Cardioprotective effects of propofol-dexmedetomidine in open-heart surgery: A prospective double-blind study

Dexmedetomidine Ameliorates Myocardial Ischemia-Reperfusion Injury by Inhibiting MDH2 Lactylation via Regulating Metabolic Reprogramming

Myocardial ischemia-reperfusion injury (MIRI) significantly worsens the outcomes of patients with cardiovascular diseases. Dexmedetomidine (Dex) is recognized for its cardioprotective properties, but the related mechanisms, especially regarding metabolic reprogramming, have not been fully clarified. A total of 60 patients with heart valve disease are randomly assigned to Dex or control group. Blood samples are collected to analyze cardiac injury biomarkers and metabolomics. In vivo and vitro rat models of MIRI are utilized to assess the effects of Dex on cardiac function, lactate production, and mitochondrial function. It is found that postoperative CK-MB and cTNT levels are significantly lower in the Dex group. Metabolomics reveals that Dex regulates metabolic reprogramming and reduces lactate level. In Dex-treated rats, the myocardial infarction area is reduced, and myocardial contractility is improved. Dex inhibits glycolysis, reduces lactate, and improves mitochondrial function following MIRI. Lactylation proteomics identifies that Dex reduces the lactylation of Malate Dehydrogenase 2（MDH2), thus alleviating myocardial injury. Further studies reveal that MDH2 lactylation induces ferroptosis, leading to MIRI by impairing mitochondrial function. Mechanistic analyses reveal that Dex upregulates Nuclear Receptor Subfamily 3 Group C Member 1（NR3C1) phosphorylation, downregulates Pyruvate Dehydrogenase Kinase 4 (PDK4), and reduces lactate production and MDH2 lactylation. These findings provide new therapeutic targets and mechanisms for the treatment for MIRI.

Dexmedetomidine administration is associated with improved outcomes in critically ill patients with acute myocardial infarction partly through its anti-inflammatory activity

Background

Dexmedetomidine (DEX) is a commonly used sedative in the intensive care unit and has demonstrated cardioprotective properties against ischemia-reperfusion injury in preclinical studies. However, the protective effects of early treatment of DEX in patients with acute myocardial infarction (AMI) and its underlying mechanism are still not fully understood. This study aims to investigate the association between early DEX treatment and in-hospital mortality in patients with AMI, and to explore the potential mediating role of white blood cell (WBC) reduction in this relationship.

Methods

A retrospective cohort analysis was conducted using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with AMI were divided into the DEX and non-DEX group, based on whether they received DEX treatment in the early stage of hospitalization. The primary outcome measured was in-hospital mortality. The study evaluated the association between DEX use and in-hospital mortality using the Kaplan-Meier (KM) method and Cox proportional hazards model. Additionally, 1:1 propensity score matching (PSM) was conducted to validate the results. Furthermore, causal mediation analysis (CMA) was utilized to explore potential causal pathways mediated by WBC reduction between early DEX use and the primary outcome.

Results

This study analyzed data from 2,781 patients, with 355 in the DEX group and 2,426 in the non-DEX group. KM survival analysis revealed a significantly lower in-hospital mortality rate in the DEX group compared to the non-DEX group. After adjusting for multiple confounding factors, the Cox regression model demonstrated a significant positive impact of DEX on the risk of in-hospital mortality in patients with AMI, with hazard ratios (HR) of 0.50 (95% confidence interval (CI): 0.35-0.71, p < 0.0001). PSM analysis confirmed these results, showing HR of 0.49 (95% CI: 0.31-0.77, p = 0.0022). Additionally, CMA indicated that 13.7% (95% CI: 1.8%-46.9%, p = 0.022) of the beneficial effect of DEX on reducing in-hospital mortality in patients with AMI was mediated by the reduction in WBC.

Conclusion

The treatment of DEX was associated with a lower risk of in-hospital mortality in patients with AMI, potentially due to its anti-inflammatory properties.

