CRP and atrial fibrillation: After 90 variables entered LASSO regression screening, 14 variables [age, AF, MI, PCI, DM, height, peak VO2, heart rate at the 8th minute after the cardiopulmonary exercise peaked (HR8min), peak diastolic blood pressure (peak DBP), peak MBP, c-reactive protein (CRP), b-type natriuretic peptide (BNP), TnI, uric acid (UA)] were obtained (Supplementary Figures 1A,B), and eight variables were retained after univariate analysis, multivariable analysis, and stepwise regression (Table 2; Supplementary Table 2).