Beta-blockers top choice for prevention and rate control for postoperative atrial fibrillation

The American College of Chest Physicians (ACCP) has released the first evidence-based clinical practice guidelines for the prevention and management of postoperative atrial fibrillation (AF) after cardiac surgery.

Published in the August issue of CHEST, the peer-reviewed journal of the ACCP, the guidelines offer specific recommendations on cardiac pacing, anticoagulation therapy, pharmaceutical prophylaxis, intraoperative interventions, and pharmacologic control of ventricular rate and rhythm. Atrial fibrillation, or irregular heartbeat, is a common condition that occurs increasingly with age and is one of the most frequent complications of cardiac surgery.

"Over one third of patients suffer from AF after cardiac surgery, which is associated with a higher risk of operative morbidity, increased hospital stay, and increased hospital cost," said Guidelines Co-Chair Peter P. McKeown, MBBS, MPH, MPA, FCCP, Veterans Affairs Medical Center, Asheville, NC. "Although previous guidelines have focused on the management of chronic AF, our guidelines are the first to address AF associated with cardiac surgery."

Through the Health and Science Policy Committee of the ACCP, the guidelines were developed by a multidisciplinary panel of experts in the fields of cardiothoracic surgery, cardiology, anesthesiology, and epidemiology. The panel included representatives from the ACCP, the American College of Cardiology, the Society of Thoracic Surgeons, and the American College of Surgeons. Based on a systematic review of randomized, controlled trials, panel members made graded recommendations based on the quality of evidence available and the net benefit of the intervention.

Recommendations center on the main issues that arise in managing patients with postoperative AF, including overall prevention; control of ventricular response rate; restoration of normal sinus rhythm; and prevention of thromboembolism and the role of anticoagulation. Overall, guidelines recommend the use of beta-blockers over calcium channel blockers, a standard therapy for chronic AF, for general prevention of postoperative AF and control of ventricular rate. Guidelines also recommend against the routine use of magnesium and digitalis for the prevention of postoperative AF. Amidarone may be considered for patients in whom beta-blockers are contraindicated and as therapy for postoperative sinus rhythm control. Atrial pacing, the use of a pacemaker to control arrhythmia, was found to reduce the incidence of AF after cardiac surgery; however, biatrial pacing is recommended over single atrial pacing. Additionally, mild hypothermia and heparin-coated circuits are recommended to reduce the occurrence of AF during intraoperative procedures. In regard to the prevention of thromboembolism, the guidelines recommend cautious anticoagulation therapy for patients in whom AF has persisted for more than 48 hours.

"Atrial fibrillation that develops after cardiac surgery places the patient at risk for thromboembolism and stroke, both which may require anticoagulants or blood-thinning agents to treat. Yet, cardiac surgery may increase a patient's tendency to bleed," said Guidelines Co-Chair David D. Gutterman, MD, FCCP, Medical College of Wisconsin, Milwaukee, WI. "Therefore, anticoagulation therapy should be carefully considered in the treatment of postoperative AF, with the risks of bleeding balanced with the risk of embolic stroke."

"The development and implementation of clinical practice guidelines allow clinicians to practice medicine based on the highest quality of data available," said Paul A. Kvale, MD, FCCP, President of the American College of Chest Physicians. "Although recommendations for the prevention and management of postoperative atrial fibrillation are intended to guide clinicians in their health-care decisions, they can be adapted to address issues of individual patient circumstance."