Dexmedetomidine as a cardioprotective drug: a narrative review

Dexmedetomidine (DEX), a highly selective alpha2-adrenoceptors agonist, is not only a sedative drug used during mechanical ventilation in the intensive care unit but also a cardio-protective drug against ischemia-reperfusion injury (IRI). Numerous preclinical in vivo and ex vivo studies, mostly evaluating the effect of DEX pretreatment in healthy rodents, have shown the efficacy of DEX in protecting the hearts from IRI. However, whether DEX can maintain its cardio-protective effect in hearts with comorbidities such as diabetes has not been fully elucidated. Multiple clinical trials have reported promising results, showing that pretreatment with DEX can attenuate cardiac damage in patients undergoing cardiac surgery. However, evidence of the post-treatment effects of DEX in clinical practice remains limited. In this narrative review, we summarize the previously reported evidence of DEX-induced cardio-protection against IRI and clarify the condition of the hearts and the timing of DEX administration that has not been tested. With further investigations evaluating these knowledge gaps, the use of DEX as a cardio-protective drug could be further facilitated in the management of patients undergoing cardiac surgery and might be considered in a broader area of clinical settings beyond cardiac surgery, including patients with acute myocardial infarction.

Dexmedetomidine combined with propofol attenuates myocardial ischemia/reperfusion injury by activating the AMPK signaling pathway

Objective

Myocardial ischemia/reperfusion (MI/R) injury is a major cause of cardiac tissue damage, with high disability and death rates. Although both dexmedetomidine (Dex) and propofol (PPF) have been indicated to alleviate MI/R injury in rat models, the effects of the combined use of these two drugs remain unclear. This study aimed to investigate the combined effects of Dex and PPF against MI/R injury and related mechanisms.

Methods

A rat model of MI/R injury was established and used to explore the combined effects of Dex and PPF on MI/R injury. Hematoxylin-eosin (HE) and Masson staining were used for histopathological evaluation. 2,3,5-triphenyltetrazolium chloride (TTC), echocardiography, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining were used to determine myocardial infarction size, cardiac function, and apoptosis, respectively. Enzyme-linked immunosorbent assay (ELISA) was performed to assess myocardial function and oxidative stress (OS). Autophagy was observed through transmission electron microscopy. Moreover, western blotting was conducted to detect autophagy markers and the AMPK pathway.

Results

The combination of Dex and PPF alleviated histopathological injury, reduced myocardial infarction, and rescued cardiac dysfunction in MI/R rats. Furthermore, Dex combined with PPF decreased the levels of MDA and ROS and increased the SOD level in MI/R rats. Besides, Dex combined with PPF inhibited myocardial apoptosis in MI/R rats. After combined treatment with Dex and PPF, the number of autophagosomes, expression levels of Beclin-1 and LC3II/LC3I were elevated, while the expression levels of p62 were reduced in MI/R rats. The combined use of Dex and PPF activated the AMPK pathway in MI/R rats. Compound C (an AMPK inhibitor) could abolish the combined effects of Dex and PPF on alleviating myocardial injury and enhancing autophagy in MI/R rats.

Conclusion

The combination of Dex and PPF attenuated MI/R injury in rats, which may be associated with the activation of the AMPK signaling pathway.

Effects of interventions targeting the systemic inflammatory response to cardiac surgery on clinical outcomes in adults

BACKGROUND

Organ injury is a common and severe complication of cardiac surgery that contributes to the majority of deaths. There are no effective treatment or prevention strategies. It has been suggested that innate immune system activation may have a causal role in organ injury. A wide range of organ protection interventions targeting the innate immune response have been evaluated in randomised controlled trials (RCTs) in adult cardiac surgery patients, with inconsistent results in terms of effectiveness.

OBJECTIVES

The aim of the review was to summarise the results of RCTs of organ protection interventions targeting the innate immune response in adult cardiac surgery. The review considered whether the interventions had a treatment effect on inflammation, important clinical outcomes, or both.

SEARCH METHODS

CENTRAL, MEDLINE, Embase, conference proceedings and two trial registers were searched on October 2022 together with reference checking to identify additional studies.

SELECTION CRITERIA

RCTs comparing organ protection interventions targeting the innate immune response versus placebo or no treatment in adult patients undergoing cardiac surgery where the treatment effect on innate immune activation and on clinical outcomes of interest were reported.

