For heart failure patients whose condition is controlled with standard care, omega-3 fatty acid supplements appear to improve their condition even more, a small study suggests.

"Adding n-3 polyunsaturated fatty acids, even in patients that had a major improvement [on standard treatment], showed a further improvement in heart function and exercise capacity," said study co-author Dr. Mihai Gheorghiade, a professor of cardiology at Northwestern University's Feinberg School of Medicine.

This shows that even in patients who respond to therapy, "we can make them much better," he added. "This opens the door for the potential of a natural therapy -- so-called macronutrients -- in the management of heart failure."

Gheorghiade cautioned that this study is not conclusive, but nutrients such as omega-3 fatty acids might extend life and quality of life for these patients.