Figure 2. A, Adjusted hazard ratio and 95% confidence intervals for each baseline clinical variable between patients with and without atrial fibrillation recurrence during follow-up. CI: confidence interval; HR: hazard ratio; LAD: left atrial diameter; BMI: body mass index; CHD: coronary heart disease; NT-proBNP: N-terminal pro brain natriuretic peptide; LVEDD: left ventricular end-diastolic diameter; LVESD: left ventricular end-systolic diameter; LVEF: left ventricular ejection fraction. B, Instruction for using the nomogram. Draw a line perpendicular from the corresponding axis of each risk factor until it reaches the top line labeled "Points." Sum up the number of points for all risk factors then draw a line descending from the axis labeled "Total Points" until it intercepts each of the survival axes to determine 3- and 12-month relapse-free survival rates. Continuous variables such as LAD and major diameter of right inferior pulmonary vein were converted to categorical variables (LADc and RIPV1c), 0 for no and 1 for yes.