Original title: Benefits and Risks of Extended Duration Dual Antiplatelet Therapy after PCI in Patients With and Without Acute Myocardial Infarction. The DAPT Study. Reference: Robert W. Yeh et al. J Am Coll Cardiol. 2015, online before print.

The risks and benefits of prolonged antiplatelet therapy after PCI could be different in patients presenting with AMI compared to those with a more stable presentation. The DAPT double blind placebo controlled trial, randomized 11648 patients to 30 months vs. 12 months of dual antiplatelet therapy after stenting.

The impact of prolonged therapy for ischemic and bleeding events was assessed both in stable patients and in those presenting with MI. Primary end point was definite or probable stent thrombosis and a composite of death, infraction or stroke. Primary safety end point was GUSTO moderate or severe bleeding.

From all randomized patients, 9961 received DES and 1687 bare metal stents. 30.7% of the population (n=3576) presented with MI. The prolonged 30 month dual antiplatelet therapy reduced stent thrombosis compared to placebo, both in stable patients and in those presenting with ACS (infarction patients 0.5% vs. 1.9%, HR 0.27; p<0.001 and stable patients 0.4% vs 1.1%, HR 0.33; p<0.001).

Reduction of combined events at 30 months was greater in MI patients (3.9% vs 6.8%, HR 0.56; p<0.001) compared to stable patients, where the difference had no statistical importance (4.4% vs 5.3%, HR 0.83, p=0.08). When considering infarctions alone as events, continued dual antiplatelet therapy was beneficial for patients with and without MI (2.2% vs 5.2%, HR 0.42; p<0.001 for acute patients and 2.1% vs. 3.5%, HR 0.60; p<0.001 for stable patients).

Stent thrombosis and infarction were reduced with 30 months of dual antiplatelet therapy at the expense of an increase in bleeding events (1.9% vs 0.8%; p=0.005 for acute patients and 2.6% vs 1.7%; p=0.007 for stable patients).

Conclusion

Compared to 12 months of dual antiplatelet therapy, 30 months reduce the risk of stent thrombosis and AMI both in stable and acute patients, at the expense of an increase in bleeding risk. 

Editorial Comment

This study, with very similar figures to those obtained by Laura Mauri at N Engl J Med 2014, contributes a difference between acute and stable patients. Many studies are being published on this topic and, although they shows similar global outcomes, they also contribute different data. Not all patients are the same, not all stents are the same, not all DES are the same; most likely, a prolonged 30 month clopidogrel therapy is not the same as prasugrel or ticagrelor therapies, etc.

SOLACI