- all centers arrange for the two index echocardiographic evaluations to be performed on schedule by an expert operator, who has to be blinded about any trajectory results, and according to recommendations of the American Society of Echocardiography. All examinations are recorded on external support (analogic or digital) and handed to the internal Echocardiography Core-Lab, which is identified among participating institutions. The Echo Core-Lab operator(s) is not directly involved in the study and is kept unaware of all trajectory results up to the end of the study;