[Basics for the Use of Andexanet]

BACKGROUND

 For life-threatening or uncontrollable bleeding in association with the thrombin inhibitor dabigatran, the monoclonal antibody fragment idarucizumab is available, and for bleeding in association with the direct factor Xa inhibitors rivaroxaban or apixaban, the modified recombinant FXa protein andexanet is available for reversal. These antidotes represent emergency drugs that are typically used only after performing guideline-compliant multimodal measures.

METHODS

 An interdisciplinary group of experienced experts in the fields of angiology, hematology, internal medicine, clinical pharmacology, laboratory medicine, transfusion medicine, anesthesiology, intensive care, and hemostaseology developed recommendations relevant to daily clinical practice based on the current scientific evidence.

RESULTS

 Reversal of oral anticoagulants should be considered for severe bleeding in the following situations: (1) life-threatening bleeding or refractory hemorrhagic shock, (2) intracerebral bleeding, or (3) endoscopically unstoppable gastrointestinal bleeding. After successful hemostasis, anticoagulation (e.g., direct oral anticoagulant, vitamin K antagonist, and heparin) should be resumed promptly, taking into account individual bleeding and thromboembolic risk.

DISCUSSION

 This article aims to facilitate the management of patients with andexanet by all medical disciplines involved, thereby ensuring optimal care of patients during bleeding episodes.

Association of coagulation markers and antiphospholipid antibodies with ischemic and bleeding risk in patients with atrial fibrillation undergoing percutaneous coronary intervention

Background

Antiphospholipid antibodies and other coagulation markers are associated with ischemic risk in patients with coronary artery disease without oral anticoagulation (OAC).

Aim

To assess the association of antiphospholipid antibodies (aPL) and conventional markers of coagulation with ischemic and bleeding risk in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI).

Patients and methods

In this prospective single center observational cohort study, patients with AF and an indication for OAC were enrolled after PCI. Dilute Russell's viper venom time (DRVVT) was used to determine lupus anticoagulants (LA) in direct OAC-free plasma. Anti-cardiolipin IgG (aCL), IgM and anti-beta2GP-1-IgG (aβ2GP1) were analyzed by enzyme linked immunosorbent assay (ELISA). Fibrinogen C (FIBC), d-dimers and prothrombin fragments 1 and 2 (PF1+2) were measured in citrated plasma. Immature platelet fraction (IPF [%]) and absolute (IPF abs. [103/μl]) were measured in EDTA-blood. The primary ischemic outcome was defined as time to major adverse cardiovascular events (MACE: all-cause death, myocardial infarction, or stroke) assessed at 6 months. Bleeding was defined according to the International Society of Thrombosis and Haemostasis (ISTH) and the Bleeding Academic Research Consortium (BARC).

Results

158 patients were enrolled between May 2020 and May 2021. The median age was 78 years (interquartile range, IQR 72–82), 111 (70%) were male, and 39 (25%) presented with acute coronary syndrome. All Patients were treated with clopidogrel and OAC, 145 (92%) in addition with acetylsalicylic acid (ASA). 32 patients (20%) had ≥1 antiphospholipid antibody (aPL; LA: 19 [12%], aCL: 14 [9%], aβ2GP1: 2 [1%]). D-dimers were elevated in 74 patients (47%), FIBC was increased in 40 (25%) and PF1+2 in 68 patients (43%). IPF [%] was elevated in 28 (18%) and IPF abs. [103/μl] in 11 (7%). The presence of aPL was neither significantly associated with MACE, nor with bleeding risk. Elevated d-dimers were significantly associated with higher risk for MACE (HR=5.1, 95% CI [1.1; 23.4], p=0.04), major ISTH bleeding events (HR= 6.9, 95% CI [1.5; 30.8], p=0.01) and BARC bleeding type 3 or 5 (HR=6.4, 95% CI [1.4; 28.7], p=0.02). Increased levels of FIBC were associated with risk of MACE (HR= 3.6, 95% CI [1.1; 12.0], p=0.03 (Table 1).

