Editor's Choice- Pathophysiology and therapy of myocardial ischaemia/reperfusion syndrome

Cardiovascular disease care and outcomes in West and South European countries

Variations in cardiovascular disease (CVD) burden between West and South European countries are rarely reported. To address this knowledge gap, The Lancet Regional Health-Europe convened experts from a broad range of countries to assess the current state of knowledge of cardiovascular disease inequalities across Europe. This Review is specifically focused on West and South European countries. Mortality, risk factor and economic data for nine West European and six South European countries were sourced from the World Health Organisation, the Global Burden of Disease study and the World Bank. Healthcare data were collected by survey of participating countries. A key finding was of declines in age-standardised mortality rates (ASMRs) across all countries since 1990. In 2019 rates per 100,000 were lower in West European countries in males (279.7 (264.1-335.9) vs 337.2 (323.7-367.2)) and females (196.2 (183.3-228.8) vs 247.3 (232.2-268.3)). Differences in risk factor exposures were small, with the exception of physical activity and dietary factors, but across all countries the prevalence of obesity has increased, affecting >20% of adults in 2019. Healthcare delivery in 2019 showed inequalities with cardiovascular procedure rates lower in South compared with West European countries. Further declines in ASMRs in West and South European countries will require population strategies to reduce obesity and address inequalities in physical activity and dietary factors. Reducing the gap in procedure rates is unlikely to match the beneficial effects of population strategies for reducing CVD burden in South European countries.

Segmental and transmural motion of the rat myocardium estimated using quantitative ultrasound with new strategies for infarct detection

Introduction: The estimation of myocardial motion abnormalities has great potential for the early diagnosis of myocardial infarction (MI). This study aims to quantitatively analyze the segmental and transmural myocardial motion in MI rats by incorporating two novel strategies of algorithm parameter optimization and transmural motion index (TMI) calculation. Methods: Twenty-one rats were randomly divided into three groups (n = 7 per group): sham, MI, and ischemia-reperfusion (IR) groups. Ultrasound radio-frequency (RF) signals were acquired from each rat heart at 1 day and 28 days after animal model establishment; thus, a total of six datasets were represented as Sham1, Sham28, MI1, MI28, IR1, and IR28. The systolic cumulative displacement was calculated using our previously proposed vectorized normalized cross-correlation (VNCC) method. A semiautomatic regional and layer-specific myocardium segmentation framework was proposed for transmural and segmental myocardial motion estimation. Two novel strategies were proposed: the displacement-compensated cross-correlation coefficient (DCCCC) for algorithm parameter optimization and the transmural motion index (TMI) for quantitative estimation of the cross-wall transmural motion gradient. Results: The results showed that an overlap value of 80% used in VNCC guaranteed a more accurate displacement calculation. Compared to the Sham1 group, the systolic myocardial motion reductions were significantly detected (p < 0.05) in the middle anteroseptal (M-ANT-SEP), basal anteroseptal (B-ANT-SEP), apical lateral (A-LAT), middle inferolateral (M-INF-LAT), and basal inferolateral (B-INF-LAT) walls as well as a significant TMI drop (p < 0.05) in the M-ANT-SEP wall in the MI1 rats; significant motion reductions (p < 0.05) were also detected in the B-ANT-SEP and A-LAT walls in the IR1 group. The motion improvements (p < 0.05) were detected in the M-INF-LAT wall in the MI28 group and the apical septal (A-SEP) wall in the IR28 group compared to the MI1 and IR1 groups, respectively. Discussion: Our results show that the MI-induced reductions and reperfusion-induced recovery in systolic myocardial contractility could be successfully evaluated using our method, and most post-MI myocardial segments could recover systolic function to various extents in the remodeling phase. In conclusion, the ultrasound-based quantitative estimation framework for estimating segmental and transmural motion of the myocardium proposed in our study has great potential for non-invasive, novel, and early MI detection.

Integrating UPLC-Q-Exactive Orbitrap/MS, network pharmacology and experimental validation to reveal the potential mechanism of Tibetan medicine Rhodiola granules in improving myocardial ischemia-reperfusion injury

ETHNOPHARMACOLOGY RELEVANCE

Rhodiola granules (RG) is a traditional Tibetan medicine prescription that can be used to improve the symptoms of ischemia and hypoxia in cardiovascular and cerebrovascular diseases. However, there is no report on its use to improve myocardial ischemia/reperfusion (I/R) injury, and its potential active ingredients and mechanism against myocardial ischemia/reperfusion (I/R) injury remain unclear.

AIM OF THE STUDY

This study aimed to reveal the potential bioactive components and underlying pharmacological mechanisms of RG in improving myocardial I/R injury through a comprehensive strategy.

MATERIALS AND METHODS

UPLC-Q-Exactive Orbitrap/MS technology was used to analyze the chemical components of RG, the potential bioactive components and targets were tracked and predicted by the SwissADME and SwissTargetPrediction databases, and the core targets were predicted through the PPI network, as well the functions and pathways were determined by GO and KEGG analysis. In addition, the molecular docking and ligation of the anterior descending coronary artery-induced rat I/R models were experimentally validated.

RESULTS

A total of 37 ingredients were detected from RG, including nine flavones, ten flavonoid glycosides, one glycoside, eight organic acids, four amides, two nucleosides, one amino acid, and two other components. Among them, 15 chemical components, such as salidroside, morin, diosmetin, and gallic acid were identified as key active compounds. Ten core targets, including AKT1, VEGF, PTGS2, and STAT3, were discovered through the analysis of the PPI network constructed from 124 common potential targets. These possible targets were involved in the regulation of oxidative stress and HIF-1/VEGF/PI3K-Akt signaling pathways. Furthermore, molecular docking confirmed that the potential bioactive compounds in RG have good potential binding abilities to AKT1, VEGFA, PTGS2, STAT3, and HIF-1α proteins. Then, the animal experiments showed that RG could significantly improve the cardiac function of I/R rats, reduce the size of myocardial infarction, improve the myocardial structure, and reduce the degree of myocardial fibrosis, inflammatory cell infiltration, and myocardial cell apoptosis rate in I/R rats. In addition, we also found that RG could decrease the concentration of AGE, Ox-LDL, MDA, MPO, XOD, SDH, Ca²⁺, and ROS, and increase the concentration of Trx, TrxR1, SOD, T-AOC, NO, ATP, Na⁺k⁺-ATPase, Ca²⁺-ATPase, and CCO. Moreover, RG could significantly down-regulate the expressions of Bax, Cleaved-caspase3, HIF-1α, and PTGS2, as well up-regulate the expressions of Bcl-2, VEGFA, p-AKT1, and p-STAT3.

