Antiplatelet therapy after coronary intervention in Asia and Japan

Prolonged dual antiplatelet therapy for Chinese ACS patients undergoing emergency PCI with drug-eluting stents: Benefits and risks

Background

In patients with acute coronary syndrome (ACS), prolonged dual antiplatelet therapy (DAPT) may reduce ischemic events and increase the risks of bleeding events differently in different ethnic groups. However, whether prolonged DAPT in Chinese patients with ACS following emergency percutaneous coronary intervention (PCI) with drug-eluting stents (DES) will be beneficial or dangerous remains unclear. This study aimed to examine the potential benefits and risks of prolonged DAPT in Chinese patients with ACS who have undergone emergency PCI with DES.

Methods

This study included 2,249 patients with ACS who underwent emergency PCI. If DAPT was continued for 12 or 12-24 months, it was classified as the standard (n = 1,011) or prolonged (n = 1,238) DAPT group, respectively. The incidence of the following endpoint events was determined and compared between the two groups: composite bleeding event (BARC 1 or 2 types of bleeding and BARC 3 or 5 types of bleeding) and major adverse cardiovascular and cerebrovascular events (MACCEs) [ischemia-driven revascularization, non-fatal ischemia stroke, non-fatal myocardial infarction (MI), cardiac death, and all-cause death].

Results

After a median period of 47 months of follow-up [47 (40, 54)], the rate of composite bleeding events was 13.2% (n = 163) in the prolonged DAPT group and 7.9% (n = 80) in the standard DAPT group [odds ratio (OR) 1.765, 95% confidence interval (CI) 1.332-2.338, p < 0.001]. The rate of MACCEs was 11.1% (n = 138) in the prolonged DAPT group and 13.2% (n = 133) in the standard DAPT group (OR 0.828, 95% CI 0.642-1.068, p = 0.146). The DAPT duration was further shown to be insignificantly correlated with MACCEs as per the multivariable Cox regression model (HR, 0.813; 95% CI, 0.638-1.036; p = 0.094). No statistically significant difference was observed between the two groups. However, the DAPT duration was a separate predictor of composite bleeding events according to the multivariable Cox regression model (HR 1.704, 95% CI 1.302-2.232, p < 0.001). Compared with the standard DAPT group, the prolonged DAPT group had substantially more BARC 3 or 5 types of bleeding events (3.0 vs. 0.9% in those with standard DAPT, OR 3.430, 95% CI 1.648-7.141, p < 0.001) and BARC 1 or 2 types of bleeding events (10.2 vs. 7.0% in those with standard DAPT, OR 1.500, 95% CI 1.107-2.032, p = 0.008).

Conclusion

The prolonged DAPT group had a considerably greater incidence of composite bleeding events than the standard DAPT group. No statistically significant difference was observed in the incidence of MACCEs between the two groups.

Efficacy and Safety of Ticagrelor vs. Clopidogrel in East Asian Patients with Acute Myocardial Infarction: A Nationwide Cohort Study

Ticagrelor improves clinical outcomes in patients with acute myocardial infarction (AMI). This study aimed to compare the efficacy and safety of ticagrelor vs. clopidogrel in East Asian patients with AMI. Between July 2013 and December 2015, patients with AMI prescribed dual antiplatelet therapy were identified from the National Health Insurance Research Database of Taiwan. Using propensity score weighting, ticagrelor was compared with clopidogrel for the primary efficacy end point (a composite of all-cause death, myocardial infarction (MI), and stroke) and bleeding. A total of 32,442 patients with AMI (ticagrelor: 10,057; clopidogrel: 22,385) were eligible for analysis. After propensity score weighting, ticagrelor was comparable to clopidogrel in the incidence rate of the primary efficacy end point (23.6 vs. 22.76/100 patient-years; hazard ratio (HR) 0.97; 95% confidence interval (CI) 0.89-1.06; P = 0.513). Ticagrelor was associated with a lower risk of stroke (1.78 vs. 2.66/100 patient-years; HR 0.64; 95% CI 0.49-0.85; P = 0.002) and higher risks of overall (21.59 vs. 18.35/100 patient-years; HR 1.16; 95% CI 1.06-1.27; P = 0.002) and Bleeding Academic Research Consortium (BARC) type 2 bleeding (18.67 vs. 15.08/100 patient-years; HR 1.22; 95% CI 1.11-1.36; P < 0.001). The risks of death, MI, and BARC 3 or 5 bleeding were comparable between ticagrelor and clopidogrel. In the present study, ticagrelor was comparable to clopidogrel in the composite of death, MI, and stroke, but had an increased risk of BARC type 2 bleeding. Ticagrelor may be beneficial in preventing post-MI stroke in East Asian patients.

