The Impact of Normobaric Hypoxia and Intermittent Hypoxic Training on Cardiac Biomarkers in Endurance Athletes: A Pilot Study.

This study explores the effects of normobaric hypoxia and intermittent hypoxic training (IHT) on the physiological condition of the cardiac muscle in swimmers. Hypoxia has been reported to elicit both beneficial and adverse changes in the cardiovascular system, but its impact on the myocardium during acute exercise and altitude/hypoxic training remains less understood. We aimed to determine how a single bout of intense interval exercise and a four-week period of high-intensity endurance training under normobaric hypoxia affect cardiac marker activity in swimmers. Sixteen young male swimmers were divided into two groups: one undergoing training in hypoxia and the other in normoxia. Cardiac markers, including troponin I and T (cTnI and cTnT), heart-type fatty acid-binding protein (H-FABP), creatine kinase-MB isoenzyme (CK-MB), and myoglobin (Mb), were analyzed to assess the myocardium's response. We found no significant differences in the physiological response of the cardiac muscle to intense physical exertion between hypoxia and normoxia. Four weeks of IHT did not alter the resting levels of cTnT, cTnI, and H-FABP, but it resulted in a noteworthy decrease in the resting concentration of CK-MB, suggesting enhanced cardiac muscle adaptation to exercise. In contrast, a reduction in resting Mb levels was observed in the control group training in normoxia. These findings suggest that IHT at moderate altitudes does not adversely affect cardiac muscle condition and may support cardiac muscle adaptation, affirming the safety and efficacy of IHT as a training method for athletes.

Mitochondrial biogenesis and apoptosis as underlying mechanisms involved in the cardioprotective effects of Gallic acid against D-galactose-induced aging.

BACKGROUND: Aging is a main risk factor for the development of cardiovascular diseases (CVDs). Gallic acid (GA) is a phenolic compound derived from a wide range of fruits. GA has a wide spectrum of pharmacological properties, including anti-oxidative, anti-inflammatory, and cardioprotective effects. This research was conducted to determine the cardioprotective effect of GA on cardiac hypertrophy in aged rats. METHODS AND RESULTS: Following histological evaluation and through observing the heart, we found that GA improved the cardiac hypertrophy induced by D-galactose (D-GAL) in cardiac cells. To clarify the causes for this anti-aging effect, we evaluated the malonic dialdehyde levels and antioxidant enzyme activity in rat cardiac tissue. The levels of lactate dehydrogenase (LDH) and creatine kinase (CK-MB) in serum were measured. The levels of genes related to mitochondrial biogenesis, mitophagy, and apoptosis in cardiac tissue were surveyed. The findings represented that GA ameliorated antioxidant enzyme activity while significantly decreasing the malonic dialdehyde levels. Real-time PCR analysis proposed that GA effectively improved mitochondrial biogenesis in the heart via regulating the expression levels of Sirtuin 1 (SIRT1), PPARγ coactivator 1α (PGC1-α), nuclear factor erythroid 2-related factor 2 (Nrf2), and mitochondrial transcription factor A (TFAM). GA also mitigated apoptosis in the heart by modulating the expression levels of B-cell lymphoma protein 2 (Bcl-2) and Bcl-2-associated X (Bax). In addition, GA improved serum LDH and CK-MB levels. CONCLUSIONS: GA may alleviate aging-induced cardiac hypertrophy via anti-oxidative, mitoprotective, and anti-apoptotic mechanisms.

[Expression and clinical significance of circRNA cSMARCA5 in patients with acute myocardial infarction].