CONCLUSION

In summary, we revealed for the first time the potential active ingredients and mechanisms of RG for myocardial I/R injury therapy through a comprehensive research strategy. RG may synergistically improve myocardial I/R injury through anti-inflammatory, regulating energy metabolism, and oxidative stress, improving I/R-induced myocardial apoptosis, which may be related to the HIF-1/VEGF/PI3K-Akt signaling pathway. Our study provides new insights into the clinical application of RG and also provides a reference for the development and mechanism research of other Tibetan medicine compound preparations.

SGLT2 inhibitor dapagliflozin alleviates intramyocardial hemorrhage and adverse ventricular remodeling via suppressing hepcidin in myocardial ischemia-reperfusion injury

Intramyocardial hemorrhage (IMH), a reperfusion therapy-associated complication, is the extravasation of red blood cells caused by severe microvascular injury. IMH is an independent predictor of adverse ventricular remodeling (AVR) after acute myocardial infarction (AMI). Hepcidin, a major regulator of iron uptake and systemic distribution, is a key factor affecting AVR. However, the role of cardiac hepcidin in the development of IMH has not been completely elucidated. This study aimed to explore if sodium-dependent glucose co-transporter 2 inhibitor (SGLT2i) exerts therapeutic effects on IMH and AVR by suppressing hepcidin and to elucidate the underlying mechanisms. SGLT2i alleviated IMH and AVR in the ischemia-reperfusion injury (IRI) mouse model. Additionally, SGLT2i downregulated the cardiac levels of hepcidin in IRI mice, suppressed M1-type macrophage polarization, and promoted M2-type macrophage polarization. The effects of hepcidin knockdown on macrophage polarization were similar to those of SGLT2i in RAW264.7 cells. SGLT2i treatment or hepcidin knockdown inhibited the expression of MMP9, an inducer of IMH and AVR, in RAW264.7 cells. Regulation of macrophage polarization and reduction of MMP9 expression by SGLT2i and hepcidin knockdown is achieved through activation of pSTAT3. In conclusion, this study demonstrated that SGLT2i alleviated IMH and AVR by regulating macrophage polarization. The potential mechanism through which SGLT2i exerted its therapeutic effect seems to involve the downregulation of MMP9 via the hepcidin-STAT3 pathway.

Intracoronary Administration of Microencapsulated HGF in a Reperfused Myocardial Infarction Swine Model

Therapy microencapsulation allows minimally invasive, safe, and effective administration. Hepatocyte growth factor (HGF) has angiogenic, anti-inflammatory, anti-apoptotic, and anti-fibrotic properties. Our objective was to evaluate the cardiac safety and effectiveness of intracoronary (IC) administration of HGF-loaded extended release microspheres in an acute myocardial infarction (AMI) swine model. An IC infusion of 5 × 106 HGF-loaded microspheres (MS+HGF, n = 7), 5 × 106 placebo microspheres (MS, n = 7), or saline (SAL, n = 7) was performed two days after AMI. TIMI flow and Troponin I (TnI) values were assessed pre- and post-treatment. Cardiac function was evaluated with magnetic resonance imaging (cMR) before injection and at 10 weeks. Plasma cytokines were determined to evaluate the inflammatory profile and hearts were subjected to histopathological evaluation. Post-treatment coronary flow was impaired in five animals (MS+HGF and MS group) without significant increases in TnI. One animal (MS group) died during treatment. There were no significant differences between groups in cMR parameters at any time (p > 0.05). No statistically significant changes were found between groups neither in cytokines nor in histological analyses. The IC administration of 5 × 106 HGF-loaded-microspheres 48 h post-AMI did not improve cardiac function, nor did it decrease inflammation or cardiac fibrosis in this experimental setting.

Revascularized ST-segment elevation myocardial infarction. Temporal trends in contemporary therapies and impact on outcomes

INTRODUCTION AND OBJECTIVES

To assess, in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous intervention, the pace of introduction in clinical practice (2010-2017) of drug-eluting stents (DES), ticagrelor, prasugrel, and prolonged dual antiplatelet therapy (DAPT) duration, and their potential impact on the risk of 2-year outcomes.

METHODS

Prospective and exhaustive community-wide cohort of 14 841 STEMI patients undergoing primary percutaneous intervention between 2010 and 2017. Index episodes were obtained from the Catalan Codi IAM Registry, events during follow-up from the Minimum Data Set and DAPT were defined by pharmacy dispensation. Follow-up was 24 months. The temporal trend for exposures and outcomes was assessed using regression models.

RESULTS

Age> 65 years, diabetes, renal failure, previous heart failure, and need for anticoagulation at discharge were more frequent in later periods (P <.001). From 2010 to 2017, the use of DES increased from 31.1% to 69.8%, ticagrelor from 0.1% to 28.6%, prasugrel from 1.5% to 23.8%, and the median consecutive months on DAPT from 2 to 10 (P <.001 for all). Adjusted analysis showed a temporal trend to a lower risk of the main outcome over time: the composite of death, acute myocardial infarction, stroke and repeat revascularization (absolute odds reduction 0.005% each quarter; OR, 0.995; 95%CI, 0.99-0.999; P=.028). The odds of all individual components except stroke were reduced, although significance was only reached for revascularization.

CONCLUSIONS

Despite a strong increase between 2010 and 2017 in the use and duration of DAPT and the use of ticagrelor, prasugrel and DES, there was no substantial reduction in major cardiovascular outcomes.

Left ventricular function, strain, and infarct characteristics in patients with transient ST-segment elevation myocardial infarction compared to ST-segment and non-ST-segment elevation myocardial infarctions

AIMS

This study aims to explore cardiovascular magnetic resonance (CMR)-derived left ventricular (LV) function, strain, and infarct size characteristics in patients with transient ST-segment elevation myocardial infarction (TSTEMI) compared to patients with ST-segment and non-ST-segment elevation myocardial infarctions (STEMI and NSTEMI, respectively).

