Background: The metabolic syndrome is associated with an increased risk of cardiovascular complications. Especially patients with evident cardiac pathology are at high risk for further complications. A sufficient weight reduction would improve the metabolic pathology and reduce the cardiovascular risk. Unfortunately, overweight and obese patients, even with complicated coronary heart disease, do not alter lifestyles regarding fat intake and physical activity, and in a quarter of these patients body weight increases in the follow-up period. Nonetheless, these patients need a weight reduction to be protected from further cardiovascular complications. Therefore, in overweight patients with insulin resistance in whom lifestyle recommendations have failed, orlistat has been used as an adjunct to decrease significantly overweight and to improve the metabolic pathology without increasing mortality. In our opinion, orlistat could also be an adjunct to lifestyle changes in adipose, diabetic patients with the metabolic syndrome and established heart pathology and signs of incipient cardiac dysfunction. Furthermore, we hypothesize that following a sufficient weight reduction improvements in metabolic pathology and, more important to us, in cardiac dysfunction should be observed. Methods: We selected 90 adipose patients with the metabolic syndrome, diabetes type 2, hypertension, mostly with coronary heart disease and concomitant cardiac dysfunction. Cardiac dysfunction was stated when the amplitude of dyspnea was greater than class 2 of the New York Heart Association (NYHA) and when resting left ventricular ejection fraction (LVEF) was <50%. Patients attended standardized nutritional counseling sessions. The caloric restriction was sufficient to create a deficit of 500 calories per day with <30% of total calories derived from fat. All patients were also enrolled in a standardized physical program and were also encouraged to walk briskly for at least 30 min per day. Patients were divided into two groups. Orlistat (120 mg t.i.d.) and placebo (1 capsule t.i.d.) were administered according to a double-blind protocol. Results: Baseline pathology was similar in the two groups, with the exception of hemoglobin (Hb) A1C, which was slightly higher in the orlistat group, the difference being statistically significant (p = 0.031). Unfortunately, lifestyle changes (diet and exercise) induced only small changes with respect to overweight in the placebo group (no orlistat). The metabolic pathology and the cardiac dysfunction did not improve. As expected, in the other group treated with orlistat in addition to lifestyle changes, weight and body mass index decreased significantly (p < 0.001 and p = 0.013, respectively). In parallel the metabolic pathology, especially dyslipidemia, was significantly reduced. Total cholesterol, LDL cholesterol, and triglycerides decreased, while HDL cholesterol increased. These changes were very significant (p < 0.001, p = 0.001, p = 0.001 and p < 0.001, respectively). Uricemia decreased slightly (p = 0.043)...