Conclusion

In patients with AF undergoing PCI, high levels of d-dimers and fibrinogen C indicate an increased ischemic risk. Elevated d-dimers are associated with higher risk for bleeding. aPL positivity was not significantly associated with outcome possibly due to low sample size. A combined panel of biomarkers might be suitable to assess ischemic and bleeding risk in patients with AF following PCI.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Faculty of Medicine, Freiburg

Comparison of various late gadolinium enhancement magnetic resonance imaging methods to high-definition voltage and activation mapping for detection of atrial cardiomyopathy

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic

Background/Introduction

Atrial cardiomyopathy (ACM) is associated with the progression from paroxysmal through persistent to permanent atrial fibrillation (AF) and increased arrhythmia recurrence rates after pulmonary vein isolation (PVI).

Purpose

We compare the most common left atrial (LA) late gadolinium enhancement magnetic resonance imaging (LGE-MRI)-methods (Utah-method and image-intensity-ratio (IIR)-methods) and endocardial voltage mapping for ACM-detection and outcome prediction after PVI for AF.

Methods

In this prospective study, 37 ablation-naive patients (66±9 years, 84% male) with persistent AF were included and electrically cardioverted into sinus rhythm. Subsequently, they underwent LA-LGE-MRI and high-definition voltage and activation mapping (2129±484 sites) in sinus rhythm prior to PVI. MRI-post-processing-analyses were performed by two independent expert laboratories (Marrek for the Utah segmentation as describers of this methodology and Adas 3D medical as developers of the Adas software for the IIR-methods) which were blinded to any clinical data. Arrhythmia recurrence was recorded within 12 months following PVI.

Results

The global ACM-extent was highly variable: median LA low-voltage substrate (LA-LVS) was 12.9% at <1.0mV and 2.7% at <0.5mV; median LA-LGE-extent using the Utah-method was 18.3% and 0.03%-93.1% using the IIR-methods. LA activation time was significantly correlated with LA-LVS (r=0.76 at <0.5mV and r=0.82 at <1.0mV, both p<0.0001), but not with LA-LGE-extent.

The highest regional matching between LA-LVS <0.5mV and LA-LGE was found for the anterior wall in 57% of patients using the Utah-method and in 59% using IIR 1.20. The corresponding values for the posterior wall were 19% and 38%, respectively.

Arrhythmia recurrence occurred in 15 (41%) patients. Freedom from arrhythmia was significantly lower in those with relevant LA-LVS (≥2cm2 at 0.5mV) but not in those with relevant LGE (Utah-stages III&IV): 43% versus 81%, p=0.009 and 50% versus 67%, p=0.338, respectively. Furthermore, relevant

LA-LVS was the only predictor for arrhythmia recurrence in multivariate regression analysis.

Conclusion

The different LA-LGE-MRI methods have large dicrepancies regarding extent and distribution of ACM and are different to the extent and regional distribution of LA-LVS as assessed in endocardial high-definition voltage mapping in sinus rhythm. Further improvements of the LA-LGE-MRI-methods are required to enable correct diagnosis of ACM and for future evaluation of MRI-guided ablation protocols.

Vericiguat: a QTc interval study in patients with coronary artery disease

Background

Vericiguat is a soluble guanylate cyclase stimulator developed for the treatment of symptomatic chronic heart failure (HF) in adult patients with ejection fraction less than 45% who had a previous decompensation event. Guidelines on QT studies recommend evaluation of investigational drugs at supratherapeutic exposures in healthy volunteers. We anticipated that supratherapeutic doses of vericiguat would decrease blood pressure. We conducted an adjusted QT study using the therapeutic range of vericiguat in patients with coronary artery disease (CAD), who were expected to be more haemodynamically stable with fewer confounders (e.g., on the electrocardiogram) than a HF population.

