The pathology of the heart following long-term anticoagulant therapy in elderly patients after myocardial infarction. The Dutch sixty-plus reinfarction study.

A pathomorphologic study of 30 hearts of elderly patients, who died during a double-blind trial to assess the long-term effects of oral anticoagulants following myocardial infarction, showed that all patients had suffered of severe and extensive obstructive coronary atherosclerotic disease. Eight hearts were obtained from patients who had received anticoagulants, while 22 hearts were obtained from patients of the placebo group. Complicated coronary arterial lesions, such as cracked plaques and coronary thrombosis, occurred more frequently in hearts of patients of the placebo group. A recurrent recent infarction was found at autopsy in 13 of the 22 patients receiving a placebo, in contrast to 3 of the 8 hearts from the group of patients receiving anticoagulants. The findings point in the same direction as the clinical trial, which showed a statistically significant reduced risk of recurrent myocardial infarction and, hence, cardiac death, but in the autopsy study do not reach statistical significance. The occurrence of grossly recognizable intraventricular thrombosis in 5 of the 22 hearts from the placebo group contrasted to none in the 8 hearts of the anticoagulant group. Although none of these differences is statistically significant they all point in one and the same direction, viz. prevention of complicating thrombotic lesions following the long-term application of anticoagulants.