American Heart Association - New Orleans

Propafenone is Effective and Safe for Conversion and Suppression of SVAs


New Orleans - Propafenone HCI is an effective and safe agent for conversion and suppression of supraventricular arrhythmias (SVAs), according to a meta-analysis reported at the 69th Scientific Sessions of the American Heart Association, held here on November 13th, 1996.

Propafenone HCI is a Class 1C antiarrhythmic that blocks the medium-fast sodium channel and exerts mild beta-blocking properties. Dr. Sharon Coplan Reimold, of the Brigham and Women’s Hospital, Boston, described the need to investigate and to document the efficacy and safety of propafenone HCI in the acute termination and chronic suppression of SVAs, as most published trials have involved only a small number of patients. Therefore, she and her colleagues performed a meta-analysis on 50 prospective randomized and non-randomized trials conducted between 1975 and 1994, with a combined total of 3,145 patients restudied.

Patients were analyzed according to arrhythmia type --- supraventricular tachycardia (SVT), Wolff-Parkinson-White (WPW), and atrial fibrillation (AF) --- and propafenone HCI’s route of administration, either oral or IV. Criteria for efficacy were conversion of acute SVA (i.e., restoration of normal sinus rhythm) and prophylaxis (total suppression of recurrent SVA).

For conversion, the meta-analysis revealed that propafenone HCI administered IV was effective but only slightly more than when administered orally. For oral prophylaxis over a period of 10 months, propafenone HCI was effective in suppressing SVT in 63% of 165 patients, and in WPW it was effective in 83% of 44 patients treated. In 453 patients treated for AF, efficacy was 51% at one year and 33% at two years.

In contrast to the results of Dr. Reimold’s meta-analysis on quinidine, propafenone HCI had an extremely low total mortality rate of less than 0.5% in the patients studied.

The investigators noted that propafenone HCI’s effectiveness in conversion varies with arrhythmia type, trial design, and route of drug administration. That notwithstanding, they concluded that propafenone HCI is effective and safe for both conversion and prophylaxis, and it compares favorably with Class 1A agents.