Dexmedetomidine Reduces Atrial Fibrillation After Adult Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials

Exploring postoperative atrial fibrillation after non-cardiac surgery: mechanisms, risk factors, and prevention strategies

Atrial fibrillation (AF) stands as the most prevalent persistent arrhythmia and a common complication after surgical procedures. Although the majority of non-cardiac surgery patients experience postoperative AF (POAF) and the condition is typically self-limited and asymptomatic, its detrimental impact on patient outcomes, prolonged hospitalization, and heightened risk of stroke and overall mortality has become increasingly evident. Of significant concern, POAF emerges as a noteworthy risk factor for stroke, myocardial infarction, and mortality in comparison to patients with non-surgical atrial fibrillation. Multiple studies have corroborated the association between POAF and an elevated risk of stroke and mortality. The development of postoperative atrial fibrillation is multifactorial, with the inflammatory response being a primary contributor; additionally, factors such as hypovolemia, intraoperative hypotension, anemia, trauma, and pain can trigger POAF. Risk factors for POAF in non-cardiac surgery primarily relate to age, hypertension, obesity, prior cardiac disease, obstructive sleep apnea, and male sex. Prophylactic treatment with β-blockers, amiodarone, or magnesium has demonstrated efficacy, but further trials are warranted, especially in high-risk populations. This review provides an account of the incidence rate, pathophysiology, and prognosis of atrial fibrillation after non-cardiac surgery, elucidates the underlying mechanisms of its occurrence, and explores various preventive strategies investigated in this domain.

Effects of Dexmedetomidine on Basic Cardiac Electrophysiology in Adults; a Descriptive Review and a Prospective Case Study

Dexmedetomidine (DEX) is a commonly used sedative agent with no or minimal effects on breathing. DEX may also be beneficial in myocardial protection. Since the mechanisms of cardiac effects are not well known, we carried out a descriptive review and examined the effects of DEX on myocardial electrical conduction in a prospective and controlled manner. For the review, clinical studies exploring DEX in myocardial protection published between 2020-2022 were explored. A case study included 11 consecutive patients at a median (range) age of 48 (38-59), scheduled for elective radiofrequency ablation of paroxysmal atrial fibrillation. A bolus dose of DEX 1 µg/kg given in 15 min was followed by a continuous infusion of 0.2-0.7 µg/kg/h. Direct intracardiac electrophysiologic measurements, hemodynamics and oxygenation were measured before and after the DEX bolus. Experimental studies show that DEX protects the heart both via stabilizing cardiac electrophysiology and reducing apoptosis and autophagy after cell injury. The clinical evidence shows that DEX provides cardiac protection during different surgeries. In a clinical study, DEX increased the corrected sinus node recovery time, prolongated the atrioventricular (AV) nodal refractory period and cycle length producing AV nodal Wenckebach retrograde conduction block. DEX has a putative role in organ protection against hypoxic, oxidative and reperfusion injury. DEX slows down the firing of the sinus node and prolongs AV refractoriness.

Dexmedetomidine Reduces Incidences of Ventricular Arrhythmias in Adult Patients: A Meta-Analysis

Purpose

To assess the antiarrhythmic properties of dexmedetomidine in patients in the intensive care unit.

Methods

A literature review was conducted with Ovid MEDLINE (R), Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, and Scopus. Study Selection. Randomized controlled trials were included, examining the incidence of ventricular arrhythmias, ventricular tachycardia, or ventricular fibrillation with dexmedetomidine compared to placebo or an alternative sedative agent. For each publication that met the selection criteria, the patient demographics, incidence of arrhythmias, mortality, and adverse events were collected. Data extraction was carried out by two authors independently.

Results

We identified 6 out of 126 studies that met the selection criteria for our meta-analysis, all of which focused on the perioperative cardiac surgery period. Patients receiving dexmedetomidine demonstrated a significant reduction of the overall incidence of ventricular arrhythmias (RR 0.35, 95% CI 0.16, 0.76). In particular, dexmedetomidine significantly decreased the risk of ventricular tachycardia compared with control (RR 0.25, 95% CI 0.08, 0.80, I² 0%). Regarding adverse events, dexmedetomidine significantly increased the frequency of bradycardia (RR 2.78 95% CI 2.00, 3.87). However, there was no significant difference in mortality (RR 0.59 95% CI 0.12, 3.02).

Conclusion

From this meta-analysis, we report a decreased incidence of ventricular tachycardia with dexmedetomidine in critically ill patients. This result favors the use of dexmedetomidine for its antiarrhythmic properties.

