MAGNEsium With meToprolol for Rate Control In Atrial Fibrillation (MAGNETIC-AF)

MAGNEsium With meToprolol for Rate Control In Atrial Fibrillation (MAGNETIC-AF)

The purpose of this research study is to find out if the use of magnesium in addition to Metoprolol, a rate controlling medication that you would be offered in the Emergency Department today unrelated to this study, will help reduce your high heart rate (rapid ventricular response).

Study Overview

• Status: Not yet recruiting
• Conditions: Atrial Flutter With Rapid Ventricular Response
• Intervention / Treatment: Drug: Magnesium Sulfate 2g; Drug: Magnesium Sulfate 4g; Drug: Saline (0.9% NaCl)

Detailed Description

Intravenous magnesium has become a commonly utilized agent in the treatment of cardiac arrhythmias as an adjunct therapy to rate and rhythm control medications, such as its use in atrial fibrillation or atrial flutter with rapid ventricular response (AFF RVR). Though its benefit in the treatment of AFF RVR has been well documented, a consensus on the optimal dosing of magnesium has yet to be achieved. Only one randomized, controlled, double-blinded study has investigated the optimal dosing of magnesium. The purpose of this prospective, randomized, double-blinded study is to further evaluate the safety and efficacy of varying doses of intravenous magnesium in the treatment of atrial fibrillation or atrial flutter with rapid ventricular response. This study will use flat-dose intravenous metoprolol for rate control to minimize confounders. Additionally, this study will not require a resulted magnesium level prior to treatment in order to avoid delays in patient care.

• Study Type: Interventional
• Enrollment (Estimated): 196
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Marc McDowell, PharmD; Phone Number: (708) 684-1078; Email: marc.mcdowell@aah.org
• Study Contact Backup: Name: Thomas Szwajnos; Email: Thomas.Szwajnos@aah.org

Study Locations

• United States
  • Illinois
    • Oak Lawn, Illinois, United States, 60453
      • Advocate Christ Medical Center Emergency Department (ACMC ED)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age > 18 years or older
• Able to provide informed consent
• Primary diagnosis atrial fibrillation or atrial flutter with rapid ventricular response (AFF RVR) greater than or equal to 120 beats per minute
• Metoprolol as rate control agent
• English speaking

Exclusion Criteria:

• Hemodynamically unstable patients (SBP <90, MAP <65)
• Impaired consciousness
• Acute heart failure exacerbation based on clinical diagnosis, physician exam, bedside echo, and/or additional imaging
• Patient in AFF RVR that is highly suspected to be a compensatory mechanism for an alternative clinical diagnosis
• Rhythms other than atrial fibrillation, such as sick sinus syndrome or wide-complex ventricular response
• Acute myocardial infarction
• Contraindications to magnesium sulfate (including myasthenia gravis)
• Allergy or sensitivity to any study drugs
• Previously enrolled in this trial during a different patient encounter
• Withdrew from study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental Arm One, Magnesium Sulfate 2g followed by metoprolol 5 mg; Study drug (Magnesium Sulfate 2 gram/50ml 0.9% NaCl) will be administered over a time interval of 15 minutes. Immediately after study drug administration, intravenous metoprolol 5 mg will be administered as an IV push over 2 minutes. Additional doses of metoprolol 5 mg as an IV push over 1 minute permissible, however additional doses of study drug will not be administered. Emergency Medicine physician may provide additional doses of intravenous metoprolol every 5 minutes based on clinical necessity.	Drug: Magnesium Sulfate 2g; Magnesium Sulfate 2g for the treatment of atrial fibrillation or atrial flutter with rapid ventricular response (AFF RVR); Other Names: Magnesium Sulfate 2 gram/50ml 0.9% NaCl
Experimental: Experimental Arm Two, Magnesium Sulfate 4g followed by metoprolol; Study drug (Magnesium Sulfate 4 gram/50ml 0.9% NaCl) will be administered over a time interval of 15 minutes. Immediately after study drug administration, intravenous metoprolol 5 mg will be administered as an IV push over 2 minutes. Additional doses of metoprolol 5 mg as an IV push over 1 minute permissible, however additional doses of study drug will not be administered. Emergency Medicine physician may provide additional doses of intravenous metoprolol every 5 minutes based on clinical necessity.	Drug: Magnesium Sulfate 4g; Magnesium Sulfate 4g for the treatment of atrial fibrillation or atrial flutter with rapid ventricular response (AFF RVR); Other Names: Magnesium Sulfate 4 gram/50ml 0.9% NaCl
Placebo Comparator: Control Arm, normal saline followed by metoprolol; 50ml 0.9% NaCl will be administered over a time interval of 15 minutes. Intravenous metoprolol 5 mg will be immediately administered as an IV push over 2 minutes. Additional doses of metoprolol 5 mg as an IV push over 1 minute permissible, however additional doses of saline will not be administered. Emergency Medicine physician may provide additional doses of intravenous metoprolol every 5 minutes based on clinical necessity.	Drug: Saline (0.9% NaCl); The control group will receive a bolus of normal saline of the same volume and infused over 15 minutes.; Other Names: Control (50ml 0.9% NaCl)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ventricular rate control	Assessing ventricular rate control within the first 2 hours of intravenous magnesium administration as defined as a ventricular rate of < 120 beats per minute.	Within the first 2 hours of intravenous magnesium administration

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean change in heart rate	Mean change in heart rate after the administration of magnesium sulfate	up to 24 hours after magnesium infusion
Incidence of hypotension	Systolic blood pressure < 90 or MAP < 65	At 1 and 2 hours after magnesium administration
Incidence of bradycardia	Heart rate < 60 beats per minute	At 1 and 2 hours after magnesium administration
Mean time to achieve goal heart rate	Mean time to achieve goal heart rate at 2 hours	at 2 hours
Rate of conversion	Rate of conversion to normal sinus rhythm	2 hours after administration of magnesium
Clinical need for rescue medication administration	Dose of rescue medications given (magnesium and metoprolol)	2 hours from metoprolol administration
Mean change in heart rhythm	Mean change in heart rhythm after the administration of magnesium sulfate	up to 24 hours after magnesium infusion
Clinical need for rescue medication administration	Route of rescue medications given (magnesium and metoprolol)	2 hours from metoprolol administration

Collaborators and Investigators

• Sponsor: Wake Forest University Health Sciences
• Investigators: Principal Investigator: Marc McDowell, PharmD, Advocate Christ Medical Center Emergency Department

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: May 21, 2026
• First Submitted That Met QC Criteria: June 2, 2026
• First Posted (Actual): June 8, 2026

Study Record Updates

• Last Update Posted (Actual): June 8, 2026
• Last Update Submitted That Met QC Criteria: June 2, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: atrial flutter; AFF RVR; intravenous magnesium
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Flutter; Sulfur Compounds; Inorganic Chemicals; Chlorine Compounds; Sulfur Acids; Sodium Compounds; Sulfates; Sulfuric Acids; Chlorides; Hydrochloric Acid; Magnesium Compounds; Magnesium Sulfate; Sodium Chloride
• Other Study ID Numbers: IRB00146620

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No