Objective: To investigate the expression level and clinical significance of cSMARCA5 in the patients with acute myocardial infarction (AMI). Methods: This study was a case-control study. A total of 100 patients with AMI and 100 patients without coronary heart disease who received treatment in the Department of Cardiology, Peking University Third Hospital from September to December 2021 were included in the study according to the principle of 1∶1 frequency matching. The expression levels of cSMARCA5 in the peripheral blood of AMI patients and control groups were measured by real-time quantitative polymerase chain reaction (RT-qPCR). The receiver operating characteristic (ROC) curve was used to calculate the diagnostic ability of cSMARCA5 for AMI. Spearman or Pearson correlation analysis was used to explore the correlation between cSMARCA5 and the degree of myocardial necrosis, coronary lesion severity and GRACE risk stratification score. Bioinformatics analysis was used to predict the possible mechanism of cSMARCA5 in pathological changes of AMI. Results: The age [M (Q1,Q3)] of AMI patients and control group was 63.0 (56.0, 71.5) and 63.0 (53.0, 75.5) (P=0.622), and the proportion of males was 75.0% (75 cases) and 46.0% (46 cases) (P<0.001), respectively. The expression level [M (Q1,Q3)] of cSMARCA5 was significantly lower in AMI patients compared with the control group [0.37 (0.22, 0.73) vs 1.03(0.71, 1.75), P<0.001]. ROC analysis showed that the area under the curve of cSMARCA5 in diagnosing AMI was 0.83 (95%CI: 0.77-0.89, P<0.001), with a sensitivity of 89.0% and specificity of 67.7%. cSMARCA5 was negatively correlated with creatine kinase isoenzyme MB (r=-0.203, P=0.041), troponin T (r=-0.230, P=0.023) and N-terminal brain natriuretic peptide precursor (r=-0.250, P=0.012), and positively correlated with left ventricular ejection fraction (r=0.201, P=0.042). In addition, the expression level of cSMARCA5 was negatively correlated with SYNTAX score (r=-0.196, P=0.048) and GRACE risk score (r=-0.321, P=0.001). Bioinformatic analysis suggested that cSMARCA5 might be involved in the process of AMI through regulating the gene expression of tumor necrosis factor. Conclusions: The expression of cSMARCA5 is significantly decreased in peripheral blood of AMI patients compared with control group, and its expression level is negatively correlated with the severity of myocardial infarction. cSMARCA5 is expected to be a potential biomarker of AMI.

Curdione Relieved Isoproterenol-Induced Myocardial Damage through Inhibiting Oxidative Stress and Apoptosis.

Isoproterenol (ISO) is widely used to treat bronchial asthma, cardiogenic or septic shock, complete atrioventricular block, and cardiac arrest. However, it can also cause myocardial damage owing to infarct-like necrosis. Curdione, an extract of the Chinese herb Rhizoma Curcumae, has a variety of pharmacological activities, including cardioprotective effects. In this study, we investigated the protective effects of curdione and its underlying mechanisms in an ISO-induced myocardial injury model. Our results showed that curdione attenuated ISO-induced H9c2 cell proliferation inhibition and lactic dehydrogenase (LDH) release. Curdione ameliorated morphological damage and reduced the ISO-induced elevation of serum creatine kinase-MB isoenzyme (CK-MB) and LDH. Furthermore, curdione inhibited ISO-induced cell apoptosis, modulated the expression of Bcl-2 and Bax proteins, repealed the accumulation of ISO-induced reactive oxygen species (ROS), prevented mitochondrial dysfunction, and activated the Nrf2/SOD1/HO-1 signaling pathway. The above results show that curdione exerts a protective effect against ISO-induced myocardial damage by inhibiting apoptosis and oxidative stress, suggesting that curdione is a potential therapeutic strategy to prevent ISO-induced myocardial damage.

Circulating small extracellular vesicle-encapsulated SEMA5A-IT1 attenuates myocardial ischemia-reperfusion injury after cardiac surgery with cardiopulmonary bypass.

Cardiomyocyte injury is a common complication during cardiac surgery with cardiopulmonary bypass (CPB). Studies have shown that circulating small extracellular vesicles (sEVs) are involved in the pathological process of cardiovascular diseases via delivering signaling molecules. This study aims to investigate the relationship between circulating sEV-encapsulated long noncoding RNAs (lncRNAs) and cardiac injury after CPB. Here, we found that the expression of sEV SEMA5A-IT1 in serum samples of patients after CPB was higher than that of pre-CPB serum samples. Moreover, serum-derived sEV SEMA5A-IT1 levels were negatively correlated with creatine kinase-MB (CK-MB) levels in patients who underwent CPB operation. Notably, circulating sEVs packaged with SEMA5A-IT1 could be uptaken by cardiomyocyte-like cells AC16 and increased SEMA5A-IT1 expression in AC16 cells. Upregulated SEMA5A-IT1 protected cardiomyocytes against hypoxia/reoxygenation injury, confirmed by increased cell viability, reduced cell apoptosis, and inhibited ferroptosis in AC16 cells. Mechanistically, SEMA5A-IT1 regulated the expression of B-cell CLL/lymphoma 2 (BCL2) and solute carrier family 7 member 11 (SLC7A11) through sponging miR-143-3p. Transfection of miR-143-3p mimics, BCL2, or SLC7A11 knockdown could attenuate the protective effect of SEMA5A-IT1 on cardiomyocytes. In conclusion, we propose that SEMA5A-IT1, which is transported to cardiomyocytes through circulating sEVs, is an important regulatory molecule that protects cardiomyocytes from ischemia-reperfusion injury, providing a target for the prevention and treatment of myocardial ischemia-reperfusion injury.

