Antiphospholipid syndrome in cardiac surgery—an underestimated coagulation disorder?

Objective: Antiphospholipid syndrome (APS) is a rare coagulation disorder associated with recurrent arterial and venous thrombotic events. We analysed our experience with five APS patients who underwent cardiac surgery. In three of them the diagnosis of APS had been established before surgery, two patients were diagnosed after surgery. Methods: From March 1999 to March 2004 five patients with APS underwent cardiac surgery using cardiopulmonary bypass (CPB). We retrospectively reviewed their clinical data, operative and postoperative courses, and the long-term results. Results: Procedures performed were heart and lung transplantation (patient 1), endoventriculoplasty and CABG (patient 2), biventricular resection of endoventricular fibrosis and thrombus (patient 3), mitral valve repair repair and coronary artery bypass grafting (CABG, patient 4), and mitral valve replacement with closure of a patent foramen ovale (patient 5). There were three perioperative deaths (patients 1, 2 and 3), two of three patients in whom the diagnosis was known before surgery, survived (patients 4 and 5). In these patients, only half the dose of protamin (patient 4) and no protamin at all (patient 5) was applied to reduce the probability of postoperative thromboembolic complications. At 1 year follow up, only patient 4 had survived, patient 5 had died of the complications of intestinal thromboembolism. Conclusions: Patients with APS undergoing cardiac surgery belong to a high risk subgroup. Thus, though rare, APS can be a critical issue in cardiac surgery. Some of the cardiac patients with unexplained perioperative thromboembolic complications, such as graft occlusion, may turn out to have an undiagnosed APS.