NEW YORK (Reuters Health) – For conversion of new-onset atrial fibrillation, intravenous amiodarone plus oral ranolazine is more effective than amiodarone alone, a Greek team reports in the American Journal of Cardiology online May 29.
“This is the first clinical report of a synergistic effect of A + R (amiodarone plus ranolazine) for conversion of AF and is it consistent with substantial experimental research that has identified a potent synergism of these 2 drugs in suppressing AF,” the authors comment.
Dr. Konstantinos C. Koskinas, with Aristotle University Medical School in Thessaloniki, and colleagues explain that the antianginal agent ranolazine has antiarrhythmic properties and prevents AF in patients with acute coronary syndrome. Until now, however, the clinical effect of combining ranolazine with amiodarone for conversion of AF has been untested.
They therefore conducted a randomized trial involving 51 patients with AF of less than 48 hours duration who were treated with intravenous amiodarone for 24 hours with or without the addition of 1500 mg ranolazine orally.
The primary endpoint of conversion within 24 hours was achieved by 65% of those in the amiodarone-only group and by 88% in the combination arm (p=0.056), according to the report.
The time to conversion in the two groups was 14.1 hours versus 9.8 hours (p=0.002), respectively, the team found.
Regarding safety, the QTc interval increased to a similar degree during treatment in both groups and no patient required discontinuation for excessive QTc prolongation. A temporary drop in systolic blood pressure occurred in 6 patients in the monotherapy arm and 8 in the combination arm. There were no proarrhythmic events in either group.
In discussing the synergy of the two agents, Dr. Koskinas and colleagues point out that ranolazine augments the effect of amiodarone in decreasing sodium channel-dependent parameters through a complementary mode of action.
Ginven their findings, they suggest, “The safety and efficacy of other dose levels of the A + R combination may merit further investigation.”