MPAACS: Magnesium for the Prevention of Atrial Arrhythmias After Cardiac Surgery

This study has been terminated.
(Terminated by DSMB; futility analysis showing Mg treatment not efficacious)
Sponsor:
Collaborator:
Heart and Stroke Foundation of Canada
Information provided by:
University of British Columbia
ClinicalTrials.gov Identifier:
NCT00250965
First received: November 7, 2005
Last updated: November 3, 2010
Last verified: March 2009
  Purpose

The objective of our research is to determine whether treatment with magnesium will reduce the incidence of atrial fibrillation in patients undergoing cardiac surgery. Several small studies of magnesium have already been conducted, but these studies were small and the results conflicting. A large, well-conducted study of magnesium treatment is required to definitively determine whether magnesium is effective in preventing this common complication after surgery. In addition, our study will include patients undergoing valvular surgery, a group previously excluded from research despite the fact that they are at increased risk of atrial fibrillation.


Condition Intervention Phase
Coronary Artery Disease
Valvular Heart Disease
Drug: intravenous magnesium
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Magnesium for the Prevention of Atrial Arrhythmias After Cardiac Surgery

Resource links provided by NLM:


Further study details as provided by University of British Columbia:

Primary Outcome Measures:
  • atrial fibrillation [ Time Frame: 0-4 days after surgery ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • stroke [ Time Frame: 0-4 days after surgery ] [ Designated as safety issue: Yes ]
  • death [ Time Frame: 0-4 days after surgery ] [ Designated as safety issue: Yes ]
  • myocardial infarction [ Time Frame: 4 days after surgery ] [ Designated as safety issue: Yes ]

Enrollment: 927
Study Start Date: July 2004
Study Completion Date: February 2009
Primary Completion Date: September 2008 (Final data collection date for primary outcome measure)
Intervention Details:
    Drug: intravenous magnesium
    Subjects will be randomized prior to surgery (1:1) to receive 5 g magnesium or placebo (saline) bolus by the anaesthesiologist upon removal of the crossclamp. On postoperative days 1 through 4, subjects will receive either IV MgSO4 (5g in 250 ml normal saline) or IV placebo (250 ml normal saline) infusion over 4 hours daily.
Detailed Description:

All patients referred for non-emergent cardiac surgery for isolated CABG, isolated valvular heart surgery, or combined valvular and CABG surgery are eligible for the study. Subjects will be randomized prior to surgery (1:1) to receive 5 g magnesium or placebo (saline) bolus by the anaesthesiologist upon removal of the crossclamp. On postoperative days 1 through 4, subjects will receive either IV MgSO4 (5g in 250 ml normal saline) or IV placebo (250 ml normal saline) infusion over 4 hours daily. Atrial fibrillation (and other arrhythmias) will be detected by placing all subjects on continuous 24-hour ECG telemetry monitoring for postoperative days 0 through 4.

The study is powered to detect at least a 30% relative reduction in postoperative atrial fibrillation in the CABG group; n=756. Because of the higher incidence of atrial fibrillation in the Valve +/- CABG group a total of 500 patients will be required to detect at least a 30% difference between treatment groups. These sample sizes are based on an alpha of 0.05 and 80% power.

  Eligibility

Ages Eligible for Study:   20 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • patient undergoing coronary artery bypass surgery with or without valve procedure
  • scheduled for on-pump or cardiopulmonary bypass protocol

Exclusion Criteria:

  • existing atrial fibrillation/flutter in the past year or on antiarrhythmic medications
  • ventricular fibrillation
  • sustained ventricular tachycardia
  • 2nd or 3rd degree heart block
  • paroxysmal supraventricular tachycardia
  • major aortic repair planned during open-heart procedure
  • permanent atrial/ventricular pacemaker implanted
  • dialysis dependent or creatinine clearance < 35 umoles/min or oliguric/anuric renal failure
  • patient intolerant of beta blockers
  • patient has reactive airways disease dependent on regular beta-adrenergic agents
  • patient is scheduled to undergo off-pump surgical protocol
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00250965

Locations
Canada, British Columbia
Vancouver General Hospital
Vancouver, British Columbia, Canada, V5Z 1L7
St. Paul's Hospital
Vancouver, British Columbia, Canada, V6Z 1Y6
Sponsors and Collaborators
University of British Columbia
Heart and Stroke Foundation of Canada
Investigators
Principal Investigator: Karin H Humphries, DSc University of British Columbia/St. Paul's Hospital
Study Chair: Hubert Wong, PhD University of British Columbia, Department of Health Care & Epidemiology
  More Information

No publications provided

Responsible Party: Dr. Karin Humphries, University of British Columbia
ClinicalTrials.gov Identifier: NCT00250965     History of Changes
Other Study ID Numbers: 20R20015
Study First Received: November 7, 2005
Last Updated: November 3, 2010
Health Authority: Canada: Health Canada

Additional relevant MeSH terms:
Heart Diseases
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Valve Diseases
Cardiovascular Diseases
Arteriosclerosis
Arterial Occlusive Diseases
Vascular Diseases

ClinicalTrials.gov processed this record on October 19, 2014