RELATION OF COAGULATION PARAMETERS TO POTENCY AND RECURRENT ISCHEMIA IN THE THROMBOLYSIS IN MYOCARDIAL-INFARCTION (TIMI) PHASE-II TRIAL

Current protocols for use of tissue-type plasminogen activator in acut e myocardial infarction include heparin estimated by the activated par tial thromboplastin time (aPTT). Recent reports indicate a risk of rec urrent ischemic events with long aPTT valves, longer aPTT values in th e Thrombolysis in Myocardial Infarction-ll (TIMI II) Trial, obtained w ithin the first 48 hours, were associated with patency at 18 to 48 hou rs acid better left ventricular function at discharge (average 9.6 day s), but also with emergency catheterizations within the first 48 hours and, weakly, with recurrent ischemia during the first 18 hours. A mod erate decrease in fibrinogen, compared with a ''small'' decrease, was also associated with potency, but a ''large'' decrease was associated with hemorrhagic events. Potency was associated with higher fibrinogen values and higher plasminogen values at baseline. The aPTT results su pport frequent monitoring during the first 24 to 48 hours to ensure op timal clinical outcome. The coagulation factor results suggest that th ere may be an optimum window for fibrinogenolysis in this setting.