Pharmacokinetics and bioequivalence of low-dose clopidogrel in healthy Chinese volunteers under fasted and fed conditions

Clopidogrel is an antiplatelet drug whose performance at a low dose (25 mg) have not been evaluated in Chinese patients, who may be subject to different effects from Caucasians. We carried out this evaluation and compared a generic (Taijia) and a reference drug (Plavix^®). We evaluated Taijia and Plavix^® in 128 subjects, with 64 in a fasted state and 64 receiving a high-fat diet, and computed C_max, AUC_0-∞, and AUC_0-t. Reference-scaled average bioequivalence (RSABE) methods and average bioequivalence (ABE) methods were used, and adverse events were assessed. Average maximum plasma concentrations (C_max) of clopidogrel were significantly greater after 25 mg dose under fed conditions compared to fasted. Reference-scaled C_max, AUC_0-t, and AUC_0-∞ were higher than the 0.294 cutoff during fasted, meeting RSABE criteria. Under fed conditions, S_WR for AUC_0-t and AUC_0-∞ were lower than 0.294, permitting use of ABE. The 90% confidence intervals for AUC_0-t and AUC_0-∞ indicated bioequivalence. Pharmacokinetic parameters differed between fasted and fed states. The generic product was bioequivalent to the reference drug, and was safe and well tolerated. This suggests that they can be used interchangeably in a clinical setting.

Cardiovascular and Bleeding Risks in Acute Myocardial Infarction Newly Treated With Ticagrelor vs. Clopidogrel in Taiwan

BACKGROUND

There are few data on ticagrelor in Asian patients. This study evaluated clinical outcomes with ticagrelor and clopidogrel in Taiwanese patients with acute myocardial infarction (AMI).Methods and Results:We used the Taiwan National Health Insurance Research Database to identify 27,339 AMI patients aged ≥18 years between January 2012 and December 2014, and only patients who survived greater than or equal to 30 days after AMI and took dual antiplatelet therapy were included. Cohorts of ticagrelor and clopidogrel were matched 1:8, based on propensity score matching, to balance baseline covariates. The primary efficacy endpoints were death from any cause, AMI, or stroke. The safety endpoints consisted of major gastrointestinal bleeding or intracerebral hemorrhage. Following propensity matching, the primary efficacy endpoint rate was 22% lower in the ticagrelor group than in the clopidogrel group (10.6% and 16.2%, respectively; adjusted HR, 0.779; 95% CI: 0.684-0.887). The safety endpoint rate was similar between the ticagrelor and clopidogrel groups (3.2% and 4.1% respectively; adjusted HR, 0.731; 95% CI: 0.522-1.026).

CONCLUSIONS

In real-world AMI Taiwanese patients, ticagrelor seemed to offer better anti-ischemic protection than clopidogrel, without an increase in the rate of major bleeding. A large-scale randomized trial is needed to assess the efficacy and safety of ticagrelor in East Asian AMI patients.

World heart federation expert consensus statement on antiplatelet therapy in east asian patients with ACS or undergoing PCI

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.

Expert consensus document: World Heart Federation expert consensus statement on antiplatelet therapy in East Asian patients with ACS or undergoing PCI

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.