[Antiprothrombinase and myocardial infarction. Apropos of 2 cases]. / Antiprothrombinase et infarctus du myocarde. A propos de deux observations.

Among the thrombotic events associated with a circulating anticoagulant of the antiprothrombinase type, myocardial infarction is exceptionally reported, which justifies the presentation of two cases. In both patients, myocardial necrosis occurred some time after the antiprothrombinase was discovered, and there was nothing special in its clinical features. No obvious atherosclerotic lesion and no image suggestive of vasculitis were found at coronary arteriography, which suggested that the antiprothrombinase played a predominant role in the genesis of infarction. Relationships between antiprothrombinase, arterial thrombosis (particularly of the coronary arteries) and the presence or absence of systemic lupus erythematosus (SLE) are discussed. As observed in thrombosis of other arteries, it is not certain that the presence of SLE constitutes an additional risk factor, except in cases with unquestionable vasculitis or if the treatment of SLE requires prolonged corticosteroid therapy. On the other hand, the appearance of an antibody directed against phospholipids is not necessarily related to the presence of SLE; in fact, this antibody itself might be a risk factor of myocardial infarction, as has recently been suggested.