We have introduced a number of modifications to minimize the deleterious effects of cardiopulmonary bypass (CPB) by reducing the surface of the extracorporeal circulation (ECC), the length of the ECC circuit, the contact surface of the oxygenator, and the volume of priming solution, in addition to employing biocompatible systems and isolation of excess blood volumes of venous reservoirs in transfusion bags very early in CPB. Encouraged by the results of our initial "Compact ECC," we have decided to improve it by implementing other techniques such as controlled hemodilution of the patient by reducing the diameter of ECC venous tubing (from 1/2 in. to 3/8 in.), limiting contact surface of the oxygenator and venous reservoir, positioning the oxygenator and venous reservoir at the level of the patient's shoulder, and employing venous cannulae adapted to vacuum assisted venous drainage (VAVD) to replace venous drainage by gravity. The purpose of this study is to evaluate postoperative outcomes of Compact ECC. Three groups of patients undergoing coronary artery bypass graft (CABG) are compared. Our new Compact ECC shows improved outcomes through reduced postoperative ventilation time, blood loss, intensive care stay, need for blood transfusion, and levels of lactate dehydrogenase despite the patients' pathologies and surgeries being more complex.