Acute myocardial infarction in young adults: evaluation of the haemorheological pattern at the initial stage, after 3 and 12 months.

Acute myocardial infarction (AMI) in young adults is considered by some authors as an autonomous disease, characterized by peculiar risk factor pattern, clinical course and prognosis. We studied, in a group of 96 patients aged < 46 years with recent AMI, the haemorheological parameters (whole-blood, plasma and serum viscosity, haematocrit, whole-blood filterability and erythrocyte deformability), and the influence of risk factors and coronary lesion extent on them. We re-examined 41 of the AMI patients after 3 and 12 months. At the initial stage, AMI subjects showed a hyperviscosity syndrome, not influenced by the number of risk factors and only slightly more evident in patients with more extensive coronary damage. In the AMI patients re-examined after 3 and 12 months, no significant variation in the haemorheological pattern emerged in comparison with basal values. The persisting alteration demonstrated that the hyperviscosity syndrome observed at the initial stage was not simply an acute reaction to AMI, and that it was not influenced by intervention on modifiable risk factors.