Breast milk mesenchymal stem cells abate cisplatin-induced cardiotoxicity in adult male albino rats via modulating the AMPK pathway.

Myocardial injury influenced by cisplatin (Cis) is a compelling reason to hunt out a treatment modality to overcome such a threat in cisplatin-treated patients. Breast Milk mesenchymal stem cells (Br-MSCs) are a non-invasive, highly reproducible source of stem cells. Herein, we investigate Br-MSCs' role in cardiotoxicity induced by cisplatin. Rats were divided into; control, Cis-treated (received 12 mg/kg single intraperitoneal injection), BrMSCs-treated (received single intraperitoneal injection of 0.5 ml sterilized phosphate-buffered saline containing 2 × 107 cells of Br-MSCs); metformin-treated (received 250 mg/kg/day orally) and BrMSCs + metformin + Cis treated groups. At the experiment end, serum creatine kinase (CK-MB) and cardiac troponin T (cTnT) activates were estimated, cardiac malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) levels were measured, cardiac expression of Bax and Bcl-2 and AMP-activated protein kinase (AMPK), as well as heart histopathology, were evaluated. Study results showed that Cis explored acute cardiotoxicity evidenced by deteriorated cardiac indices, induction of oxidative stress, and inflammation with myocardium histological alterations. Treatment with Br-MSCs restored heart function and structure deteriorated by Cis injection. The antioxidant/anti-inflammatory/anti-apoptotic results of Br-MSCs were supported by AMPK activation denoting their protective role against cisplatin-induced cardiac injury. These results were superior when metformin was added to the treatment protocol.

L-Carnitine Mitigates Trazadone Induced Rat Cardiotoxicity Mediated via Modulation of Autophagy and Oxidative Stress.

Trazodone (TRZ) is an antidepressant drug which widely used to treat insomnia, but it has a cardiotoxic effect which considered one of the TRZ limitations. The aim of this study was to investigate the protective role of L-carnitine in rats against TRZ-induced cardiotoxicity, as well as to look into the molecular mechanisms underlying its cardioprotective effects via autophagy-mediated cell death and oxidative stress. Male albino rats were randomized into four experimental groups (n = 8): normal control, TRZ group (TRZ, 20 mg/kg/day), L-carnitine group (LC, 200 mg/kg/day), and Co-treated group (L-carnitine and TRZ). All treatments were administered via oral gavage for 4 weeks. Cardiac enzymes (AST & CK-MB) and serum cardiac troponin T(cTnI) were assessed. Oxidative stress biomarkers in heart tissue (malondialdehyde; MDA, total thiol, and catalase activity) were measured. Autophagy related-genes (ATG-5 and Beclin-1), P62, and TNF-α were quantified. AST and CK-MB and cTnI significantly (p < 0.001) were increased with enhanced autophagy as well as severe histopathological changes which were manifested as scattered chronic inflammatory cells with focal fragmentation of myocardial fibers and loss of nuclei in TRZ-treated group. However, daily administration of L-carnitine (200 mg/kg) for 28 days completely reversed TRZ-induced the increased cardiac enzymes, autophagy, and myocardial inflammatory processes to the normal values. TRZ administration might have the potential to cause cardiotoxic effects that can be treated with L-carnitine administration.

The impact of CK-MB elevation in patients with acute type A aortic dissection with coronary artery involvement.

