Left main or proximal left anterior descending coronary artery disease location identifies high-risk patients deriving potentially greater benefit from prolonged dual antiplatelet therapy duration

Selected in EuroIntervention by S. Brugaletta

References

Authors

Costa F, Adamo M, Ariotti S, Ferrante G, Navarese EP, Leonardi S, Garcia-Garcia H, Vranckx P, Valgimigli M

Reference

EuroIntervention. 2016 Feb 12;11(11):e1222-30

Published

12 February 2016

Link

Read the abstract

My Comment

What is known

Successful revascularisation of lesions located in the left main coronary artery (LM) and/or in the proximal left anterior descending coronary artery (pLAD) improves survival as compared to medical therapy only. Overall, the duration of dual antiplatelet therapy after coronary stenting, which maximises benefits over risks, remains debated. While clinical trials have shown an ischaemic benefit after a prolonged course of therapy beyond 12 months, recent meta-analysis have raised concerns about a possible increase in mortality after such treatment. Whether the presence of lumen narrowing of the LM and/or pLAD in patients undergoing stenting should affect the decision making with respect to the duration of DAPT remains unknown. This article retrospectively explored the differential outcomes of 24 or six-month DAPT in this high-risk population in the Prolonging Dual Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia (PRODIGY) trial.

Major findings 

  • In the Prolonging Dual Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia (PRODIGY) study, 953 (54.3%) patients with and 801 (45.7%) without LM/pLAD lumen narrowing at the qualifying coronary intervention were randomised to six or 24 months of DAPT.
  • Twenty-four month as compared to six-month DAPT reduced the occurrence of definite, probable or possible stent thrombosis by 50% in patients with (2.8% vs. 5.6%; HR 0.45, 95% CI: 0.23-0.89; p=0.02) but not in those without LM/pLAD lumen narrowing, with a highly significant interaction testing (PINT= 0.002).
  • This result remained consistent irrespective of whether stenting was (PINT: 0.01) or was not (PINT: 0.02) performed in the LM/pLAD. 

My comment

This interesting paper explores the usefulness of prolonged dual antiplatelet treatment in patients with LM/pLAD stenosis. The authors found a possible benefit of a prolonged treatment in such patients irrespectively of whether those lesions were treated by stent or not. The results are interesting, because it potentially identifies a subpopulation with benefits of prolonged dual antiplatelet treatment counterbalancing risk of bleeding. This population has indeed a high risk for ischemic events, which can be fatal taking into account the myocardium at risk. Unfortunately only stent thrombosis was significantly different between the two groups analysed, without any benefit in terms of hard clinical endpoints, such as cardiac death and myocardial infarction. Future sub-analyses from other trials exploring short vs. long dual antiplatelet treatment will help us understand to which point the benefits of a prolonged dual antiplatelet regimen may overcome the bleeding risk in these patients.

What is your attitude with a patient with LM/pLAD stenting with regard to the dual antiplatelet regimen duration?

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