Purpose

To assess the effect of vericiguat 10 mg once-daily on placebo-adjusted change from baseline of the Fridericia-corrected QT interval (QTcF) in patients with stable CAD.

Methods

This was a randomised, Phase Ib, placebo-controlled, double blind, double-dummy, multicentre study (NCT03504982). Test drug was vericiguat once-daily (up-titrated from 2.5 mg to 5 mg and then to 10 mg [treatments A, B, C] at 14-day intervals). The positive control was moxifloxacin 400 mg (single dose on Day 8 or Day 50 with placebo on other days [treatment D]; Figure). Patients were randomised to one of two sequences.

We evaluated QTcF interval prolongation potential of vericiguat at increasing doses up to 10 mg, steady state. We investigated the pharmacokinetics, safety and tolerability of vericiguat. A clinically meaningful effect was defined as a QTcF change from baseline >10 ms relative to placebo. Assay sensitivity for moxifloxacin was confirmed by the lower limit of the 90% confidence interval (CI) of the time-matched, baseline-adjusted mean difference to placebo exceeding 5 ms at >1 time point.

Results

A total of 74 patients (66 males and 8 females) with CAD, mean (standard deviation) age 63.4 (8.0) years, were included. Mean difference between vericiguat and placebo in QTcF change from baseline (≤7 h post-dose) was <6 ms; no upper limit of the 90% CIs crossed the threshold of 10 ms. Lower limits of the two-sided 90% CI of the differences between moxifloxacin and placebo in QTcF change from baseline were >5 ms at 3 of 4 time points (Table).

Peak plasma concentration (Cmax) of vericiguat following administration of vericiguat 10 mg was 322 μg/l and median time of maximum concentration (Tmax) was 4.5 h post-dose, in line with concentrations observed following administration of vericiguat 10 mg to patients with HF [1]. For moxifloxacin 400 mg, Cmax was 1960 μg/l and median Tmax was 3 h post-dose, in line with previously reported values [2]. Vericiguat up to 10 mg was generally safe and well tolerated.

Conclusion

This study supports the assessment that administration of vericiguat 10 mg is not associated with clinically meaningful QTc prolongation. These data contribute to the overall safety profile of vericiguat for the treatment of patients with HF.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Funding was provided by Bayer AG, Berlin, Germany, and Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA QTc study design

Next Generation Sequencing reveals profound transcriptomic differences between reticulated and non-reticulated platelets from healthy donors, CCS- and STEMI patients

Background

The youngest circulating platelets – so called reticulated platelets (RP) – represent a highly prothrombotic platelet subpopulation. Previous studies showed that patients with chronic coronary syndrome (CCS) as well as patients with ST-elevation myocardial infarction (STEMI) have higher amounts of RP compared to healthy subjects. It has been suggested that intrinsic properties of RP impact on cardiovascular risk. However, it is unknown if transcriptomic alterations contribute to the prothrombotic properties of RP.

Purpose

This study sought to investigate differences in the transcriptomic landscape of sorted RP versus non-RP, i.e. young and old platelets, in healthy subjects, CCS- and STEMI-patients.

Methods

Blood samples were obtained from healthy subjects as well as from patients with CCS/STEMI (n=8 each) the day after PCI. After staining with SYTO 13, platelets from each donor were sorted into a RP and a non-RP fraction based on their RNA-content. Next Generation Sequencing (NGS) was applied to generate sequencing reads for sorted RP and non-RP from the 3 cohorts. Data was analyzed by use of the Freiburg bioinformatics platform “Galaxy”.