BACKGROUND: Acute type A aortic dissection (ATAAD) is a fatal disease and requires emergency surgery. In particular, it is known that mortality is high when a coronary artery is involved. However, the degree of myocardial damage of the coronary acute artery involvement (ACI) varies and may or may not increase creatine kinase muscle and brain isoenzyme (CK-MB). It is unknown how CK-MB elevation affects the surgical outcome. This study compared the surgical results between the two groups of ACI with or without CK-MB elevation. METHODS: Among 348 patients who underwent an emergency operation for acute type A aortic dissection, there were 28 (8.0%) patients complicated by ACI and underwent additional coronary artery bypass grafting. We divided 26 of those patients into two groups; the MI group ( with CK-MB elevation) and the NMI group (without CK-MB elevation), and compared both groups. RESULTS: Of the 26, sixteen were in the MI group, and ten were in the NMI group. The average CK-MB in the MI group was 225.5 IU/L, and that in the NMI group was 13.5 IU/L. The mean time from onset to surgery was 248 min in the MI group and 250 min in the NMI group. There was statistical significance in mortality ( 69% vs. 13%, p = 0.03). There was no significance in major complications (ICU days, reintubation, reoperation, pneumonia, sepsis). CONCLUSIONS: Acute coronary artery involvement was associated with 8.0% of patients with ATAAD, and 62% had myocardial ischemia with CK-MB elevation. The MI group had significantly higher mortality than the NMI group. It is crucial for cases with suspected ACI to obtain coronary perfusion as soon as possible to prevent CK-MB from elevating.

Protective Effects and Mechanisms of Melatonin on Stress Myocardial Injury in Rats.

ABSTRACT: Prolonged and intense stress can exceed the body's normal self-regulation and limited compensatory and repair capacity, resulting in pathological damage to the body. In this study, we established a rat stress myocardial injury (SMI) model to explore the protective effect of melatonin (MLT) on SMI and its possible mechanisms of action. Adult female Sprague Dawley (SD) rats were randomly divided into 5 groups: blank control group (NC), SMI group, MLT low-dose group, MLT medium-dose group, and MLT high-dose group, and 10 rats in each group were used to establish a SMI model by the water immersion restraint method. We observed the changes in body weight and tail vein glucose of each group. Serum levels of corticosterone (Cort), creatine kinase isoenzyme (CK-MB), and Troponin Ⅰ (Tn-Ⅰ) and activity of lactic acid dehydrogenase were measured by ELISA. Transcriptome sequencing was used to find differentially expressed genes in the control and model groups, and the results were verified by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). HE staining was used to visualize the pathological changes in the heart tissue of each group, and Western blot was used to study the differences in protein expression in the cardiomyocytes of each group to further corroborate the results. The body weight growth rate of rats in the SMI group was significantly lower than that of the NC group ( P < 0.01), and the body weight growth rate of rats in the MLT high-dose group was significantly higher than that of the SMI group ( P < 0.05) with no significant difference compared with the NC group rats. The mean blood glucose of rats in the SMI group was significantly higher compared with the NC group ( P < 0.001), while the mean blood glucose of rats in the MLT administration groups was dose-dependently reduced compared with the SMI group. By RNA-seq and bioinformatics tools such as KEGG and Gene ontology, we found that the circadian clock-related genes Ciart , Arnt1 , Per1 , and Dbp were significantly downregulated in the SMI group during water immersion stress, and differentially expressed genes were enriched in the p38MAPK signaling pathway and p53 signaling pathway. Moreover, genes related to inflammation and apoptosis were differentially expressed. ELISA results showed that Cort, CK-MB, and Tn-Ⅰ levels were significantly higher in the SMI group compared with the NC group ( P < 0.01) and melatonin reduced the levels of Cort, CK-MB, and Tn-Ⅰ and decreased lactic acid dehydrogenase activity in rat serum. HE staining results showed that melatonin could attenuate stress-generated myocardial injury. Western blot showed that melatonin reduced the expression of p38MAPK, p53, Bax, and caspase-3 and increased the expression of Bcl-2 protein in rat heart. Melatonin can inhibit myocardial injury caused by water immersion, and its mechanism of action may be related to the regulation of the expression of circadian clock genes such as Ciart , Arnt1 , Per1 , and Dbp ; the inhibition of the expression of proapoptotic proteins such as p38MAPK, p53, Bax, and caspase-3; and the increase of the expression of Bcl-2 antiapoptotic protein.

