Despite improvements in cardiac surgery and anesthesia in the face of sicker and elderly patients, numerous ssues remain to be clarified concerning the best treatment options for ischemic mitral valve regurgitation and novel therapy for pulmonary hypertension. These important questions are difficult to answer with single center trials even in centers with a high volume of complex valvular surgery. The NIH has decided to form a network of clinical centers to address this challenge. The U of Montreal Cardiac Surgery Clinical Investigation Group (UMCSCIG) is proposing to join the NIH Network to help attain its goals of bringing innovative experimental strategies for the treatment of cardiac surgical pathology from the laboratory to the bedside. The U of M investigation Group is made up of 3 tertiary university hospital centers on 5 sites in the city of Montreal, treating over 3000 patients by 17 surgeons which represents close to 50% of the cardiac surgical volume of the Province of Quebec (population 8 million). The Group has a number of special attributes, and brings with it expertise that would be helpful for the NIH network as a whole. Its members belong to a single payer socialized medicine system, which facilitates patient follow-up and data generation. The close collaboration of cardiac surgical investigators with extensive experience in clinical trials with cardiologists, clinician-scientists and basic researchers within the research centers of the 3 hospital centers by their affiliation to the University of Montreal plus the hook-up with the Canadian East-West Network and the Quebec Heart Failure Society dedicated to Heart Failure Research are definite advantages. The MHI has a long and successful tradition of working with the NIH, it has an experienced clinical research co-ordinating center. The group has access to state of the art investigative technology, expertise in blood sampling, transportation and performs a large spectrum of open and minimally invasive coronary, valvular and aortic surgery as well as heart transplantation and implantable artificial heart program and emerging strength in cell therapy and seven new hybrid technology operating rooms are currently under construction at MHI. The U of Montreal Research Group proposes a project to evaluate the effect of a new treatment option for severe ischemic mitral regurgitation and a second project test a new pharmacological management of pulmonary hypertension in patients experiencing difficult separation from cardiopulmonary bypass.