title: Residual platelet reactivity and outcomes with 5 mg prasugrel therapy in elderly patients undergoing percutaneous coronary intervention.
abstract: BACKGROUND
  In acute coronary syndrome (ACS) patients older than 75 years old, prasugrel 10 mg maintenance therapy has shown less clinical efficacy and higher risk of bleeding. In patients older than 75 years, a prasugrel dose of 5 mg should be used if treatment is deemed necessary.
  
  
  OBJECTIVE
  The aim of this study was to compare platelet reactivity and outcomes in elderly patients receiving prasugrel 5mg therapy with non-elderly patients receiving prasugrel 10 mg therapy.
  
  
  RESULTS
  Consecutive ACS patients undergoing percutaneous coronary intervention (PCI) treated with prasugrel were included. Of 718 patients, 228 (32%) had ≥75 years and received prasugrel 5 mg/day. Residual platelet reactivity (RPR) was 47±18% and 36±16% in the elderly and non-elderly group, respectively (p=0.001). High RPR (≥70%) was found in 9% and 2% (p=0.0001) in elderly and non-elderly patients, respectively. In the 6-month follow-up, there was no difference in mortality, stent thrombosis, and reinfarction rates between the 2 groups but a higher rate of TIMI minor bleeding (7.9% vs 2.4%; p=0.001) in elderly as compared with younger patients. Age≥75 years was independently associated with bleeding events (HR 2.162 [1.105-4.229]; p=0.024).
  
  
  CONCLUSIONS
  Elderly patients receiving prasugrel 5mg are more likely to experience high RPR than younger patients treated by prasugrel 10 mg. Despite the use of a reduced prasugrel maintenance dose and a higher level of RPR, elderly patients show increased risk of bleeding during prasugrel therapy as compared to younger patients.
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy; Post-graduate School in Cardiology, University of Florence, Italy. Electronic address: parodiguido@gmail.com.
authors.forename: Guido
authors.initials: G
authors.lastname: Parodi
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Bellandi
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Comito
authors.affiliation: Cardiovascular Department, Ferrarotto Hospital, University of Catania, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Capodanno
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy.
authors.forename: Renato
authors.initials: R
authors.lastname: Valenti
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy; Post-graduate School in Cardiology, University of Florence, Italy; Department of Clinical and Experimental Medicine, University of Florence, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Marcucci
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy.
authors.forename: Nazario
authors.initials: N
authors.lastname: Carrabba
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Migliorini
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy; Post-graduate School in Cardiology, University of Florence, Italy; Department of Clinical and Experimental Medicine, University of Florence, Italy; Don Carlo Gnocchi Foundation, Centro S. Maria agli Ulivi, Onlus IRCCS, Florence, Italy.
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Gensini
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy; Post-graduate School in Cardiology, University of Florence, Italy; Department of Clinical and Experimental Medicine, University of Florence, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Abbate
authors.affiliation: Department of Heart and Vessels, Careggi Hospital, Florence, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Antoniucci
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000188:drug therapy* / Q000601:surgery; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000639:trends*; D010879:Piperazines / Q000494:pharmacology / Q000627:therapeutic use*; D015539:Platelet Activation / Q000187:drug effects* / Q000502:physiology; D000068799:Prasugrel Hydrochloride; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D013876:Thiophenes / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D010879:Piperazines; D058921:Purinergic P2Y Receptor Antagonists; D013876:Thiophenes; D000068799:Prasugrel Hydrochloride
keywords: Acute coronary syndrome; Bleeding; Elderly; Prasugrel; Stent