Young (<43 years) male myocardial infarcts. Relevance of a number of assays in identifying this group after infarction

A small (n=17) group of young (<43 years) male patients were admitted to hospital emergency in the acute phase of myocardial infarction (MI). All were seen at the coronary care unit where blood was taken into citrate, spun, the plasmas snap frozen in liquid nitrogen and stored at -80°C. Samples were taken within l h of admittance and prior to thrombolytic therapy. All patients survived and were discharged after lytic therapy. The plasma samples were thawed and assayed for a variety of markers of hypercoagulibility e.g. soluble fibrin (SF), fibrinolytic potential (bioimmunoassay BIA) fibrinolytic activity (X-oligomers, D-dimer), lipid imbalance (Lpa) and miscellaneous presumed markers of thrombosis (fibrinogen and activated protein C resistance, APC-R). All assays were conducted following thawing of each plasma sample only once. An approximately age matched group (n=7) of laboratory staff were used as a control group in all assays. Parameter Significance X-Oligomer Significant P<0.01 Soluble fibrin Significant P<0.05 (N I BSC) D-Dimer Significant P<0.05 Fibrinogen Non-significant BLA Non-significant APC-R Non-significant LP(a) Non-significant Soluble Fibrin significant P<0.01 (commercial) The above Table shows the data obtained in this limited sized but valuable group of patients. The presumed markers of thrombosis, fibrinogen and APC-R, showed no significance for identification of the MI Group, nor indeed did the Lpa and fibrinolytic potential (BIA). However, both assays for SF, one based on enhancement of the tissue plasminogen activator-plasminogen reaction and the other a new 2-site ELISA assay, significantly delineated the MI group as did the two types of fibrinolytic activity assays, D-dimer and Xoligomer. It is conceded that samples were taken after the acute event of myocardial infarction and may reflect the event rather than propensity to the event. However, it is interesting that the increased turnover of fibrinogen via the coagulation and fibrinolytic systems seems to be most reflected during the post MI stage.