Omega-3 Fatty Acid Therapy in Patients Wwith Ventricular Tachyarrhythmias - Omega-3 Fatty Acid Therapy in Patients With Ventricular Tachyarrhythmias
The goal of the trial was to evaluate whether treatment with omega-3 polyunsaturated fatty acid therapy (fish oil) is associated with a reduction in time to ventricular tachycardia (VT) or ventricular fibrillation (VF) compared with placebo in patients with ventricular tachyarrhythmias implanted with an implantable cardioverer defibrillator (ICD).
Treatment with omega-3 polyunsaturated fatty acid therapy (fish oil) will be associated with a reduction in time to VT or VF compared with placebo in patients with ventricular tachyarrhythmias.
Patients Enrolled: 200
Mean Follow Up: 2 years
Mean Patient Age: mean age 63 years
Mean Ejection Fraction: Mean baseline ejection fraction 35-36%
New ICD implant for sustained VT or VF or treatment for VT or VF within three months of an existing ICD
Time to first VT or VF
Time to first VT or VF by subgroup of patients enrolled due to 1) VT and 2) VF; and time to recurrent VT or VF
Patients were randomized to treatment with omega-3 polyunsaturated fatty acid therapy (1.8 g/d, given in two capsules) or matching placebo therapy (two capsules filled with olive oil).
There was no difference in the primary endpoint of time to first VT or VF by treatment group (p=0.19), but unlike the hypothesis, there was a trend toward an increase in ventricular arrhythmias in the fish-oil arm. At six months, 47% of patients in the fish oil arm and 36% in the placebo arm had experienced a VT or VF; by two years, the data were 66% and 60%, respectively.
In the subgroup of patients enrolled in the study due to a VT, time to first VT/VF occurred sooner in the fish oil arm versus placebo (p=0.007). There was no difference in time to first VT/VF by treatment group in the subgroup of patients with VF (p=0.38).
Recurrent episodes of VT/VF occurred significantly more frequently in the fish oil arm versus placebo (p<0.01). Mortality trended lower in the fish oil arm (p=0.09), but mortality was not a prespecified endpoint and the study was not powered to detect a difference in clinical events. There was no difference in the electrophysiologic changes between baseline and three-month follow-up.
Among patients with ventricular tachyarrhythmias implanted with an ICD, treatment with omega-3 polyunsaturated fatty acid therapy was not associated with a reduction in the primary endpoint of time to first VT/VF compared with placebo. On the contrary, the data trended in the opposite direction suggest the possibility that fish oil may be associated with increases in ventricular tachyarrhythmias in patients with an ICD.
These data differ from studies in the setting of postmyocardial infarction, which showed a beneficial effect of omega-3 polyunsaturated fatty acid therapy on sudden death. Data from the present trial should be interpreted in the context of the study population and should not extract to other populations, which have shown different effects.
Presented by Dr. Merritt Raitt at the November 2003 American Heart Association Annual Scientific Sessions, Orlando, FL.
Keywords: Infarction, Tachycardia, Ventricular, Follow-Up Studies, Fish Oils, Plant Oils, Ventricular Fibrillation, Death, Sudden, Fatty Acids, Unsaturated, Capsules, Defibrillators, Implantable
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