Apparently, some studies indicate omega-3 does help avoid fibrillations, but other studies show no such effect. What would be helpful would be to see the studies done in Europe that have convinced them.
It isn't always just the drug companies, you know. It may be the European studies have been no more definitive than the American ones.
I take omega-3 twice daily. It provides, after I researched it, a number of possible benefits. I do know that it smooths out mood, and my cholesterols have never moved out of the perfect range since I began taking it. But I also think that may not work for everyone.