective effect. This study supplied valuable information to develop novel cardioprotective agents from NP extract.

Erythropoietin mediates brain-vascular-kidney crosstalk and may be a treatment target for pulmonary and resistant essential hypertension

Organ crosstalk pathways represent the next frontier for target-mining in molecular medicine for existing syndromes. Pulmonary hypertension and resistant essential hypertension are syndromes that have been proven elusive in etiology, and frequently refractory to first-line management. Underlying crosstalk mechanisms, not yet considered in these treatments, may hinder outcomes or unlock novel treatments. This review focuses systematically on erythropoietin, a synthesizable molecule, as a mediator of brain-kidney crosstalk. Insights gained from this review will be applied to cardiovascular diseases in a clinician-directed fashion.

Effect of Erythropoietin in patients with acute myocardial infarction: five-year results of the REVIVAL-3 trial

BACKGROUND

Erythropoietin (EPO) has been suggested to promote cardiac repair after MI. However, the randomized, double-blind, placebo controlled REVIVAL-3 trial showed that short term high dose EPO in timely reperfused myocardium does not improve left ventricular ejection fraction after 6 months. Moreover, the study raised safety concerns due to a trend towards a higher incidence of adverse clinical events as well as a increase in neointima formation after treatment with EPO. The present study therefore aimed to assess the 5-year clinical outcomes.

METHODS

After successful reperfusion 138 patients with STEMI were randomly assigned to receive epoetin beta (3.33×10⁴ U, n = 68) or placebo (n = 70) immediately, 24 and 48 h after percutaneous coronary intervention. The primary outcome of the present study- the combined incidence of MACE 5 years after randomization - occurred in 25% of the patients assigned to epoetin beta and 17% of the patients assigned to placebo (RR 1.5; 95% CI 0.8-3.5; p = 0.26). Target lesion revascularization was required in 15 patients (22.1%) treated with epoetin-ß and 9 patients (12.9%) treated with placebo (p = 0.15). Analysis of patients in the upper and lower quartile of baseline hemoglobin as an indirect estimate of endogenous erythropoietin levels revealed no significant impact of endogenous erythropoietin on efficiency of exogen administered epoetin-ß in terms of death and MACE.

CONCLUSION

These long-term follow-up data show that epoetin beta does not improve clinical outcomes of patients with acute myocardial infarction.

TRIAL REGISTRATION

URL www.clinicaltrials.gov ; Unique identifier NCT00390832; trial registration date October 19th 2006.

Novel perspectives on the PHD-HIF oxygen sensing pathway in cardioprotection mediated by IPC and RIPC

Reperfusion of ischemic cardiac tissue is the standard treatment for improving clinical outcome following myocardial infarction but is inevitably associated with ischemia-reperfusion injury (IRI). Ischemic myocardial injury can be alleviated by exposing the heart to brief episodes of sublethal ischemia-reperfusion prior to the ischemic insult, a phenomenon that has been termed ischemic preconditioning (IPC). Similarly, remote IPC (RIPC) is defined as transient episodes of ischemia at a distant site before a subsequent prolonged injury of the target organ. In this setting, adaptive responses to hypoxia/ischemia in peripheral tissues include the release of soluble factors that have the potential to protect cardiomyocytes remotely. Oxygen fluctuations is a hallmark of insufficient tissue perfusion and ischemic episodes. Emerging evidence indicates that prolyl hydroxylase oxygen sensors (PHDs) and hypoxia-inducible transcription factors (HIFs) are critical regulators of IPC and RIPC. In this review, we discuss recent findings concerning the role of the PHD-HIF axis in IPC and RIPC-mediated cardioprotection and examine molecular pathways and cell types that might be involved. We also appraise the therapeutic value of targeting the PHD-HIF axis to enhance cardiac tolerance against IRI.