METHODS AND RESULTS

In total, 407 patients were enrolled in this multicentre observational prospective cohort study. All patients underwent CMR examination 2-8 days after the index event. CMR cine imaging was performed for functional assessment and late gadolinium enhancement to determine infarct size and identify microvascular obstruction (MVO). TSTEMI patients demonstrated the highest LV ejection fraction and the most preserved global LV strain (longitudinal, circumferential, and radial) across the three groups (overall P ≤ 0.001). The CMR-defined infarction was less frequently observed in TSTEMI than in STEMI patients [77 (65%) vs. 124 (98%), P < 0.001] but was comparable with NSTEMI patients [77 (65%) vs. 66 (70%), P = 0.44]. A remarkably smaller infarct size was seen in TSTEMI compared to STEMI patients [1.4 g (0.0-3.9) vs. 13.5 g (5.3-26.8), P < 0.001], whereas infarct size was not significantly different from that in NSTEMI patients [1.4 g (0.0-3.9) vs. 2.1 g (0.0-8.6), P = 0.06]. Whilst the presence of MVO was less frequent in TSTEMI compared to STEMI patients [5 (4%) vs. 53 (31%), P < 0.001], no significant difference was seen compared to NSTEMI patients [5 (4%) vs. 5 (5%), P = 0.72].

CONCLUSION

TSTEMI yielded favourable cardiac LV function, strain, and infarct-related scar mass compared to STEMI and NSTEMI. LV function and infarct characteristics of TSTEMI tend to be more similar to NSTEMI than STEMI.

The potential of remdesivir to affect function, metabolism and proliferation of cardiac and kidney cells in vitro

Remdesivir is a prodrug of a nucleoside analog and the first antiviral therapeutic approved for coronavirus disease. Recent cardiac safety concerns and reports on remdesivir-related acute kidney injury call for a better characterization of remdesivir toxicity and understanding of the underlying mechanisms. Here, we performed an in vitro toxicity assessment of remdesivir around clinically relevant concentrations (C_max 9 µM) using H9c2 rat cardiomyoblasts, neonatal mouse cardiomyocytes (NMCM), rat NRK-52E and human RPTEC/TERT1 cells as cell models for the assessment of cardiotoxicity or nephrotoxicity, respectively. Due to the known potential of nucleoside analogs for the induction of mitochondrial toxicity, we assessed mitochondrial function in response to remdesivir treatment, early proteomic changes in NMCM and RPTEC/TERT1 cells and the contractile function of NMCM. Short-term treatments (24 h) of H9c2 and NRK-52E cells with remdesivir adversely affected cell viability by inhibition of proliferation as determined by significantly decreased ³H-thymidine uptake. Mitochondrial toxicity of remdesivir (1.6–3.1 µM) in cardiac cells was evident by a significant decrease in oxygen consumption, a collapse of mitochondrial membrane potential and an increase in lactate secretion after a 24–48-h treatment. This was supported by early proteomic changes of respiratory chain proteins and intermediate filaments that are typically involved in mitochondrial reorganization. Functionally, an impedance-based analysis showed that remdesivir (6.25 µM) affected the beat rate and contractility of NMCM. In conclusion, we identified adverse effects of remdesivir in cardiac and kidney cells at clinically relevant concentrations, suggesting a careful evaluation of therapeutic use in patients at risk for cardiovascular or kidney disease.

MicroRNA-503 Exacerbates Myocardial Ischemia/Reperfusion Injury via Inhibiting PI3K/Akt- and STAT3-Dependent Prosurvival Signaling Pathways

Acute myocardial infarction is a leading cause of death worldwide, while restoration of blood flow to previously ischemic myocardium may lead to ischemia/reperfusion (I/R) injury. Accumulated evidence shows that microRNAs play important roles in cardiovascular diseases. However, the potential role of microRNA-503 (miR-503) in myocardial I/R injury is little known. Thus, this study is aimed at determining whether and how miR-503 affects myocardial I/R injury in vivo and in vitro. A mouse model of myocardial I/R injury and H9c2 cell model of hypoxia/reoxygenation (H/R) injury were established. The postischemic cardiac miR-503 was downregulated in vivo and in vitro. Mechanistically, PI3K p85 and Bcl-2 are miR-503 targets. The post-ischemic cardiac PI3K p85 protein level was decreased in vivo. Agomir-503 treatment exacerbated H/R-induced injuries manifested as decreased cell viability, increased lactate dehydrogenase activity, and cell apoptosis. Agomir-503 treatment reduced cell viability under normoxia as well and reduced both PI3K p85 and Bcl-2 protein levels under either normoxia or H/R condition. It reduced phosphorylation of Stat3 (p-Stat3-Y705) and Akt (T450) in cells subjected to H/R. In contrast, Antagomir-503 treatment attenuated H/R injury and increased p-Stat3 (Y705) under normoxia and increased p-Akt (T450) under either normoxia or H/R condition. It is concluded that miR-503 exacerbated I/R injury via inactivation of PI3K/Akt and STAT3 pathways and may become a therapeutic target in preventing myocardial I/R injury.

Hypercholesterolemia attenuates cardioprotection of ischemic preconditioning and postconditioning with α7 nicotinic acetylcholine receptor agonist by enhancing inflammation and inhibiting the PI3K/Akt/eNOS pathway

The present study aimed to evaluate the effects of hypercholesterolemia on cardioprotection of ischemic preconditioning and α7 nicotinic acetylcholine receptor (α7nAChR) agonist postconditioning and explore the potential mechanisms that hypercholesterolemia affected their cardioprotection. Hypercholesterolemic and normal rats were divided into the four groups that received the following treatments: i) Hypercholesterolemic control and normal control groups; ii) hypercholesterolemic ischemia/reperfusion (HI) and normal ischemia/reperfusion (NI) groups; iii) hypercholesterolemic ischemic preconditioning (HIPC) and normal ischemic preconditioning (NIPC) groups; and iv) hypercholesterolemic PNU282987 postconditioning (HPNU) and normal PNU282987 postconditioning (NPNU) groups. Serum lactate dehydrogenase (LDH), creatine kinase isoenzyme MB (CK-MB), cardiac troponin I (cTnI), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) levels after ischemia/reperfusion were assayed. Furthermore, infarct size and expression levels of Akt, phosphorylated (p)-Akt and endothelial nitric oxide synthase (eNOS) in ischemic myocardium were assessed. Compared with the NI group, serum LDH, CK-MB, cTnI, TNF-α and IL-6 levels and infarct size were significantly decreased, and myocardial p-Akt/Akt and eNOS/GAPDH ratios were significantly increased in the NIPC and NPNU groups. Compared with the HI group, serum CK-MB, cTnI, TNF-α and IL-6 levels and infarct size were significantly decreased in the HIPC group; however, myocardial p-Akt/Akt and eNOS/GAPDH ratios did not significantly change in the HIPC group. Furthermore, there were no significant difference between the HI and HPNU groups in serum LDH, CK-MB, cTnI, TNF-α and IL-6 levels, infarct size, myocardial p-Akt/Akt and eNOS/GAPDH ratios. In conclusion, hypercholesterolemia could aggravate myocardial ischemia/reperfusion injury, attenuate cardioprotection of ischemic preconditioning and eliminate cardioprotection from α7nAChR agonist postconditioning by enhancing inflammation and inhibiting PI3K/Akt/eNOS pathway.

