Korean J Intern Med.  2021 Mar;36(Suppl 1):S80-S89. 10.3904/kjim.2020.085.

Clinical significance of high on-treatment platelet reactivity in patients with prolonged clopidogrel therapy

• Kim S
• Han D
• Choi JH
• Park EJ
• Shin DG
• Kang MK
• Choi S
• Lee N
• Cho JR

• KMID: 2513816
• DOI: http://doi.org/10.3904/kjim.2020.085

Abstract

Background/Aims
Prolonged dual antiplatelet therapy (DAPT) with aspirin and clopidogrel beyond 1 year has been shown to reduce ischemic events at the expense of increased bleeding. However, limited data are available on the clinical significance of platelet reactivity (PR) at 1 year.
Methods
We retrospectively identified 331 patients who underwent percutaneous coronary intervention (PCI) and assessed the on-clopidogrel PR using VerifyNow P2Y12 assay at 1 year in a single center. Two hundred eleven patients were on DAPT for > 1 year. The relationship between high on-treatment platelet reactivity (HPR) at 1 year and clinical outcomes beyond 1 year, as well as the longitudinal change in PR was analyzed.
Results
At 1 year, 135 (64%) patients showed HPR and 76 (36%) did not. There was a significant increase in ischemic endpoint events, including cardiovascular death, non-fatal myocardial infarction, and stroke/transient ischemic attack in patients with compared to without HPR at 1 year (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.06 to 6.77; p = 0.036). However, the incidence of any Bleeding Academic Research Consortium bleeding was significantly lower in the HPR group (HR, 0.11; 95% CI, 0.02 to 0.65; p = 0.015). In the longitudinal analysis, PR significantly decreased from post-load to 1 year after index PCI in the non-HPR group. Conversely, the HPR group showed high PR from baseline through 1 year.
Conclusions
HPR at 1 year may be a useful surrogate for predicting ischemic and bleeding events in patients on prolonged DAPT. Patients with and without HPR at 1 year showed different patterns of longitudinal change in PR.

Keyword

Dual anti-platelet therapy; Percutaneous coronary intervention; Platelet function tests; Retrospective study