DATA COLLECTION AND ANALYSIS

Searches, study selection, quality assessment, and data extractions were performed independently by pairs of authors. The primary inflammation outcomes were peak IL-6 and IL-8 concentrations in blood post-surgery. The primary clinical outcome was in-hospital or 30-day mortality. Treatment effects were expressed as risk ratios (RR) and standardised mean difference (SMD) with 95% confidence intervals (CI). Meta-analyses were performed using random effects models, and heterogeneity was assessed using I2.

MAIN RESULTS

A total of 40,255 participants from 328 RCTs were included in the synthesis. The effects of treatments on IL-6 (SMD -0.77, 95% CI -0.97 to -0.58, I2 = 92%) and IL-8 (SMD -0.92, 95% CI -1.20 to -0.65, I2 = 91%) were unclear due to heterogeneity. Heterogeneity for inflammation outcomes persisted across multiple sensitivity and moderator analyses. The pooled treatment effect for in-hospital or 30-day mortality was RR 0.78, 95% CI 0.68 to 0.91, I2 = 0%, suggesting a significant clinical benefit. There was little or no treatment effect on mortality when analyses were restricted to studies at low risk of bias. Post hoc analyses failed to demonstrate consistent treatment effects on inflammation and clinical outcomes. Levels of certainty for pooled treatment effects on the primary outcomes were very low.

AUTHORS' CONCLUSIONS

A systematic review of RCTs of organ protection interventions targeting innate immune system activation did not resolve uncertainty as to the effectiveness of these treatments, or the role of innate immunity in organ injury following cardiac surgery.

Dexmedetomidine as a myocardial protector in pediatric heart surgery using cardiopulmonary bypass: a systematic review

Background

In recent years, dexmedetomidine has been studied as a cardioprotective agent. However, studies on its application in pediatric heart surgery using cardiopulmonary bypass (CPB) remain limited. This systematic review aimed to provide information on the cardioprotective effect of dexmedetomidine in children undergoing heart surgery using CPB.

Methods

The authors searched several databases (MEDLINE, Embase, Cochrane Library, etc.) to identify all trials comparing the levels of myocardial injury via biomarkers, including pediatric patients undergoing heart surgery using CPB who received dexmedetomidine versus placebo or other anesthetic agents. Literatures from non-primary studies were excluded. Two reviewers independently screened studies for eligibility and extracted data. The Cochrane Risk-of-Bias tool was implemented to evaluate any potential biases. Information from eligible studies was summarized and correspondingly reviewed based on any quantitative outcomes.

Results

We identified six trials composed of 419 participants, three of which (n=241) showed significantly reduced interleukin-6 (IL-6) levels in the dexmedetomidine group, while one study (n=40) showed no IL-6 difference between groups. Cardiac troponin I (cTnI) and creatinine kinase-myocardial band (CK-MB), as myocardial injury biomarkers, were found to be lower in two trials (n=180). Despite several limitations hindering this review from pooling the data objectively, the majority of published studies indicated that dexmedetomidine is a seemingly efficacious agent protecting against cardiac injury during bypass.

Conclusions

These studies suggest that dexmedetomidine has cardioprotective effects through the lowering of cardiac injury biomarkers while improving its clinical outcomes after heart surgery using bypass.

Efficacy of dexmedetomidine on myocardial ischemia/reperfusion injury in patients undergoing cardiac surgery with cardiopulmonary bypass: A protocol for systematic review and meta-analysis

BACKGROUND

Cardiac surgery using cardiopulmonary bypass has been shown to cause reversible postischemic cardiac dysfunction and is associated with reperfusion injury and myocardial cell death. Therefore, it is very important to have a series of measures in place to reduce oxygen consumption and provide myocardial protection. We performed a protocol for systematic review and meta-analysis to evaluate the effect of dexmedetomidine administration on myocardial ischemia/reperfusion injury in patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

This review protocol is registered in the PROSPERO International Prospective Register of systematic reviews, registration number CRD42023386749. A literature search is performed in January 2023 without restriction to regions, publication types or languages. The primary sources were the electronic databases of PubMed, Embase, Web of Science, the Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure database, Chinese Biomedical Database, and Chinese Science and Technology Periodical database. Risk of bias will be assessed according to the Cochrane Risk of Bias Tool. The meta-analysis is performed using Reviewer Manager 5.4.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This meta-analysis will evaluate the efficacy and safety of dexmedetomidine in patients undergoing cardiac surgery with cardiopulmonary bypass.

