Inverse association between plasma long-chain omega-3-PUFAs content and sudden cardiac death after ACS

Plasma Omega-3 Fatty Acids and the Risk of Cardiovascular Events in Patients After an Acute Coronary Syndrome in MERLIN-TIMI 36

Literature - Zelniker TA, Morrow DA, Scirica BM et al. - J Am Heart Assoc 2021, DOI: 10.1161/JAHA.120.017401

Introduction and methods

Long-chain omega-3 polyunsaturated fatty acids (PUFAs) include eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosaheaenoic acid (DHA), which are primarily obtained from marine sources. α-Linolenic acid (ALA) is obtained through plant-derived intake. Studies, both randomized controlled trials on CV markers and experimental studies [1,2], have shown many CV benefits of supplementation with omega-3-PUFAs, but clinical outcome trials have shown inconsistent findings [3-8]. In absence of supplementation, it was shown that higher omega-3-PUFAs content was associated with lower risk of CV and sudden cardiac death and weaker associated with risk of MI or stroke [9,10]. Therefore, supplementation of omega-3-PUFAs may provide benefit after ACS, when patients have increased risk of arrhythmic events.

In this study, the association between omega-3-PUFAs content and risk of CV events, including arrhythmic events, was investigated in a large clinical trial population with ACS (the MERLIN-TIMI 36 trial).

The MERLIN-TIMI 36 trial enrolled 6560 patients hospitalized with a non-ST-segment-elevation ACS within 48 hours of onset of symptoms. Plasma sample was drawn at randomization. The present metabolomics array study was a case-cohort study and included 2407 patients (203 subjects with CV death, 325 patients with MI, 271 with ventricular tachycardia, and 161 with AF events as cases and 1612 event-free subjects as controls). Baseline plasma omega-3-PUFAs composition including ALA and the long-chain marine-based omega-3-PUFAs EPA, DPA and DHA was assessed by gas chromatography. The composition of omega-3-PUFAs is expressed as the percentage of the total fatty acid content by weight.

Main results

  • Omega-3-PUFAs comprised 3.8% of all fatty acids. Among the omega-3-PUFAs, DHA contributed 52.5% to the total omega-3 content, followed by EPA (19.6%), ALA (14.4%) and DPA (13.5%).
  • Higher plasma content of the long-chain omega-3-PUFAs was associated with reduced CV death (adjusted OR per 1 SD: 0.82, 95%CI: 0.68-0.98), which appeared to be driven by 27% lower risk of sudden cardiac death (adjusted OR per 1 SD: 0.73, 95%CI: 0.55-0.97).
  • The magnitude of the relationship was not as strong for ALA (adjusted OR per 1 SD: 0.92, 95%CI:0.74-1.14) compared to the long chain omega-3-PUFAs.
  • There was a stepwise decrease in risk of sudden cardiac death with higher long-chain omega-3-PUFA content (Ptrend=0.025).
  • A consistent, nearly linear decrease in the probability of sudden cardiac death was observed for increasing proportions of the long-chain omega-3-PUFAs by adjusted natural cubic regression splines.
  • No association was found for any of the omega-3-PUFAs with any of the other outcomes of interest, including MI, atrial fibrillation, or early post-ACS ventricular tachycardia.

Conclusion

In this case-control study using data of a large clinical trial population of patients after ACS, higher content of plasma long-chain omega-3-PUFAs was associated with reduced risk of sudden cardiac death independent of traditional risk factors.

References

1. Lavie CJ, Milani RV, Mehra MR, Ventura HO. Omega-3 polyunsaturated fatty acids and cardiovascular diseases. J Am Coll Cardiol. 2009;54:585–594. DOI: 10.1016/j.jacc.2009.02.084.

2. Mozaffarian D, Wu JH. Omega-3 fatty acids and cardiovascular disease: Effects on risk factors, molecular pathways, and clinical events. J Am Coll Cardiol. 2011;58:2047–2067. DOI: 10.1016/j.jacc.2011.06.063.

3. Alexander DD, Miller PE, Van Elswyk ME, Kuratko CN, Bylsma LC. A meta-analysis of randomized controlled trials and prospective cohort studies of eicosapentaenoic and docosahexaenoic long-chain omega-3 fatty acids and coronary heart disease risk. Mayo Clin Proc. 2017;92:15–29. DOI: 10.1016/j.mayocp.2016.10.018.

4. Aung T, Halsey J, Kromhout D, Gerstein HC, Marchioli R, Tavazzi L, Geleijnse JM, Rauch B, Ness A, Galan P, et al. Associations of omega-3 fatty acid supplement use with cardiovascular disease risks: meta-analysis of 10 trials involving 77917 individuals. JAMA Cardiol. 2018;3:225–234. DOI: 10.1001/jamacardio.2017.5205.

5. Bhatt DL, Steg PG, Miller M, Brinton EA, Jacobson TA, Ketchum SB, Doyle RT Jr, Juliano RA, Jiao L, Granowitz C, et al. Cardiovascular risk reduction with icosapent ethyl for hypertriglyceridemia. N Engl J Med. 2019;380:11–22. DOI: 10.1056/NEJMoa1812792.

6. Group ASC, Bowman L, Mafham M, Wallendszus K, Stevens W, Buck G, Barton J, Murphy K, Aung T, Haynes R, et al. Effects of n-3 fatty acid supplements in diabetes mellitus. N Engl J Med. 2018;379:1540–1550.

7. Manson JE, Cook NR, Lee I-M, Christen W, Bassuk SS, Mora S, Gibson H, Albert CM, Gordon D, Copeland T, et al. Marine n-3 fatty acids and prevention of cardiovascular disease and cancer. N Engl J Med. 2019;380:23–32. DOI: 10.1056/NEJMoa1811403

8. GISSI-Prevenzione Investigators Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvivenza nell’infarto miocardico. Lancet. 1999;354:447–455.

9. Siscovick DS, Lemaitre RN, Mozaffarian D. The fish story: a diet-heart hypothesis with clinical implications: N-3 polyunsaturated fatty acids, myocardial vulnerability, and sudden death. Circulation. 2003;107:2632–2634. DOI: 10.1161/01.CIR.0000074779.11379.62.

10. Mozaffarian D, Rimm EB. Fish intake, contaminants, and human health: evaluating the risks and the benefits. JAMA. 2006;296:1885–1899. DOI: 10.1001/jama.296.15.1885

Find this article online at J Am Heart Assoc

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