Platelet counts in myocardial infarction, angina pectoris and peripheral artery disease.

Serial determinations of peripheral venous platelet counts were performed in 43 consecutive patients with acute chest pain. On admission, patients with acute myocardial infarction (AMI) had a significantly lower mean platelet count (p less than 0.05). Thereafter a further reduction was seen with steadily reduced platelet counts by about 20%, both in comparison with healthy controls (p less than 0.001) (n = 113) and patients with peripheral artery disease (PAD) without heart symptoms (p less than 0.005) (n = 54). The platelet number increased one week after admission and even thrombocytosis was observed. The changes in platelet number during AMI seem to parallel the changes in platelet function. Patients with PAD had normal mean platelet counts. Female patients as well as healthy subjects had significantly higher values than men (p less than 0.01).