Benefit of switching dual antiplatelet therapy after acute coronary syndrome: the TOPIC (timing of platelet inhibition after acute coronary syndrome) randomized study
European Heart Journal (2017) doi:10.1093/eurheartj/ehx175
Objective: To evaluate the benefit of switching dual antiplatelet therapy (DAPT) from aspirin plus a newer P2Y12 blocker (ticagrelor/prasugrel) to aspirin plus clopidogrel 1 month after ACS.
- An open-label, monocentric, and randomized trial at Timone Hospital, Marseille, France.
- 646 patients (admitted with ACS requiring PCI, on aspirin and a newer P2Y12 blocker and without adverse event at 1 month) were randomised to switch to aspirin and clopidogrel (switched DAPT, n=323) or continuation of their drug regimen (unchanged DAPT, n=323).
- The primary outcome : A composite of cardiovascular death, urgent revascularization, stroke and bleeding Bleeding Academic Research Consortium (BARC) >2 at 1 year
post ACS. This combination of both ischaemic and bleeding events was defined as “net clinical benefit”.
- Follow up : 1 year
- 1 year follow up was performed for 316 (98.1%) patients in the switched DAPT group and 318 (98.5%) in the unchanged DAPT group. Median Duration: 359 days
- Mean Age: 60 years. 43% patients were on ticagrelor, 57% on prasugrel.
- 40% patients had STEMI, 60% had either unstable angina or NSTEMI
- Drug Eluting Stents were used in 91% patients, 96% PCI done by radial route
- The rate of primary endpoint (“Net Clinical Benefit”) was significantly less in switched DAPT group (13.4%) Vs unchanged DAPT group 26.3% (HR 95%CI 0.48 (0.34–0.68),
P< 0.01) (Figure below)
- No difference in both groups for ischemic events (switched DAPT Vs Unchanged DAPT ; 9.3% Vs 11.5%, P=0.36)
- BARC Bleedings > 2 was 70% lower in switched DAPT group (4%) Vs Unchanged DAPT group (14.9%) p < 0.01
- No difference between both groups for unplanned revascularization, TIMI major bleeding,
- No difference between both groups for stent thrombosis, CV death and stroke (events very less)
- All end points are mentioned in the table below
In patients on aspirin + ticagrelor/prasugrel without an adverse event in 1st month following an ACS treated with PCI, switching DAPT to aspirin + clopidogrel may reduce the risk of bleeding recurrence without increased risk of ischaemic events.
Limitations of the study
- Single Center, open label study
- Study size was small and not decisive for Stent Thrombosis or Total Mortality
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