Investigations of antithrombin III-activity in patients after myocardial infarction and a long-term coumarin therapy.

In 40 M.I. patients with long-term anticoagulant treatment, (Falithrom), the AT III-activity was determined at an interval of three years by means of Chromozym TH. We have found a mean AT III-value in the first testing period of 79.67 (+/- 14.16) per cent and in the second assessment of 82.5 (+/- 10.42) per cent. The difference is not significant. However, we were unable to confirm the comparatively marked increase AT III for dicoumarol treatment found by Roka and Bleyl. In acute M.I.-patients was demonstrated a decreased AT III-activity in the first 3-4 days and a normalisation tendency in the next 10-14 days. Our values of the mean AT III-activity were in the lower normal range for patients with long-term coumarin therapy. In dead patients (average age 70 years) there is a trend of a risk to an untimely death in the presence of pathologic AT III-activity (despite a good anticoagulation of an individual mean quick test from greater than or equal to 0.20 to less than or equal to 0.30) or a bad anticoagulation (mean individual quick tests greater than or equal to 0.30 to 0.35), but a normal AT III-activity. The three dimensional analysis was not significant.