Not sure what your takeaway is from the piece you kindly provided. The author's conclusions are not exactly inspiring:

ω-3 PUFAs supplement may prevent POAF in patients undergoing CABG or reduce AF recurrence after cardioversion; however, high-dose ω-3 PUFAs may increase the risk of AF development. Although earlier clinical studies suggested that ω-3 PUFAs may be associated with reduced risk of ventricular arrhythmias, mortality, and hospitalization among known patients with HF, the evidence remains limited and seems not reproducible in large clinical studies in the contemporary medical setting.

I do agree (very much) with you on the diet and lifestyle manipulation to optimize health. I virtually always lead with lifestyle, for myself and for my patients.

Best,

Michael