Dipyridamole in the Management of Severe Heparin-associated Thrombocytopenia

Severe heparin-associated thrombocytopenia (SHAT) is a rare, life-threatening condition. The aim of this prospective pilot study was to determine the safety and efficacy of dipyridamole-heparin infusion (DHI) in the management of the condition. We studied 6 patients (4 males and 2 females) aged 28 to 80 years (mean 50.5±14.2) with deep venous thrombosis and/or pulmonary embolism who developed SHAT a few days following heparin therapy. Heparin-dependent platelet aggregating factor was demonstrated ex vivo in the plasma of 4 patients. 240-300 mg of dipyridamole/day (4 mg/kg/day) was mixed with heparin in the same bag and given as a continuous intravenous infusion. Anticoagulation was continued successfully along with significant platelet recovery over a few days. This regimen was without side-effects. We conclude that DHI may provide an effective therapy for patients with SHAT.