Elderly patients are hyperresponsive to potent P2Y12 inhibitors

Area of Science:

• Cardiology
• Gerontology
• Pharmacology

Background:

• Aging is linked to altered platelet activation, with increased response to ADP but decreased response to thrombin.
• Previous studies noted these changes in individuals not on antiplatelet therapy.

Purpose of the Study:

• To evaluate platelet aggregation in elderly patients (≥70 years) receiving dual antiplatelet therapy with potent P2Y12 inhibitors.
• To compare responses to various agonists between elderly and younger patients.

Main Methods:

• Platelet aggregation was measured using multiple electrode aggregometry in 156 patients post-percutaneous coronary intervention.
• Agonists included arachidonic acid (AA), ADP, collagen, SFLLRN (PAR-1), and AYPGKF (PAR-4).
• Patients received either prasugrel (n=79) or ticagrelor (n=77).

Main Results:

• Overall, elderly patients (n=33) exhibited lower aggregation to AA, ADP, and SFLLRN compared to younger patients.
• Elderly patients on prasugrel (n=13) showed reduced aggregation to all tested agonists versus younger counterparts.
• Elderly patients on ticagrelor (n=20) had only reduced ADP-induced aggregation; responses to other agonists were similar.
• Prasugrel users aged ≥70 had lower aggregation to AA, collagen, and AYPGKF than ticagrelor users in the same age group.

Conclusions:

• Elderly patients on potent P2Y12 inhibitors demonstrate enhanced inhibition of ADP-induced platelet aggregation.
• Prasugrel use in elderly patients is associated with a diminished response to arachidonic acid, collagen, SFLLRN, and AYPGKF compared to younger patients.