Low dose t-PA for prosthetic valve thrombosis in pregnancy

Low dose t-PA for prosthetic valve thrombosis in pregnancy

Low dose slow infusion of tissue plasminogen activator (t-PA) has been found to be useful in prosthetic valve thrombosis in pregnancy [1]. Prosthetic valve thrombosis is a life threatening condition, more so in pregnancy with high maternal and fetal risk. Cardiac surgery in this setting carries high risk of maternal and fetal mortality. Efficacy of low dose t-PA (25 mg) given as a slow infusion given over 6 hours has been evaluated in twenty eight prosthetic valve thrombosis episodes in twenty five pregnancies in twenty four women over a period between 2004 and 2012. Thrombolysis was monitored by trans esophageal echocargiograms. There was complete resolution of thrombus in all cases with only one patient having preterm labour due to placental hemorrhage, but a live birth at 30 weeks and another with minor bleeding. Infusion was repeated after 24 hours if needed, with a maximum of up to 6 times and cumulative dose of 150 mg. The transplacental passage of t-PA is minimal and insufficient to cause any fetal bleeding. Heparinisation with activated partial thromboplastin time (aPTT) levels 1.5 to 2 times control was initiated immediately after t-PA. If repeat dosing of t-PA was needed, heparin infusion was with held till aPTT levels were less than 50 seconds before starting the t-PA infusion. In this series, thrombolytic success was hundred percent and fetal mortality was twenty percent. There was no maternal mortality.

Reference

1. Mehmet Özkan, Beytullah Çakal, Süleyman Karakoyun, Ozan Mustafa Gürsoy, Cihan Çevik, Macit Kalçık, Ali Emrah Oğuz, Sabahattin Gündüz, Mehmet Ali Astarcioglu, Ahmet Çağrı Aykan, Zübeyde Bayram, Murat Biteker, Evren Kaynak, Gökhan Kahveci, Nilüfer Ekşi Duran, Mustafa Yıldız. Thrombolytic Therapy for the Treatment of Prosthetic Heart Valve Thrombosis in Pregnancy With Low-Dose, Slow Infusion of Tissue-Type Plasminogen Activator.  Circulation. 2013 Jul 30;128(5):532-40.