April 10, 2017
Making Anticoagulant-Antiplatelet Combination Therapy Safer: Patients with atrial fibrillation (AF) who are at high risk of stroke traditionally receive warfarin therapy. These AF patients who also have ischemic heart disease and undergo coronary artery stent placement are candidates for dual antiplatelet therapy (DAPT) with a P2Y12 inhibitor plus low-dose aspirin. However, triple therapy (warfarin plus DAPT) greatly increases bleeding risk in these patients. The PIONEER AF-PCI study showed that once-daily rivaroxaban and a P2Y12 inhibitor (eg, clopidogrel) appears to be safer and more convenient than warfarin plus DAPT in patients with AF who receive a coronary artery stent.
CHAPTER SUMMARY FROM THE PHARMACOTHERAPY HANDBOOK
For the chapter in the Wells Handbook, please go to Chapter 5. Acute Coronary Syndromes.
The cause of an acute coronary syndrome (ACS) is the rupture of an atherosclerotic plaque with subsequent platelet adherence, activation, and aggregation, and the activation of the clotting cascade. Ultimately, a clot forms composed of fibrin and platelets.
National guidelines exist for ACS patient care for ST-segment elevation (STE) myocardial infarction (MI) and non–ST-segment elevation (NSTE) ACS, including guidelines for patients undergoing percutaneous coronary intervention (PCI).
Patients with ischemic chest discomfort and suspected ACS are risk-stratified based on a 12-lead electrocardiogram (ECG), clinical presentation, past medical history, and results of the troponin assays. The diagnosis of MI is confirmed based on the results of the troponin biochemical marker tests.
Early reperfusion therapy with primary PCI of the infarct artery is recommended for patients presenting with STEMI within 12 hours of symptom onset.
The most recent PCI practice guidelines recommend coronary angiography with either PCI or coronary artery bypass graft (CABG) surgery revascularization as an early treatment (early invasive strategy) for patients with NSTE-ACS at an elevated risk for death or MI, including those with a high risk score or patients with refractory angina, acute heart failure, other symptoms of cardiogenic shock, or arrhythmias.
In addition to reperfusion therapy, other early pharmacotherapy that all patients with STEMI and without contraindications should receive within the first day of hospitalization, and preferably in the emergency department (ED), are intranasal oxygen (if oxygen saturation is low), sublingual (SL) nitroglycerin (NTG), aspirin, a P2Y12 inhibitor (clopidogrel, prasugrel, or ticagrelor depending on reperfusion strategy), and anticoagulation with bivalirudin, unfractionated heparin (UFH), enoxaparin, or fondaparinux (Agent dependent on reperfusion strategy). A glycoprotein IIb/IIIa inhibitor (GPI) may be considered if UFH is selected as the anticoagulant for patients undergoing primary PCI. A high-intensity statin should be administered prior to PCI. Intravenous (IV) β-blockers and IV NTG should be administered cautiously in selected patients. Oral β-blockers should be initiated within the first day in patients without contraindications.
In the absence of contraindications, all patients with NSTE-ACS should be treated in the ED with intranasal oxygen (if oxygen saturation is low), SL NTG, aspirin, and an anticoagulant (UFH, enoxaparin, fondaparinux, ...