Nutrition in chronic heart failure patients: a systematic review.

Nutrition is the primary source of energy production for myocardial contractility and to maintaining cardiac efficiency. Although many studies provided evidence of the benefits of nutritional intervention in chronic heart failure patients (CHF), these effects are not still completely understood. We searched in PubMed and Embase articles related to the following keywords: "chronic heart failure" with "diet," "nutrition," "insulin resistance," and "caloric restriction." Of the 975 retrieved articles, 20 have been selected. The primary endpoint was the left ventricular (LV) function and the secondary mortality rate in HF patients. Some studies showed that the Mediterranean diet (MedDiet) had a beneficial effect on cardiac function, while others did not find any positive impact. Nutritional supplements and hypercaloric intake had positive effects on underweight HF patients, while hypocaloric diet was beneficial in obese HF patients improving glucose control and cardiac function. The effect of MedDiet in HF patients showed conflicting results. Changes in the dietary pattern can reduce the evolution of HF, considering not only the quality of food but also the caloric intake. The discriminant factor to prescribe a diet regime in HF patients is represented by body mass index (BMI). A well-balanced caloric diet represents an effective therapy in overweight HF patients to reduce the mortality rate. Long-term studies evaluating cause-effect of energy and macronutrients intake on cardiac function in HF patients are necessary.