Myocardial infarction caused by cardiac microvasculopathy in a patient with the primary antiphospholipid syndrome.

Antiphospholipid antibodies occur in various clinical states, including the primary antiphospholipid syndrome. Clinical features in these conditions appear to be caused by vasculopathy associated with the presence of these antibodies. We report the case of a patient with primary antiphospholipid syndrome who experienced cardiac necrosis secondary to myocardial microvasculopathy in the absence of vasculitis. This case demonstrates unequivocally that noninflammatory myocardial microvasculopathy occurs in the primary antiphospholipid syndrome per se without any clinical or immunologic signs of systemic lupus erythematosus or other disease process. The histopathologic findings in the skin and myocardial biopsies showed a noninflammatory vasculopathy characterized by bland thrombi and lack of infiltration of the vessel wall by inflammatory cells. Ultrastructural examination of the myocardial biopsy confirmed the vascular thrombosis and endothelial activation and showed no deposits in basement membranes. The patient survived after appropriate treatment. Evidence presented here supports the concept that the vasculopathy in the antiphospholipid syndrome is distinct from other types of vascular occlusions seen in systemic lupus erythematosus. We suggest that myocardial biopsy can be crucial in showing an underlying myocardial ischemic process despite "normal" findings on coronary angiography. Results of the biopsy hastened the decision to use potentially lifesaving plasmapheresis and anticoagulation therapy in this patient.