Results

Investigation of transcriptomic alterations in non-RP versus RP by differential gene expression analysis revealed a total number of 2,476 transcripts that were differentially expressed in platelets from healthy donors, 2,075 in CCS-patients and 1,852 in STEMI patients, respectively (adj. p<0.05 in all analyses). Comparison of these transcripts revealed a large overlap of 500 mRNAs which were downregulated and 660 mRNAs which were upregulated in RP in all 3 cohorts. However, there are also distinct groups of transcripts that are differentially expressed in only one of the 3 cohorts. Gene ontology (GO)-analysis of the 500 uniformly enriched transcripts in RP yielded 38 overrepresented GO-terms. A large group was related to cytoskeleton and shape change. Furthermore, GO-terms associated to the platelet activation cascade were overrepresented. Upregulated transcripts included well-known examples like GP6 and GP9, P-selectin, integrin β3, integrin a-IIb, and tubulin α4a. GO-analysis of enriched transcripts in non-RP showed a large group associated to mitosis and cell nucleus/DNA which is surprising since platelets neither contain DNA nor a nucleus. Gene set enrichment analysis (GSEA) determined higher normalized enrichment scores for several gene sets associated to platelet degranulation, aggregation and activation in the STEMI-cohort. Gene sets affecting cell adhesion and platelet calcium homeostasis were overexpressed in particular in CCS-patients.

Conclusion

NGS-results indicate a highly prothrombotic transcriptome of RP from each cohort with high amounts of differentially expressed transcripts overlapping. However, GSEA identified gene sets that are particularly overexpressed in CCS- or STEMI-patients which might contribute to platelet hyperreactivity in these cohorts.

Gene set enrichment analysis

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): PharmCompNet Baden-Wuerttemberg: Kompetenznetzwerk Pharmakologie Baden-Wuerttemberg - Wirkstoffnetzwerke als Grundlagen der individualisierten Arzneistofftherapie

Impact of on-clopidogrel platelet reactivity on incidence of peri-interventional bleeding in patients undergoing transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) has become clinical routine for patients at intermediate to high risk for surgical aortic valve replacement. The optimal antithrombotic strategy following TAVI is still not well defined. Antithrombotic treatment is administered to prevent hypo-attenuated leaflet thickening, valve thrombosis, or ischemic stroke. However, most of these patients are also at high risk for bleeding. Current guidelines recommend dual antiplatelet therapy although the clinical evidence is limited.

Methods

This analysis enrolled patients undergoing TAVI from 11/2013 until 04/2018. Patients were either on long-term dual antiplatelet therapy with clopidogrel and aspirin or received a loading dose 300 to 600mg of clopidogrel and 400mg aspirin before TAVI. Platelet reactivity was determined by multi-electrode impedance aggregometry after stimulation with arachidonic acid and adenosine diphosphate (ADP) before TAVI as well as at day 1 and 5 thereafter. Peri-interventional bleeding was assessed up to 5 days following TAVI and coded according to BARC-classification.

Results

The present analysis included 484 patients (median age 83 [79–86] years; female sex 54.5%). There were 199 (41.1%) patients with a bleeding event. Most frequent were BARC 2 bleedings in 117 (24.2%) cases followed by BARC 1 (6.0%), BARC 3b in 25 (5.2%) and BARC 3a in 22 (4.5%) cases. On-clopidogrel platelet reactivity tested after stimulation with ADP was significantly lower in patients with bleeding events as compared to patients without bleeding (Figure). No differences were observed in arachidonic acid-induced platelet reactivity as marker for aspirin-efficacy between both groups over time. Multivariate logistic regression analysis identified on-clopidogrel platelet reactivity and use of oral anticoagulation as strongest independent predictors for bleeding events.

Conclusion

On-clopidogrel platelet reactivity is an independent predictor for peri-interventional bleeding in patients undergoing TAVI. Taken together with previous data indicating no association of on-clopidogrel platelet reactivity with peri-interventional ischemic events, the present data question the need for a strong peri-interventional dual antiplatelet therapy in patients undergoing TAVI.

Funding Acknowledgement

Type of funding source: None

55Non-invasive ECG-imaging for identification of atrial arrhythmogenic low voltage substrate in patients with persistent atrial fibrillation

Background/Introduction

Left atrial (LA) fibrosis is associated with increased arrhythmia recurrence rates after pulmonary vein isolation (PVI) and increased stroke risk in patients with atrial fibrillation (AF). So far, detection and quantification of LA fibrosis is only feasible by invasive electrophysiological mapping of low-voltage-substrate (LVS) or delayed enhancement areas in MRI.