Long non-coding RNA muscleblind like splicing regulator 1 antisense RNA 1 (LncRNA MBNL1-AS1) promotes the progression of acute myocardial infarction by regulating the microRNA-132-3p/SRY-related high-mobility-group box 4 (SOX4) axis.

Long non-coding RNA muscleblind like splicing regulator 1 antisense RNA 1 (LncRNA MBNL1-AS1) exerts vital role in various physiological processes. However, its functions in acute myocardial infarction (AMI) are not elucidated. AMI model was constructed using Wistar rats and it was found that LncRNA MBNL1-AS1 was upregulated in AMI model according to the quantitative real-time polymerase chain reaction (qRT-PCR) results. The left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) and maximum rate of rise/fall of left ventricle pressure (±dp/dt max) were detected through hemodynamics test, which showed that knockdown of MBNL1-AS1 improved cardiac function in AMI model. Next, the myocardial infarction area was estimated by triphenyltetrazole chloride (TTC) staining, and the levels of cardiac troponin I (cTn-I) and creatine kinase-MB (CK-MB) were detected by enzyme-linked immunosorbent assay (ELISA) kit. The results revealed that silencing MBLN1-AS1 alleviated myocardial injury in AMI model. Additionally, MBNL1-AS1 knockdown inhibited apoptosis of myocardial cells and reduced the expression of apoptotic proteins. According to DIANA database and luciferase reporter assay, miR-132-3p was the direct target of MBNL1-AS1 and was negatively regulated by MBNL1-AS1. Furthermore, Targetscan database predicted that SRY-related high-mobility-group box 4 (SOX4) was the direct target of miR-132-3p and was regulated by MBNL1-AS1 through miR-132-3p. Moreover, overexpression of SOX4 partially eliminated effects of MBNL1-AS1 on myocardial cells. In conclusion, this investigation for the first time revealed that LncRNA MBNL1-AS1 was the potential target for treating AMI and expounded the underlying mechanisms of it.

Acute myocardial injury secondary to severe acute liver failure: A retrospective analysis supported by animal data.

To investigate whether acute liver failure (ALF) leads to secondary acute myocardial injury, 100 ALF patients that were retrospectively identified in a single center based on ICD 10 codes and 8 rats from an experimental study that died early after bile duct ligation (BDL) were examined. Creatine kinase (CK), creatine kinase-MB isoenzyme (CKMB) and cardiac troponin-I (cTnI) were analyzed as markers of myocardial injury. For histological analysis, hematoxylin-eosin (HE), elastic Van Gieson (EVG), CD41 and myeloperoxidase were used to stain rat hearts. Major adverse cardiac events (MACEs) were a critical factor for mortality (p = 0.037) in human ALF. Deceased patients exhibited higher levels of CKMB than survivors (p = 0.023). CKMB was a predictor of mortality in ALF (p = 0.013). Animals that died early after BDL exhibited increased cTnI, CKMB, tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) levels compared to controls (cTnI: p = 0.011, CKMB: p = 0.008, TNFα: p = 0.003, IL-6: p = 0.006). These animals showed perivascular lesions and wavy fibers, microthrombi and neutrophilic infiltration in the heart. MACEs are decisive for mortality in human ALF, and elevated CKMB values indicate that this might be due to structural myocardial damage. Accordingly, CKMB was found to have predictive value for mortality in ALF. The results are substantiated by data from a rat BDL model demonstrating diffuse myocardial injury.

Canagliflozin is a potential cardioprotective drug but exerts no significant effects on pirarubicin­induced cardiotoxicity in rats.

