title: Dosage of statin, cardiovascular comorbidities, and risk of atrial fibrillation: a nationwide population-based cohort study.
abstract: BACKGROUND
  Statin has potential protective effects against atrial fibrillation. Clinically, there is a need to predict the atrial fibrillation protective effects in statin-treated patients. The purpose of this study was to investigate if cardiovascular co-morbidities or cumulative defined daily doses (cDDDs) of statin use could predict statin efficacy in atrial fibrillation prevention.
  
  
  METHODS
  Patients aged ≥ 50 years were identified from the Taiwan National Health Insurance Research Database. Medical records of 171,885 patients were used in this study, and 40,001 (23.3%) of the patients received statin therapy (≥ 28 cDDDs). Risk of new-onset atrial fibrillation in statin users and non-users (<28 cDDDs) was estimated.
  
  
  RESULTS
  During the 9-year follow-up period, 6049 patients experienced new-onset atrial fibrillation. Overall, statin therapy reduced the risk of atrial fibrillation by 28% (adjusted hazard ratio [HR] 0.72; 95% CI 0.68 to 0.77). There was a dose-response relationship between statin use and the risk of atrial fibrillation. The adjusted HRs for atrial fibrillation were 1.04, 0.85, and 0.50 when cDDDs ranged from 28 to 90, 91 to 365, and more than 365, respectively. Subgroup analysis showed that statin use was more beneficial in patients with higher CHADS2 and CHA2DS2VASc scores than those with a score of 0 (P value for interaction<0.001). The therapy provided no obvious beneficial effect in those with a CHADS2 score of 0, a CHA2DS2VASc score of 0, or cDDDs less than 91.
  
  
  CONCLUSIONS
  Statin therapy reduces the risk of new-onset atrial fibrillation in a dose-dependent manner, and is beneficial in patients with cardiovascular co-morbidities.
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Chen-Ying
authors.initials: CY
authors.lastname: Hung
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Lin
authors.forename: Kuo-Yang
authors.initials: KY
authors.lastname: Wang
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Huang
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Hsieh
authors.forename: El-Wui
authors.initials: el-W
authors.lastname: Loh
authors.forename: Tsuo-Hung
authors.initials: TH
authors.lastname: Lan
authors.forename: Pesus
authors.initials: P
authors.lastname: Chou
authors.forename: Chih-Tai
authors.initials: CT
authors.lastname: Ting
authors.forename: Tsu-Juey
authors.initials: TJ
authors.lastname: Wu
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000453:epidemiology*; D002318:Cardiovascular Diseases / Q000188:drug therapy / Q000453:epidemiology; D015331:Cohort Studies; D016208:Databases, Factual; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors