CRH and atrial fibrillation: Similar proportions of CRH users and nonusers (CRH users: 205/804, 25.5% and CRH nonusers: 5393/19,583, 27.5%) had none of these diagnoses, that is, had a primary diagnosis other than atrial fibrillation or flutter, heart failure, valvular heart disease, or ischemic heart disease.