Prosthetic mechanic valve thrombosis in pregnancy: a single center study of 7 cases

Abstract

Pregnancy in women with mechanical prosthetic heart valves carried an increased risk of thromboembolic complications due to changes in haemostasis. Prosthetic valve thrombosis is a serious complication resulting in high mortality. Ten patients from 20 to 38 years of age had 12 thromboses of mechanical heart prostheses during pregnancy. The prosthesis was mitral in 8 cases and aortic in 4 cases. The prosthesis was a ball valve in 1 case, a tilting disc in 3 cases and bi-leaflet in 8 cases. Initial emergency treatment was surgical in 3 cases and medical in 9 cases (thrombolysis in 7 cases and simple heparin therapy in 2 cases). Secondary surgery was carried out in one patient after failure of heparin therapy. There was one death in the surgical group (4 cases, 25%) and 30% foetal mortality in the surviving women. In the thrombolysis group (7 cases), two women died (28%) after failure of treatment. Both patients had mitral valve prostheses and were in cardiogenic shock. Three women, of the other 5 thrombolysed cases, were able to complete their pregnancies and had healthy babies with no foetal mortality. No per-thrombolytic embolic complications were observed. However, there was one severe bleeding complication which was successfully managed by surgical drainage. Finally, a global success rate of 75% (9 out of 12 patients) and a mortality of 30% (3 maternal deaths in the 10 patients--all with mitral valve protheses) were observed irrespective of the therapeutic protocol used. Thrombosis is the most life-threatening complication for women with prosthetic heart valve during pregnancy. Emergency surgery for valve replacement or thrombectomy is the commonest treatment. Trombolysis is classically limited by the risk of haemorrhagic and thromboembolic complications reported in the literature. In this study, thrombolysis was effective in the 71% of cases with a low risk of haemorrhagic complications.