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.

Sex disparities in in-hospital outcomes of left ventricular aneurysm complicating acute myocardial infarction: A United States nationwide analysis

Background

Previous studies have reported sex-specific differences in the presentation, mechanisms, and outcomes of acute myocardial infarction (AMI). We assessed differences between women and men in the incidence and in-hospital outcomes of left ventricular (LV) aneurysm complicating AMI.

Methods

Hospitalizations for AMI with LV aneurysm were identified retrospectively in the National Inpatient Sample (NIS) from 2001 to 2017. Incidence and trends in in-hospital mortality, complications, length of stay and costs were analyzed in women and men.

Results

A total of 16,334 AMI hospitalizations with concomitant LV aneurysm were identified including 6994 (42.8%) women and 9340 (57.2%) men. Among these hospitalizations, women had a higher incidence of LV aneurysm compared to men (0.16% vs. 0.14%; p < 0.001). Unadjusted in-hospital mortality was higher in women than men (12.7% vs. 7.2%; p < 0.001). After adjusting for demographic and baseline characteristics and excluding inter-hospital transfers, women with AMI complicated by LV aneurysm had 49% greater odds of in-hospital mortality than men (OR 1.49, 95% confidence interval 1.06-2.10, p = 0.02). Women with LV aneurysm were less likely than men to undergo percutaneous coronary intervention (28.5% vs. 35.4%; p < 0.001), bypass surgery (15.8% vs. 25.1%; p < 0.001), coronary atherectomy (0.8% vs. 1.9%; p = 0.009) and LV aneurysm surgery (7.8% vs. 11.1%; p = 0.001).

Conclusions

In this large population-based cohort study, women had a slightly higher incidence but dramatically higher in-hospital mortality associated with LV aneurysm complicating AMI compared to men. Further research is necessary to validate strategies to ensure that women receive guideline-directed therapy for AMI and LV aneurysm to address the sex disparity in mortality.

Recurrence of angina after ST-segment elevation myocardial infarction: the role of coronary microvascular obstruction

BACKGROUND

The recurrence of angina after percutaneous coronary intervention affects 20-35% of patients with stable coronary artery disease; however, few data are available in the setting of ST-segment elevation myocardial infarction. We evaluated the relation between coronary microvascular obstruction and the recurrence of angina at follow-up.

METHODS

We prospectively enrolled patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. Microvascular obstruction was defined as thrombolysis in myocardial infarction flow less than 3 or 3 with myocardial blush grade less than 2. The primary endpoint was the recurrence of angina at follow-up. Moreover, angina status was evaluated by the Seattle angina questionnaire summary score (SAQSS). Therapy at follow-up and the occurrence of major adverse cardiovascular events were also collected.

RESULTS

We enrolled 200 patients. Microvascular obstruction occurred in 52 (26%) of them. Follow-up (mean time 25.17±9.28 months) was performed in all patients. Recurrent angina occurred in 31 (15.5%) patients, with a higher prevalence in patients with microvascular obstruction compared with patients without microvascular obstruction (13 (25.0%) vs. 18 (12.2%), P=0.008). Accordingly, SAQSS was lower and the need for two or more anti-anginal drugs was higher in patients with microvascular obstruction compared with patients without microvascular obstruction. At multiple linear regression analysis a history of previous acute coronary syndrome and the occurrence of microvascular obstruction were the only independent predictors of a worse SAQSS. Finally, the occurrence of major adverse cardiovascular events was higher in patients with microvascular obstruction compared with patients without microvascular obstruction.

CONCLUSIONS

The recurrence of angina in ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention is an important clinical issue. The occurrence of microvascular obstruction portends a worse angina status and is associated with the use of more anti-anginal drugs.

Rationale and design of the pragmatic clinical trial tREatment with Beta-blockers after myOcardial infarction withOut reduced ejection fracTion (REBOOT)

BACKGROUND

There is a lack of evidence regarding the benefits of β-blocker treatment after invasively managed acute myocardial infarction (MI) without reduced left ventricular ejection fraction (LVEF).

METHODS AND RESULTS

TREatment with Beta-blockers after myOcardial infarction withOut reduced ejection fraction (REBOOT) trial is a pragmatic, controlled, prospective, randomized, open-label blinded endpoint (PROBE design) clinical trial testing the benefits of β-blocker maintenance therapy in patients discharged after MI with or without ST-segment elevation. Patients eligible for participation are those managed invasively during index hospitalization (coronary angiography), with LVEF >40%, and no history of heart failure (HF). At discharge, patients will be randomized 1:1 to β-blocker therapy (agent and dose according to treating physician) or no β-blocker therapy. The primary endpoint is a composite of all-cause death, nonfatal reinfarction, or HF hospitalization over a median follow-up period of 2.75 years (minimum 2 years, maximum 3 years). Key secondary endpoints include the incidence of the individual components of the primary composite endpoint, the incidence of cardiac death, and incidence of malignant ventricular arrhythmias or resuscitated cardiac arrest. The primary endpoint will be analyzed according to the intention-to-treat principle.

CONCLUSION

The REBOOT trial will provide robust evidence to guide the prescription of β-blockers to patients discharged after MI without reduced LVEF.

