Efficacy and safety of standard and low dose ticagrelor versus clopidogrel in east AsianPatients with chronic total occlusion undergoing percutaneous coronary intervention: a single center retrospective study

Influence of early dose reduction of ticagrelor on clinical outcomes following percutaneous coronary intervention for complex lesions

Ticagrelor-based dual antiplatelet therapy (DAPT) provides potent antiplatelet inhibition but may increase the bleeding risk in Asian populations. We investigated the influence of early ticagrelor dose reduction (120 mg) on clinical outcomes in Korean patients undergoing percutaneous coronary intervention (PCI). A multicenter prospective clinical cohort study was conducted with patients who received standard-dose ticagrelor-based DAPT (180 mg) after PCI for complex lesions. Major adverse cardiovascular event (MACE: a composite of cardiovascular death, myocardial infarction, stroke, and repeat revascularization), bleeding, and net adverse clinical events (NACE: a composite of MACE and bleeding) were assessed. Among the 772 patients on standard-dose ticagrelor-based DAPT, 115 (14.8%) switched to low-dose ticagrelor-based DAPT (120 mg) within 6 months. Common reasons for the regimen changes were switching as planned (38.8%), dyspnea (25.5%), and bleeding (23.6%). A multivariable Cox proportional hazard model (CPH) showed that the risks of MACE, bleeding, and NACE were not different between the low-dose and standard-dose groups throughout the entire follow-up period and the period beyond 6 months post-PCI. Time-varying multivariable CPH models of the ticagrelor dose reduction yielded similar results. A reduction of the ticagrelor dose within 6 months after PCI is feasible and safe even in patients with complex lesions harboring a high ischemic event risk.

Ticagrelor is related to nuisance bleeding after flow diversion of unruptured intracranial aneurysms

Nuisance bleeding (NB) without urgent medical attention is rarely characterized despite its frequent occurrence in patients with cerebral aneurysms undergoing flow diversion (FD) who are maintained on dual antiplatelet therapy (DAPT). This study explored the risk factors for NB. Patients with unruptured cerebral aneurysms who underwent intervention using FD (July 2018 to May 2022) and had follow-up data were enrolled. Patient demographics, clinical characteristics, aneurysm features and follow-up data were analysed. Bleeding complications were classified as NB, internal bleeding and alarming bleeding. NB was characterized by easy bruising, bleeding from small cuts and nonfatal petechiae and ecchymosis. Univariate and multivariate logistic regression analyses were performed to determine risk factors for NB. This study assessed 121 patients. Of these, 52 (43.0%) patients had NB. Compared with the non-bleeding group, the NB group had more females (82.7% vs. 56.5%; p = 0.003), lower smoking rate (7.7% vs. 23.2%; p = 0.027) and smaller aneurysms (6.65 mm [4.60-9.60 mm] vs. 8.82 mm [5.65-15.65 mm]; p = 0.007) and had more patients maintained on ticagrelor-containing DAPT regimen (90.4% vs. 66.7%; p = 0.002). Multivariate logistic regression revealed that ticagrelor-containing DAPT regimen (odds ratio, 3.91; 95% confidence interval, 1.29-11.87; p = 0.016) was associated with NB. These results suggest that NB is a common bleeding complaint in patients on DAPT. In patients undergoing FD, DAPT with ticagrelor was the only independent risk factor for NB.