Dexmedetomidine for adult cardiac surgery: a systematic review, meta-analysis and trial sequential analysis

The effects of dexmedetomidine in adults undergoing cardiac surgery are inconsistent. We conducted a systematic review and meta-analysis to analyse the effects of peri-operative dexmedetomidine in adults undergoing cardiac surgery. We searched MEDLINE via Pubmed, EMBASE, Scopus and Cochrane for relevant randomised controlled trials between 1 January 1990 and 1 March 2022. We used the Joanna Briggs Institute methodology checklist to assess study quality and the GRADE approach to certainty of evidence. We assessed the sensitivity of results to false data. We used random-effects meta-analyses to analyse the primary outcomes: durations of intensive care and tracheal intubation. We included 48 trials of 6273 participants. Dexmedetomidine reduced the mean (95%CI) duration of intensive care by 5.0 (2.2-7.7) h, p = 0.001, and tracheal intubation by 1.6 (0.6-2.7) h, p = 0.003. The relative risk (95%CI) for postoperative delirium was 0.58 (0.43-0.78), p = 0.001; 0.76 (0.61-0.95) for atrial fibrillation, p = 0.015; and 0.49 (0.25-0.97) for short-term mortality, p = 0.041. Bradycardia and hypotension were not significantly affected. Trial sequential analysis was consistent with the primary meta-analysis. Adjustments for possible false data reduced the mean (95%CI) reduction in duration of intensive care and tracheal intubation by dexmedetomidine to 3.6 (1.8-5.4) h and 0.8 (0.2-1.4) h, respectively. Binary adjustment for methodological quality at a Joanna Briggs Institute score threshold of 10 did not alter the results significantly. In summary, peri-operative dexmedetomidine reduced the durations of intensive care and tracheal intubation and the incidence of short-term mortality after adult cardiac surgery. The reductions in intensive care stay and tracheal intubation may or may not be considered clinically useful, particularly after adjustment for possible false data.

Adoption of Dexmedetomidine in Different Doses at Different Timing in Perioperative Patients

Dexmedetomidine (Dex) is an alpha-2 agonist used for sedation during various procedures. Dex activates 2-adrenoceptors, and causes the decrease of sympathetic tone, with attenuation of the neuroendocrine and hemodynamic responses to anesthesia and surgery; it reduces anesthetic and opioid requirements; and causes sedation and analgesia.

OBJECTIVE

it was to compare the perioperative effects of different doses of Dex at different timing in patients using Dex during the perioperative period adopting a medical data classification algorithm based on optimized semi-supervised collaborative training (Tri-training).

METHODS

495 patients requiring surgical treatment in Xingtai People's Hospital were randomly selected as the study subjects. The patients were divided into group A (used before induction), group B (used during induction), and group C (used after induction) according to different induction timing, with 165 cases in each group. Then, groups A, B, and C were divided into groups A1, B1, and C1 (0.4 μg/(kg·h) rate), groups A2, B2, and C2 (0.6 μg/(kg·h) rate), and groups A3, B3, and C3 (0.8 μg/(kg·h) rate) according to the dose used, with 55 cases in each group. Intraoperative anesthesia and postoperative adverse reactions were compared among the 9 groups.

RESULTS

the similarity between the Tri-training algorithm optimized by Naive Bayes (NB) classification algorithm and the actual classification (93.49%) was clearly higher than that by decision tree (DT) and K-nearest neighbor (kNN) classification algorithm (76.21%, 74.31%); heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) values decreased obviously after Dex used in groups B1, C1, B2, C2, B3, and C3 (P <0.05), but did not change significantly in groups A1, A2, and A3 (P >0.05); the proportion of patients with satisfactory Ramsay score in group A3 was distinctly superior than that in groups A1, A2, B1, B2, B3, C1, C2, and C3 (P <0.05); the incidence of adverse reactions in group A3 was significantly inferior than that in groups A1, A2, B1, B2, B3, C1, C2, and C3 (P <0.05).