Pirarubicin (THP), one of the anthracycline anticancer drugs, is widely used in the treatment of various types of cancer, but its cardiotoxicity cannot be ignored. Canagliflozin, the first sodium­glucose co­transporter­2 inhibitor approved by the USA FDA, has been shown to have a significant effect on cardiovascular damage caused by diabetes. However, it has not been reported whether it can resist THP­induced cardiotoxicity. The aim of the present study was to investigate the effect of canagliflozin on THP­induced cardiotoxicity and its mechanism. A rat model of cardiotoxicity induced by THP was established and canagliflozin treatment was performed at the same time. The changes of electrocardiography, cardiac coefficient and echocardiogram were observed. The levels of lactate dehydrogenase, brain natriuretic peptide, creatine kinase MB, cardiac troponin T, superoxide dismutase (SOD) and malondialdehyde were detected. The expression of SOD2, NADPH oxidase 2, pro/cleaved­caspase­ and Bcl­2/Bax were evaluated by western blotting. The primary culture of cardiomyocytes was prepared to explore the effect in vitro. After eight weeks, a series of cardiotoxicity manifestations were observed in THP rats. However, canagliflozin treatment had no significant effect on the above adverse reactions. Similarly, further studies showed that canagliflozin had no significant effect on THP­induced cardiomyocyte injury in vitro. The present study showed that there was no significant protective effect of canagliflozin on THP­induced cardiotoxicity and cardiomyocyte injury.

Cardioprotective effect of boswellic acids against doxorubicin induced myocardial infarction in rats.

The aim of the present study was to evaluate the cardioprotective activity of boswellic acids in doxorubicin (DOX) induced cardiotoxicity. DOX (2.5mg/kg) was used intraperitoneally in rats to induce cardiotoxicity in six divided doses every alternate day over a period of two weeks. Dexrazoxane (10:1) was used as a standard drug. Boswellic acids (250, 500 and 750 mg/kg) were orally administered to rats for 14 days. After 14 days, rats were sacrificed, and blood was withdrawn through cardiac puncture. The blood lipid profile and cardiac biomarkers including LDH, CK-MB, CPK, SGOT and troponin T were measured. The heart of rats was isolated for histopathological studies. Graphpad Prism was used for statistical analysis. There was a significant increase in the level of cardiac enzymes and complete lipid profile parameters in diseased group as compared to control group. Pre-treatment with boswellic acids decreased level of all the measured parameters and decreased the severity of myocardial damage as supported by histopathological studies. It was concluded that boswellic acids possess cardioprotective potential by lowering cardiac biomarkers and blood lipid profile. Thus, boswellic acids might act as cardioprotective agent against doxorubicin induced cardiotoxicity.

Inhibition of inducible nitric oxide synthase protects against the deleterious effects of sub-lethal sepsis and ethanol in the cardiorenal system.

We tested the hypothesis that ethanol would aggravate the deleterious effects of sub-lethal cecal ligation and puncture (SL-CLP) sepsis in the cardiorenal system and that inhibition of inducible nitric oxide synthase (iNOS) would prevent such response. Male C57BL/6 mice were treated with ethanol for 12 weeks. One hour before SL-CLP surgery, mice were treated with N6-(1-iminoethyl)-lysine (L-NIL, 5 mg/kg, i.p.), a selective inhibitor of iNOS. A second dose of L-NIL was administered 24 h after SL-CLP surgery. Mice were killed 48 h post surgery and the blood, the renal cortex, and the left ventricle (LV) were collected for biochemical analysis. L-NIL attenuated the increase in serum creatinine levels induced by ethanol, but not by SL-CLP. Ethanol, but not SL-CLP, increased creatine kinase (CK)-MB activity and L-NIL did not prevent this response. In the renal cortex, L-NIL prevented the redox imbalance induced by ethanol and SL-CLP. Inhibition of iNOS also decreased lipoperoxidation induced by ethanol and SL-CLP in the LV. L-NIL prevented the increase of pro-inflammatory cytokines and reactive oxygen species induced by ethanol and (or) SL-CLP in the cardiorenal system, suggesting that iNOS modulated some of the molecular mechanisms that underlie the deleterious effects of both conditions in the cardiorenal system.

Cytoprotective Potential of Aged Garlic Extract (AGE) and Its Active Constituent, S-allyl-l-cysteine, in Presence of Carvedilol during Isoproterenol-Induced Myocardial Disturbance and Metabolic Derangements in Rats.

