Thrombolytic Therapy forAcute Coronary Obstruction: Status in1986

Theeffect ofthrombolysis inacutemyocardial infarction on enzymatic infarct size, left ventricularfunction, andearly mortality was studied insubsets ofpatients inarandomized trial atTheNetherlands Interuniversity Cardiological Institute during a5-year period. Early thrombolytic therapy with intracoronary streptokinase (152 patients) or with intracoronary streptokinase preceded byintravenous streptokinase (117 patients) wascompared toconventional treatment (264patients). All533patients wereadmitted tothecoronary careunit within 4hours after onset ofsymptoms indicative ofacute myocardial infarction. There were488patients eligible forthis detailed analysis, ofwhom245were allocated forthrombolytic therapy. Early angiography wasperformed in212ofthe245patients. Patency oftheinfarct-related artery was achieved in181patients (85%). Enzymatic infarct size measured from cumulative alpha HBDH release wassmaller inpatients allocated to thrombolytic therapy (median 760Ullvs.1179Ullincontrols, p = 0.0001). LVEFmeasured byradionuclide angiography before discharge washigher after thrombolytic therapy (median 50%vs.43%incontrols, p = 0.0001). The12-month mortality waslower inpatients allocated tothrombolytic therapy (8%vs.16%inthecontrol group, p< 0.01). Inmultivariate regression analysis, infarct size limitation, improvement ofLVEF,anda3-month mortality werepredicted byST,time fromonset ofsymptoms toadmission, andKillip class atadmission. Thrombolysis wasmostuseful inpatients admitted within 2hoursafter onset of symptoms andinpatients with STof1.2mVormore.Ontheother hand, nobeneficial effects ofstreptokinase onenzymatic infarct size, left ventricularfunction, ormortality wereobserved inthesubset ofpatients with STless than1.2mVadmitted 2to4hours after onset ofsymptoms. Inthelongterm, improved survival andenhanced quality oflife are mostevident after thrombolytic therapy inpatients withlarger anterior wallinfarction, andless pronounced inpatients withsmaller inferior wallinfarction. (Texas HeartInstitute Journal 1986; 13.433445)