Lesion Complexity and Extended DAPT After PCI

Study Questions:

What is the effect of 30 versus 12 months of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI), based on the presence or absence of anatomically complex target lesions?

Methods:

The investigators assessed combined myocardial infarction (MI) or stent thrombosis and moderate/severe bleeding in the DAPT (Dual Antiplatelet Therapy) study, in enrolled (n = 25,416) and randomized (n = 11,554) subjects. Complex lesions had any of the following characteristics: unprotected left main, >2 lesions per 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. The effects of continued thienopyridine versus placebo for subjects with and without anatomic complexity were assessed using Cox proportional hazards regression models, and are expressed as hazard ratios (HRs).

Results:

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 event-free at 12 months, rates of MI or stent thrombosis between 12-30 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%; HR, 0.55; 95% confidence interval [CI], 0.38-0.79; p = 0.001) and without (2.0% vs. 3.8%; HR, 0.52; 95% CI, 0.39-0.69; p < 0.001) anatomic complexity (Pinteraction = 0.81), as was increase in moderate/severe bleeding (Pinteraction = 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 comparing risk differences = 0.03).

Conclusions:

The authors concluded that complex target-lesion anatomy is associated with increased ischemic events, particularly within the first year after PCI.

Perspective:

This post hoc analysis reports that those undergoing PCI with more complex coronary artery target lesions had a higher rate of subsequent ischemic events, particularly within the first year after PCI, compared with patients without complex lesions. Furthermore, among patients reaching 1 year after PCI without a major ischemic or bleeding event, the magnitude of ischemic benefit associated with continuing thienopyridine for an additional 18 months was not greater among patients with complex coronary lesion characteristics. These findings would suggest that complex target lesion anatomy may be a more useful discriminator for predicting the benefit of DAPT within the first year after PCI, but not so useful for predicting the benefit of longer durations after 12 months.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Prevention

Keywords: Coronary Vessels, Hemorrhage, Myocardial Infarction, Myocardial Ischemia, Percutaneous Coronary Intervention, Platelet Aggregation Inhibitors, Secondary Prevention, Stents, Thienopyridines, Thrombosis


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