Extended DAPT Reduced Major Ischemic Events After Stenting in Multivessel Disease
Patients with multivessel coronary artery disease who completed a full year of dual antiplatelet therapy after drug-eluting stent implantation faced a familiar clinical question: stop clopidogrel and continue aspirin alone, or keep suppressing platelet activity for another year. In a large randomized trial from 97 centers in China, extending dual antiplatelet therapy for 12 additional months lowered the risk of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke compared with aspirin monotherapy.
The signal was modest in absolute terms but clinically meaningful. Over a median 34.3 months of follow-up, the 36-month cumulative incidence of the primary efficacy endpoint was 5.8% with extended DAPT and 6.8% with aspirin alone. The hazard ratio of 0.82 reflected a relative reduction in ischemic risk that is consistent with the biology of diffuse coronary atherosclerosis, where multiple vulnerable plaques can remain active long after the index stent procedure. In a population already selected for being event-free through the first year, the benefit argues that residual thrombotic risk does not disappear once the stent is endothelialized.
One sentence captures the trial’s central tension: longer platelet inhibition helped, but did not appear to cost more bleeding.
Event-Free Patients Still Carried Residual Thrombotic Risk
Enrollment focused on adults 18 to 75 years old who had multivessel coronary artery disease and no major ischemic or bleeding events during the initial 12 months of DAPT after placement of a drug-eluting stent. That design matters because it isolates a more stable post-PCI population than many earlier antiplatelet studies, which often include higher-risk or more heterogeneous patients. These were not patients in the middle of an acute coronary syndrome; they had already declared a degree of early treatment tolerance and stability.
At that point, the therapeutic question shifts from preventing acute stent thrombosis to managing ongoing atherothrombotic risk across the coronary tree. Multivessel disease is a marker of systemic vascular injury, and platelet reactivity remains central to recurrent infarction and ischemic stroke. Extending clopidogrel plus aspirin for another year likely preserved a broader anti-thrombotic buffer during a period when plaque rupture or erosion can still trigger catastrophic events outside the original stented segment.
The trial randomized 8,250 patients in a 1:1 ratio to continued DAPT with clopidogrel plus aspirin or to aspirin monotherapy. The scale of the study strengthens confidence in the event rates, especially because the composite endpoint was adjudicated over long follow-up across many centers. Event prevention in this setting is not driven by a single mechanism; the combined regimen suppresses platelet aggregation through two complementary pathways, reducing the likelihood that a small plaque disruption becomes an occlusive coronary event.
Bleeding Rates Stayed Low Despite Longer Platelet Inhibition
The most important counterweight to any discussion of extended antiplatelet therapy is bleeding. Here, the safety endpoint was clinically relevant or major bleeding, defined as Bleeding Academic Research Consortium type 2 or higher. Clinically relevant or major bleeding occurred in 1.4% of the DAPT group and 1.5% of the aspirin-monotherapy group, with a hazard ratio of 0.89 and no statistically significant difference between groups.
That finding will matter at the bedside. In routine practice, prolonged DAPT is often shortened or abandoned because of concern for hemorrhage, especially gastrointestinal bleeding, bruising, anemia, or more serious bleeding that complicates adherence and erodes net benefit. In this trial, however, the bleeding profile did not worsen with the extra year of clopidogrel, at least in this selected population of patients who had already tolerated 12 months of treatment without major complications. The result suggests that careful patient selection can preserve the ischemic benefit of extended therapy without paying a bleeding penalty.
The absolute bleeding event numbers were small: 51 patients in the DAPT group and 57 in the aspirin group. Low event rates improve reassurance but also narrow the margin for interpretation. A trial like this does not erase the need for individual risk assessment, especially in patients with prior hemorrhage, frailty, concurrent anticoagulation, or other conditions that shift the benefit-risk balance toward simpler regimens.
What the Trial Means for Coronary Practice
The 36-month cumulative incidence of the primary efficacy endpoint fell from 6.8% with aspirin alone to 5.8% with extended DAPT. In a disease state defined by diffuse atherosclerotic burden, that reduction fits a coherent mechanistic story: continued platelet inhibition reduces the chance that residual coronary plaque instability translates into myocardial infarction or stroke. The benefit emerged without an accompanying bleeding increase, which is precisely the result clinicians hope for when they extend antiplatelet treatment beyond the conventional 12-month window.
Even so, the trial’s design shapes how broadly the findings can be applied. It was open-label, conducted entirely in China, and restricted to patients who had remained event-free for a full year after stenting. Those features create a selected cohort that may not mirror every post-PCI patient in daily practice. Patients at higher hemorrhagic risk, those with prior events during the first year, and populations outside the enrolled age range were not studied in the same way.
The data still strengthen the case that the standard 12-month stopping point for DAPT after drug-eluting stent implantation is not a fixed biological boundary. In multivessel disease, the coronary circulation remains vulnerable beyond the first year, and platelet inhibition can continue to prevent clinically important ischemic events. The unanswered question is not whether extended DAPT works in this study population; it does. The next step is deciding which post-stent patients gain enough absolute benefit to justify longer treatment, and which patients should remain on aspirin alone because bleeding risk or competing therapies make escalation less favorable.