Clinical predictors of early infarct-related artery patency following thrombolytic therapy: importance of body weight, smoking history, infarct-related artery and choice of thrombolytic regimen: the GUSTO-I experience

Objectives. The purpose of this study was to determine patient characteristics that are priori predictors of early infarct related artery patency following thrombolytic therapy, and to provide paradigm which may identify patients who would be most likely to achieve restoration of normal (TIMI 3) coronary flow in response to thrombolytic therapy. Background. Restoration of infarct-related artery perfusion in acute myocardial infarction is necessary for preservation of ventricular function and mortality reduction. Clinical variables that are priori predictors of early patency with currently available thrombolytic regimens have not been fully characterized. Methods. The probability of early infarct-related artery patency (TIMI 3 flow) was determined by multivariable logistic regression. We determined reduced (parsimonious) model for predicting early (90 min) infarct-related artery patency (TIMI grade 3) based on dat from 1,030 patients in the GUSTO-I Angiographic study. Results. Predictors of 90 min TIMI 3 flow are use of an accelerated t-P regimen (vs. streptokinase containing regimens) (χ2 = 39.1; p ≤ 0.0001), infarct related artery (RCA/Lcx vs. LAD) (χ2 = 12.7; p = 0.0004), body weight (χ2 = 10.3; p = 0.001) and history of smoking (χ2 = 7.4; p = 0.007). Time from symptom onset to treatment was not significant (p = 0.71). Conclusions. The efficacy of currently available thrombolytic regimens is chiefly dependent on choice of thrombolytic regimen, body weight, infarct-related coronary artery and smoking history. Clinical variables alone correctly predict priori TIMI 3 flow in the infarct-related artery 64% of the time. Patients with body weights greater than 85 kg are at significant disadvantage with regard to achieving successful thrombolysis compared to those with lesser body weights.