This study was conducted to determine the potential interaction of aged garlic extract (AGE) with carvedilol (CAR), as well as to investigate the role of S-allyl-l-cysteine (SAC), an active constituent of AGE, in rats with isoproterenol (ISO)-induced myocardial dysfunction. At the end of three weeks of treatment with AGE (2 and 5 mL/kg) or SAC (13.1 and 32.76 mg/kg), either alone or along with CAR (10 mg/kg) in the respective groups of animals, ISO was administered subcutaneously to induce myocardial damage. Myocardial infarction (MI) diagnostic predictor enzymes, lactate dehydrogenase (LDH) and creatinine kinase (CK-MB), were measured in both serum and heart tissue homogenates (HTH). Superoxide dismutase (SOD), catalase, and thiobarbituric acid reactive species (TBARS) were estimated in HTH. When compared with other groups, the combined therapy of high doses of AGE and SAC given alone or together with CAR caused a significant decrease in serum LDH and CK-MB activities. Further, significant rise in the LDH and CK-MB activities in HTH was noticed in the combined groups of AGE and SAC with CAR. It was also observed that both doses of AGE and SAC significantly increased endogenous antioxidants in HTH. Furthermore, histopathological observations corroborated the biochemical findings. The cytoprotective potential of SAC and AGE were dose-dependent, and SAC was more potent than AGE. The protection offered by aged garlic may be attributed to SAC. Overall, the results indicated that a high dose of AGE and its constituent SAC, when combined with carvedilol, has a synergistic effect in preventing morphological and physiological changes in the myocardium during ISO-induced myocardial damage.

Cardiac Biomarker Abnormalities Are Closely Related to Prognosis in Patients with COVID-19.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is erupting and spreading globally. Cardiovascular complications secondary to the infection have caught notice. This study aims to delineate the relationship of cardiac biomarkers and outcomes in severe cases of corona virus disease 2019 (COVID-19). One hundred forty-eight critically ill adult patients with COVID-19 were enrolled. From these patients, the demographic data, symptoms, cardiac biomarkers, treatments, and clinical outcomes were collected. Data were compared between survivors and non-survivors. Four patients in the non-survivor group were selected, and their cardiac biomarkers were collected and analyzed. Among the 148 patients, the incidence of cardiovascular complications was 19 (12.8%). Five of them were survivors (5.2%), and 14 of them were non-survivors (26.9%). Compared with the survivors, the non-survivors had higher levels of high-sensitivity cardiac troponin I, creatine kinase isoenzyme-MB, myoglobin, and N-terminal pro-brain natriuretic peptide (P < 0.05). The occurrence of cardiovascular events began at 11-15 days after the onset of the disease and reached a peak at 14-20 days. COVID-19 not only is a respiratory disease but also causes damage to the cardiovascular system. Cardiac biomarkers have the potential for early warning and prognostic evaluation in patients with COVID-19. It is recommended that cardiac biomarker monitoring in patients with COVID-19 should be initiated at least from the 11th day of the disease course.

The Clinical Efficacy of N-Acetylcysteine in the Treatment of ST Segment Elevation Myocardial Infarction.

The aim of this study was to evaluate the clinical efficacy of N-acetylcysteine (NAC) in the treatment of ST segment elevation myocardial infarction (STEMI).PubMed, EMBASE, Cochrane Library, and Web of Science were searched systematically from the establishment of the database to June 2020. Two researchers independently completed literature screening and data extraction and conducted a meta-analysis.Nine articles including 1419 patients were enrolled. Meta-analysis showed that all-cause mortality [RR = 0.56, 95%CI (0.33, 0.93), P = 0.02], occurrence of major adverse cardiovascular events (MACE) [RR = 0.63, 95%CI (0.47, 0.85), P = 0.002], and myocardial enzyme hs-TnT level [SMD = -0.42, 95%CI (-0.71, -0.13), P = 0.005] were significantly lower in patients with STEMI treated with NAC than those in the control group. There was no significant difference between the NAC group and the control group in new congestive heart failure [RR = 0.94, 95%CI (0.48, 1.82), P = 0.84], ejection fraction [MD = 2.00, 95%CI (-0.59, 4.60), P = 0.13], and CK-MB [SMD = -0.18, 95%CI (-0.47, 0.11), P = 0.23]. There was no significant difference in the occurrence of adverse reactions between the NAC group and the control group [RR = 1.04, 95%CI (0.57-1.89), P = 0.90].NAC can reduce the all-cause mortality and MACE cases of STEMI.

