Feasibility Study of Omega-3 Fatty Acids in Dialysis Patients

Overview

Cardiovascular disease and mortality is the largest comorbidity within the dialysis population. Nearly 50% of hemodialysis patients will have congestive heart failure at initiation. According to the most recent United States Renal Data System (USRDS), 40% of incident dialysis patients will have a cardiovascular event or die within the first 9 months of dialysis. It has been postulated that Omega-3 fatty acids could provide beneficial cardioprotection in hemodialysis patients. The investigators propose to evaluate Omega-3 fatty acid doses on cardiovascular parameters in an incident hemodialysis population. Initially, this will be a pilot study. Ultimately, the information will be used to adequately plan for a larger intervention trial using Omega-3 fatty acids in incident hemodialysis patients.

Cardiovascular disease and mortality is the largest comorbidity within the dialysis population. Nearly 50% of hemodialysis patients will have congestive heart failure at initiation. According to the most recent USRDS data, 40% of incident dialysis patients will have a cardiovascular event or die within the first 9 months of dialysis. The risk of sudden cardiac death is estimated to be 6.9% per year of dialysis. Despite this, a recent study found that only 8% of dialysis patients received an implantable defibrillator. Numerous studies have looked at the acute cardiac effects of hemodialysis. Changes in the QT interval, elevations in troponins, increased heart rate variability and heart have all been noted. The mechanisms behind these changes and potential preventative measures remain unknown. It has been postulated that Omega-3 fatty acids could provide beneficial cardioprotection in hemodialysis patients. In nonhemodialysis populations, omega-3 fatty acids (FA) have established anti-arrhythmic properties and have been shown to reduce the risk of sudden death and to reduce cardiac mortality. In a study of hemodialysis patients, a high dose of omega-3 FA (5 grams daily) had beneficial effects on electrocardiographic (ECG) surrogate markers of sudden death, such as heart rate, heart rate variability, and baroreflex sensitivity. One small 2-year study of 1.7 grams omega-3 FA in 206 hemodialysis subjects showed a significant reduction in myocardial infarction but was not large enough to detect an effect on cardiac or total mortality. While these studies are suggestive, the potential therapeutic benefit remains unclear and the appropriate dose of Omega-3 in dialysis patients to achieve benefit is unknown. Doses of Omega-3 that have shown electrocardiogram benefits were high and require 6-8 capsules daily. Long-term adherence is likely to be suboptimal with this high pill burden. Studies with smaller doses have been of insufficient size to determine any cardiovascular benefit. We propose to evaluate two Omega-3 fatty acid doses on cardiovascular parameters in a hemodialysis population. Initially, this will be a pilot study. Ultimately, the information will be used to adequately plan for a larger intervention trial using Omega-3 fatty acids in incident hemodialysis patients. I.5 Specify your research question(s), study aims or hypotheses (do not indicate "see protocol") Specific aim 1. Determine recruitment and medication adherence rates Recruitment will take place over 6 months and include incident hemodialysis patients with a 4 month follow-up. Total expected time for the pilot is one year. Participants will be randomized to either moderate dose Omega-3 (4 grams), or 4 tables of placebo. Rates of participation, medication adherence and drop out rates will be used to plan future trials. HawkIRB https://hawkirb.research.uiowa.edu/hawkirb/summary/projects.page?mode=pf\&OID=5961841\[1/27/2010 2:46:08 PM\] Specific aim 2. Assess the effectiveness of two Omega-3 fatty acid doses compared to placebo on electrocardiographic parameters. All participants will have a cardiovascular evaluation at baseline and at end of study. This will include a 48-hour Holter monitor, vital signs and blood studies of various cardiovascular risk markers. Specifically, we will be assessing heart rate variability, heart rate and QT dispersion. Specific aim 3. Assess the side effect profiles of 3.4 g Omega-3 fatty acids to placebo. The success of future trials will require subject compliance with therapy. By evaluating the side effects of Omega-3, we will be better able to determine the tolerability for future studies. I Selection of study endpoints. Since this is a feasibility study there will be insufficient power to detect changes in physiologic parameters. Omega-3 FA have been shown to beneficially influence autonomic function parameters measured by 48-hour Holter we have selected as our secondary endpoints changes HRV, heart rate, and QT duration for a dose-ranging study. Blood samples will be obtained and properly stored for future studies.