title: Primary Prevention of Myocardial Infarction in Rheumatoid Arthritis Using Aspirin: A Case-crossover Study and a Propensity Score-matched Cohort Study.
abstract: Subjects with rheumatoid arthritis (RA) are at higher risk of developing cardiovascular disease, which is their leading cause of death. Conflicting evidence exists regarding the efficacy of aspirin (ASA) as primary prevention. We evaluated whether a protective association exists between ASA and myocardial infarction (MI) in RA subjects.
  
  
  
  In the United Kingdom, persons age ≥ 60 years receive free ASA by prescription and 75% of use is by prescription. Subjects ≥ 60 years with RA in the population-based The Health Improvement Network database constituted our study population. We excluded patients with history of MI, angina, stroke, peripheral vascular disease, or coronary artery procedures. Our main outcome was the occurrence of fatal and nonfatal MI. We performed a case-crossover study with each subject contributing a hazard period and a control period 90 days prior to the MI. In addition, to minimize confounding by indication, a propensity score (PS)-matched cohort study was performed, considering all patients with RA with an incident prescription of low-dose ASA as our exposed group.
  
  
  
  We did not find a protective effect in the case-crossover study (OR 1.83, 95% CI 0.71-4.71), with 55 subjects exposed in the hazard period and 44 in the control period. Similarly, among 1836 subjects included in the PS-matched cohort study (918 ASA users and 918 ASA non-users), we did not find a protective effect of low ASA on MI (HR 1.39, 95% CI 0.87-2.23).
  
  
  
  We did not find a protective effect of ASA on MI in patients with RA when used as primary prophylaxis.
authors.affiliation: From the Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, Santiago, Chile; Clinical Epidemiology Unit, Boston University School of Medicine, Boston, Massachusetts, USA; Arthritis Research UK Epidemiology Unit, University of Manchester; Manchester UK National Institute for Health Research Biomedical Research Unit, Manchester, UK. jgduran@uc.cl.|J. Durán, MD, MSc, Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, and Clinical Epidemiology Unit, Boston University School of Medicine; C. Peloquin, MPH, Clinical Epidemiology Unit, Boston University School of Medicine; Y. Zhang, DSc, Clinical Epidemiology Unit, Boston University School of Medicine; D.T. Felson, MD, MPH, Clinical Epidemiology Unit, Boston University School of Medicine, and Arthritis Research UK Epidemiology Unit, University of Manchester, and Manchester UK National Institute for Health Research Biomedical Research Unit. jgduran@uc.cl.
authors.forename: Josefina
authors.initials: J
authors.lastname: Durán
authors.affiliation: From the Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, Santiago, Chile; Clinical Epidemiology Unit, Boston University School of Medicine, Boston, Massachusetts, USA; Arthritis Research UK Epidemiology Unit, University of Manchester; Manchester UK National Institute for Health Research Biomedical Research Unit, Manchester, UK.|J. Durán, MD, MSc, Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, and Clinical Epidemiology Unit, Boston University School of Medicine; C. Peloquin, MPH, Clinical Epidemiology Unit, Boston University School of Medicine; Y. Zhang, DSc, Clinical Epidemiology Unit, Boston University School of Medicine; D.T. Felson, MD, MPH, Clinical Epidemiology Unit, Boston University School of Medicine, and Arthritis Research UK Epidemiology Unit, University of Manchester, and Manchester UK National Institute for Health Research Biomedical Research Unit.
authors.forename: Christine
authors.initials: C
authors.lastname: Peloquin
authors.affiliation: From the Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, Santiago, Chile; Clinical Epidemiology Unit, Boston University School of Medicine, Boston, Massachusetts, USA; Arthritis Research UK Epidemiology Unit, University of Manchester; Manchester UK National Institute for Health Research Biomedical Research Unit, Manchester, UK.|J. Durán, MD, MSc, Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, and Clinical Epidemiology Unit, Boston University School of Medicine; C. Peloquin, MPH, Clinical Epidemiology Unit, Boston University School of Medicine; Y. Zhang, DSc, Clinical Epidemiology Unit, Boston University School of Medicine; D.T. Felson, MD, MPH, Clinical Epidemiology Unit, Boston University School of Medicine, and Arthritis Research UK Epidemiology Unit, University of Manchester, and Manchester UK National Institute for Health Research Biomedical Research Unit.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: From the Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, Santiago, Chile; Clinical Epidemiology Unit, Boston University School of Medicine, Boston, Massachusetts, USA; Arthritis Research UK Epidemiology Unit, University of Manchester; Manchester UK National Institute for Health Research Biomedical Research Unit, Manchester, UK.|J. Durán, MD, MSc, Rheumatology Department, Pontificia Universidad Católica de Chile School of Medicine, and Clinical Epidemiology Unit, Boston University School of Medicine; C. Peloquin, MPH, Clinical Epidemiology Unit, Boston University School of Medicine; Y. Zhang, DSc, Clinical Epidemiology Unit, Boston University School of Medicine; D.T. Felson, MD, MPH, Clinical Epidemiology Unit, Boston University School of Medicine, and Arthritis Research UK Epidemiology Unit, University of Manchester, and Manchester UK National Institute for Health Research Biomedical Research Unit.
authors.forename: David T
authors.initials: DT
authors.lastname: Felson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000150:complications*; D001241:Aspirin / Q000627:therapeutic use*; D018592:Cross-Over Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000517:prevention & control*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011322:Primary Prevention; D016896:Treatment Outcome; D006113:United Kingdom
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin
keywords: ASPIRIN; CARDIOVASCULAR DISEASE; MYOCARDIAL INFARCTION; PRIMARY PREVENTION; PROPHYLAXIS; RHEUMATOID ARTHRITIS