Intravenous metoprolol during ongoing STEMI ameliorates markers of ischemic injury: a METOCARD-CNIC trial electrocardiographic study

Besides its protective effect against neutrophil-mediated injury at reperfusion, intravenous (IV) metoprolol was recently shown to reduce the progression of ischemic injury in a pig model of ST-segment elevation myocardial infarction (STEMI). Here, we tested the hypothesis that IV metoprolol administration in humans with ongoing STEMI blunts the time‑dependent progression of ischemic injury assessed by serial electrocardiogram (ECG) evaluations before reperfusion. The METOCARD-CNIC trial randomized 270 anterior STEMI patients to IV metoprolol or control before reperfusion by percutaneous coronary intervention (PCI). In 139 patients (69 IV metoprolol, 70 controls), two ECGs were available (ECG-1 before randomization, ECG-2 pre-PCI). Between-group ECG differences were analyzed using univariate and multivariate regression models. No significant between-group differences were observed on ECG-1. On ECG-2, patients who received IV metoprolol had a narrower QRS than those in the control group (84 ms vs. 90 ms, p = 0.029), a lower prevalence of QRS distortion (10% vs. 26%, p = 0.017), and a lower sum of anterior and total ST-segment elevation (10.1 mm vs. 13.6 mm, p = 0.014 and 10.4 mm vs. 14.0 mm, p = 0.015, respectively). Adjusted analysis revealed similar results. Significant associations were observed between ECG-2 variables and cardiac magnetic resonance imaging measurements (extent of myocardial edema, infarct size, microvascular obstruction, and left-ventricular ejection fraction) after STEMI. In summary, IV metoprolol administration before reperfusion ameliorates ECG markers of myocardial ischemia in anterior STEMI patients. These data confirm that IV metoprolol is able to reduce ischemic injury and highlight the ability of ECG analysis to provide relevant real-time information on the effect of cardioprotective therapies before reperfusion.

Revisiting the lipid paradox in ST-elevation myocardial infarction in the Chinese population: findings from the CCC-ACS project

AIMS

Previous observations revealed a negative association between low-density lipoprotein cholesterol (LDL-C) and clinical outcomes following myocardial infarction, i.e., the lower level the higher mortality, which was referred to as lipid paradox. We sought to re-evaluate this association in ST-elevation myocardial infarction (STEMI) in contemporary practice.

METHODS AND RESULTS

We examined the association between admission LDL-C and in-hospital mortality among 44 563 STEMI patients enrolled from 2014 to 2019 in a nationwide registry in China. A total of 43 covariates, which were temporally classified into the following three domains were used for adjustment: (i) pre-admission characteristics; (ii) percutaneous coronary intervention (PCI)-related variables; and (iii) other in-hospital medications. In-hospital mortality was 2.01% (897/44 563). When no covariate adjustment was performed, an inversely 'J-shaped' curve was observed between admission LDL-C levels and in-hospital mortality by restricted cubic spline in logistic regression, with a threshold value of <75 mg/dL that associated with increased risk for in-hospital mortality. However, a gradual attenuation for this association was noted when step-wise adjustments were performed, with the threshold values for LDL-C decreasing from 75 mg/dL to 70 mg/dL after accounting for pre-admission characteristics, further to 65 mg/dL after accounting for PCI-related variables, and finally to no statistical association after further adjustment for other in-hospital medications.

CONCLUSIONS

In a nationwide registry in China, our findings do not support the lipid paradox in terms of in-hospital mortality in STEMI patients in contemporary practice. Previous findings in this scenario are possibly due to inadequate control for confounders.

Left ventricular end-diastolic pressure predicts in-hospital outcomes in takotsubo syndrome

AIMS

Takotsubo syndrome (TTS) is associated to serious adverse in-hospital complications. We evaluated the role of invasively assessed left ventricular end-diastolic pressure (LVEDP) for predicting in-hospital complications in TTS patients compared to the most widely used echocardiographic parameters of ventricular function.

METHODS AND RESULTS 

We prospectively enrolled 130 patients (mean age 71.2 ± 11.3 years, 114 [87.7%] female) with TTS. Invasive measurement of LVEDP was performed at the time of cardiac catheterization. The rate of in-hospital complications (composite of acute heart failure, life-threatening arrhythmias and all-cause death) was examined. In-hospital complications occurred in 37 (28.5%) patients. Patients who experienced in-hospital complications had a higher prevalence of neurological trigger and lower prevalence of emotional trigger, higher LVEDP and mean E/e' ratio and lower LV ejection fraction (LVEF) values compared to those who did not experience in-hospital complications. At multivariate logistic regression, higher LVEDP [odds ratio (OR) 1.12, 95% confidence interval (CI) [1.05-1.20], P < 0.001] and lower LVEF (OR 0.95, 95% CI [0.91-0.99], P = 0.011) remained independently predictors of in-hospital complications, while emotional trigger was associated to a lower risk (OR 0.24, 95% CI [0.06-0.96], P = 0.044). The area under the curve (AUC) for LEVDP in the prediction of in-hospital events was 0.776 (95% CI [0.69-0.86], P <0.001, with a sensitivity and specificity of 95% and 58% using a LVEDP cut-off value of 22.5 mmHg). The AUC was significantly higher for LVEDP than for E/e' ratio (P = 0.037).

CONCLUSIONS 

LVEDP measured at the time of catheterization may help in identifying TTS patients at higher risk of cardiovascular deterioration with relevant therapeutic implications.

Assessment of the ESC quality indicators in patients with acute myocardial infarction: a systematic review

AIMS

To help improving quality of care in patients with acute myocardial infarction (AMI), the European Society of Cardiology (ESC) set 20 quality indicators (QIs). There is a need to compile and summarize QI availability, feasibility, and global compliance in real-world registries.

METHODS AND RESULTS

A systematic review of PubMed and Web of Science was conducted including all original articles reporting the use of the ESC QIs in AMI patients. Methods and reporting follow the guidelines of the PRISMA Statement and the protocol was registered in PROSPERO (CRD42020190541). Among the 220 screened citations, 9 studies met the inclusion criteria after full-text review. Among these 9 studies, there were 11 different cohorts. Patients were recruited from three different continents (31 countries). The number of QIs assessed ranged from 6 to 20, with 5 studies (56%) reporting data for at least 75% of the 20 QIs. There were room for improvement in terms of data availability (i.e. domain 6 measuring patient's satisfaction), feasibility (i.e. difficulties to find all data for composite QIs in domain 7), and attainment (i.e. high levels of compliance with the percentage of reperfused ST-segment elevation myocardial infarction patients, but low levels for a timely reperfusion).

CONCLUSIONS

Our systematic review has shown that it is possible to measure most QIs in existing registries, and that there is room for improvement in terms of data availability, feasibility, and levels of attainment to QIs. Our findings may influence the design of future registries to capture this information and help in QIs definition updates.

Predicting 30-day mortality after ST elevation myocardial infarction: Machine learning- based random forest and its external validation using two independent nationwide datasets

BACKGROUND

Various prognostic models for mortality prediction following ST-segment elevation myocardial infarction (STEMI) have been developed over the past two decades. Our group has previously demonstrated that machine learning (ML)-based models can outperform known risk scores for 30-day mortality post-STEMI. The study aimed to redevelop an ML-based random forest prediction model for 30-day mortality post-STEMI and externally validate it on a large cohort.

