Recombinant tissue type plasminogen activator treatment of thrombosed mitral valve prosthesis during pregnancy

Prosthetic heart valve thrombosis occurring during pregnancy is a life-threatening complication. Surgical treatment requires clot removal under cardiopulmonary bypass (CPB) and carries a high mortality. We describe the successful use of thrombolytic therapy for recurrent thrombosed valve prosthesis in a pregnant patient.

A 32-yr-old patient whose pregnancy was complicated by two episodes of a thrombosed St Jude mitral prosthesis is reported. The first episode occurred at 20 wk of pregnancy during the change of oral anticoagulant therapy (acenocoumarol 4 mg a day) to sc heparin. As the patient was in cardiogenic shock, the valve thrombus was treated by clot removal under CPB., with a cross clamp time of 32 min, a perfusion pressure above 70 mmHG. There was no fetal cardiac rhythm during CPB which lasted < 45 min. The second episode occurred at the 28th gestational week in a patient in cardiogenic shock and because reoperation was thought to carry too high a risk, the thrombus was successfully treated with 50 mg recombinant tissue plasminogen activators (rtPA) i.v. Following this, the course of pregnancy was uneventful and carried to term and the patient delivered vaginally. Pain relief was achieved with intravenous patient-controlled analgesia with alfentanil (bolus 100 mug; lock out = five minutes). Although rtPA has been used before, this is the first report in which pregnancy was carried to term and standard vaginal delivery performed.

This case provides evidence for the efficacy and relative safety of rtPA as thrombolytic therapy in the treatment of haemodynamically compromised valve heart thrombosis in pregnancy.