Atrial fibrillation after coronary artery bypass surgery - A model for preoperative risk stratification

Background-Atrial fibrillation (AF) occurs in 20% to 40% of patients after CABG. Identification of patients vulnerable for arrhythmia will allow targe ting of those most likely to benefit from prophylactic therapy. The aim of the present study was to evaluate accuracy of a prospectively defined signa l-averaged P-wave duration (SAPD) cutoff and additional preoperative charac teristics for the prediction of AF after CABG. Methods and Results-Patients undergoing elective isolated CABG were recruit ed to the present prospective study. SAPD was recorded in all patients. Fil tered signals from 3 orthogonal leads were combined in a vector analysis, a nd total SAPD was measured preoperatively, Postoperative in-hospital AF occ urred in 92 (28.2%) of 326 patients. Patients who developed AF were older ( 65.9 versus 61.7 years of age; P<0.0005) and had longer SAPD (158 versus 14 5 ms; P<0.0005) than non-AF patients. Incidence of AF increased in patients greater than or equal to 75 years of age and increased progressively throu ghout the range of SAPD, Stepwise logistic regression analysis of preoperat ive variables identified that SAPD >155 ms (odds ratio, 5.37; 95% CI, 3.10 to 9.30; P<0.0005), advanced age (odds ratio, 1.53; 95% CI, 1.26 to 1.86 pe r 5-year increase in age; P<0.0005), and male sex (odds ratio, 2.88; 95% CI , 1.30 to 6.40; P<0.01) independently predicted AF. Prospectively defined S APD >155 ms predicted AF with positive and negative predictive accuracy of 49% and 84%, respectively. Conclusions-A combination of prolonged SAPD,;advanced age, and male sex ide ntifies patients at high risk for development of AF after CABG.