DHA/EPA Supplementation Improves Heart Functioning and Exercise Capacity in Selected Heart Failure Patients
Nodari, S. et al., J. Am. College Cardiology, 57 : 870-879 , 2011
Section of Cardiovascular Diseases , University of Brescia, Brescia, Italy
Despite treatment, heart failure patients often experience a progressive deterioration in both cardiac functioning and exercise capacity along with high rates of hospitalization. In the present study, 133 patients (average age of 63 years) who developed chronic heart failure secondary to NICM (nonischemic dilated cardiomyopathy) were assigned to receive either a placebo (controls) or omega-3 supplementation for a 12-month period. All patients were receiving appropriate medical treatment (including various medications) throughout. The omega-3 group received 4250 - 4410 mg of encapsulated DHA/EPA daily for the first month followed by 1700-1764 mg daily for the duration of the trial. At initiation and at the trial’s end, assessments of functional cardiac capacity included EF (ejection fraction) , LV (left ventricular ) function using echocardiography, cardiopulmonary exercise testing , and other clinical measures.
A significant improvement in cardiac functioning based on the LV-EF was found in the DHA/EPA group after 12 months (increased by 10 %) in contrast to the decrease (by 5 %) seen in the placebo (control) group. Exercise testing (via bicycle ergometry) revealed a 6.2 % improvement in peak oxygen uptake in the omega-3 group but a 4.5 % decrease in the control group. The tolerable workload improved in the omega-3 group (not in the control group) and a 7.5 % increase in exercise duration (from 10.4 to 11.2 minutes) resulted in the former group while the controls showed a 4.8 % decrease . Finally, a hospitalization rate of 30.3 % due to worsening heart failure was found during the 12 months for the control group in striking contrast to only 5.9 % for the omega-3 group. The authors also indicated that their findings of benefit to this particular group of heart failure (HF) patients cannot be generalized to other HF groups or to those patients with more advanced disease.
Dr. Holub's Comments:
This very impressive clinical trial and the significant improvements in cardiac functioning, exercise capacity, and reduced hospitalizations with complementary DHA/EPA supplementation should stimulate future trials in a wide range of heart failure patients (with varying severities) using differing absolute intakes and ratios of DHA/EPA. In the present study, the high initial doses of DHA/EPA up to 4410 mg daily cannot be reached and maintained without supplementation as neither can the subsequent intake of 1700-1764 mg/day for most patients. Based on experimental studies in rodents, faster rates of cardiac muscle contraction and relaxation and an increased efficiency of oxygen utilization while supporting cardiac output may underlie the effects of omega-3 fatty acids as observed in the present trial.