A novel risk score to identify the need for triple antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention: a post hoc analysis of the RE-DUAL PCI trial.

BACKGROUND: Current guidelines recommend treating atrial fibrillation (AF) patients who undergo percutaneous coronary intervention (PCI) with triple antithrombotic therapy (TAT) for up to one month in patients at high thrombotic risk. It is unclear how to select these high-risk patients. AIMS: The aim of this study was to identify patients at high thrombotic risk who might benefit from TAT over double antithrombotic therapy (DAT). METHODS: This study was a post hoc subanalysis of the RE-DUAL PCI trial. A Cox proportional hazards model was built by stepwise selection of plausible predictor variables for a composite ischaemic endpoint, defined as cardiovascular death, myocardial infarction (MI), stent thrombosis (ST) or ischaemic stroke. The effect of TAT versus DAT was calculated for those patients with the highest proportion of predicted thrombotic risk. A simplified risk score was constructed based on beta-coefficients. RESULTS: For 209 patients (7.7%) the composite ischaemic endpoint occurred during the first year. The simplified risk score contained six variables. In patients with a score ≥5 (n=154, 5.7%), a significant reduction in the composite of MI and ST was observed with TAT versus DAT (6.3% vs 21.0%, p=0.041), without a penalty in terms of bleeding. In patients at low thrombotic risk, a significant increase in bleeding was observed without a reduction of ischaemic events. CONCLUSIONS: Our findings support the use of DAT in the majority of patients. A small subgroup of patients might benefit from TAT and we propose a novel clinical risk score to select these patients.

Dual versus triple antithrombotic therapy after percutaneous coronary intervention: the prospective multicentre WOEST 2 Study.

BACKGROUND: For patients on oral anticoagulants (OAC) undergoing percutaneous coronary intervention (PCI), European guidelines have recently changed their recommendations to dual antithrombotic therapy (DAT; P2Y12 inhibitor and OAC) without aspirin. AIMS: The prospective WOEST 2 registry was designed to obtain contemporary real-world data on antithrombotic regimens and related outcomes after PCI in patients with an indication for OAC. METHODS: In this analysis, we compare DAT (P2Y12 inhibitor and OAC) to triple antithrombotic therapy (TAT; aspirin, P2Y12 inhibitor, and OAC) on thrombotic and bleeding outcomes after one year. Clinically relevant bleeding was defined as Bleeding Academic Research Consortium classification (BARC) grade 2, 3, or 5; major bleeding as BARC grade 3 or 5. Major adverse cardiac and cerebrovascular events (MACCE) was defined as a composite of all-cause mortality, myocardial infarction, stent thrombosis, ischaemic stroke, and transient ischaemic attack. RESULTS: A total of 1,075 patients were included between 2014 and 2021. Patients used OAC for atrial fibrillation (93.6%) or mechanical heart valve prosthesis (4.7%). Non-vitamin K oral anticoagulants (NOAC) were prescribed in 53.1% and vitamin K antagonists in 46.9% of patients. At discharge, 60.9% received DAT, and 39.1% TAT. DAT was associated with less clinically relevant and similar major bleeding (16.8% vs 23.4%; p<0.01 and 7.6% vs 7.7%, not significant), compared to TAT. The difference in MACCE between the two groups was not statistically significant (12.4% vs 9.7%; p=0.17). Multivariable adjustment and propensity score matching confirmed these results. CONCLUSIONS: Dual antithrombotic therapy is associated with a substantially lower risk of clinically relevant bleeding without a statistically significant penalty in ischaemic events.

Antithrombotic therapy in patients undergoing transcatheter aortic valve implantation.

