Objective: To investigate the value of non-invasive reperfusion indices in acute myocardial infarction, avoiding the possible need for acute coronary angiography and subsequent angioplasty.
Design: In a prospective angiographic study, seven potential ECG or clinical markers of reperfusion were analysed in 230 patients with acute myocardial infarction. In all patients two 12 lead ECGs were used: the ECG on admission and the ECG immediately before coronary angiography. Non-invasive markers of reperfusion determined just before coronary angiography were prospectively correlated to thrombolysis in myocardial infarction (TIMI) flow. Data analysis correlated these non-invasive indices with coronary flow (analysis A: TIMI 2-3 v TIMI 0-1 flow; analysis B: TIMI 3 v TIMI 0-2 flow).
Results: A sudden decrease in chest pain was the most common sign of reperfusion (36%), followed by reduction in ST segment elevation by >/= 50% (30%), and the development of a terminal negative T wave (20%) in the lead with the highest ST segment elevation. Reduction in ST segment elevation by > or = 50% and the appearance of an accelerated idioventricular rhythm (AIVR) had the highest positive predictive value for reperfusion. For analyses A and B, the positive predictive values were 85% and 66% for resolution of ST segment elevation, and 94% and 59% for AIVR, respectively. The presence of three or more non-invasive markers of reperfusion predicted TIMI 3 flow accurately in 80% of cases.
Conclusions: The prospective use of non-invasive indices of reperfusion is simple, practical, and can be of value in assessing coronary patency in patients admitted with acute myocardial infarction. Using these indices, discrimination between TIMI 0-1 and TIMI 2-3 flow can be made with good accuracy. However, TIMI 3 flow cannot be determined reliably. The use of such non-invasive indices depends on the goal of reperfusion.