CONCLUSION

the optimization effect of NB classification algorithm was the best, and the injection of Dex at the injection rate of 0.8 μg/(kg·h) before induction of anesthesia could apparently improve the fluctuation of HR, SBP, and DBP during perioperative period, and effectively reduce the occurrence of adverse reactions in patients, with better sedative effect on patients.

Effects of dexmedetomidine on cardioprotection and other postoperative complications in elderly patients after cardiac and non-cardiac surgerie

BACKGROUND

After cardiac and non-cardiac surgeries, elderly patients have a high probability of developing cardiac complications and postoperative delirium. Although several clinical trials have investigated whether perioperative intravenous dexmedetomidine can protect the heart and reduce postoperative complications such as delirium in elderly patients, the obtained results have been inconsistent. We conducted a meta-analysis to investigate the effects of dexmedetomidine on cardioprotection and other postoperative complications in elderly patients undergoing cardiac or non-cardiac surgery.

AIM

To investigate the effects of dexmedetomidine on cardiac complications and delirium in elderly patients undergoing cardiac or non-cardiac surgery.

METHODS

The PubMed, Cochrane Library, web of science, and other sources were comprehensively searched for all randomized controlled trials published before May 2021 that investigated the efficacy of dexmedetomidine in the prevention of cardiac and postoperative delirium (POD).

RESULTS

In total, 18 studies involving 1025 patients were included in the meta-analysis. Intravenous dexmedetomidine significantly reduced cardiac troponin I (cTnI) and the inflammatory factor tumor necrosis factor-α (TNF-α) was comparable to the control group. Dexmedetomidine also reduced the POD and mortality rates. However, patients in the dexmedetomidine group were more likely to have a decreased heart rate (within the normal range) and hypotension during dexmedetomidine administration than those in the control group. There was no difference in the occurrence of myocardial infarction, bradycardia, or stroke between the two groups. Dexmedetomidine significantly shortened the time to extubate; however, it did not shorten the length of stay in the intensive care unit.

CONCLUSION

The administration of dexmedetomidine during cardiac and non-cardiac surgeries can provide myocardial protection by inhibiting inflammation and cTnI, which may be beneficial for the rapid recovery of patients. Meanwhile, the administration of dexmedetomidine reduced the incidence of POD and decreased mortality (in-hospital).

Quo Vadis Anesthesiologist? The Value Proposition of Future Anesthesiologists Lies in Preserving or Restoring Presurgical Health after Surgical Insult

This Special Issue of the Journal of Clinical Medicine is devoted to anesthesia and perioperative care [...].

Myocardial protective and anti-inflammatory effects of dexmedetomidine in patients undergoing cardiovascular surgery with cardiopulmonary bypass: a systematic review and meta-analysis

Cardiopulmonary bypass (CPB) technology provides potential for cardiac surgery, but it is followed by myocardial injury and inflammation related to ischemia–reperfusion. This meta-analysis aimed to systematically evaluate the cardioprotective effect of dexmedetomidine on cardiac surgery under CPB and its effect on accompanied inflammation. PubMed, Cochrane Library, EMBASE and Web of Science databases were comprehensively searched for all randomized controlled trials (RCTs) published before April 1st, 2021 that explored the application of dexmedetomidine in cardiac surgery. Compared with the control group (group C), the concentrations of CK-MB in the perioperative period and cTn-I at 12 h and 24 h after operation in dexmedetomidine group (group D) were significantly decreased (P < 0.05). In addition, in group D, the levels of interleukin-6 at 24 h after operation, tumor necrosis factor-a at the 12 h and 24 h after operation were significantly decreased (P < 0.05). At the same time, the length of Intensive Care Unit stay in group D was significantly shorter than group C (P < 0.05). However, there was no significant difference in interleukin-10 level, C reactive protein level, the time on ventilator and length of hospital stay between the two groups (P > 0.05). The application of dexmedetomidine in cardiac surgery with CPB can reduce CK-MB and cTn-I concentration and interleukin-6, tumor necrosis factor-α levels to a certain extent and shorten the length of Intensive Care Unit stay, but it has no significant effect on IL-10 level, C reactive protein level, the time on ventilator and length of hospital stay.

