Prognostic implication of activated partial thromboplastin time after reteplase or half-dose reteplase plus abciximab: results from the GUSTO-V trial

Aims To evaluate the relationship between activated partial thromboplastin time (aPTT) and clinical outcomes in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO-V) trial comparing standard-dose reteplase to half-dose reteplase and abciximab. Methods and results We analysed data on 11 420 patients receiving unfractionated heparin. Peak aPTT levels recorded during the hospitalization were correlated with clinical outcomes. Multivariable logistic regression models examined the relationship between peak aPTT levels and (i) moderate-to-severe bleeding, (ii) intracerebral haemorrhage, (iii) reinfarction, and (iv) 30-day mortality. Non-linear relationships were explored in the models using cubic spline functions. Higher rates of significant complications were seen in both groups when aPTT levels were 70 s. In the combination therapy group, the relationship between aPTT levels and bleeding appeared accentuated. Reinfarction rates increased gradually as aPTT levels were >70 s in both groups, but the relationships were not statistically significant. Peak aPTT levels <50 s were associated with increased 30-day mortality even after multivariable adjustment. Conclusion Peak aPTT levels 70 s are associated with worse clinical outcomes in the modern era of fibrinolytic therapy; these relationships are different in patients receiving standard reteplase vs. combination therapy.