Comparison of effects of thrombolytic therapy followed by elective coronary intervention and direct coronary intervention in acute myocardial infarction: Usefulness of dobutamine stress echocardiography

The effects of intravenous administration of tissue plasminogen activator (t-PA) followed by elective percutaneous transluminal coronary angioplasty (PTCA) were compared to those of direct PTCA (d-PTCA) in patients with acute myocardial infarction using dobutamine stress echocardiography 1 week and 1 month after the acute episode. There were 12 patients in the t-PA group and nine patients in the d-PTCA group. Dobutamine was infused at incremental doses (5 μg/kg/min for each 5 min step). Wall motion changes were classified during infusion into four patterns, improvement, biphasic, worsening and no change. One week after the acute episode, seven of 12 patients in the t-PA group showed biphasic the pattern and five showed the improvement pattern. The biphasic pattern was observed in three patients in the d-PTCA group, worsening in one and improvement in five. One month later, the biphasic pattern in five patients in the t-PA group changed to the improvement pattern. No patients in the d-PTCA group showed changes in the wall motion pattern. There was no difference between the two groups in the frequency of the change of wall motion patterns I week and I month after infarction, but the improvement pattern was significantly increased from five to 10 patients in the t-PA group after 1 month (p<0.05). The sensitivity, specificity and accuracy of the biphasic pattern in the t-PA group for indicating remnant coronary stenosis were 78%, 100% and 83%, respectively. Evaluation of wall motion pattern by dobutamine stress echocardiography is useful for assessment of reperfusion therapy for acute myocardial infarction. The administration of t-PA followed by elective PTCA has similar efficacy to d-PTCA.