NPPB and Arrhythmia: Of the blood biomarkers, higher NT-proBNP levels showed the strongest association with both the composite endpoint of death or arrhythmia (hazard ratio [HR], 1.94; 95% confidence interval [CI], 1.26-3.00) and death or intervention (HR, 2.06, 95% CI, 1.33-3.20).