The main object here is the use of omega-3 polyunsaturated fatty acids (as ethyl esters, hereinafter called "n-3 PUFA") as a medicament, either alone or in combination with other therapeutic agents, for reducing mortality for a cardiovascular cause, in particular arrhythmia or for reducing hospitalization for any cause, in particular a cardiovascular cause and for the daily administration to patients with symptomatic heart failure (HF) for more than 3.5 years.