Prasugrel Linked to Fewer Total MI Events in Patients With Acute Coronary Syndrome

In patients with acute coronary syndrome (ACS) who are receiving an invasive assessment, use of a prasugrel-based strategy is associated with a reduction in total myocardial infarction (MI) events, compared with a ticagrelor-based strategy, according to the results of a post hoc analysis published in the European Heart Journal – Cardiovascular Pharmacotherapy.

The investigators sought to examine the treatment effect of a prasugrel- vs a ticagrelor-based strategy in patients with ACS receiving an invasive management procedure when both initial and recurrent nonfatal ischemic and bleeding events are taken into account. Although prasugrel has been shown to be superior to ticagrelor in time-to-first event analysis in patients presenting with ACS who are scheduled for invasive evaluation, the effect of a prasugrel-based approach compared with a ticagrelor-based approach on total ischemic and bleeding events has not been evaluated in this population.

In the post hoc analysis of the randomized, controlled ISAR-REACT-5 (Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment; ClinicalTrials.gov identifier: NCT01944800) trial, the primary endpoints were ischemic events (MI and stroke) and bleeding events (Bleeding Academic Research Consortium [BARC] type 3 to 5 bleeding). Definite or probable stent thrombosis was an additional endpoint. The researchers examined the effect of the prasugrel-based and ticagrelor-based strategies on these endpoints in both time-to-first event and total event analyses. A total of 4018 patients were included. Of these individuals, 2006 were assigned to the prasugrel group and 2012 to the ticagrelor group.

Results of study showed that 169 participants experienced a single nonfatal ischemic event, 23 participants experienced multiple nonfatal ischemic events, and 3826 participants experienced no ischemic events. The multiple ischemic events comprised 16 recurrent MI events, 2 recurrent stroke events, and 5 were a combination of first MI and first stroke events.

Further, a single BARC type 3 to 5 bleeding event was reported in 204 individuals, multiple BARC type 3 to 5 bleeding events were reported in 22 individuals, and 3792 individuals experienced no BARC type 3 to 5 bleeding events. Among the 22 patients who reported multiple BARC type 3 to 5 bleeding events, 7 patients experienced a second occurrence and 2 patients experienced a third occurrence. A combination of ischemic and bleeding events (≥1 ischemic event and ≥1 bleeding event) was reported in 41 participants.

Patients in the prasugrel treatment arm had a lower risk for MI compared with those in the ticagrelor arm with respect to both time-to-first event (hazard ratio [HR], 0.61; 95% CI, 0.44-0.85) and total event (HR, 0.62; 95% CI, 0.45-0.86) analyses. The risk for BARC type 3 to 5 bleeding was similar between the prasugrel and the ticagrelor groups on both time-to-first event (HR, 0.96; 95% CI, 0.75-1.25) and total events (HR, 0.99; 95% CI, 0.76-1.31).

Limitations of the study include it being a post hoc analysis of a randomized, controlled trial, which means all results should be regarded as hypothesis-generating. Further, this post hoc analysis has the limitations of an open-label study, although with blinded adjudication of endpoints.

“Given the importance of this topic, future studies to confirm these findings would be welcome,” the study authors wrote.

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.