Background: One of the main goals of the Cardiopulmonary By-Pass (CPB) is targeting an adequate Mean Arterial Pressure (MAP), in order to maintain appropriate perfusion pressures in all end-organs during heart surgery. As inheritance of early studies, a value of 50-60 mmHg has been historically accepted as the gold standard MAP. However, in the last decades, the CPB management has remarkably changed, thanks to the evolution of technology and the availability of new biomaterials. Therefore, as already highlighted by the latest European Guidelines, the current management of CPB can no longer refer to those pioneering studies. To date, only few single-centre studies have compared different strategies of MAP management during CPB, but with contradictory findings and without achieving a real consensus. Therefore, what should be the ideal strategy of MAP management during CPB is still on debate. This trial will be the first multicentre, randomized, controlled study to compare three different strategies of MAP management during the CPB. *

Methods: We described herein the methodology of a multicenter, randomized, controlled trial comparing three different approaches to MAP targeting during CPB in patients undergoing elective cardiac surgery: the historically accepted standard MAP (50-60 mmHg), the high MAP (70-80 mmHg) and the patient-tailored MAP (comparable to the patient's preoperative MAP). It is the aim of the study to find the most suitable management in order to obtain the most adequate perfusion of end-organs during cardiac surgery. For this purpose, the primary endpoint will be the peak of serum lactate (Lmax) released during CPB, as index of tissue hypoxia. The secondary outcomes will include all the intraoperative parameters of tissues oxygenation and major post-operative complications related to organ malperfusion. * Discussion: This trial will assess the best strategy to target the MAP during CPB to further improve the outcomes of cardiac surgery.