METHODS

This was a retrospective, supervised learning, data mining study developed on the Acute Coronary Syndrome Israeli Survey (ACSIS) registry and the Myocardial Ischemia National Audit Project (MINAP) for external validation. Patients included received reperfusion therapy for STEMI between 2006 and 2016. Discrimination and calibration performances were assessed for two developed models and compared with the Global Registry of Acute Cardiac Events (GRACE) score.

RESULTS

The ACSIS cohort (2,782 included /15,212 total) and MINAP cohort (22,693 included/735,000 total) were significantly different in most variables, yet similar in 30-day mortality rate (4.3-4.4%). Random forest models were developed on the ACSIS cohort with a full model including all 32 variables and a simple model including the 10 most important ones. Features' importance was calculated using the varImp function measuring how much each feature contributes to the data's homogeneity. Applying the optimized models on the MINAP validation cohort showed high discrimination of area under the curve (AUC) = 0.804 (0.786-0.822) for the full model, and AUC = 0.787 (0.748-0.780) using the simple model, compared with the GRACE risk score discrimination of AUC = 0.764 (0.748-0.780). All models were not well calibrated for the MINAP data. Following Platt scaling on 20% of the MINAP data, the random forest models calibration improved while the GRACE calibration did not change.

CONCLUSIONS

The random forest predictive model for 30-day mortality post STEMI, developed on the ACSIS national registry, has been validated in the MINAP large external cohort and can be applied early at admission for risk stratification. The model performed better than the commonly used GRACE score. Furthermore, to the best of our knowledge, this is the first externally validated ML-based model for STEMI.

Number of Antithrombotic Drugs Used Early and In-hospital Outcomes in Acute Coronary Syndromes

Antithrombotic drug use for acute coronary syndromes (ACS) varies considerably. The number of antithrombotic drugs (excluding oral anticoagulants) used pre- and in-hospital was recorded in ACS survivors enrolled at hospital discharge in the long-tErm follow-uP of antithrombotic management patterns In acute CORonary syndrome patients (EPICOR) registry ( NCT01171404 ), a prospective cohort study. Among 10,568 patients, the number of antithrombotic drugs used early/patient ranged from 0 to 8 (interquartile range = 3-4). Overall, 250 patients (2.4%) experienced ≥ 1 in-hospital ischemic event and 343 (3.2%) ≥ 1 non-fatal bleeding event. While there was no difference in the rate of ischemic events (p = 0.75 for-trend) according to the number of antithrombotic drugs, a significantly higher incidence of non-fatal bleeds was observed (p < 0.0001 for-trend), with OR = 1.68 (95%CI = 1.51-1.88) per additional antithrombotic drug, which remained after adjustment by patient characteristics. In conclusion, careful balancing of the short-term risks for ischemic and bleeding events should be considered when adding new antithrombotic drugs.

[Impact of COVID-19 on ST-segment elevation myocardial infarction care. The Spanish experience]

INTRODUCTION AND OBJECTIVES

The COVID-19 outbreak has had an unclear impact on the treatment and outcomes of patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to assess changes in STEMI management during the COVID-19 outbreak.

METHODS

Using a multicenter, nationwide, retrospective, observational registry of consecutive patients who were managed in 75 specific STEMI care centers in Spain, we compared patient and procedural characteristics and in-hospital outcomes in 2 different cohorts with 30-day follow-up according to whether the patients had been treated before or after COVID-19.

RESULTS

Suspected STEMI patients treated in STEMI networks decreased by 27.6% and patients with confirmed STEMI fell from 1305 to 1009 (22.7%). There were no differences in reperfusion strategy (> 94% treated with primary percutaneous coronary intervention in both cohorts). Patients treated with primary percutaneous coronary intervention during the COVID-19 outbreak had a longer ischemic time (233 [150-375] vs 200 [140-332] minutes, P < .001) but showed no differences in the time from first medical contact to reperfusion. In-hospital mortality was higher during COVID-19 (7.5% vs 5.1%; unadjusted OR, 1.50; 95%CI, 1.07-2.11; P < .001); this association remained after adjustment for confounders (risk-adjusted OR, 1.88; 95%CI, 1.12-3.14; P = .017). In the 2020 cohort, there was a 6.3% incidence of confirmed SARS-CoV-2 infection during hospitalization.

CONCLUSIONS

The number of STEMI patients treated during the current COVID-19 outbreak fell vs the previous year and there was an increase in the median time from symptom onset to reperfusion and a significant 2-fold increase in the rate of in-hospital mortality. No changes in reperfusion strategy were detected, with primary percutaneous coronary intervention performed for the vast majority of patients. The co-existence of STEMI and SARS-CoV-2 infection was relatively infrequent.

Impact of COVID-19 on ST-segment elevation myocardial infarction care. The Spanish experience

INTRODUCTION AND OBJECTIVES

The COVID-19 outbreak has had an unclear impact on the treatment and outcomes of patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to assess changes in STEMI management during the COVID-19 outbreak.

METHODS

Using a multicenter, nationwide, retrospective, observational registry of consecutive patients who were managed in 75 specific STEMI care centers in Spain, we compared patient and procedural characteristics and in-hospital outcomes in 2 different cohorts with 30-day follow-up according to whether the patients had been treated before or after COVID-19.

RESULTS

Suspected STEMI patients treated in STEMI networks decreased by 27.6% and patients with confirmed STEMI fell from 1305 to 1009 (22.7%). There were no differences in reperfusion strategy (> 94% treated with primary percutaneous coronary intervention in both cohorts). Patients treated with primary percutaneous coronary intervention during the COVID-19 outbreak had a longer ischemic time (233 [150-375] vs 200 [140-332] minutes, P<.001) but showed no differences in the time from first medical contact to reperfusion. In-hospital mortality was higher during COVID-19 (7.5% vs 5.1%; unadjusted OR, 1.50; 95%CI, 1.07-2.11; P <.001); this association remained after adjustment for confounders (risk-adjusted OR, 1.88; 95%CI, 1.12-3.14; P=.017). In the 2020 cohort, there was a 6.3% incidence of confirmed SARS-CoV-2 infection during hospitalization.

CONCLUSIONS

The number of STEMI patients treated during the current COVID-19 outbreak fell vs the previous year and there was an increase in the median time from symptom onset to reperfusion and a significant 2-fold increase in the rate of in-hospital mortality. No changes in reperfusion strategy were detected, with primary percutaneous coronary intervention performed for the vast majority of patients. The co-existence of STEMI and SARS-CoV-2 infection was relatively infrequent.

