Factors influencing probability of reperfusion with intracoronary ostial infusion of thrombolytic agent in patients with acute myocardial infarction.

A multivariate logistic regression equation was used to evaluate variables related to successful intracoronary thrombolytic therapy. One hundred seventeen patients with a totally occluded infarct-related artery were randomly given ostial infusions of urokinase or streptokinase in a blinded study. The opening rate was 57%. The agent used and time from onset of symptoms to beginning of treatment did not significantly influence opening rate (p greater than .25). The site of occlusion was a strong predictor of opening rate (p = .0004). The anterior descending coronary artery was successfully opened more frequently than the left circumflex or right coronary artery (p = .012). Presence of collaterals adversely affected the recanalization rate in all groups (p = .0004). These variables had an additive effect on the probability of opening. Patients with proximal anterior descending occlusion and no collaterals had a 90% recanalization rate, while those with distal occlusions in vessels other than the anterior descending and with collaterals had only a 24% chance for reperfusion. Thus location of occlusion and presence or absence of collaterals may strongly influence opening rates.