Combination of Oral Anticoagulants and Single Antiplatelets versus Triple Therapy in Nonvalvular Atrial Fibrillation and Acute Coronary Syndrome: Stroke Prevention among Asians

Abstract

Atrial fibrillation (AF), the most prevalent arrhythmic disease, tends to foster thrombus formation due to hemodynamic disturbances, leading to severe disabling and even fatal thromboembolic diseases. Meanwhile, patients with AF may also present with acute coronary syndrome (ACS) and coronary artery disease (CAD) requiring stenting, which creates a clinical dilemma considering that majority of such patients will likely receive oral anticoagulants (OACs) for stroke prevention and require additional double antiplatelet treatment (DAPT) to reduce recurrent cardiac events and in-stent thrombosis. In such cases, the gentle balance between bleeding risk and atherothromboembolic events needs to be carefully considered. Studies have shown that congestive heart failure, hypertension, age ≥ 75 years (doubled), diabetes mellitus, and previous stroke or transient ischemic attack (TIA; doubled)-vascular disease, age 65 to 74 years, sex category (female; CHA ₂ DS ₂ -VASc) scores outperform other scoring systems in Asian populations and that the hypertension, abnormal renal/liver function (1 point each), stroke, bleeding history or predisposition, labile international normalized ratio (INR), elderly (>65 years), drugs/alcohol concomitantly (1 point each; HAS-BLED) score, a simple clinical score that predicts bleeding risk in patients with AF, particularly among Asians, performs better than other bleeding scores. A high HAS-BLED score should not be used to rule out OAC treatment but should instead prompt clinicians to address correctable risk factors. Therefore, the current review attempted to analyze available data from patients with nonvalvular AF who underwent stenting for ACS or CAD and elaborate on the direct-acting oral anticoagulant (DOAC) and antiplatelet management among such patients. For majority of the patients, "triple therapy" comprising OAC, aspirin, and clopidogrel should be considered for 1 to 6 months following ACS. However, the optimal duration for "triple therapy" would depend on the patient's ischemic and bleeding risks, with DOACs being obviously safer than vitamin-K antagonists.

Keywords: acute coronary syndrome; antiplatelets; nonvalvular atrial fibrillation; oral anticoagulants; stroke; thromboembolic diseases; triple therapy.

Fig. 1

Intraprocedural antithrombotic strategies in AF patients undergoing PCI, in relation to vitamin K antagonist or DOAC use. For DOAC in elective/NSTE-ACS, interruption (12–24 hour in advance, based on renal function and agent) is preferred. A, aspirin; AF, atrial fibrillation; C, clopidogrel; H, heparin; NOAC, nonvitamin K antagonist oral anticoagulant; NSTE-ACS, non-ST-elevation acute coronary syndrome; O, oral anticoagulation; PCI, percutaneous coronary intervention; STEMI, ST-elevation myocardial infarction; VKA, vitamin-K antagonist; UFH, unfractionated heparin. (Reproduced with permission from Lip et al. 27 )

Fig. 2

Management algorithm for AF patients presenting with elective PCI or ACS undergoing PCI A, aspirin; ACS, acute coronary syndrome; AF, atrial fibrillation; C, clopidogrel; GRACE, the global registry of acute coronary events; HAS-BLED, HAS-BLED, hypertension, abnormal renal/liver function (1 point each), stroke, bleeding history or predisposition, labile INR, elderly (>65 years), drugs/alcohol concomitantly (1 point each); LAD, left anterior descending; MI, myocardial infarction; NOAC, novel oral anticoagulant; OAC, oral anticoagulant; PCI, percutaneous coronary intervention; P2Y ₁₂ inhibitor, adenosine diphosphate receptor inhibitor; SYNTAX score, synergy between PCI with Taxus and cardiac surgery; TTR, time to therapeutic range; VKA, vitamin-K antagonist. (Reproduced with permission from Lip et al. 27 )

Fig. 3

Management algorithm for stroke prevention in Asian patients with nonvalvular atrial fibrillation. A, apixaban; AF, atrial fibrillation; CHA ₂ DS ₂ -VASc, congestive heart failure, hypertension, age ≥ 75 (doubled), diabetes, stroke (doubled)–vascular disease, age 65–74 years, sex category (female); D, dabigatran; E, edoxaban; NOAC, nonvitamin K antagonist oral anticoagulant; SAMe-TT ₂ R ₂ , sex female, age less than 60 years, medical history (more than two comorbidities), treatment (interacting medications, e.g., amiodarone), tobacco use (doubled), race (doubled); R, rivaroxaban; VKA, vitamin-K antagonist (reprinted from Chiang et al 30 ).