title: Cessation of dual antiplatelet treatment and cardiac events after percutaneous coronary intervention (PARIS): 2 year results from a prospective observational study.
abstract: BACKGROUND
  Dual antiplatelet therapy (DAPT) cessation increases the risk of adverse events after percutaneous coronary intervention (PCI). Whether risk changes over time, depends on the underlying reason for DAPT cessation, or both is unknown. We assessed associations between different modes of DAPT cessation and cardiovascular risk after PCI.
  
  
  METHODS
  The PARIS (patterns of non-adherence to anti-platelet regimens in stented patients) registry is a prospective observational study of patients undergoing PCI with stent implantation in 15 clinical sites in the USA and Europe between July 1, 2009, and Dec 2, 2010. Adult patients (aged 18 years or older) undergoing successful stent implantation in one or more native coronary artery and discharged on DAPT were eligible for enrolment. Patients were followed up at months 1, 6, 12, and 24 after implantation. Prespecified categories for DAPT cessation included physician-recommended discontinuation, brief interruption (for surgery), or disruption (non-compliance or because of bleeding). All adverse events and episodes of DAPT cessation were independently adjudicated. Using Cox models with time-varying covariates, we examined the effect of DAPT cessation on major adverse events (MACE [composite of cardiac death, definite or probable stent thrombosis, myocardial infarction, or target-lesion revascularisation]). Incidence rates for DAPT cessation and adverse events were calculated as Kaplan-Meier estimates of time to the first event. This study is registered with ClinicalTrials.gov, number NCT00998127.
  
  
  RESULTS
  We enrolled 5031 patients undergoing PCI, including 5018 in the final study population. Over 2 years, the overall incidence of any DAPT cessation was 57·3%. Rate of any discontinuation was 40·8%, of interruption was 10·5%, and of disruption was 14·4%. The corresponding overall 2 year MACE rate was 11·5%, most of which (74%) occurred while patients were taking DAPT. Compared with those on DAPT, the adjusted hazard ratio (HR) for MACE due to interruption was 1·41 (95% CI 0·94-2·12; p=0·10) and to disruption was 1·50 (1·14-1.97; p=0·004). Within 7 days, 8-30 days, and more than 30 days after disruption, adjusted HRs were 7·04 (3·31-14·95), 2·17 (0·97-4·88), and 1·3 (0·97-1·76), respectively. By contrast with patients who remained on DAPT, those who discontinued had lower MACE risk (0·63 [0·46-0·86]). Results were similar after excluding patients receiving bare metal stents and using an alternative MACE definition that did not include target lesion revascularisation.
  
  
  CONCLUSIONS
  In a real-world setting, for patients undergoing PCI and discharged on DAPT, cardiac events after DAPT cessation depend on the clinical circumstance and reason for cessation and attenuates over time. While most events after PCI occur in patients on DAPT, early risk for events due to disruption is substantial irrespective of stent type.
  
  
  BACKGROUND
  Bristol-Myers Squibb and Sanofi-Aventis.
authors.affiliation: Icahn School of Medicine at Mount Sinai, New York, NY, USA. Electronic address: roxana.mehran@mountsinai.org.
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.forename: Usman
authors.initials: U
authors.lastname: Baber
authors.forename: Philippe Gabriel
authors.initials: PG
authors.lastname: Steg
authors.forename: Cono
authors.initials: C
authors.lastname: Ariti
authors.forename: Giora
authors.initials: G
authors.lastname: Weisz
authors.forename: Bernhard
authors.initials: B
authors.lastname: Witzenbichler
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Henry
authors.forename: Annapoorna S
authors.initials: AS
authors.lastname: Kini
authors.forename: Thomas
authors.initials: T
authors.lastname: Stuckey
authors.forename: David J
authors.initials: DJ
authors.lastname: Cohen
authors.forename: Peter B
authors.initials: PB
authors.lastname: Berger
authors.forename: Ioannis
authors.initials: I
authors.lastname: Iakovou
authors.forename: George
authors.initials: G
authors.lastname: Dangas
authors.forename: Ron
authors.initials: R
authors.lastname: Waksman
authors.forename: David
authors.initials: D
authors.lastname: Antoniucci
authors.forename: Samantha
authors.initials: S
authors.lastname: Sartori
authors.forename: Mitchell W
authors.initials: MW
authors.lastname: Krucoff
authors.forename: James B
authors.initials: JB
authors.lastname: Hermiller
authors.forename: Fayaz
authors.initials: F
authors.lastname: Shawl
authors.forename: C Michael
authors.initials: CM
authors.lastname: Gibson
authors.forename: Alaide
authors.initials: A
authors.lastname: Chieffo
authors.forename: Maria
authors.initials: M
authors.lastname: Alu
authors.forename: David J
authors.initials: DJ
authors.lastname: Moliterno
authors.forename: Antonio
authors.initials: A
authors.lastname: Colombo
authors.forename: Stuart
authors.initials: S
authors.lastname: Pocock
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003324:Coronary Artery Disease / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000209:etiology; D054855:Drug-Eluting Stents; D006083:Graft Occlusion, Vascular / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D015425:Myocardial Reperfusion; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D010975:Platelet Aggregation Inhibitors