Prophylaxis of atrial fibrillation with magnesium sulfate after coronary artery bypass grafting

doi:10.1016/0003-4975(91)90918-G

The Annals of Thoracic Surgery

Volume 52, Issue 3, September 1991, Pages 529-533

https://doi.org/10.1016/0003-4975(91)90918-G Get rights and content

Abstract

Ninety-nine consecutive consenting patients were prospectively entered into a randomized, double-blind, placebo-controlled trial to determine the efficacy of postoperative magnesium therapy on the incidence of cardiac arrhythmias after elective coronary artery bypass grafting. No patient had documented or suspected arrhythmias preoperatively. Forty-nine patients received 178 mEq of magnesium given over the first 4 postoperative days, and 50 patients received only placebo. The clinical characteristics of both groups were similar. The preoperative mean serum magnesium concentration was similar in both study (1.90 mEq/L) and placebo (1.90 mEq/L) groups. The mean postoperative serum magnesium concentration in study patients was significantly elevated over postoperative days 1 through 4 when compared with preoperative levels (p < 0.001). The postoperative mean serum magnesium concentration in control patients declined and remained significantly depressed through postoperative day 3 (p < 0.001), but increased to preoperative levels by postoperative day 4. The mean serum magnesium concentration was significantly greater in the study patients as compared with the control patients over postoperative days 1 through 4 (p < 0.001). Although there was no significant difference between groups with respect to episodes of ventricular arrhythmias, there was a significant decrease in the number of episodes of atrial fibrillation in the group receiving magnesium therapy (p < 0.02). There were no recognized adverse effects of magnesium therapy. Prophylactic magnesium administration seems to lessen the incidence and severity of atrial fibrillation after coronary artery bypass grafting.

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Cited by (163)

