Dual Antiplatelet Therapy After Drug-Eluting Stent Implantation

Percutaneous coronary intervention (PCI) including stent implantation for the treatment of coronary lesions has been shown to improve patient functional status and outcome. The expanding use of PCI, coupled with refinements in technology including the introduction of drug-eluting stents (DESs) and more intensive adjunctive pharmacological treatment, resulted in treatment of complex coronary lesions and patients with a history of clinically significant cardiovascular disease and/or coexisting conditions. The DESs have improved outcomes of PCI due to the reduced restenosis compared to bare-metal stents, especially in specific subgroups (ie, patients with diabetes mellitus); however, they also extended the period during which patients are at risk of stent thrombosis. The PCI is established as an invasive approach for the treatment of stable and unstable coronary syndromes. However, this procedure (balloon inflation and/or stenting) can potentiate a prothrombotic state around lesion areas leading to ischemic complications. Platelet aggregates can occur in response to PCI or spontaneous disruption of a vulnerable plaque. In view of the central role of platelets in coronary thrombosis, and enhanced platelet activation after PCI, the choice and duration of concomitant pharmacological environment (dual or even triple antiplatelet therapy and/or anticoagulants) have become critical. The PCI may be complicated by adverse cardiac events and a need for urgent revascularization, some of which are attributed to acute, subacute, or late stent thrombosis. Modulation of thrombotic and coagulation potential is a key factor in improving early ( 30 days) or even very late (>1 year) DES thrombosis. While this recommendation is supported by several mechanistic investigations suggesting a delayed healing process or a prolonged inflammatory response of the vessel wall after DES implantation, clinical evidence is controversial. A number of recently published meta-analyses of randomized trials (Table 1) have attempted to address these issues. The most recent meta-analysis by Verdoia et al published in this issue of Angiology summarizes the available evidence from 11 randomized trials (32 372 patients). The authors conclude that short duration of DAPT (S-DAPT; 3-6 months) can be safely considered, whereas a long duration of DAPT (L-DAPT; 24-36 months) increases the risk of major bleeding complications. These findings should be interpreted in view of multiple almost concomitantly published meta-analyses in the field. As shown in Table 1, a number of meta-analyses with differentiated inclusion criteria and statistical approaches (pairwise and network meta-analyses, individual patient-level data metaanalysis or hierarchical Bayesian) have been published by independent groups. Among these meta-analyses, diverse grouping criteria have been used to specify the use of S-DAPT and L-DAPT against the current recommendations of the American College of Cardiology Foundation/American Heart Association