This review provides a comprehensive overview of the available data on antithrombotic therapy after transcatheter aortic valve implantation (TAVI). In the absence of large randomised clinical trials, clinical practice is leaning towards evidence reported in other populations. Due to the greater risk of major bleeding associated with oral anticoagulation using a vitamin-K antagonist (VKA), antiplatelet therapy (APT) may be considered as the first-line treatment of patients undergoing TAVI. Overall, single rather than dual APT is preferred. However, dual APT should be considered in patients with a recent acute coronary syndrome (ie, within 6 months), complex coronary stenting, large aortic arch atheromas or previous non-cardioembolic stroke. Monotherapy with VKA should be considered if concomitant atrial fibrillation or any other indication for long-term oral anticoagulation is present. APT on top of VKA seems only reasonable in patients with recent acute coronary syndrome, extensive or recent coronary stenting or large aortic arch atheromas. A direct-acting oral anticoagulant may be considered if oral anticoagulation is indicated in the absence of contraindications. Initiation of VKA is indicated in clinical valve thrombosis, for example, with high transvalvular gradient, whereas the role of VKA in the case of subclinical leaflet thrombosis is currently uncertain.

Usefulness of Clopidogrel Loading in Patients Who Underwent Transcatheter Aortic Valve Implantation (from the BRAVO-3 Randomized Trial).

P2Y12-inhibitor initiation with clopidogrel using a loading dose (LD) versus no LD (NLD) provides more rapid inhibition of platelet activation and reduced risk of ischemic events after coronary stenting. Whether a similar beneficial effect is achieved in the setting of transcatheter aortic valve implantation (TAVI) is unknown. We evaluate the effects of preprocedural clopidogrel LD versus no NLD on 48-hour and 30-day clinical outcomes after TAVI. In the BRAVO-3 trial, 802 patients with severe aortic stenosis who underwent transfemoral TAVI were randomized to intraprocedural anticoagulation with bivalirudin or unfractionated heparin. Administration of clopidogrel LD was left to the discretion of the treating physician. For this analysis, patients were stratified according to receiving clopidogrel LD (n = 294, 36.6%) or NLD (n = 508, 63.4%) before TAVI. LD patients more often received a self-expandable prosthesis using larger sheaths. P2Y12-inhibitor maintenance therapy pre-TAVI was similar in patients with LD versus NLD (28.2% vs 33.1%, p = 0.16). LD versus NLD was associated with similar incidences of major adverse cardiovascular events (i e., death, myocardial infarction, or stroke) (4.1% vs 4.1%, p = 0.97) and major bleeding (8.5% vs 7.7%, p = 0.68), but a higher rate of major vascular complications (11.9% vs 7.1%, p = 0.02). Multivariable adjustment showed that clopidogrel LD did not affect any of the studied clinical events, including major vascular complications (odds ratio 0.91, 95% confidence interval 0.60 to 1.39, p = 0.67). Also patients on clopidogrel maintenance therapy and thus considered in steady state were not at reduced risk of major adverse cardiovascular events compared with patients not on clopidogrel (3.7% vs 5.2%, p = 0.36). In conclusion, in patients who underwent TAVI, use of clopidogrel LD was associated with higher vascular complications and otherwise similar clinical events compared to NLD patients.

Towards personalized medicine based on platelet function testing for stent thrombosis patients.

Stent thrombosis (ST) is a severe and feared complication of coronary stenting. Patients who have suffered from ST are usually treated according to the "one-size-fits-all" dosing regimen of aspirin and clopidogrel. Many ST patients show high on-treatment platelet reactivity (HPR) despite this antiplatelet therapy (APT). It has been shown that HPR is a risk factor for major adverse cardiac events. Therefore, ST patients with HPR are at a high risk for recurrent atherothrombotic events. New insights into the variable response to clopidogrel and the advent of stronger P2Y12 inhibitors prasugrel and ticagrelor have changed the attention from a fixed APT treatment strategy towards "personalized APT strategies." Strategies can be based on platelet function testing, which gives insight into the overall response of a patient to APT. At our outpatient ST clinic, we practice personalized APT based on platelet function testing to guide the cardiologist to a presumed optimal antiplatelet treatment of ST patients. Beside results of platelet function testing, comedication, clinical characteristics, and genetics have to be considered to decide on personalized APT. Ongoing studies have yet to reveal the optimal personalized APT strategy for cardiologists to prevent their patients from atherothrombotic and bleeding events.