title: Association of dual-antiplatelet therapy with reduced major adverse cardiovascular events in patients with symptomatic peripheral arterial disease.
abstract: OBJECTIVE
  This study was conducted to determine whether there is additive benefit of dual-antiplatelet therapy (DAPT) with aspirin (acetylsalicylic acid [ASA]) and clopidogrel compared with ASA monotherapy among patients with symptomatic peripheral arterial disease.
  
  
  METHODS
  This was an observational cohort analysis that included 629 patients with claudication or critical limb ischemia. The prevalence of patients taking ASA monotherapy vs DAPT was assessed monthly for up to 3 years. A propensity model was constructed to adjust for baseline demographic characteristics and to assess the effect of DAPT on major adverse cardiovascular events (MACEs) and major adverse limb events.
  
  
  RESULTS
  At baseline, 348 patients were taking DAPT and 281 were taking ASA monotherapy. During 3 years of follow-up, 50 events (20%) occurred in the DAPT group vs 59 (29%) in the ASA monotherapy group. After propensity weighting, DAPT use was associated with a decreased risk of MACEs (adjusted hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.44-0.96) and overall mortality (adjusted HR, 0.55; 95% CI, 0.35-0.89). No association was found between DAPT use and the risk of major amputation (adjusted HR, 0.69; 95% CI, 0.37-1.29). In a subgroup of 94 patients who underwent point-of-care platelet function testing, 21% had decreased response to ASA and 55% had a decreased response to clopidogrel. No association was found between a reduced response to ASA or clopidogrel and adverse events at 1 year.
  
  
  CONCLUSIONS
  DAPT may be associated with reduced rates of MACEs and death among patients with symptomatic peripheral arterial disease.
authors: Division of Cardiology, University of Colorado, and Veterans Affairs Eastern Colorado Health Care System, Denver, Colo.
authors: Ehrin J
authors: EJ
authors: Armstrong
authors: Vascular Center and Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Sacramento, Calif.
authors: David R
authors: DR
authors: Anderson
authors: Vascular Center and Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Sacramento, Calif.
authors: Khung-Keong
authors: KK
authors: Yeo
authors: Vascular Center and Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Sacramento, Calif.
authors: Gagan D
authors: GD
authors: Singh
authors: Division of Biostatistics, Department of Public Health Sciences, University of California, Davis, Sacramento, Calif.
authors: Heejung
authors: H
authors: Bang
authors: Vascular Center and Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Sacramento, Calif.
authors: Ezra A
authors: EA
authors: Amsterdam
authors: Department of Surgery, University of California, Davis, Sacramento, Calif.
authors: Julie A
authors: JA
authors: Freischlag
authors: Vascular Center and Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Sacramento, Calif. Electronic address: john.laird@ucdmc.ucdavis.edu.
authors: John R
authors: JR
authors: Laird
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical; D001241:Aspirin / Q000627:therapeutic use*; D002140:California; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D016009:Chi-Square Distribution; D000077144:Clopidogrel; D016638:Critical Illness; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D007511:Ischemia / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010979:Platelet Function Tests; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D057216:Propensity Score; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin