Related Experiment Video
Updated: Oct 10, 2025

Turbidimetry on Human Washed Platelets: The Effect of the Pannexin1-inhibitor Brilliant Blue FCF on Collagen-induced Aggregation
Published on: April 6, 2017
Ischemic and Bleeding Events in PENDULUM Patients With High Bleeding Risk and High Platelet Reactivity
Raisuke Iijima1, Kazushige Kadota2, Koichi Nakao3
1Division of Cardiovascular Medicine, Toho University Ohashi Medical Center.
Background:
The balance between thrombotic and bleeding risk is of great concern in high bleeding risk (HBR) patients. This study evaluated the relationship between perioperative antiplatelet reactivity and thrombotic and bleeding events in patients at HBR undergoing percutaneous coronary intervention (PCI).
Methods And Results:
In this post hoc analysis of the PENDULUM (Platelet rEactivity in patieNts with DrUg eLUting stent and balancing risk of bleeding and ischeMic event) registry, patients undergoing PCI were categorized as HBR or non-HBR, and stratified as having high platelet reactivity (HPR; P2Y12reaction unit [PRU] >208) or non-HPR (PRU ≤208). Cumulative incidences of cardiovascular and cerebrovascular events (Journal of the American College of Cardiology expert definitions) and bleeding events (Bleeding Academic Research Consortium criteria) were assessed 12 months after index PCI. The incidence of ischemic and bleeding events was ~3-fold higher in HBR vs. non-HBR patients. Thrombotic/ischemic events were significantly more common in the HPR subgroup in HBR patients (hazard ratio [HR]: 1.59; 95% confidence interval [CI]: 1.11-2.28; P=0.012), but there was no difference in non-HBR patients. After adjustment for covariates, HPR in HBR patients remained an independent factor for thrombotic and ischemic events (HR: 1.69; 95% CI: 1.13-2.54; P=0.011), but not for bleeding events (HR: 1.56; 95% CI: 0.78-3.11; P=0.210).
Conclusions:
Maintaining adequate PRU levels during PCI is an important factor in improving clinical outcomes, especially for HBR patients.
Related Concept Videos
Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
Disorders of Hemostasis
Thromboembolic Disorders
Two factors primarily cause thromboembolic conditions.
Formation of the Platelet Plug
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
Pulmonary Embolism II: Diagnostic Studies and Interprofessional Care
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Introduction to Hemostasis
The three phases of hemostasis involve many clotting factors present in plasma and several substances released by platelets and injured tissue cells. It is a fast, localized,...

