Abstract 4337: Early Activated Partial Thromboplastin Time (APTT) is a Predictor of 30-day and One-year Mortality in ST-elevation Myocardial Infarction (STEMI) Patients Treated With Percutaneous Coronary Intervention (PCI) and Unfractionated Heparin (UFH)
Background Little is known about the influence on mortality of early anticoagulation levels in ST-elevation myocardial infarction (STEMI) patients treated with unfractionated heparin (UFH) after primary percutaneous coronary intervention (PCI). In addition, there is lack of evidence supporting the current recommended activated partial thrombo-plastin time (APTT) range (between 50 and 70 seconds).
Methods We examined the relationship between APTT values immediately after primary PCI and 30-day and one year mortality in 1459 STEMI patients treated with UFH between 2003 and 2008. We stratified APTT values into four groups: <50 s, 50 –70 s, 70 –150 s and >150 s. Hazard ratios were calculated using Cox regression analysis and adjusted for age, sex, smoking habits, history of prior myocardial infarction, hypertension, hypercholesteromia, and diabetes.
Results The median APTT was 92 s (IQR 58 –172 s). Only 18 % (256/1459) of early APTT values were within the recommended range. Table 1⇓ depicts 30-day mortality rates, 1-year mortality rates and hazard ratios for the four stratified APTT groups. APTT values below 50 s and above 150 s were associated with an increase in 1-year mortality (HR 2,23 and 2,27).
Conclusion The First APTT value after primary PCI for STEMI patients is an independent predictor of 30 day and one-year mortality. APTT values below 50 s were associated with an increase in mortality, possibly due to an increase in ischemic/thrombotic events. APTT values above 150 s were also associated with an increase in mortality, possibly due to an increase in hemorrhagic events. APTT values between 70 and 150 s were not associated with an increase in mortality justifying further research to establish the optimal APTT range for STEMI patients treated with PCI and UFH.