Assessment of quality indicators for acute myocardial infarction management in 28 countries and use of composite quality indicators for benchmarking

Background:

The European Society of Cardiology established a set of quality indicators for the management of acute myocardial infarction. Our aim was to evaluate their degree of attainment, prognostic value and potential use for centre benchmarking in a large international cohort.

Methods:

Quality indicators were extracted from the long-tErm follow-uP of antithrombotic management patterns In acute CORonary syndrome patients (EPICOR) (555 hospitals, 20 countries in Europe and Latin America, 2010–2011) and EPICOR Asia (218 hospitals, eight countries, 2011–2012) registries, including non-ST-segment elevation acute myocardial infarction (n=6558) and ST-segment elevation acute myocardial infarction (n=11,559) hospital survivors. The association between implementation rates for each quality indicator and two-year adjusted mortality was evaluated using adjusted Cox models. Composite quality indicators were categorized for benchmarking assessment at different levels.

Results:

The degree of attainment of the 17 evaluated quality indicators ranged from 13% to 100%. Attainment of most individual quality indicators was associated with two-year survival. A higher compliance with composite quality indicators was associated with lower mortality at centre-, country- and region-level. Moreover, the higher the risk for two-year mortality, the lower the compliance with composite quality indicators.

Conclusions:

When EPICOR and EPICOR Asia were conducted, the European Society of Cardiology quality indicators would have been attained to a limited extent, suggesting wide room for improvement in the management of acute myocardial infarction patients. After adjustment for confounding, most quality indicators were associated with reduced two-year mortality and their prognostic value should receive further attention. The two composite quality indicators can be used as a tool for benchmarking either at centre-, country- or world region-level.

Five-year risk of heart failure and death following myocardial infarction with cardiogenic shock: a nationwide cohort study

AIMS

More patients survive myocardial infarction (MI) with cardiogenic shock (CS), but long-term outcome data are sparse. We aimed to examine rates of heart failure hospitalization and mortality in MI hospital survivors.

METHODS AND RESULTS

First-time MI patients with and without CS alive until discharge were identified using Danish nationwide registries between 2005 and 2017. One-, 5-, and 1- to 5-year rates of heart failure hospitalization and mortality were compared using landmark cumulative incidence curves and Cox regression models. We identified 85 865 MI patients of whom 2865 had CS (3%). Cardiogenic shock patients were of similar age as patients without CS (median age years: 68 vs. 67), and more were men (70% vs. 65%). Cardiogenic shock was associated with a higher 5-year rate of heart failure hospitalization compared with patients without CS [40% vs. 20%, adjusted hazard ratio (HR) 2.90 (95% confidence interval (CI) 2.67-3.12)]. The increased rate of heart failure hospitalization was evident after 1 year and in the 1- to 5-year landmark analysis among 1-year survivors. All-cause mortality was higher at 1 year among CS patients compared with patients without CS [18% vs. 8%, adjusted HR 3.23 (95% CI 2.95-3.54)]. However, beyond the first year, the mortality for CS was not markedly different compared with patients without CS [12% vs. 13%, adjusted HR 1.15 (95% CI 1.00-1.33)].

CONCLUSION

Among MI hospital survivors, CS was associated with a markedly higher rate of heart failure hospitalization and 1-year mortality compared with patients without CS. However, among 1-year survivors, the remaining 5-year mortality was similar for MI patients with and without CS.

Development and Long-Term Follow-Up of an Experimental Model of Myocardial Infarction in Rabbits

Simple Summary

Ischemic heart disease is one of the leading causes of death. A series of processes occur during acute myocardial infarction that contribute to the development of ventricular dysfunction, with subsequent heart failure and ventricular arrhythmias, which account for most episodes of sudden cardiac death in these patients. These complications are associated with the adverse cardiac remodeling that occurs during the healing process following an acute episode. The remodeling causes the appearance of a substrate that can trigger life-threatening arrhythmias, such as tachycardia and/or ventricular fibrillation. The development of experimental models for analyzing the basic mechanisms involved in the pathophysiology of myocardial infarction enables the study of different therapeutic approaches aimed at improving the patient´s prognosis. The present study describes the methodology and the results obtained in a 5-week chronic infarction (one hour followed by reperfusion) in a rabbit model. The viability of the model, the care provided, the characteristics and extent of the lesions, the inducibility of arrhythmias, and the reproducibility of the methods and results have been analyzed.

Abstract

A chronic model of acute myocardial infarction was developed to study the mechanisms involved in adverse postinfarction ventricular remodeling. In an acute myocardial infarction (AMI), the left circumflex coronary artery of New Zealand White rabbits (n = 9) was occluded by ligature for 1 h, followed by reperfusion. A specific care protocol was applied before, during, and after the intervention, and the results were compared with those of a sham operated group (n = 7). After 5 weeks, programmed stimulation and high-resolution mapping were performed on isolated and perfused hearts using the Langendorff technique. The infarct size determined by 2,3,5-triphenyltetrazolium chloride inside of the area at risk (thioflavin-S) was then determined. The area at risk was similar in both groups (54.33% (experimental infarct group) vs. 58.59% (sham group), ns). The infarct size was 73.16% as a percentage of the risk area. The experimental infarct group had a higher inducibility of ventricular arrhythmias (100% vs. 43% in the sham group, p = 0.009). A reproducible chronic experimental model of myocardial infarction is presented in which the extent and characteristics of the lesions enable the study of the vulnerability to develop ventricular arrhythmias because of the remodeling process that occurs during cardiac tissue repair.

Coexistence of transmural and lateral wavefront progression of myocardial infarction in the human heart

INTRODUCTION AND OBJECTIVES

According to the wavefront phenomenon described in the late 1970s, myocardial infarction triggered by acute coronary occlusion progresses with increasing duration of ischemia as a transmural wavefront from the subendocardium toward the subepicardium. However, whether wavefront progression of necrosis also occurs laterally has been disputed. We aimed to assess the transmural and lateral spread of myocardial damage after acute myocardial infarction in humans and to evaluate the impact of metoprolol on these.

METHODS

We assessed myocardial infarction in the transmural and lateral dimensions in a cohort of 220 acute ST-segment elevation myocardial infarction (STEMI) patients from the METOCARD-CNIC trial (Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction). The patients underwent cardiac magnetic resonance imaging at 5 to 7 days and 6 months post-STEMI.

