I don’t think so. It looks much more likely that omega-6 is causing heart disease by causing the inflammation and clotting that promotes the formation of plaque in the arteries. There are many studies showing the association between omega-3 and heart health, like this one:
Most of the articles that point out benefits of omega-3 do not tell you that you have to reduce the omega-6 in your body to raise the omega-3 substantially. When you look at the biochemistry of these lipids and how they are stored and converted to hormones in your cells it is easy to see why. My book shows you the biochemistry and the sources of omega-6 in various foods.
Our doctors should be monitoring the omega-6/3 ratio in our blood instead of the cholesterol–the omega-6/3 ratio in our blood has a 0.99 correlation to your risk of heart disease. Cholesterol is not that strongly correlated to heart disease–over 50% of people admitted to the hospital with heart attacks have normal cholesterol.