Failure of thrombolysis by streptokinase: detection with a simple electrocardiographic method

Objective-To determine whether simple, readily applicable ECG criteria will allow early prediction of inadequate (< TIMI 3) flow in the infarct relate d vessel in patients receiving thrombolytic treatment for acute myocardial infarction; and to determine the success of streptokinase in achieving adeq uate antegrade flow in the infarct related vessel two hours after starting treatment. Design-Cohort study. Setting-Regional cardiothoracic unit. Patients-100 sequential patients with acute myocardial infarction. Interventions-Coronary angiography two hours after the initiation of thromb olytic treatment, proceeding to rescue angioplasty for inadequate flow in t he infarct related Vessel where appropriate. Main outcome measures-Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of six ECG criteria for the detecti on of inadequate antegrade flow in the infarct related vessel. Results-The ECG test that performed best as a positive test for < TIMI 3 fl ow in the infarct related vessel was < 50% resolution of the ST segment ele vation in the worst lead and no accelerated idioventricular rhythm. This ha d a sensitivity of 81%, specificity of 88%, positive predictive value of 87 %, negative predictive value of 83%, and overall accuracy of 85%. Conclusions-Sensitive, specific, and simple ECG criteria are defined for di agnosing failure of thrombolytic treatment with streptokinase. These allow the early detection of patients at high risk of further adverse events from a persistently occluded vessel. They may be used without recourse to sophi sticated equipment or complex analyses. Such patients can then be considere d for alternative treatments or enrolment into appropriate research protoco ls.