The very high values of interleukin-6 (IL 6), suggestive for an immune hyperactivity, may show that the preoperative status of the patient (patient who had pulmonary edema, an chronic severe mitral regurgitation) could influence the marked increase in IL-6 in the postoperative period and favor the occurrence of noncardiogenic pulmonary edema. Here, IL6 is linked to mitral valve insufficiency.