Have there been any studies which have provided daily dosages of DHA/EPA to those who have suffered a heart attack?

The most extensive clinical trial ever performed on this topic was the GISSI-Prevenzione trial from Italy where daily supplementation with 900 mg of DHA/EPA per day as given to patients following their heart attack (on top of their pharmaceutical treatments and advice to consume their Mediterranean diet) indicated a 45% reduction in the risk of sudden cardiac death during the next few years of follow-up relative to those patients who were not given supplemental DHA/EPA.