What are the recommendations for stopping dual antiplatelet therapy (DAPT) (aspirin and P2Y12 inhibitor, such as clopidogrel or prasugrel) in adult patients with coronary artery disease who have received drug-eluting stents?

STOP-DAPT Trial Summary

The STOP-DAPT trial was a prospective multicenter Japanese study that demonstrated stopping dual antiplatelet therapy (DAPT) at 3 months after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation was safe and potentially superior to prolonged DAPT regimens, with a primary endpoint incidence of only 2.8% at 1 year. 1

Trial Design and Population

• Study structure: Prospective, multicenter, single-arm trial conducted across 58 Japanese centers between September 2012 and October 2013 1
• Enrollment: 1,525 patients with complete 1-year follow-up in 1,519 patients (99.6% follow-up rate) 1
• Intervention: Thienopyridine discontinued within 4 months in 94.7% of patients (1,444 patients), with aspirin monotherapy continued thereafter 1
• Stent type: All patients received cobalt-chromium everolimus-eluting stents (CoCr-EES), representing contemporary drug-eluting stent technology 1

Primary Endpoint Results

• Composite primary endpoint: Cardiovascular death, myocardial infarction (MI), stroke, definite stent thrombosis, and TIMI major/minor bleeding at 1 year 1
• Cumulative 1-year incidence: 2.8% (upper 97.5% CI: 3.6%), which was significantly lower than the pre-defined performance goal of 6.6% (P < 0.0001) 1
• Event rates beyond 3 months were remarkably low: cardiovascular death 0.5%, MI 0.1%, stent thrombosis 0%, stroke 0.7%, and TIMI major/minor bleeding 0.8% 1

Comparison to Historical Controls (RESET Trial)

When compared to the RESET trial's CoCr-EES group (where nearly 90% continued DAPT at 1 year), STOP-DAPT demonstrated superior outcomes:

• Primary endpoint: 2.8% in STOP-DAPT versus 4.0% in RESET (P = 0.06), with adjusted hazard ratio of 0.64 (95% CI 0.42-0.95, P = 0.03) 1
• Stent thrombosis: Zero patients (0%) in STOP-DAPT versus 5 patients (0.3%) in RESET for definite/probable stent thrombosis (P = 0.03) 1
• This comparison suggests that abbreviated DAPT may actually reduce thrombotic complications compared to prolonged regimens, likely due to reduced bleeding risk and better medication adherence 1

Clinical Implications and Context

The STOP-DAPT trial challenged the prevailing paradigm that longer DAPT duration is always better, demonstrating that 3-month DAPT can be safe in selected patients with contemporary drug-eluting stents. 1 This finding has been incorporated into current guidelines, where the 2021 ACC/AHA/SCAI guidelines now recommend that shorter-duration DAPT (1-3 months) with subsequent transition to P2Y12 inhibitor monotherapy is reasonable in selected patients to reduce bleeding risk (Class IIa, Level A). 2

Important Caveats

• Patient selection: The trial enrolled "selected patients," meaning those without high ischemic risk features or complex coronary anatomy 1
• Stent technology: Results apply specifically to contemporary cobalt-chromium everolimus-eluting stents, which have lower thrombogenicity than earlier-generation drug-eluting stents 3, 1
• Geographic considerations: The trial was conducted exclusively in Japanese centers, and results may not fully generalize to all populations 1
• Clinical presentation: The trial included both stable coronary artery disease and acute coronary syndrome patients, though specific subgroup analyses were not the primary focus 1

How STOP-DAPT Fits Current Practice

Current guidelines now support abbreviated DAPT strategies based on trials like STOP-DAPT, but emphasize individualized risk assessment: 2, 4

• For stable CAD patients at high bleeding risk, 3-month DAPT may be reasonable (Class IIb) 2
• For patients not at high bleeding or ischemic risk, stopping DAPT at 1-3 months may be considered 2
• The default remains 6 months for stable CAD and 12 months for ACS, with flexibility based on bleeding and ischemic risk assessment 2, 4

Common Pitfalls to Avoid

• Do not apply 3-month DAPT to high ischemic risk patients (complex left main, bifurcation stenting, prior stent thrombosis, suboptimal stenting results) without careful consideration 2, 4
• Do not assume all drug-eluting stents have the same safety profile with abbreviated DAPT; STOP-DAPT specifically used contemporary cobalt-chromium everolimus-eluting stents 1
• Do not stop DAPT early in ACS patients without documented high bleeding risk, as the default 12-month duration remains standard (Class I, Level B) 2, 4
• Do not forget that STOP-DAPT used aspirin monotherapy after stopping the P2Y12 inhibitor, whereas newer strategies may favor P2Y12 inhibitor monotherapy after stopping aspirin 2, 4