Effect of Dexmedetomidine on Tachyarrhythmias After Cardiac Surgery: A Systematic Review and Meta-Analysis

ABSTRACT

Tachyarrhythmias after cardiac surgery is a common occurrence in clinical practice, which can be life threatening. We searched 6 databases, including Embase, PubMed, Cochrane, CNKI, Wanfang, and Sinomed, to evaluate the effect of dexmedetomidine on tachyarrhythmias after adult cardiac surgery. The primary end point was the number of patients with atrial fibrillation (AF) after cardiac surgery. The secondary end points included the number of patients with supraventricular tachycardia or with ventricular tachycardia or with ventricular fibrillation or with myocardial infarction or deceased patients, the duration of mechanical ventilation, the intensive care unit stay, hospital stay, and the number of patients with bradycardia and those with hypotension. Among the 1388 retrieved studies, 18 studies (n = 3171 participants) met our inclusion criteria. Dexmedetomidine reduced the incidence of AF by 17% [relative risk (RR) = 0.83; 95% confidence interval (CI), 0.73-0.93; P = 0.002]. Through subgroup analysis, we found that when the maintenance dose of dexmedetomidine was >0.7 µg·kg-1·h-1, the effect of preventing AF was obvious (RR = 0.58; 95%CI 0.43-0.78; P = 0.0003). Dexmedetomidine also reduced the incidence of supraventricular tachycardia by approximately 70% (RR = 0.29; 95% CI, 0.11-0.77; P = 0.01) and the incidence of ventricular tachycardia by approximately 80% (RR = 0.23; 95% CI, 0.08-0.63; P = 0.004) but had no effect on ventricular fibrillation (RR = 1.02; 95% CI, 0.14-7.31; P = 0.99). The major side effect of dexmedetomidine was bradycardia. Dexmedetomidine can reduce the incidence of AF (especially high dosages), supraventricular tachycardia, and ventricular tachycardia after cardiac surgery in adults, but it does not affect the occurrence of ventricular fibrillation.

Comparison between dexmedetomidine and propofol on outcomes after coronary artery bypass graft surgery: a retrospective study

Background

Dexmedetomidine (DEX) has a pharmacological profile that should allow rapid recovery and prevent undesirable outcomes such as pulmonary complications.

Methods

This large retrospective study compared the beneficial effects of perioperative infusion of DEX with propofol on the postoperative outcome after coronary artery bypass graft surgery. We reviewed patients’ medical notes at Luoyang Central Hospital from 1st January 2012 to 31st December 2019. All continuous variables, if normally distributed, were presented as mean ± SD; Otherwise, the non-normally distributed data and categorical data were presented as median (25-75 IQR) or number (percentage). The Mann-Whitney U test and Chi-square test were used to evaluate the difference of variables between the DEX and propofol groups. Multivariate logistic regression analysis was performed on the main related and differential factors in the perioperative period.

Results

A total of 1388 patients were included in the study; of those, 557 patients received propofol infusion, and 831 patients received dexmedetomidine. DEX significantly reduced postoperative pulmonary complications compared with propofol, 7.82% vs 13.29%; P < 0.01, respectively. When compared with propofol, DEX significantly shortened the duration of mechanical lung ventilation, 18 (13,25) hours vs 21 (16,37) hours; P < 0.001, the length of stay in the intensive care unit, 51 (42,90) vs 59 (46,94.5) hours; P = 0.001 and hospital stay, 20 (17,24) vs 22 (17,28) days; P < 0.001, respectively. The incidences of postoperative wound dehiscence and infection were significantly reduced with DEX compared with propofol groups, 2.53% vs 6.64%; P < 0.001, respectively. Interestingly, patients receiving DEX had significantly shorter surgical time compared to propofol; 275 (240,310) vs 280 (250,320) minutes respectively (P = 0.005) and less estimated blood loss (P = 0.001).

Conclusion

Perioperative infusion of dexmedetomidine improved the desirable outcomes in patients who had coronary artery bypass graft surgery compared with propofol.

Influence of Dexmedetomidine on Post-operative Atrial Fibrillation After Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials

Background: Previous clinical studies and meta-analysis evaluating the influence of dexmedetomidine on postoperative atrial fibrillation showed inconsistent results. We performed an updated meta-analysis to evaluate the influence of dexmedetomidine on incidence of postoperative atrial fibrillation after cardiac surgery.

Methods: Randomized controlled trials that evaluated the potential influence of dexmedetomidine on the incidence of atrial fibrillation after cardiac surgery were obtained by search of PubMed, Embase, and Cochrane's Library databases from inception to April 12, 2021. A random-effects model incorporating the potential publication bias was used to pool the results. Influences of patient or study characteristics on the efficacy of dexmedetomidine on atrial fibrillation after cardiac surgery were evaluated by meta-regression and subgroup analyses.

Results: Fifteen studies with 2,733 patients were included. Pooled results showed that dexmedetomidine significantly reduced the incidence of atrial fibrillation compared to control (OR: 0.72, 95% CI: 0.55–0.94, p = 0.02) with mild heterogeneity (I² = 26%). Subgroup analysis showed that dexmedetomidine significantly reduced the incidence of atrial fibrillation in studies from Asian countries (OR: 0.41, 95% CI: 0.26–0.66, p < 0.001), but not in those from non-Asian countries (OR: 0.89, 95% CI: 0.71–1.10, p = 0.27; p for subgroup difference = 0.004). Meta-regression analysis showed that the mean age and proportion of male patients may modify the influence of dexmedetomidine on POAF (coefficient = 0.028 and 0.021, respectively, both p < 0.05). Subgroup analysis further showed that Dex was associated with reduced risk of atrial fibrillation after cardiac surgery in studies with younger patients (mean age ≤ 61 years, OR = 0.44, 95% CI: 0.28–0.69, p = 0.004) and smaller proportion of males (≤74%, OR = 0.55, 95% CI: 0.36–0.83, p = 0.005), but not in studies with older patients or larger proportion of males (p for subgroup difference = 0.02 and 0.04).

