Effects of Polyunsaturated Fatty Acid Treatment on Postdischarge Outcomes After Acute Myocardial Infarction.

Clinical trials studying the efficacy of n-3 polyunsaturated fatty acids (PUFA) in reducing adverse events after acute myocardial infarction (AMI) have yielded conflicting results, and data regarding the influence of n-3 PUFA treatment after AMI in routine clinical practice are scarce. We conducted a retrospective observational cohort study including patients from 5 Italian Local Health Units who were discharged from the hospital with a primary diagnosis of AMI from January 1, 2010, to December 31, 2011. Using unique patient identifiers, patients were linked across governmental hospital discharge, medication prescription, and mortality databases and followed for 12-months post-index discharge. Patient characteristics and risk of all-cause mortality and repeat AMI were compared by n-3 PUFA prescription after discharge (for outcome analyses, defined as ≥ 2 prescriptions) at a presumed dose of 1 g/day. Overall, 11,269 patients met inclusion criteria, of which 2,425 patients (21.5%) were prescribed n-3 PUFA during follow-up. Patients treated with n-3 PUFA tended to be younger, men, and carry a diagnosis of diabetes and were more likely to be receiving guideline-recommended post-AMI medical therapy, including β blockers, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, statins, and antiplatelet therapy (all p <0.001). After adjusting for patient characteristics and concurrent therapies, n-3 PUFA treatment was associated with reduced all-cause mortality (hazard ratio 0.76, 95% CI 0.59 to 0.97) and recurrent AMI (hazard ratio 0.65, 95% CI 0.49 to 0.87) through 12-month follow-up. In conclusion, in this large, contemporary, observational study of "real-world" Italian patients hospitalized for AMI, the use of n-3 PUFA was independently associated with a robust reduction in all-cause mortality and recurrent AMI. These data support further randomized controlled trials with n-3 PUFA therapy in the post-AMI setting.