The EFFect of hIgh-dose ClopIdogrel treatmENT in patients with clopidogrel resistance (the EFFICIENT trial)

Int J Cardiol. 2012 Jun 14;157(3):374-80. doi: 10.1016/j.ijcard.2010.12.083. Epub 2011 Jan 15.


Objectives: The aim of this study was to evaluate the effect of high-dose clopidogrel continuation treatment on the development of MACCE after elective PCI in patients with clopidogrel resistance.

Methods: The study group consisted of 192 patients. Of these, 98 participants without resistance served as the control group (Group 1) and received 75 mg/day clopidogrel for 1 month. Ninety-four patients with resistance were randomly divided into two groups: 47 patients in the standard-dose group (Group 2) received 75 mg/day continuation therapy, whereas 47 patients in the high-dose group (Group 3) received 150 mg/day continuation therapy for 1 month. Clopidogrel resistance was evaluated with the VerifyNow P2Y12 test. Patients with a platelet inhibition value lower than 40% were classified as resistant.

Results: During the 6-month follow-up for MACCE, the event-rate in Group 2 was significantly higher than both Groups 1 and 3 (Group 1 vs Group 2; p=0.019, Group 1 vs Group 3; p=0.82, Group 2 vs Group 3; p=0.045). Total bleeding rate in all groups were similar (Group 1 vs Group 2; p=0.54, Group 1 vs Group 3; p=0.27, Group 2 vs Group 3; p=0.16). The rate of NACE was similar in all groups (Group 1 vs Group 2; p=0.08, Group 1 vs Group 3; p=0.50, Group 2 vs Group 3; p=0.39).

Conclusion: In patients who underwent elective PCI and had clopidogrel resistance, high-dose clopidogrel continuation therapy was more efficient in preventing MACCE than the standard dose. High-dose continuation therapy did not increase the risk of bleeding complication (The EFFICIENT Trial; number: NCT01032668).

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Angioplasty, Balloon, Coronary / adverse effects
  • Cardiovascular Diseases / drug therapy*
  • Cardiovascular Diseases / etiology
  • Cardiovascular Diseases / physiopathology
  • Clopidogrel
  • Drug Resistance / drug effects*
  • Drug Resistance / physiology
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Platelet Aggregation Inhibitors / administration & dosage*
  • Prospective Studies
  • Ticlopidine / administration & dosage
  • Ticlopidine / analogs & derivatives*
  • Treatment Outcome


  • Platelet Aggregation Inhibitors
  • Clopidogrel
  • Ticlopidine

Associated data