ASSESSMENT OF SAFETY AND EFFICACY OF CONVENTIONAL HEPARIN DOSE IN PERCUTANEOUS CORONARY INTERVENTIONS CHARACTERIZED BY MEANS OF ACTIVATED CLOTTING TIME

BackgroundPercutaneous coronary intervention (PCI) is an invasive procedure which traumatizes the coronary vessel wall and serves as a potent stimulus for thrombus formation. Unfractionated heparin is used routinely during the procedures to reduce the likelihood of acute thrombotic complications. Activated clotting time (ACT) is the preferred assay to determine the degree of anticoagulation during PCI. Our aim was to assess ACT values during PCI after administering heparin with conventional dose (10000 u) and determining ischemic and bleeding complications. MethodsCoronary artery disease (CAD) patients (N=205) receiving conventional heparin dose and undergoing PCI were included in this study. ACT was assessed 10 minutes after heparin injection. Demographic data and cardiovascular risk factors were registered in the forms and the patients were followed up for about one month or complications. ResultsACT range 10 minutes after heparin injection was 160 – 682 sec (mean 353 sec, SD: 94.5 sec). ACT was lower than 250 in 12.7% of patients (95% CI: 8.2%-17.2%). ACT had a range of 250-350 seconds in 37% of patients. Overall, 21 patients (10.3%) had ischemic complications (including chest pain, new ischemic changes in EKG, unstable angina and 2 deaths) and 3 patients (1.5%) had bleeding complications. Ischemic complications were significantly higher in smokers (16%) versus nonsmokers (6%, P=0.038) and in patients with ≥2 risk factors (12%) versus those with ≤1 risk factor (4%, P=0.046). All three patients with bleeding complications were hypertensive (P=0.02). ConclusionAlthough this study shows relative safety of conventional heparin dose in PCI, but only about one third of our patients reached desired ACT values (250-350 sec). So it seems appropriate to use weight adjusted heparin doses (e.g. 100u/kg) instead of conventional dose and to assess ACT in all patients and use additional heparin doses to maintain ACT at optimal levels (Iranian Heart Journal 2008; 9 (1): 18-21).