Impact of 6- versus 12-month dual antiplatelet therapy on clinical prognosis in patients with high bleeding risk: Insights from the 4-year results of the I LOVE IT 2 study

Antiplatelet Therapy Aims and Strategies in Asian Patients with Acute Coronary Syndrome or Stable Coronary Artery Disease

Dual antiplatelet therapy (DAPT) has been the mainstay treatment to reduce ischemic events, such as myocardial infarction or stroke, in patients with coronary artery disease (CAD). The development of potent P2Y₁₂ inhibitors (ticagrelor and prasugrel) has helped to further reduce ischemic events, particularly among high-risk patients. Meanwhile, the evolution of newer generations of drug-eluting stents are also improving outcomes of percutaneous coronary intervention. Research studies on antiplatelet therapy in recent years have focused on balancing ischemic and bleeding risks through different strategies, which include P2Y₁₂ inhibitor monotherapy, escalation and de-escalation, and extended DAPT. Because results from the large number of clinical studies may sometimes appear conflicting, this review aims to summarize recent advances, and demonstrate that they are aligned by a general principle, namely, strategies may be adopted based on treatment aims for specific patients at several time points. Another aim of this review is to outline the important considerations for using antiplatelet therapy in Asian patients, in whom there is a greater prevalence of CYP2C19 loss-of-function mutations, and a common increased risk of bleeding, despite high platelet reactivity (the so-called "East Asian Paradox").

New Insights Into Long- Versus Short-Term Dual Antiplatelet Therapy Duration in Patients After Stenting for Left Main Coronary Artery Disease: Findings From a Prospective Observational Study

BACKGROUND

The appropriate duration of dual antiplatelet therapy (DAPT) and risk-benefit ratio for long-term DAPT in patients with left main (LM) disease undergoing percutaneous coronary intervention remains uncertain.

METHODS

Four thousand five hundred sixty-one consecutive patients with stenting of LM disease at a single center from January 2004 to December 2016 were enrolled. Decision to discontinue or remain on DAPT after 12 months was left to an individualized decision-making based on treating physicians by weighing the patient's risks of ischemia versus bleeding and considering patient preference. The primary outcome was a composite of death, myocardial infarction, stent thrombosis, or stroke at 3 years. Key safety outcome was 3-year rate of Bleeding Academic Research Consortium 2, 3, or 5 bleeding.

RESULTS

Of 3865 patients free of ischemic and bleeding events at 12 months, 1727 (44.7%) remained on DAPT (mostly clopidogrel based [97.7%]) beyond 12 months after LM percutaneous coronary intervention. DAPT>12-month versus ≤12-month DAPT was associated with a significant reduced risk of 3-year primary outcome (2.6% versus 4.6%; adjusted hazard ratio: 0.59 [95% CI, 0.41-0.84]). The same trend was found for other ischemic end points: death (0.9% versus 3.0%; P_log-rank<0.001), cardiovascular death (0.5% versus 1.7%; P_log-rank=0.001), myocardial infarction (0.8% versus 1.9%; P_log-rank=0.005), and stent thrombosis (0.4% versus 1.1%; P_log-rank=0.017). The key safety end point was not significantly different between 2 regimens (1.8% versus 1.6%; adjusted hazard ratio: 1.07 [95% CI, 0.65-1.74]). The effect of DAPT>12 month on primary and key safety outcomes was consistent across clinical presentations, high bleeding risk, P2Y₁₂ inhibitor, and LM bifurcation percutaneous coronary intervention approach.

CONCLUSIONS

In a large cohort of patients free from clinical events during the first year after LM percutaneous coronary intervention and at low apparent future bleeding risk, an individualized patient-tailored approach to longer duration (>12 month) of DAPT with aspirin plus a P2Y₁₂ inhibitor (mostly clopidogrel) improved both composite and individual efficacy outcomes by reducing ischemic risk, without a concomitant increase in clinically relevant bleeding.