Purpose

The aim of this study was to assess the distribution and extent of atrial fibrosis by non-invasive ECG-Imaging (ECGI) in patients with persistent AF prior to PVI.

Methods

Thirty-seven consecutive patients (66 ± 9 years, 84% male) presenting for their first PVI were included. Patients with AF were cardioverted into sinus rhythm (SR). One day prior to AF ablation procedure, patients underwent ECGI in SR using the 252-electrode-array (CardioInsight) and a low-X-ray-dose, non-injected cardiac CT-scan to assess the relationship between ECGI-electrodes and cardiac epicardial structures. Prior to PVI, high-density biatrial voltage and activation maps were acquired in SR (CARTO-3). Localization and extent of atrial LVS (relevant fibrosis: LA-LVS: ≥5cm2 at <0.5mV threshold) and biatrial activation times depicted by CARTO were compared with atrial activation/conduction times assessed by non-invasive ECGI.  Presence of LA-LVS was classified according to its extent into 3 stages and compared to the inter- and intraatrial conduction delay in ECGI.

Results

Relevant atrial fibrosis was found in 17/37(46%) patients. Presence of biatrial LVS resulted in a linear increase of the biatrial activation time in CARTO-SR-maps (146 ± 18ms in patients without LVS vs 184 ± 27ms in patients with LVS, p < 0.001) and in non-invasive ECGI (133 ± 11ms vs 170 ± 20ms, p < 0.001).

Both the extent of biatrial LVS and invasively measured total activation time correlated well with non-invasive total atrial conduction time (TACT) in ECGI (r = 0.91 and r = 0.82, respectively, figure). Moreover, the extent of LA-LVS showed an excellent correlation to TACT in ECGI (r = 0.89).

A combination of inter-atrial (RA-LA) conduction delay and TACT in ECGI allowed to quantify the extent of LA-LVS and to distinguish between three stages of LA-LVS: Stage 1 (minimal LA-LVS: 1 ± 2cm2): ECGI revealed rapid RA&LA activation with short TACT 132 ± 9ms; Stage 2 (moderate LA-LVS: 14 ± 8cm2 involving the anteroseptal LA) was associated with delayed LA activation and prolonged TACT measuring 161 ± 7ms; Stage 3 (extensive LA-LVS involving the anteroseptal and posterior LA: 26 ± 17cm2) was characterized by a significantly delayed LA activation with a TACT of 178 ± 24ms in ECGI.

Conclusion

Analysis of interatrial conduction delay and total atrial conduction time (TACT) in non-invasive ECGI allows accurate staging of patients with arrhythmogenic atrial LVS who present an increased risk for arrhythmia recurrences and stroke.

Abstract Figure.

2349Selatogrel, a novel P2Y12 inhibitor for emergency use, achieves rapid, consistent and sustained platelet inhibition following single-dose subcutaneous administration in stable CAD patients

Background

In the setting of AMI, rapid platelet inhibition is desirable but the onset of pharmacodynamic (PD) effect of oral platelet P2Y12 inhibitors is delayed, sometimes for hours. Subcutaneous (s.c) administration of a rapidly-acting P2Y12 inhibitor would overcome many of the limitations of available therapies. Patients with stable CAD were investigated initially.

Purpose

To characterise the inhibition of platelet aggregation and pharmacokinetics (PK) of a single dose of selatogrel, a novel s.c P2Y12 inhibitor, in patients with stable CAD.