Conclusions: Current evidence supports that perioperative administration of dexmedetomidine may reduce the risk of incidental atrial fibrillation after cardiac surgery, particularly in Asians.

Safe electrophysiologic profile of dexmedetomidine in different experimental arrhythmia models

Previous studies suggest an impact of dexmedetomidine on cardiac electrophysiology. However, experimental data is sparse. Therefore, purpose of this study was to investigate the influence of dexmedetomidine on different experimental models of proarrhythmia. 50 rabbit hearts were explanted and retrogradely perfused. The first group (n = 12) was treated with dexmedetomidine in ascending concentrations (3, 5 and 10 µM). Dexmedetomidine did not substantially alter action potential duration (APD) but reduced spatial dispersion of repolarization (SDR) and rendered the action potentials rectangular, resulting in no proarrhythmia. In further 12 hearts, erythromycin (300 µM) was administered to simulate long-QT-syndrome-2 (LQT2). Additional treatment with dexmedetomidine reduced SDR, thereby suppressing torsade de pointes. In the third group (n = 14), 0.5 µM veratridine was added to reduce the repolarization reserve. Further administration of dexmedetomidine did not influence APD, SDR or the occurrence of arrhythmias. In the last group (n = 12), a combination of acetylcholine (1 µM) and isoproterenol (1 µM) was used to facilitate atrial fibrillation. Additional treatment with dexmedetomidine prolonged the atrial APD but did not reduce AF episodes. In this study, dexmedetomidine did not significantly alter cardiac repolarization duration and was not proarrhythmic in different models of ventricular and atrial arrhythmias. Of note, dexmedetomidine might be antiarrhythmic in acquired LQT2 by reducing SDR.

Major Publications in the Critical Care Pharmacotherapy Literature: 2020

OBJECTIVES

To summarize selected meta-analyses and trials related to critical care pharmacotherapy published in 2020.

DATA SOURCES

The Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update group screened 36 journals monthly for impactful publications.

STUDY SELECTION

The group reviewed a total of 119 articles during 2020 according to relevance for practice.

DATA EXTRACTION

Articles were selected with consensus and importance to clinical practice from those included in the monthly Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update. The group reviewed articles according to Grading of Recommendations, Assessment, Development, and Evaluations criteria. Articles with a 1A grade were selected.

DATA SYNTHESIS

Several trials were summarized, including two meta-analyses and five original research trials. Original research trials evaluating vitamin C, hydrocortisone, and thiamine versus hydrocortisone in sepsis, the use of nonsedation strategies, dexmedetomidine in cardiac surgery, remdesivir for severe acute respiratory syndrome coronavirus 2, and thrombectomy in acute ischemic stroke. Two meta-analyses determining the impact of norepinephrine initiation in patients with septic shock and the use of corticosteroids in severe acute respiratory syndrome coronavirus 2 was included.

CONCLUSIONS

This clinical review provides summary and perspectives of clinical practice impact on influential critical care pharmacotherapy publications in 2020.

Atrial Fibrillation after Lung Cancer Surgery: Prediction, Prevention and Anticoagulation Management

Simple Summary

Atrial fibrillation that occurs after surgery raises further questions with respect to spontaneous atrial fibrillation, being an event unquestionably related to the surgical act itself and always quite self-limiting. The purpose of this review is to present the knowledge gained so far, including the most recent findings, regarding this peculiar form of arrhythmia. Its prognostic impact and the possibility of predicting and preventing it were the subject of our analysis, as well as the similarities and differences with spontaneous atrial fibrillation in relation to anticoagulation. Where possible, the search for evidence has focused on studies involving lung cancer patients undergoing thoracic surgery, highlighting any differences with cardiac surgery.

Abstract

Atrial fibrillation (AF) is a common complication of the early postoperative period of various types of surgery, including that for lung cancer. Although induced by the homeostatic alterations related to surgery, there is evidence that it is not a mere stand-alone transitory event, but it represents a relevant complication of surgery, bearing considerable prognostic consequences. Different methods have therefore been explored to predict the occurrence of postoperative atrial fibrillation (POAF) and prevent it. In particular, the age among clinical factors, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP), as a marker, have proven to be good predictors, and the use of beta-blockers or amiodarone in primary prevention seems to reduce its incidence significantly. There is growing evidence that POAF significantly increases the risk of stroke and global mortality in the long term; therefore, it should be managed in the same way as spontaneous atrial fibrillation. In this review, we will present the strongest evidence found so far and the most recent findings regarding the management of POAF, with a special focus on patients undergoing thoracic surgery for lung cancer.