Bleeding events and maintenance dose of prasugrel: BLESS pilot study

Area of Science:

• Cardiology
• Pharmacology
• Clinical Trials

Background:

• Residual platelet reactivity (RPR) may fluctuate post-acute coronary syndrome (ACS).
• Prasugrel's optimal RPR level and its impact on clinical events require investigation.

Purpose of the Study:

• To assess changes in RPR over time with 5mg vs 10mg prasugrel maintenance doses (MD) after ACS.
• To evaluate the rates of bleeding and ischemic events for different prasugrel MD regimens.

Main Methods:

• Patients received a 60mg prasugrel loading dose, followed by 10mg/day for 1 month.
• Randomization to 10mg/day (Group A) or 5mg/day (Group B) MD for up to 1 year.
• RPR assessed at baseline, 37 days, and 180 days; primary endpoint was Bleeding Academic Research Consortium (BARC) bleeding events ≥2.

Main Results:

• RPR significantly increased from baseline to 37 days in both groups, with a higher increase in the 5mg group (Group B).
• At 180 days, Group A (10mg) had a lower rate of high RPR compared to Group B (5mg).
• BARC ≥2 bleeding events occurred in 12.6% of Group A vs 4.1% of Group B; secondary endpoints showed no significant difference.

Conclusions:

• Reducing prasugrel MD to 5mg one month post-ACS increases RPR.
• The 10mg MD regimen was associated with a lower bleeding risk.
• Larger clinical trials are necessary to validate the clinical significance of these pharmacodynamic findings.