title: Frequency of the use of low- versus high-dose aspirin in dual antiplatelet therapy after percutaneous coronary intervention (from the Dual Antiplatelet Therapy study).
abstract: In randomized trials, low-dose (LD) and high-dose (HD) aspirin (ASA) are equally effective in reducing ischemic complications, but HD ASA is associated with an increased risk of bleeding in the setting of dual antiplatelet therapy after percutaneous coronary intervention (PCI). ASA dose after PCI varies across countries, but little is known about variation within the United States (US) and whether this variation can be explained by clinical characteristics of patients. We used enrollment data from the Dual Antiplatelet Therapy Study, a randomized trial designed to compare 12 versus 30 months of dual antiplatelet therapy after PCI, to quantify the variation in ASA dosing after PCI in the US subjects and assess the extent to which dose variability was attributable to patient characteristics. Of the 23,336 patients enrolled in the US, 28.0% were prescribed LD ASA at discharge after PCI. Patient characteristics explained 1.6% of total variance in ASA dose, whereas the study site accounted for 45.9% of the unexplained variability. The median odds ratio comparing sites was 5.05 (95% confidence interval 4.29 to 5.85), which was greater than any individual predictor of ASA dose. In conclusion, LD ASA after PCI in the US was used in a minority of patients, and heterogeneity in its selection was mainly influenced by the site of enrollment rather than patient characteristics. As HD ASA may be associated with adverse events in the setting of dual antiplatelet therapy, reducing local practice variation in the dose of ASA may be a target for quality improvement.
authors: Brigham and Women's Hospital, Boston, Massachusetts.
authors: Alexis
authors: A
authors: Matteau
authors: Massachusetts General Hospital, Boston, Massachusetts; Harvard Clinical Research Institute, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts.
authors: Robert W
authors: RW
authors: Yeh
authors: The Christ Hospital Heart and Vascular Center and The Lindner Center for Research and Education, Cincinnati, Ohio.
authors: Dean
authors: D
authors: Kereiakes
authors: Brigham and Women's Hospital, Boston, Massachusetts.
authors: E John
authors: EJ
authors: Orav
authors: Harvard Clinical Research Institute, Boston, Massachusetts; Boston University, Boston, Massachusetts.
authors: Joseph
authors: J
authors: Massaro
authors: Hopital Bichat, Paris, France; Université Paris Diderot, Paris, France.
authors: P Gabriel
authors: PG
authors: Steg
authors: Harvard Medical School, Boston, Massachusetts; Harvard School of Public Health, Boston, Massachusetts.
authors: Sharon-Lise
authors: SL
authors: Normand
authors: Harvard Clinical Research Institute, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts; Beth Israel Deaconess Medical Center, Boston, Massachusetts.
authors: Donald E
authors: DE
authors: Cutlip
authors: Brigham and Women's Hospital, Boston, Massachusetts; Harvard Clinical Research Institute, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts. Electronic address: lmauri1@partners.org.
authors: Laura
authors: L
authors: Mauri
mesh_terms: D001241:Aspirin / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000628:therapy*; D062645:Percutaneous Coronary Intervention; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D011184:Postoperative Period; D011725:Pyridines / Q000008:administration & dosage*; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D011725:Pyridines; C446540:thienopyridine; D001241:Aspirin