Testing Responsiveness To Platelet Inhibition On Chronic Antiplatelet Treatment For Acute Coronary Syndromes - TROPICAL-ACS

Contribution To Literature:

The TROPICAL-ACS trial showed that de-escalation of maintenance antiplatelet therapy was noninferior to 1 year of prasugrel.


The goal of the trial was to evaluate de-escalation of maintenance antiplatelet therapy compared with control among patients who received a coronary stent for an acute coronary syndrome.

Study Design

  • Randomized
  • Parallel
  • Stratified

Patients with acute coronary syndrome who underwent percutaneous coronary intervention (PCI) were randomized to de-escalation of antiplatelet therapy (n = 1,304) vs. prasugrel for 12 months (n = 1,306). In the de-escalation group, participants were treated with prasugrel for 1 week, then clopidogrel for 1 week at which time they underwent platelet function testing. If high platelet reactivity was documented, they were switched back to prasugrel. Otherwise, they remained on clopidogrel for 1 year.

Inclusion criteria:

  • ST-segment elevation MI (STEMI) or NSTEMI
  • Underwent PCI
  • Planned use of prasugrel for 12 months
  • Total number of enrollees: 2,610
  • Duration of follow-up: 12 months
  • Mean patient age: 59 years
  • Percentage female: 78%
  • Percentage with diabetes: 22%

Other salient features/characteristics:

  • Presentation: STEMI in 55%, NSTEMI in 45%

Principal Findings:

The primary outcome, incidence of cardiovascular death, MI, stroke, or bleeding (Bleeding Academic Research Consortium [BARC] ≥2), occurred in 7% of the de-escalation group vs. 9% of the control group (p for noninferiority = 0.0004).

Secondary outcomes:

  • All-cause mortality: 1% vs. 1% (p = 0.85), respectively, for de-escalation vs. control  
  • MI: 2% vs. 2% (p = 0.59), respectively, for de-escalation vs. control 
  • BARC type 3 or 5 bleeding: 2% vs. 1% (p = 0.63), respectively, for de-escalation vs. control 


Among patients with acute coronary syndrome (STEMI or NSTEMI), de-escalation of maintenance antiplatelet therapy was noninferior to 12 months of prasugrel. De-escalation of antiplatelet therapy was guided by platelet function testing. This strategy was associated with noninferiority regarding the primary outcome of cardiovascular death, MI, stroke, or bleeding BARC ≥2. Especially if affordability of medications is an issue, this approach could be an alternative.


Sibbing D, Aradi D, Jacobshagen C, et al., on behalf of the TROPICAL-ACS Investigators. Guided de-escalation of antiplatelet treatment in patients with acute coronary syndromes undergoing percutaneous coronary intervention (TROPICAL-ACS): a randomised, open-label, multicenter trial. Lancet 2017;390:1747-57.

Editorial Comment: Angiolillo DJ. Dual antiplatelet therapy guided by platelet function testing. Lancet 2017;390:1718-20.

Presented by Dr. Dirk Sibbing at the European Society of Cardiology Congress, Barcelona, Spain, August 27, 2017.

Clinical Topics: Acute Coronary Syndromes, Anticoagulation Management, Invasive Cardiovascular Angiography and Intervention, Anticoagulation Management and ACS, Interventions and ACS

Keywords: Acute Coronary Syndrome, Anticoagulants, Blood Platelets, ESC Congress, ESC2017, Hemorrhage, Myocardial Infarction, Percutaneous Coronary Intervention, Platelet Aggregation Inhibitors, Stents, Stroke

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