Efficacy of immunomodulation in the treatment of profound thrombocytopenia after adult cardiac surgery

ObjectiveCauses of profound thrombocytopenia (platelet count <60 K) developing days after cardiac surgery include heparin platelet factor 4 antibodies, thrombotic thrombocytopenic purpura–like antibodies, and endotoxin generated by pulmonary infections. Modulation of immune-mediated profound thrombocytopenia with intravenous immunoglobulin could be efficacious for any of these conditions.MethodsFrom 2002 to 2010, profound thrombocytopenia developed in 20 consecutive patients within days after cardiac surgery; 19 patients underwent valve or aortic operations, and 1 patient underwent coronary bypass. Risk profiles were high preoperatively: Patients’ mean age was 73 years, 50% underwent nonelective procedures, 100% had comorbidities, and 25% underwent reoperations. When decreasing platelet counts approached 60 K, intravenous immunoglobulin was started at 1.5 g/kg intravenously over 5 days. Anticoagulation and platelet transfusions were avoided. In 1 patient, profound thrombocytopenia failed to reverse promptly, and daily plasmapheresis was introduced. Platelet counts before and after interventions were assessed with linear regression analyses over time, including a spline function and statistical knot coincident with starting intravenous immunoglobulin.ResultsIn 19 of 20 patients, profound thrombocytopenia stabilized and rebounded within 2 to 4 days after initiating intravenous immunoglobulin. In the remaining slow-responding patient, addition of plasmapheresis was associated with rapid recovery. In every patient, coincident multiorgan failure reversed, and 19 of 20 patients recovered uneventfully and survived hospitalization with no limb ischemia or tissue loss. No complications of intravenous immunoglobulin therapy or plasmapheresis were observed.ConclusionsAlthough mechanisms of profound thrombocytopenia after cardiac surgery are poorly understood, they likely relate to inappropriate autoimmune moieties causing peripheral platelet aggregation and multiorgan failure. A protocol involving immunomodulation with intravenous immunoglobulin supplemented by plasmapheresis appeared safe and efficacious. Direct immunologic interventions for profound thrombocytopenia could improve postoperative outcomes.