Reviwer  : Dr. Dursun AKASLAN

Name of Study : The TALOS-AMI trial (TicAgrelor Versus CLOpidogrel in Stabilized Patients With Acute Myocardial Infarction)

Presented in Congress : ACC21

Full text linki : https://eurointervention.pcronline.com/article/a-prospective-multicenter-randomized-open-label-trial-to-compare-efficacy-andsafety-of-clopidogrel-vs-ticagrelor-in-stabilized-patients-with-acute-myocardialinfarction-after-percutaneous-coronary-interventionrationale-and-design-of-the-talos-ami-trial

Background :
It has been shown in PLATO and TRITON-TIMI-38 studies that the use of more potent P2Y12 inhibitors such as ticagrelor and prasugrel instead of clopidogrel treatment for 1 year in patients with acute coronary syndrome undergoing percutaneous coronary intervention significantly reduces the frequency of ischemic events. While the risk of ischemic events is significantly higher in the first month, the risk of bleeding is known to be higher in the long term. Therefore, the effect of using a lower potency P2Y12 after the first month has not been fully investigated. The TOPIC (Timing of Optimal Platelet Inhibition After Acute Coronary Syndrome) study is the only randomized study to test this hypothesis. However, the study has limitations such as limited sample size, single center, self-report for bleeding, and discontinuation of treatment.

Objective :
The aim of the TALOS-MI trial was to evaluate whether reduction of dual antiplatelet therapy (DAPT) with clopidogrel instead of ticagrelor 1 month after percutaneous coronary intervention for acute myocardial infarction would be a non-inferior strategy.

Methods :
In this multicenter, open-label, randomized prospective study, they were divided into two groups as aspirin+clopidogrel and aspirin+ticagrelor after taking aspirin+ticagrelor for the first month after successful percutaneous intervention. The primary endpoint was cardiovascular death, MI, stroke, and bleeding type 2, 3, or 5 according to Academic Research Consortium (BARC) criteria for cardiovascular death, 1 to 12 months after index PCI. The study included 2697 patients living in East Asia. 80% of the patients were male and the mean age was 60 years. At the end of one-year follow-up, 104 (8.2%) patients in the ticagrelor group had a primary outcome, while 59 patients (4.6%) in the clopidogrel group had a primary outcome (HR 0.55, 95%CI 0.40-0.76, Absolute difference-3.6%, p for non-inferiority <0.001, p<0.001 for superiority). 3% of patients in the clopidogrel group experienced bleeding requiring medical attention, compared with 5.6% in the ticagrelor group. Ischemia rates were similar in the two groups.

Conclusion :
This study show that in patients undergoing PCI for MI and who successfully completed 1 month of DAPT with aspirin and ticagrelor, switching to aspirin + clopidogrel for the next 11 months met the criteria for non-inferiority and superiority compared to continuing with aspirin + ticagrelor.

Interpretation :
It is thought that the main factor in meeting the criteria of non-inferiority and superiority is the reduction in major bleeding. In addition, the absence of a significant difference in ischemic events suggests that there is no harm in the use of lower potent clopidogrel. However, patients who were switched to clopidogrel were switched without genotype testing or reloading. It is uncertain whether the study was conducted only on the South Asian population and whether it would give the same result in other ethnicities.