A 75-year-old woman with diabetes mellitus, chronic obstructive pulmonary disease, end-stage renal disease on hemodialysis, and hypertension is admitted to the hospital with chest pain and shortness of breath. Her pulse is 82 beats/min, blood pressure is 141/53 mmHg, and oxygen saturation is 96% on room air. An electrocardiogram demonstrates normal sinus rhythm with non-specific T-wave abnormality. Troponin T is elevated (0.656 ng/mL; reference range 0.000-0.029 ng/mL). She is diagnosed with non-ST-segment elevation myocardial infarction and treated with aspirin, clopidogrel, and unfractionated heparin. An echocardiogram demonstrates left ventricular ejection fraction of 62% with mild mitral regurgitation. She undergoes coronary angiography (Figure 1) that reveals severely calcified 90% stenosis of the left main trunk, 95% stenosis of the ostial left circumflex, and 70% stenosis of the proximal left anterior descending coronary arteries. The patient is treated with complex coronary intervention including rotational atherectomy and Culotte bifurcation stenting of the left main trunk bifurcation. The patient tolerates the procedure well and is planned for discharge.
Which of the following statements regarding dual antiplatelet therapy (DAPT) in this patient is correct?
The correct answer is: B. DAPT duration should be at least 12 months based on presentation with acute coronary syndrome irrespective of treatment strategy selected.
Current American College of Cardiology and American Heart Association guidelines on duration of DAPT give a Class 1 recommendation for 12 months of DAPT in patients with acute coronary syndromes irrespective of treatment with medical therapy, coronary artery bypass graft, or percutaneous coronary intervention (PCI). In acute coronary syndrome patients with significant overt bleeding or high bleeding risk (e.g., treatment with oral anticoagulant therapy or major intracranial surgery), the guidelines give a Class IIb recommendation for shortening DAPT duration to 6 months. Recommendations regarding duration of DAPT in acute coronary syndrome patients treated with PCI are irrespective of stent type and generation. Although it is reasonable to consider >12 months of DAPT in patients who have tolerated 12 months of DAPT without clinically significant bleeding or high bleeding risk (Class IIb recommendation), it is not mandatory to extend DAPT duration to 3 years in all patients treated with two-stent bifurcation stenting.
Clopidogrel, prasugrel, and ticagrelor are the currently available oral P2Y12 inhibitors. In PLATO (Platelet Inhibition and Patient Outcomes), a randomized controlled trial of ticagrelor versus clopidogrel in 18,624 patients with acute coronary syndrome, ticagrelor was associated with reduced risk of a composite of death from vascular causes, myocardial infarction, or stroke at 1 year (9.8% vs. 11.7%; hazard ratio 0.84; 95% confidence interval, 0.77-0.92; p < 0.001) and a lower all-cause death at 1 year (4.5% vs. 5.9%; p < 0.001) with no difference in major bleeding. Thus, there is a Class IIa recommendation to select ticagrelor over clopidogrel in acute coronary syndrome patients treated with PCI or medical therapy. However, the rate of fatal intracranial bleeding was significantly higher with ticagrelor (0.1% vs. 0.01%; p = 0.02) in PLATO. Ticagrelor should not be used in patients with a history of intracranial hemorrhage, but there is no contraindication to its use in patients with prior ischemic stroke or transient ischemic attack. However, prasugrel should not be used in patients with prior stroke or transient ischemic attack, and it is relatively contraindicated in patients >75 years of age or <60 kg due to higher bleeding risk in these patients.
Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA Guideline Focused Update on Duration of Dual Antiplatelet Therapy in Patients With Coronary Artery Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 2016;68:1082-115.
Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC Guideline for the Management of Patients with Non-ST-Elevation Acute Coronary Syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;64:e139-e228.
Valgimigli M, Bueno H, Byrne RA, et al. 2017 ESC focused update on dual antiplatelet therapy in coronary artery disease developed in collaboration with EACTS: The Task Force for dual antiplatelet therapy in coronary artery disease of the European Society of Cardiology (ESC) and of the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J 2018;39:213-60.