Atrial Fibrillation Following Coronary Artery Bypass Graft: Where Do We Stand?
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Atrial fibrillation (AF) is the most common atrial arrhythmia following coronary artery bypass graft (CABG). Its prevalence is 15–45% and is associated with poor long-term prognosis. Risk factors can be patient-related, intraoperative, and/or postoperative. Therapeutic and preventive strategies have been developed to curtail AF burden. Cardioversion is recommended for unstable or symptomatic patients and rate control if asymptomatic. Anticoagulation is challenging with risk of thromboembolism and bleeding. However, patients should be anticoagulated after cardioversion or if AF persists >48 h and risk factors of stroke exist. A minimum of 4 weeks is recommended but longer duration should be considered in patients at high risk of stroke irrespective of recurrence of AF.
Continuous Magnesium Infusion to Prevent Atrial Fibrillation After Cardiac Surgery: A Sequential Matched Case-Controlled Pilot Study
2020, Journal of Cardiothoracic and Vascular Anesthesia
The authors aimed to test whether a bolus of magnesium followed by continuous intravenous infusion might prevent the development of atrial fibrillation (AF) after cardiac surgery.
Sequential, matched, case-controlled pilot study.
Tertiary university hospital.
Matched cohort of 99 patients before and intervention cohort of 99 consecutive patients after the introduction of a continuous magnesium infusion protocol.
The magnesium infusion protocol consisted of a 10 mmol loading dose of magnesium sulphate followed by a continuous infusion of 3 mmol/h over a maximum duration of 96 hours or until intensive care unit discharge.
The study groups were balanced except for a lower cardiac index in the intervention cohort. The mean duration of magnesium infusion was 27.93 hours (95% confidence interval [CI]: 24.10-31.76 hours). The intervention group had greater serum peak magnesium levels: 1.72 mmol/L ± 0.34 on day 1, 1.32 ± 0.36 on day 2 versus 1.01 ± 1.14 and 0.97 ± 0.13, respectively, in the control group (p < 0.01). Atrial fibrillation occurred in 25 patients (25.3%) in the intervention group and 40 patients (40.4%) in the control group (odds ratio 0.49, 95% CI, 0.27-0.92; p = 0.023). On a multivariate Cox proportional hazards model, the hazard ratio for the development of AF was significantly less in the intervention group (hazard ratio 0.45, 95% CI, 0.26-0.77; p = 0.004).
The magnesium delivery strategy was associated with a decreased incidence of postoperative AF in cardiac surgery patients. These findings provide a rationale and preliminary data for the design of future randomized controlled trials.
Magnesium status and magnesium therapy in cardiac surgery: A systematic review and meta-analysis focusing on arrhythmia prevention
2017, Journal of Critical Care
Citation Excerpt :
Some studies excluded patients taking anti-arrhythmic medications. Twenty-two were double-blinded [11-15,17-19,21-27,32,33,36-39,41]. We found significant methodological heterogeneity in dosage, timing and method of magnesium administration (Supplemental digital content, Table S3).
To investigate magnesium as prophylaxis or treatment of postoperative arrhythmias in cardiac surgery (CS) patients. To assess impact on biochemical and patient-centered outcomes.
We searched MEDLINE, CENTRAL and EMBASE electronic databases from 1975 to October 2015 using terms related to magnesium and CS. English-Language RCTs were included involving adults undergoing CS with parenterally administered magnesium to treat or prevent arrhythmias, compared to control or standard antiarrythmics. We extracted incidence of postoperative arrhythmias, termination following magnesium administration and secondary outcomes (including mortality, length of stay, hemodynamic parameters, biochemistry).
Thirty-five studies were included, with significant methodological heterogeneity. Atrial fibrillation (AF) was most commonly reported, followed by ventricular, supraventricular and overall arrhythmia frequency. Magnesium appeared to reduce AF (RR 0.69, 95% confidence interval (95%CI) 0.56–0.86, p = 0.002), particularly postoperatively (RR 0.51, 95%CI 0.34–0.77, p = 0.003) for longer than 24 h. Maximal benefit was seen with bolus doses up to 60 mmol. Magnesium appeared to reduce ventricular arrhythmias (RR = 0.46, 95%CI 0.24–0.89, p = 0.004), with a trend to reduced overall arrhythmias (RR = 0.80, 95%CI 0.57–1.12, p = 0.191). We found no mortality effect or significant increase in adverse events.
Magnesium administration post-CS appears to reduce AF without significant adverse events. There is limited evidence to support magnesium administration for prevention of other arrhythmias.
The effect of magnesium sulfate on post off-pump coronary artery bypass grafting bleeding
2016, Indian Heart Journal
Magnesium level alteration may cause coagulation abnormality resulting in bleeding complication after off-pump coronary artery bypass grafting. In this study, we investigated the effect of magnesium on the postoperative coagulation profile and bleeding in OPCAB patients.
In a double blind clinical trial, six hundred patients were randomly allocated to two groups: group A (n = 150) and group B (n = 450). Group A received 50 mg/kg of magnesium sulfate (MS) in 100 ml 0.9% NaCl solution over 20 min before the anesthesia induction. Group B or control group received only 100 ml 0.9% NaCl solution at the same time points. OPCAB was performed with standard technique and device. Blood samples were collected 30 min before and 6 h after the surgery to analyze hemoglobin and blood coagulation tests. Postoperative exploration for bleeding, blood transfusion, and volume of transfusion was recorded. The two groups compared with t-test and χ² tests and p-valve <0.05 were considered as significant.
However, postoperative hemoglobin was statistically lower in group A compared with group B, but platelet, PT, and aPTT tests were not statistically different between two groups. The serum MS level, exploration for bleeding, volume of packed cell transfusion, and volume of postoperative bleeding were statistically different between group A vs group B.
Preoperative MS use may be associated with the postoperative platelet dysfunction and increased tendency to bleeding. This is an important risk factor for postoperative bleeding in the OPCAB in absence of CPB use.
Postoperative atrial fibrillation significantly increases mortality, hospital readmission, and hospital costs
2014, Annals of Thoracic Surgery
New-onset postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery. However, the magnitude of POAF on length of stay, resource utilization, and readmission rates remains an area of clinical interest. The purpose of this study was to examine the risk-adjusted impact of POAF on measures of mortality, hospital resources, and costs among multiple centers.
A total of 49,264 patient records from a multi-institutional Society of Thoracic Surgeons (STS) certified database for cardiac operations (2001 to 2012) were extracted and stratified by the presence of POAF (19%) versus non-POAF (81%). The influence of POAF on outcomes was assessed by hierarchic regression modeling, adjusted for calculated STS predictive risk indices.
Mean age was 64 ± 11 years, and median STS predicted risk of mortality for patients who developed POAF were incrementally higher (2% vs 1%, p < 0.001) compared with non-POAF patients. The rate of POAF was highest among those undergoing aortic valve replacement + coronary artery bypass grafting, aortic valve, and mitral valve replacement operations. The POAF patients had a higher unadjusted incidence of mortality, morbidity, hospital readmission, longer intensive care unit (ICU) and postoperative length of stay, and higher hospital costs. After risk adjustment, POAF was associated with a twofold increase in the odds of mortality (adjusted odds ratio = 2.04, p < 0.001), greater hospital resource utilization, and increased costs; POAF was associated with 48 additional ICU hours (p < 0.001), 3 additional hospital days (p < 0.001), and $3,000 (p < 0.001) and $9,000 (p < 0.001) of increased ICU and total hospital-related costs, respectively.
New onset POAF is associated with increased risk-adjusted mortality, hospital costs, and readmission rates. Protocols to reduce the incidence of POAF have the potential to significantly impact patient outcomes and the delivery of high-quality, cost-effective patient care.
Postoperative atrial fibrillation: Incidence, mechanisms, and clinical correlates
2014, Cardiology Clinics

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Original articleProphylaxis of atrial fibrillation with magnesium sulfate after coronary artery bypass grafting

Abstract

Ann Thorac Surg

Am Heart J

J Am Coll Cardiol

Am J Cardiol

Am J Cardiol

J Am Coll Cardiol

Am Heart J

J Thorac Cardiovasc Surg

Efficacy and safety of timolol for prevention of supraventricular tachyarrhythmias after coronary artery bypass surgery

Circulation

Immediate postoperative digitalization in the prophylaxis of supraventricular arrhythmias following coronary artery bypass

J Thorac Cardiovasc Surg

Prophylaxis of supraventricular tachyarrhythmia after coronary artery bypass surgery with oral verapamil: a randomized, double-blind trial

Ann Thorac Surg

Magnesium in the prevention of lethal arrhythmias in acute myocardial infarction

Arch Intern Med

Magnesium therapy in acute myocardial infarction: a double blind study

Magnesium

Original article
Prophylaxis of atrial fibrillation with magnesium sulfate after coronary artery bypass grafting