Age and CHADS(2) Score Predict the Effectiveness of Renin-Angiotensin System Blockers on Primary Prevention of Atrial Fibrillation

Renin-angiotensin system (RAS) blockers have potential protective effects against atrial fibrillation (AF). The purpose of this study was to determine if patient characteristics and underlying co-morbidities could predict the efficacy of RAS blockers in AF prevention. Patients aged ≥ 45 years with hypertension were identified from the Taiwan National Health Insurance Research Database. After propensity-score matching, a total of 22,324 patients were included in this study. Risk of new-onset AF in RAS blockers users and non-users was estimated. During up to 10 years of follow-up, 1,475 patients experienced new-onset AF. Overall, RAS blockers reduced the risk of AF by 36% (adjusted HR 0.64; 95% CI 0.58 to 0.71; p < 0.001). Subgroup analysis showed that RAS blockers use was beneficial for AF prevention in patients aged ≥ 55 years or with a CHADS(2) score of 1, 2, or 3. The therapy provided no obvious beneficial effect for AF prevention in those aged less than 55 years or with a CHADS(2) score ≥ 4. In conclusion, RAS blockers reduced the risk of new-onset AF in patients aged ≥ 55 years or with a CHADS(2) score of 1, 2, or 3, but not in patients aged less than 55 years or with a CHADS(2) score ≥ 4.