Abstract 1712: High Fat Diet Improves Systolic Function and Prevents Progressive Left Ventricular Dilation in Dogs with Chronic Heart Failure
Background: Abnormalities in myocardial energy metabolism occur in chronic heart failure (HF) and appear to contribute, in part, to the left ventricular (LV) dysfunction. Free fatty acids (FFA) are the preferred substrate in adult myocardium supplying 60–80% of the energy requirement for ATP synthesis. Studies in patients with HF have shown that FFA oxidation is increased in HF whereas others showed a shift to a greater dependence on glucose oxidation. The present study tested the hypothesis that a high fat diet in dogs with HF leads to worsening of LV function and progressive LV dilation.
Methods: Studies were performed in 14 dogs with intracoronary microembolization-induced HF (LV ejection fraction, EF 30%–40%) and in 6 normal (NL) dogs. HF dogs were randomized to 3 months of high fat diet (HFD, n=7) or to standard chow (SCD, n=7). NL dogs were fed the HFD also for 3 months. The HFD contained 24% by weight of fat, 20% protein and 46% carbohydrate. The SCD contained 16% fat, 26% protein and 36% carbohydrate. Body weight (BW) and left ventriculograms were obtained before initiating the diets (PRE) and 3 months thereafter (POST). Ventriculograms were used to measure LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF.
Results: Data are shown in the table⇓. The HFD increased BW but had no significant effect on EDV, ESV or EF of NL dogs. HF dogs fed the SCD had no change in BW and showed a characteristic increase of LV EDV and ESV and a decrease of LV EF. Dogs with HF fed a HFD increased their BW but contrary to our hypothesis, showed preservation of EDV, a significant reduction of ESV and a marked and significant increase of LV EF.
Conclusions: In the absence of any background therapy, dogs with chronic HF fed a diet high in fat that increased BW manifested a marked improvement of LV systolic function along with prevention of progressive LV dilation. Additional studies are needed to explore the exact mechanisms that underly these remarkable benefits.