Lesion Complexity and Outcomes of Extended Dual Antiplatelet Therapy After Percutaneous Coronary Intervention

Subjects undergoing coronary stenting with complex lesion anatomy may experience different risks and benefits with prolonged dual antiplatelet therapy.

The authors assessed the effect of 30 months versus 12 months of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) based on the presence or absence of anatomically-complex target lesions.

In the DAPT Study, combined myocardial infarction (MI) or stent thrombosis and moderate/severe bleeding were assessed in enrolled (n = 25,416) and randomized (n = 11,554) subjects. Complex lesions had any of the following characteristics: unprotected left main, >2 lesions/vessel, length ≥30 mm, bifurcation with side branch ≥2.5 mm, vein bypass graft, or thrombus-containing lesion. Events were evaluated according to increasing number of complexity characteristics and compared according to DAPT score.

Enrolled subjects with more complex target lesions had higher rates of MI or stent thrombosis in the first 12 months after PCI (3.9% vs. 2.4%; p < 0.001). Among those who were event-free at 12 months, rates of MI or stent thrombosis between 12 and 30 months were similar between those with versus without complex anatomy (3.5% vs. 2.9%; p = 0.07). Reduction of MI or stent thrombosis with continued thienopyridine beyond 12 months versus placebo was similar for subjects with (2.5% vs. 4.5%; hazard ratio: 0.55; 95% confidence interval: 0.38 to 0.79; p = 0.001) and without (2.0% vs. 3.8%; hazard ratio: 0.52; 95% confidence interval: 0.39 to 0.69; p < 0.001) anatomic complexity (p_interaction = 0.81), as was increase in moderate/severe bleeding (p_interaction = 0.44). Among subjects with anatomic complexity, those with DAPT scores ≥2 randomized to continued thienopyridine had greater reductions in MI or stent thrombosis (3.0% vs. 6.1%; p < 0.001) compared with subjects with scores <2 (1.7% vs. 2.3%; p = 0.42; p value comparing risk differences = 0.03).

Complex target-lesion anatomy is associated with increased ischemic events, particularly within the first year after PCI. Among those without events in the first 12 months, the benefits of extending DAPT were similar in subjects with and without complex lesions. A high DAPT score identified those experiencing the most benefit from extended treatment among patients with and without complex anatomy. (The Dual Antiplatelet Therapy Study [DAPT Study]; NCT00977938).