Atrial arrhythmias complicate recovery in at least 40% of patients who coronary surgery. These arrhythmias increase morbidity and probably mortality. Patients who experience them stay longer in the hospital, and require expensive treatment to control heart rate and prevent stroke or myocardial infarction.

The most effective therapy for this condition is the use of beta-blockers. Numerous trials have shown that beta-blockers reduce the incidence of atrial arrhythmias by as much as 50%.

The powerful antiarrhythmic drug propafenone is approved in the United States and many other countries for prophylaxis of atrial arrhythmia.

In a new study presented in a late-breaking clinical trials session, Dr. Kowey examined the clinical and economic impact of propafenone for atrial fibrillation following bypass surgery.

They randomized 293 patients from seven sites to low-dose propafenone (450 mg/day), moderate-dose propafenone (675 mg/day), or placebo. Most also received digoxin (93%) and beta-blockers (84%).

Results of this trial show unequivocally that the moderate dose of propafenone reduced incidence of arrhythmia to 12.4%, compared with 22.2% for low-dose propafenone and 22.7% for placebo.

The drug was safe. Of almost 300 patients in the trial, there was only one death, which occurred in the moderate-dose arm. However, Dr. Kowey said the numbers of patients in the trial is so small that this is not a clinically relevant difference.

Despite this safety and efficacy, investigators could not prove a significant difference in the economics of arrhythmia. Moderate-dose propafenone did not reduce hospital length of stay, as seen in the table below.

According to Dr. Kowey, individual clinicians and institutions must decide whether it is more important to follow the economic imperative, or relieve patients of the burden of atrial arrhythmia.

* p<0.022 versus placebo