Prophylactic Intravenous Magnesium Sulphate in Addition to Oral β-Blockade Does Not Prevent Atrial Arrhythmias After Coronary Artery or Valvular Heart Surgery

Autor: Karin H. Humphries, Victoria Bernstein, Richard S. Slavik, Michael T. Janusz, May K. Lee, Richard C. Cook, Kenneth Gin, Mats Tholin
Rok vydání: 2009
Předmět:
Zdroj: Circulation. 120
ISSN: 1524-4539
0009-7322
DOI: 10.1161/circulationaha.108.841221
Popis: Background— Atrial arrhythmias (AA) are an important cause of morbidity after cardiac surgery. Efforts at prevention of postoperative AA have been suboptimal. Perioperative beta-blocker administration is the standard of care at many centers. Although prophylactic administration of magnesium sulfate (MgSO 4 ) has been recommended, review of all previously published trials of MgSO 4 reveals conflicting results. This study was designed to address methodological shortcomings from previous studies and is the largest randomized, placebo-controlled trial of intravenous (IV) MgSO 4 for the prevention of AA after coronary artery bypass grafting or cardiac valvular surgery. Methods and Results— A total of 927 nonemergent cardiac surgery patients were stratified into 2 groups: isolated coronary artery bypass grafting (n=694), or valve surgery with or without coronary artery bypass grafting (n=233), and randomized to receive either 5g IV MgSO 4 or placebo on removal of the cross-clamp, followed by daily 4-hour infusions, from postoperative day 1 until postoperative day 4. All patients were treated according to an established oral β-blocker protocol. Postoperative serum Mg levels were checked and standard of care was to administer IV MgSO 4 for low serum levels. The primary end point was AA lasting ≥30 minutes or requiring treatment for hemodynamic compromise. There were no differences in the incidence of AA between patients who received IV MgSO 4 or placebo (26.4% versus 24.3%, respectively). The results were similar when broken down according to stratified groups. Conclusions— In patients treated with a protocol for postoperative oral β-blocker after nonemergent cardiac surgery, the addition of prophylactic IV MgSO 4 did not reduce the incidence of AA.
Databáze: OpenAIRE