The following subgroups have been specified through consensus with clinical members of the review team: age, gender, type of HF, severity of HF, baseline BNP levels, New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF), blood pressure (BP), body mass index (BMI), atrial fibrillation (AF), diabetes, cardiomyopathy, and risk score for mortality. The gene discussed is NPPB; the disease is atrial fibrillation.