RESULTS

On day 5 to 7 post-STEMI cardiac magnetic resonance, there was a strong linear correlation between the transmural and lateral extent of infarction (delayed gadolinium enhancement) (r=-0.88; P<.001). Six months after STEMI, myocardial scarring (delayed gadolinium enhancement) was significantly less extensive in the transmural and lateral dimensions, suggesting that infarct resorption occurs in both. Furthermore, progression in both directions occurred both in patients receiving metoprolol and control patients, implying that myocardial salvage occurs both in the transmural and the lateral direction.

CONCLUSIONS

Our findings challenge the assumption that irreversible injury does not spread laterally. A "circumferential" or multidirectional wavefront would imply that cardioprotective therapies might produce meaningful salvage at lateral borders of the infarct. This trial was registered at ClinicalTrial.gov (Identifier: NCT01311700).

Impact of previous coronary artery bypass grafting in patients presenting with an acute coronary syndrome: Current trends and clinical implications

BACKGROUND

Among patients presenting with an acute coronary syndrome, those with previous coronary artery bypass grafting are a particular subset.

AIMS

The purpose of this study was to investigate the prognostic impact of previous coronary artery bypass grafting in acute coronary syndrome patients and to identify the current trends in their clinical management.

METHODS

We performed a cohort analysis of patients prospectively enrolled in the Portuguese Registry of acute coronary syndrome between 2010-2019 with known previous coronary artery bypass grafting status. The co-primary endpoints were in-hospital and one-year mortality.

RESULTS

A total of 19,334 (962 coronary artery bypass grafting and 18,372 non-coronary artery bypass grafting) and 9402 (479 coronary artery bypass grafting and 8923 non-coronary artery bypass grafting) patients were included in the analyses of in-hospital and mid-term outcomes, respectively. Coronary artery bypass grafting patients were older and had a higher incidence of comorbidities. They were less likely to undergo invasive angiography (74.9 vs 84.6%, p<0.001), but were equally likely to receive dual antiplatelet therapy (91.0 vs 90.8%, p=0.823). In-hospital mortality was similar between groups (3.6 vs 3.4%, p=0.722). Unadjusted one-year mortality was higher in the coronary artery bypass grafting group (hazard ratio 1.48, 95% confidence interval 1.09-2.01, p=0.012), but similar in both groups after propensity-matching and multivariate analysis (hazard ratio 0.63, 95% confidence interval 0.37-1.09, p=0.098).

CONCLUSIONS

Among patients with acute coronary syndrome, a previous history of coronary artery bypass grafting was associated with a high burden of comorbidities and a high-risk profile but was not an independent predictor of adverse events. Treatment decisions should be made on a case-by-case basis, and should not be based on previous coronary artery bypass grafting status alone.

CIBER-CLAP (CIBERCV Cardioprotection Large Animal Platform): A multicenter preclinical network for testing reproducibility in cardiovascular interventions

Despite many cardioprotective interventions have shown to protect the heart against ischemia/reperfusion injury in the experimental setting, only few of them have succeeded in translating their findings into positive proof-of-concept clinical trials. Controversial and inconsistent experimental and clinical evidence supports the urgency of a disruptive paradigm shift for testing cardioprotective therapies. There is a need to evaluate experimental reproducibility before stepping into the clinical arena. The CIBERCV (acronym for Spanish network-center for cardiovascular biomedical research) has set up the "Cardioprotection Large Animal Platform" (CIBER-CLAP) to perform experimental studies testing the efficacy and reproducibility of promising cardioprotective interventions based on a pre-specified design and protocols, randomization, blinding assessment and other robust methodological features. Our first randomized, control-group, open-label blinded endpoint experimental trial assessing local ischemic preconditioning (IPC) in a pig model of acute myocardial infarction (n = 87) will be carried out in three separate sets of experiments performed in parallel by three laboratories. Each set aims to assess: (A) CMR-based outcomes; (B) histopathological-based outcomes; and (C) protein-based outcomes. Three core labs will assess outcomes in a blinded fashion (CMR imaging, histopathology and proteomics) and 2 methodological core labs will conduct the randomization and statistical analysis.

Hydrogen-rich saline alleviates inflammation and apoptosis in myocardial I/R injury via PINK-mediated autophagy

Ischemia/reperfusion (I/R)-induced inflammatory reaction is one of the most important elements in myocardial I/R injury. In addition, autophagy serves an important role in normal cardiac homeostasis, and obstructions to the autophagy process lead to severe consequences for the heart. Hydrogen exerts an effective therapeutic role in numerous diseases associated with I/R injury via its anti-inflammation, anti-apoptosis and anti-oxidative properties. Therefore, the present study investigated the effect of hydrogen on the myocardial inflammation response and apoptosis in myocardial ischemic/reperfusion (MI/R) injury, and further explored the mechanism of PTEN-induced kinase 1 (PINK1)/Parkin-induced mitophagy in the protection of hydrogen on MI/R injury. MI/R injury was performed by surgical ligation of the left coronary artery in vivo and H9C2 cell injury was performed by hypoxia/reoxygenation (H/R) in vitro. Hydrogen-rich saline was administered twice through intraperitoneal injection at a daily dose of 10 ml/kg following the operation in the in vivo model, and hydrogen-rich medium culture was used for cells instead of normal medium in vitro. The infarction size of hearts, the levels of creati-nine kinase-muscle/brain (CK-MB) and cardiac troponin I (cTnI), cardiac function, cell viability and lactate dehydrogenase (LDH) release, levels of cytokines, apoptosis and the expression of autophagy-associated proteins were detected in the different treatment groups in vivo and in vitro. The results demonstrated that treatment with hydrogen improved the myocardial infarction size of hearts, cardiac function, apoptosis and cytokine release following MI/R in rats. In vitro, hydrogen improved cell viability and LDH release following hypoxia/reoxygenation in myocardial cells. In addition, it was demonstrated that hydrogen exerted an anti-inflammatory and anti-apoptotic effect in myocardial cells induced by H/R via PINK1/Parkin mediated autophagy. These results suggested that hydrogen-rich saline alleviated the inflammation response and apoptosis induced by MI/R or H/R in vivo or in vitro, and that hydrogen-rich saline contributed to the increased expression of proteins associated with autophagy. In summary, the present study indicated that treatment with hydrogen-rich saline improved the inflammatory response and apoptosis in MI/R via PINK1/Parkin-mediated mitophagy.