Effects of intravenous recombinant tissue-type plasminogen activator therapy on the incidence and associations of left ventricular thrombus in patients with a first acute Q wave anterior myocardial infarction

Abstract

Consecutive survivors of a first Q wave anterior myocardial infarction were studied to observe the impact of recombinant tissue-type plasminogen activator (rt-PA) therapy on the incidence and associations of left ventricular thrombus. Fifty-four patients recelved rt-PA within 4 hours after the onset of cardiac pain, followed by heparin infusion. Forty-four patients who did not qualify for rt-PA therapy but who were anticoagulated with heparin served as a control group. Two-dimensional echocardiography was performed in all patients on days 3 and 7 to detect thrombl and analyze wall motion. Election fraction was determined by radionuclide angiography in all patients on day 7. Apical thrombl were detected on day 3 in three patients (5.5%) who recelved rt-PA and in eight control patients (18%) ( p < 0.05). All patients with a thrombus had apical dyskinesis and 8 of 11 (73%) had an aneurysm. Of the 87 patients without thrombosis, apical dyskinesis and aneurysm were present in 42 (48%) and 11 (13%) patients, respectively ( p < 0.01). Ejection fractions and wall motion scores of patients without a thrombus were significantly better when compared with data from those with thrombus. There were fewer patients with apical dyskinesis (17 of 54) in the group recelving rt-PA therapy compared with the control group (36 of 44) ( p < 0.01). Ejection fractions and wall motion scores were better in patients who recelved rt-PA compared with control subjects ( p < 0.01). Thus rt-PA reduced the incidence of ventricular thrombosis by 70% in patients with anterior myocardial infarction by preserving apical wall motion, and this decrease in relative risk was significant in comparison with the risk in patients recelving heparin therapy.