THROMBOTIC THROMBOCYTOPENIC PURPURA FOLLOWING CORONARY-ARTERY BYPASS GRAFT-SURGERY - PROSPECTIVE OBSERVATIONS OF AN EMERGING SYNDROME

Thrombotic thrombocytopenic purpura (TTP) is a rapidly progressive syn drome of thrombocytopenia, microangiopathic hemolysis, and organ dysfu nction. While most TTP is idiopathic, we have observed four cases foll owing coronary artery bypass graft (CABG) surgery in a 2-year period. We have studied these cases prospectively to define the natural histor y, and potentially unique characteristics, of a post-CABG TTP syndrome . On average, the onset occurred 4.75 days postoperatively (post-op), but the diagnosis was made 8.5 days post-op. All four patients exhibit ed microangiopathic hemolysis, thrombocytopenia, mental status changes , and severe renal failure. Three also had unexplained fever. All pati ents received therapeutic plasma exchange for 5, 6, 8, and 11 days, re spectively, and all achieved complete hematological remission. Three p atients required dialysis for 7, 15, and 16 days, respectively, but we re restored to baseline renal function if they survived. One patient w ith severe pre-existing peripheral vascular disease died of Candida se psis. None of the surviving patients have relapsed at a median follow- up of 19 months. These cases appear distinguished by a delay in diagno sis despite intensive medical supervision, a florid presentation with most, or all, of the components of the classic TTP pentad, an excellen t and rapid response to plasma exchange, and a tendency not to relapse . As such, they may represent a subgroup characterized by a more rapid and severe onset, but also a rapid response to therapy and earlier re covery than the typical idiopathic form of TTP. An aggressive approach to management is warranted. (C) 1997 Wiley-Liss, Inc.