Meta-analysis of the effectiveness of prophylactic drug therapy in preventing supraventricular arrhythmia early after coronary artery bypass grafting

Abstract

There has been considerable interest in evaluating the usefulness of drug therapy in patients who undergo operative coronary revascularization procedures to prevent the development of supraventricular tachyarrhythmia after surgery. 1,2 Much concern stems from the fact that postoperative atrial fibrillation prolongs hospitalization, thus increasing the cost of this already expensive and frequently used procedure. 3 There is an attendant risk of severe complications of atrial fibrillation (most importantly stroke), which necessitates anticoagulation in a significant percentage of these patients. 4 Furthermore, the medications used to convert atrial fibrillation to sinus rhythm and to prevent recurrence are not innocuous, and arguably may increase the risk of death during follow-up. 5 For all these reasons, it is worthwhile to investigate whether medication, administered either before or immediately after the procedure, may prevent atrial fibrillation and other supraventricular arrhythmias. Currently, the most frequently used medications for preventing the development of supraventricular tachyarrhythmia after surgery are β-adrenergic blocking agents and digitalis. Several studies have been undertaken to study their effectiveness. 6–17 Unfortunately, no consensus opinion has been reached regarding their relative usefulness. In fact, there has been considerable inconsistency of results. Consequently, in most hospitals there is no uniform policy regarding their routine use. Much of the problem occurs because of the small number of patients in each study, and the relatively modest treatment effect in most of these. The technique of meta-analysis can often help to interpret this kind of diverse data. 18 By combining the information obtainable from a number of small but well-done studies, it is possible to draw some conclusions about the relative magnitude of treatment effect. We reviewed 12 full-length reports in which digitalis or β-blocker therapy, or both, was compared with control therapy, combined the information and herein report the results.