Abstract 251: Effects of n-3 Fatty Acids Supplementation on Endothelial Function and Inflammation in Peripheral Artery Disease: The OMEGA-PAD Trial

Abstract

Background Patients with peripheral artery disease (PAD) have an increased risk for cardiovascular events, likely related to inflammation and impaired endothelial function. n-3 polyunsaturated fatty acids (n3-PUFAs) have been shown to improve endothelial function and reduce inflammation in other cohorts. We hypothesized that n3-PUFAs would improve endothelial function and the inflammatory profile in patients with PAD. Methods This is a randomized, double-blind, placebo-controlled trial: the OMEGA-PAD trial ( NCT01310270 ). Eighty patients aged 50 and more with intermitted claudication and an ankle-brachial index (ABI) of <0.9 presenting to vascular surgery clinic at the Veterans Affairs Medical Center in San Francisco will be randomized to n3-PUFAs 2.2 g orally twice daily (total of 4.4gm/day) or a matched placebo for 1 month. Outcome measurements are done at baseline and after 1 month. The primary endpoint is a change in endothelial function measured by brachial artery flow mediated, endothelium-dependent vasodilation (FMD). Secondary endpoints include a change in inflammatory markers (C-reactive protein, IL-6, sICAM-1 and TNF-α), improvement in lipid profile (LDL, triglycerides, HDL), blood pressure and walking distance by questionnaire. The omega-3 index will be measured to ensure physiological treatment effect. Results Recruitment for the OMEGA-PAD trial started in April 2011. Fifty male veterans have been enrolled and randomized. The mean age is 67 ± 9 years. Mean index limb ABI is 0.8 ± 0.2. CAD is present in 36%, hypertension in 92%, and diabetes mellitus in 32%. 47% are current smokers and 45% are former smokers. Mean HgA1c is 8±1, LDL 93±37 mg/dL, triglycerides 160±98 mg/dL and HDL 43 ±12 mg/dL. Baseline brachial FMD is 7±4% indicating an overall impairment of endothelial function in this cohort. The inflammatory burden of this cohort is substantial as evidenced by hsCRP 5±5 mg/L. The baseline omega-3 index is 5±2%. Conclusions The OMEGA-PAD trial will test the novel hypothesis that n3-PUFAs supplementation improves functional and inflammatory parameters in a cohort at high vascular risk. The results of this study will provide valuable mechanistic insight into PUFAs as well as inform on this class of agents for cardiovascular outcome trials.