Efficacy and Safety of Aspirin Combined with Low-Dose P2Y12 Receptor Antagonists in East Asian Patients Undergoing PCI

Previous studies have indicated that low-dose new generation of P2Y12 receptor antagonists may be more suitable compared with clopidogrel at a standard dose for the dual antiplatelet therapy (DAPT) for East Asian patients receiving percutaneous coronary intervention (PCI). However, there remains no consensus in clinical practice. Thus, in this study, we aimed to determine the efficacy and safety of low-dose P2Y12 receptor antagonists, compared to clopidogrel at a standard dose, in DAPT in East Asian patients after PCI. We systematically searched literatures for randomized controlled trials (RCT) comparing low-dose P2Y12 receptor antagonists with standard-dose clopidogrel for the treatment of East Asian patients undergoing PCI. The endpoints of efficacy include major adverse cardiac events (MACEs), all-cause mortality, and the number of target vessel revascularization. The indicators of safety include major and minor bleeding events. Heterogeneity was evaluated by I² statistic test. Begg's and Egger's tests were used to evaluate publication bias. In total, 2,747 subjects from 8 RCT studies were included. Low-dose new P2Y12 receptor antagonists, that is, ticagrelor or prasugrel, showed significantly lower incidence of MACEs, as compared with standard-dose clopidogrel, in the East Asian patients who are in DAPT after undergoing PCI. Further, no difference was noted for the risk of major and minor bleeding events. In East Asian patients undergoing PCI and receiving DAPT, the use of low-dose P2Y12 receptor antagonists, ticagrelor or prasugrel, has been determined to be superior than clopidogrel at standard dose; this has been evidenced by a lower incidence of MACEs without increasing the risk of bleeding.

Antithrombotic Therapy in Chronic Total Occlusion Interventions

Chronic total occlusion (CTO) recanalization is among the most complex subsets of coronary interventions. Hence, optimum peri- and post-procedural anticoagulation and antiplatelet therapy is key for the achievement of successful revascularization and reduction of major adverse cardiovascular outcomes in patients undergoing CTO percutaneous coronary intervention (PCI). Unfractionated heparin is still considered the gold standard anticoagulant because its action can be reversed by protamine administration, with bivalirudin being reserved mainly for patients with heparin-induced thrombocytopenia. However, small studies comparing unfractionated heparin with bivalirudin in CTO interventions have shown similar outcomes. Glycoprotein IIb/IIIa inhibitors should, in general, be avoided. Aspirin in combination with clopidogrel for 6–12 months is the standard post CTO PCI dual antiplatelet regimen. For the most complex cases, clopidogrel can be substituted by a more potent P2Y12 inhibitor, namely ticagrelor or prasugrel.

Pharmacodynamic and clinical efficacy of reduced ticagrelor maintenance doses in patients with coronary artery disease

OBJECTIVE

An increasing body of data indicates that a reduction of ticagrelor maintenance dose (MD) in stabilized patients might improve ticagrelor's safety profile and adherence to the treatment. The aim of this review was to discuss the rationale and summarize the current pharmacodynamic and clinical outcomes-based evidence from reduced MD of ticagrelor in patients with coronary artery disease (CAD).

METHODS

A narrative systematic review based on a literature search using the PubMed database from its inception through to June 2020. A search strategy included a combination of relevant search terms regarding ticagrelor reduced MD. The pre-determined inclusion criteria were: (1) randomized or observational trials; (2) presentation of clinical or pharmacodynamic results; (3) evaluation of any ticagrelor MD below 90 mg BID in patients with CAD.

RESULTS

Studies evaluating the following ticagrelor reduced MD have been identified: 90 mg QD, 60 mg BID, 60 mg QD, 45 mg BID, 22.5 mg BID. Majority of trials assessing doses <60 mg BID were performed in Asian patients only. Antiplatelet effect of ticagrelor in CAD decreases with the dose, however even reduced MDs provide sufficient platelet inhibition, which is greater than in clopidogrel-treated patients. De-escalation of ticagrelor dose shows a propensity towards a reduced rate of bleeding and non-bleeding adverse events.

CONCLUSIONS

Ticagrelor doses below 90 mg BID generally show an acceptable profile of platelet inhibition. The number of studies reporting clinical outcomes in CAD patients receiving reduced MD of ticagrelor are limited, however available results indicate that in a stable setting this strategy offers improved safety with preserved efficacy in the prevention of thrombotic events.