Ischaemic preconditioning-induced serum exosomes protect against myocardial ischaemia/reperfusion injury in rats by activating the PI3K/AKT signalling pathway.

Ischaemia/reperfusion (I/R) injury can lead to severe arrhythmia and aggravate myocardial damage. Exosomes are small-membrane vesicles that play a protective role in myocardial I/R injury. This study aimed to explore the protective effects of ischaemic preconditioning (IPC)-induced serum exosomes (IPC-Exo) on myocardial I/R injury in rats and its underlying mechanism. Serum exosomes were extracted from IPC rats and quantified using a bicinchoninic acid assay kit. IPC-Exo (50 µg) was injected into the infarcted myocardium immediately after ligation. Rats were randomly divided into Sham, I/R, IPC-Exo + I/R, I/R + LY294002, and I/R + IPC-Exo + LY294002 groups. Haemodynamic parameters were measured by physiological recording. Transthoracic echocardiography was used to detect cardiac function. The serum levels of creatine kinase isomer-MB, lactate dehydrogenase, aspartate transaminase, tumour necrosis factor-alpha, interleukin (IL)-1ß, and IL-10 were detected by enzyme-linked immunosorbent assay. Triphenyl tetrazolium chloride staining was used to measure the myocardial infarct size. Apoptosis in myocardial tissues was detected by TUNEL staining. Western blotting was used to detect the levels of PI3K/AKT and apoptosis-related proteins. Our results showed that treatment with IPC-Exo ameliorated cardiac function and reduced inflammatory factor production, cardiomyocyte apoptosis, and myocardial infarct size. Moreover, IPC-Exo treatment promoted the protein expression of Bcl-2, p-PI3K, and p-AKT but inhibited that of caspase-3 and Bax. However, treatment with LY294002 significantly reversed that IPC-Exo-induced increase in p-PI3K and p-AKT levels, improvement of haemodynamics, and decrease of inflammatory factor production and apoptosis in the I/R + IPC-Exo group. Taken together, our results suggest that IPC-Exo may alleviate I/R injury via activating the PI3K/AKT signalling pathway.

Microplegia in cardiac surgery: Systematic review and meta-analysis.

BACKGROUND: Consensus on the optimum choice of cardioplegia remains elusive. One possibility that has been suggested to have beneficial properties is microplegia, a cardioplegia of reduced crystalloid volume. The aim of this meta-analysis is to comprehensively investigate microplegia against a range of clinical outcomes. METHODS: To identify potential studies, systematic searches were carried out in four databases (eg, Pubmed, EMBASE). The search strategy included the key concepts of "microplegia" OR "mini-cardioplegia" OR "miniplegia" AND "cardiac surgery." This was followed by a meta-analysis investigating: mortality, crystalloid volume; cardiopulmonary bypass time; cross-clamp time; intra-aortic balloon pump use; spontaneous heartbeat recovery; inotropic support; low cardiac output syndrome; myocardial infarction; acute renal failure; atrial fibrillation, reoperation for bleeding; creatine kinase myocardial band (CK-MB); intensive care unit (ICU) time and hospital stay. RESULTS: Eleven studies comprising 5798 participants were analyzed. Microplegia used a lower volume of crystalloids and led to a higher spontaneous return of heartbeat, odds ratio (OR) 4.271 (95% confidence intervals [CIs]: 1.935, 9.423; I2 = 76.57%; P < .001) and a lower requirement for inotropic support, OR: 0.665 (95% CI: 0.47, 0.941; I2 = 3.53%; P = .021). Microplegia was also associated with a lower CK-MB release, mean difference (MD) -6.448 ng/mL (95% CI: -9.386, -3.511; I2 = 0%; P < .001) and a shorter ICU stay, MD: -0.411 days (95% CI: -0.812, -0.009; I2 = 17.65%; P = .045). All other comparisons were nonsignificant. CONCLUSIONS: Microplegia has similar effects to other types of cardioplegia and is beneficial with regard to spontaneous return of heartbeat, inotropic support, ICU stay, and CK-MB release.