Antithrombotic management and long-term outcomes following percutaneous coronary intervention for acute coronary syndrome in Asia

Guideline recommendations on the use of dual antiplatelet therapy (DAPT) in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention (PCI) have been formulated by both the ACC/AHA and the ESC. These recommendations are based primarily on large, phase III, randomized, controlled trials of the P2Y12 inhibitors clopidogrel, prasugrel, and ticagrelor. However, few East Asian patients have been included in the trials to assess the use of these agents, particularly the newer agents prasugrel and ticagrelor. Additionally, an increasing body of data suggests that East Asian patients have differing risk profiles for both thrombophilia and bleeding compared with white patients, and that a different 'therapeutic window' of on-treatment platelet reactivity might be appropriate in East Asian patients. Furthermore, a phenomenon referred to as the 'East Asian paradox' has been described, in which East Asian patients have a similar or even a lower rate of ischaemic events after PCI compared with white patients, despite a higher level of platelet reactivity during DAPT. Recognizing these concerns, the World Heart Federation has undertaken this evidence-based review and produced this expert consensus statement to determine the antiplatelet treatment strategies that are most appropriate for East Asian patients.

Clinical experiences have suggested that East Asians show the higher risk of warfarin-related intracranial hemorrhage compared with Westerners. Therefore, different target of the International Normalized Ratio (INR) in East Asians (1.6-2.6) has been proposed and adapted in clinical practice. In terms with antiplatelet therapy, recent evidence has supported the concept of "therapeutic level of platelet reactivity" to balance clinical efficacy and safety in patients undergoing percutaneous coronary intervention (PCI) or those with acute coronary syndrome (ACS). In line with the warfarin experiences, multiple clinical and pharmacodynamic data from East Asians have shown their different therapeutic level of platelet reactivity following PCI or ACS ("East Asian Paradox"). Furthermore, like most cardiovascular drugs, P2Y12 receptor blockers have marked interethnic differences in the pharmacokinetics and pharmacodynamics. The currently performed clinical trials evaluating the clinical efficacy and safety of potent P2Y12 inhibitors mostly don't include enough number of East Asians to draw reliable conclusions. Therefore, dedicated research and guideline(s) for East Asians are required before we can apply Western recommendations for potent P2Y12 inhibitors in East Asian population. It is a time to consider the paradigm shift from "one-guideline-fits-all races" to "race-tailored antiplatelet therapy" in treating ACS patients.

Ischemic heart disease (IHD) is the greatest single cause of mortality and loss of disability-adjusted life years worldwide, and a substantial portion of this burden falls on low- and middle-income countries (LMICs). Deaths from IHD and acute coronary syndrome (ACS) occur, on average, at younger ages in LMICs than in high-income countries, often at economically productive ages, and likewise frequently affect the poor within LMICs. Although data about ACS in LMICs are limited, there is a growing literature in this area and the research gaps are being steadily filled. In high-income countries, decades of investigation into the risk factors for ACS and development of behavioral programs, medications, interventional procedures, and guidelines have provided us with the tools to prevent and treat events. Although similar tools can be, and in fact have been, implemented in many LMICs, challenges remain in the development and implementation of cardiovascular health promotion activities across the entire life course, as well as in access to treatment for ACS and IHD. Intersectoral policy initiatives and global coordination are critical elements of ACS and IHD control strategies. Addressing the hurdles and scaling successful health promotion, clinical and policy efforts in LMICs are necessary to adequately address the global burden of ACS and IHD.