Continuous Magnesium Infusion to Prevent Atrial Fibrillation After Cardiac Surgery: A Sequential Matched Case-Controlled Pilot Study

Eduardo A. Osawa, Salvatore L. Cutuli, Luca Cioccari, Laurent Bitker, Leah Peck, Helen Young, Lara Hessels, Fumitaka Yanase, Julia T. Fukushima, Ludhmila A. Hajjar, Siven Seevanayagam, George Matalanis, Glenn M. Eastwood, Rinaldo Bellomo

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Objective: 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. Design: Sequential, matched, case-controlled pilot study. Setting: Tertiary university hospital. Participants: Matched cohort of 99 patients before and intervention cohort of 99 consecutive patients after the introduction of a continuous magnesium infusion protocol. Interventions: 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. Measurements and Main Results: 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). Conclusion: 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.

Original languageEnglish
Pages (from-to)2940-2947
Number of pages8
JournalJournal of Cardiothoracic and Vascular Anesthesia
Issue number11
Publication statusPublished - Nov 2020


  • cardiac surgery
  • case-control
  • intensive care
  • magnesium
  • sequential matching

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