Abnormal fibrinolysis in familial pulmonary hypertension

Abstract

The familial occurence of pulmonary hypertension is well documented, but the pathogenesis of this disease remains relatively obscure. Recurrent pulmonary embolization with impaired fibrinolytic mechanisms has been postulated as a possible etiologic factor. Data have been obtained from 10 members of a kindred comprising 4 generations. Of the 10, 5 have had electrocardiographic evidence of right ventricular hypertrophy. Of the five, four underwent cardiac catheterization and were found to have pulmonary hypertension. Coagulation studies were made in 7 of the 10 members. Factors 5, 7, 8, 9, 10, 12, antithrombin 3, plasminogen, platelet aggregation, fibrinogen and antiurokinase were within normal limits. In all these seven and in one additional family member, antiplasmin levels were abnormally elevated (p < 0.001). These findings suggest that the increased incidence of pulmonary hypertension in this family may be related to an impaired ability to lyse postulated, but not documented, recurrent pulmonary microemboli.