Is It Possible to Safely Administer Early a Loading Dose of Clopidogrel Before Coronary Angiography to Patients Who Are Candidates for Percutaneous Coronary Intervention?

Current American College of Cardiology/American Heart Association guidelines reeommend loading clopidogrel 6 hours before percutaneous coronary intervention. Other American College of Cardiology guidelines advise withholding clopidogrel for 5 days before coronary artery bypass grafting (CABG) to avoid excessive bleeding. Previously published rules for predicting early CABG after coronary angiography (CA) were developed in selected patients with non-ST-segment elevation-acute coronary syndrome and not tested in community practice settings. Using logistic regression analysis we sought to develop an accurate decision rule to identify patients at higher risk for early CABG, in unselected community hospital patients undergoing diagnostic CA, who were candidates for percutaneous coronary intervention. The study was conducted at a community hospital in Ann Arbor, Michigan. A total of 986 randomly selected records from 2004 were reviewed. Sixty-two percent were men and mean age was 64 years. Twelve percent underwent CABG within 5 days of CA. Of those with previous CABG, only 2% underwent early CABG. From several potential predictor variables examined, age, male gender, previous CABG, history of typical angina pectoris, previous CA, and hypertension were identified through multivariate logistic regression and incorporated in a simple risk score. Sensitivity and specificity of a risk score >12 were 66% (95% confidence interval 56 to 74) and 66% (95% confidence interval 62 to 69), respectively, with an area under the receiver operating characteristics curve of 0.72. In conclusion, early CABG in those undergoing CA can be predicted with only modest accuracy from preprocedure clinical variables. (C) 2009 Elsevier Inc. All rights reserved. (Am J Cardiol 2009;104:1505-1510)