Effects of dexmedetomide, propofol and remifentanil on perioperative inflammatory response and lung function during lung cancer surgery

OBJECTIVE

To investigate the effects of combined anesthesia with dexmedetomide, propofol and remifentanil on perioperative inflammatory response and pulmonary function in patients with lung cancer.

METHODS

90 patients with lung cancer admitted to our hospital from April 2017 to April 2019 were selected. According to different anesthesia schemes, patients undergoing combined anesthesia with propofol and remifentanil were included in group A (GA), and patients receiving combined anesthesia with dexmedetomidine, propofol and remifentanil were included in group B (GB). The blood gas, pulmonary function index, inflammatory factor level in serum, anesthetic effect and complications were compared between the two groups.

RESULTS

HR indexes at T1 and T2 in GB were significantly lower than those in GA (P<0.001). There was no significant fluctuation in PaCO2 and PaO2 indexes in the two groups at different time points (P>0.05). At T0, T1 and T2, RV/TLC levels in serum increased significantly in the two groups. (MVV-VE)/FEV1 and MVV/FEV levels were significantly decreased (all P<0.05). The fluctuation levels of RV/TLC, (MVV-VE)/FEV1 and MVV/FEV levels in serum of GB were significantly lower than those of GA at T1 and T2 (P<0.05). At T0, T1 and T2, the levels of inflammatory factors in serum were significantly decreased in the two groups (P<0.05), but the levels of inflammatory factors in serum of GB were significantly lower than those of GA at T1 and T2 (P<0.05). The VAS scores of GB were significantly lower than those of GA at 1 hour and 4 hours after operation (P<0.05). Ramsay scores of GB were significantly higher than those of GA at 1 hour and 4 hours after operation (P<0.05). The restlessness score and choking cough score in GB were lower than those in GA (P<0.05). Perioperative complications in GB were better than those in GA (P<0.05).

CONCLUSION

On the basis of propofol and remifentanil anesthesia, the combination of dexmedetomidine for anesthesia induction can achieve satisfactory anesthesia effect. On the basis of propofol and remifentanil anesthesia combined with dexmedetomidine for anesthesia induction, it can significantly inhibit the inflammatory response of lung cancer patients during perioperative period and it can more effectively stabilize the blood gas microcirculation and lung function of patients.

Pharmacological Conditioning of the Heart: An Update on Experimental Developments and Clinical Implications

The aim of pharmacological conditioning is to protect the heart against myocardial ischemia-reperfusion (I/R) injury and its consequences. There is extensive literature that reports a multitude of different cardioprotective signaling molecules and mechanisms in diverse experimental protocols. Several pharmacological agents have been evaluated in terms of myocardial I/R injury. While results from experimental studies are immensely encouraging, translation into the clinical setting remains unsatisfactory. This narrative review wants to focus on two aspects: (1) give a comprehensive update on new developments of pharmacological conditioning in the experimental setting concentrating on recent literature of the last two years and (2) briefly summarize clinical evidence of these cardioprotective substances in the perioperative setting highlighting their clinical implications. By directly opposing each pharmacological agent regarding its recent experimental knowledge and most important available clinical data, a clear overview is given demonstrating the remaining gap between basic research and clinical practice. Finally, future perspectives are given on how we might overcome the limited translatability in the field of pharmacological conditioning.

Perioperative Cardioprotection: Clinical Implications

Perioperative cardioprotection aims to minimize the consequences of myocardial ischemia-reperfusion injury. In isolated tissue and animal experiments, several treatments have been identified providing cardioprotection. Some of these strategies have been confirmed in clinical proof-of-concept studies. However, the final translation of cardioprotective strategies to really improve clinical outcome has been disappointing: large randomized controlled clinical trials mostly revealed inconclusive, neutral, or negative results. This review provides an overview of the currently available evidence regarding clinical implications of perioperative cardioprotective therapies from an anesthesiological perspective, highlighting nonpharmacological as well as pharmacological strategies. We discuss reasons why translation of promising experimental results into clinical practice and outcome improvement is hampered by potential confounders and suggest future perspectives to overcome these limitations.