Risks of anticoagulant therapy in pregnant women with artificial heart valves.

In an attempt to identify the best treatment for pregnant women with cardiac-valve prostheses who are receiving oral anticoagulants, we studied 72 pregnancies prospectively. In 23 pregnancies (Group I), the coumarin derivative acenocoumarol was discontinued and the patients received 5,000 U of subcutaneous heparin every 12 hours from the 6th to the 12th week of gestation, in 12 pregnancies (Group II), heparin was not substituted for the coumarin derivative until after the 7th week, and in 37 pregnancies, detected after the first trimester (Group III), the coumarin derivative was given throughout gestation. In most patients heparin was again substituted for the oral anticoagulant after the 38th week. Three mothers had thrombosis of a tilting-disk mitral prosthesis (two cases were fatal) during heparin treatment. No differences were found in the rates of spontaneous abortion in the three groups. Coumarin embryopathy occurred in 25 percent and 29.6 percent of the pregnancies in Groups II and III, respectively. We conclude that in the second and third trimesters of pregnancy, coumarin derivatives provide effective protection against thromboembolism while causing few fetopathic effects, but that these agents are contraindicated from the 6th to the 12th weeks of gestation. Low-dose heparin does not protect against prosthetic-valve thrombosis, and the possibility that a larger dose might be more effective requires further exploration.

[Procoagulant activity associated with mononuclear cells in active rheumatic fever]. / Actividad procoagulante asociada a células mononucleares en fiebre reumática activa.

Acute rheumatic fever (ARF) is associated with disseminated inflammation and tissue lesions with heavy fibrin deposition, specially in heart valves and myocardium. The immune pathogenesis of ARF has been suspected, but not satisfactorily proven. An active cellular immune reaction generates cell activators (lymphokines) from T cells, which are able to induce a procoagulant activity (PCA) in mononuclear cells. We studied PCA in peripheral blood mononuclear cells isolated form ARF patients as well as normal controls. The PCA from ARF was 1.5 to 15 times higher than the PCA from controls. This activity was associated with the presence of C-reactive protein and other acute phase markers. The PCA from mononuclear cells in ARF may be one of the mechanisms responsible for fibrin deposition.