A common arrhythmia characterized by irregular and rapid twitching of the atrial wall, atrial fibrillation is associated with substantial morbidity. The inability of the heart to pump effectively can lead to pooled blood, clots, and stroke, and when present with other coronary conditions, it can be more dangerous. Two new studies out of Europe, however, are helping to make treatment easier.
The "pill in the pocket."
Research has shown that inhospital treatment of atrial fibrillation with oral doses of flecainide and propafenone is effective for bringing an end to such episodes. Scientists in Italy decided to find out whether a "pill-in-the-pocket" approach to treatment, in which patients administered one of the two drugs themselves at the first signs of symptoms, would work.
The researchers followed 268 patients who had been treated in a hospital for recent-onset atrial fibrillation with either flecainide or propafenone; 58 were excluded from out-of-hospital treatment because of adverse effects or treatment failure. Upon discharge, the remaining 210 patients were given one of the drugs (whichever the prescribing physician preferred) with instructions to use it if they had another arrhythmic event. The patients were followed for a mean of 15.5 months.
Of these patients, 165 (79%) reported at least one episode of arrhythmia; the total number of events was 618. Of those, 569 were treated with the "pill in the pocket," and 94% of those episodes resolved successfully within six hours. Three percent took longer than six hours to resolve but didn't require ED treatment, and 5% did involve contact with an ED. (Of the 49 episodes not treated, five required ED contact.)
The researchers concluded that self-administration with either flecainide or propafenone was effective. In addition, the numbers of ED visits per month were lower, when the study patients were compared with patients treated in the year before enrollment (4.9 versus 45.6, respectively), as were the number of hospitalizations per month (1.6 versus 15). The study was limited by the lack of definitive diagnoses of atrial fibrillation and the inherent imprecision in the records kept by the patients. Also noteworthy was the fact that a patient's favorable response to either drug in the hospital didn't guarantee that the patient would tolerate the same drug in the field.
Radiofrequency ablation.
A combination of atrial fibrillation and congestive heart failure can have unfortunate consequences, compounding morbidity and even hastening death, the "intersection of the two conditions creat[ing] a vicious circle," as the authors of the second study write, each condition "promoting the development" of the other. And using antiarrhythmic drugs to achieve and maintain sinus rhythm can be dangerous in patients with congestive heart failure. The French researchers therefore examined whether catheter ablation-proven effective in patients resistant to drug therapy and standard rate control-would be effective in patients with congestive heart failure.
Enrolled in the study were 58 patients with atrial fibrillation and congestive heart failure that was resistant to drug therapy and 58 controls without congestive heart failure who matched them for classification of atrial fibrillation, age, and sex. All patients underwent radiofrequency ablation; nearly half needed a second ablative procedure.
After a mean follow-up of 12 months, 78% of subjects and 84% of controls remained in sinus rhythm. Among those with congestive heart failure, the mean New York Heart Association classification had dropped from 2.3 before ablation to 1.4 afterward, indicating improved ability to tolerate physical activity. Favorable changes were seen in left ventricular function, exercise capacity, and overall quality of life, "even in the presence of concurrent structural heart disease and adequate ventricular rate control before ablation."
Even though mortality wasn't examined (because of the small sample size), the study authors say, the survival rate among patients with congestive heart failure might also be improved if atrial fibrillation is treated with catheter ablation rather than drug therapy.-Doug Brandt
Alboni P, et al. N Engl J Med 2004; 351 (23):2384-91;
Hsu L-F, et al. N Engl J Med 2004;351(23):2373-83.