Prolonged Dual Antiplatelet Therapy After Stent Implantation: What Are the Risks and Benefits?

Summary and Comment |
November 16, 2014

Prolonged Dual Antiplatelet Therapy After Stent Implantation: What Are the Risks and Benefits?

  1. Howard C. Herrmann, MD

In a large, randomized study, reduced rates of ischemic events offset an increased bleeding risk in patients who continued DAPT beyond 1 year.

  1. Howard C. Herrmann, MD

Whether to continue dual antiplatelet therapy (DAPT) for more than 12 months after drug-eluting stent (DES) implantation is controversial. In this international, industry-funded, randomized, placebo-controlled trial, 9961 DES recipients who received DAPT for 1 year were assigned to aspirin plus a thienopyridine or placebo for an additional 18 months. Only patients without a major event or significant bleeding in the first year after stenting were eligible for randomization.

Between 12 and 30 months, the incidence of definite or probable stent thrombosis was significantly lower in the DAPT group than in the placebo group (0.4% vs. 1.4%; hazard ratio, 0.29) as was the incidence of major adverse cardiovascular and cerebrovascular events (4.3% vs. 5.9; HR, 0.71). The rate of myocardial infarction was reduced by approximately 50% with prolonged DAPT (2.1% vs. 4.1%; HR, 0.47; P<0.001), even in patients without stent thrombosis (HR, 0.59; P<0.001). An increased rate of moderate or severe bleeding (by the GUSTO criteria) with DAPT (2.5% vs. 1.6%; HR, 1.61; 95% P=0.001) was attributable mainly to patients with moderate, not severe, bleeding; fatal bleeding did not differ between the two groups. Cardiovascular mortality was similar in the two groups, and an increase in all-cause mortality in the DAPT group was nonsignificant after adjustment for cancer diagnosed before enrollment. A subgroup analysis suggested greater ischemic benefit of prolonged DAPT with paclitaxel-eluting stents (HR, 0.52) than with everolimus-eluting stents (HR, 0.89; P=0.05 for interaction).

Comment

This large, randomized trial demonstrates both risks and benefits of DAPT beyond 1 year after DES implantation. Despite the absence of a significant difference in cardiovascular mortality, the significant reduction in stent thrombosis and myocardial infarction with an increase primarily in moderate bleeding with prolonged DAPT suggests a net benefit in most patients. Nonetheless, as editorialists note, clinicians will need to weigh the relative benefits and risks for individual patients and possibly also for the type of lesion and stent.

Editor Disclosures at Time of Publication

  • Disclosures for Howard C. Herrmann, MD at time of publication Consultant / Advisory board Gerson Lehrman Group; Siemens; St. Jude Medical; Leerink Swann; Wells Fargo; Massachusetts Medical Society; Morgan Stanley; Edwards Lifesciences Speaker's bureau Society of Cardiovascular Angiography and Interventions; Montefiore Medical Center; American Association for Thoracic Surgery Equity Micro-Interventional Devices, Inc. Grant / Research support Abbott Vascular; Edwards Lifesciences; Gore; Medtronic; St. Jude Medical; Siemens; Boston Scientific; Regado Biosciences; Cordis; Cardiokinetix; University of Laval; MitraSpan Editorial boards Catheterization and Cardiovascular Interventions; Circulation-Cardiovascular Interventions; Journal of Interventional Cardiology; Journal of Invasive Cardiology Expert Testimony Mount Sinai Medical Center, Miami, FL

Citation(s):

Reader Comments (1)

Paul Bartley Physician, Endocrinology, Clinical consultant

The problem in practice is that cardiologists do not follow up looking for bleeding in patients on DAP therapy long term. The vast majority of bleeding episodes are seen by gastroenterologists and neurologists.

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