Methods

Patients with stable CAD receiving oral antiplatelet therapy (aspirin and/or oral P2Y12 inhibitor) were randomized to 1 of 8 groups based on treatment (selatogrel or matching placebo), dose (8 mg or 16 mg) and s.c injection site (thigh or abdomen). Venous blood samples were collected into PPACK anticoagulant tubes. Platelet reactivity was assessed by VerifyNow PRU (P2Y12 reaction units) test before and 15 min, 30 min and 1, 2, 4, 8 and 24 h after injection. Light-transmittance aggregometry (LTA; ADP 20 uM) was also performed. PK samples were collected up to 24 h post-dose. Adverse events occurring within 30 days were recorded. Responders were defined as having PRU <100 at 30 min after injection and lasting ≥3 h.

Results

345 patients (mean age 65 y; 20% female; 31% diabetes) received selatogrel 8 mg (n=114), selatogrel 16 mg (n=115) or placebo (n=116). 97% were on background therapy with aspirin (or its derivative carbasalate) and 35% with oral P2Y12 inhibitor (clopidogrel 23%, prasugrel 4%, ticagrelor 8%). 89% of subjects were responders to selatogrel 8 mg, 90% to selatogrel 16 mg and 16% to placebo (P<0.0001). At 15 min post-dose, PRU values (mean±SD) were 10±25 with selatogrel 8 mg, 5±10 with selatogrel 16 mg and 163±73 with placebo (Figure). PRU levels were maintained at 2 and 4 h for both doses and gradually returned to pre-dose levels by 24 h post-dose (Figure). LTA results were consistent with the VerifyNow results. PD responses were similar for thigh and abdomen injection sites. Selatogrel was well tolerated: mild dyspnoea (or moderate dyspnoea, n=1, with 16 mg) occurred in 5% and 9% with selatogrel 8 mg and 16 mg, respectively, vs 0% with placebo; dizziness occurred in 4% and 4% vs 1%, respectively, without significant haemodynamic or ECG changes. Bleeding events occurred in 9.6% and 4.3% with selatogrel 8 mg and 16 mg, respectively, vs 6.9% with placebo. Pharmacokinetic data will be presented.

Conclusions

Selatogrel has a rapid PD effect following s.c injection in patients with stable CAD, within 15 min in most patients. The consistent and high levels of P2Y12 inhibition with a single 8 mg or 16 mg dose are sustained for over 4 hours, following which platelet reactivity progressively recovers over 24 h. Selatogrel was well tolerated, with mostly mild, transient dyspnoea observed in <10% patients. These data support further studies of selatogrel for emergency treatment of AMI patients.

Acknowledgement/Funding

Fully funded by Idorsia Pharmaceuticals Ltd

P3502Transmission electron microscopy reveals ultrastructural differences between reticulated and non-reticulated human platelets

Acknowledgement/Funding

PharmCompNet Baden-Württemberg: Kompetenznetzwerk Pharmakologie Baden-Württemberg

252Guided de-escalation of antiplatelet treatment in patients with acute coronary syndrome and multivessel coronary artery disease: a post-hoc analysis of the TROPICAL-ACS trial

Background

The TROPICAL-ACS trial showed that platelet function testing (PFT) guided de-escalation of P2Y12-inhibitor is a safe alternative treatment strategy in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). No specific data are available on the efficacy of this strategy in patients with multivessel coronary artery disease (CAD).

Purpose

To investigate the safety and efficacy of guided de-escalation of P2Y12-inhibitor treatment in patients with multivessel CAD.

Methods

Two-thousand six-hundred-two biomarker-positive ACS patients were 1:1 randomized to either conventional treatment with prasugrel for 12 months (control group) or to a PFT guided de-escalation treatment strategy (guided de-escalation group). The primary endpoint (net clinical benefit) was defined as the composite of cardiovascular mortality (CVM), myocardial infarction (MI), stroke, and clinically overt bleeding (bleeding ≥ grade 2 according to the BARC criteria). The ischemic endpoint was defined as the composite of CVM, MI or stroke. We used log-rank statistics and Cox regression analysis with interaction testing to assess the effect of multivessel CAD on the primary and ischemic endpoints.

Results

Patients with multivessel (n=709) versus single-vessel CAD (n=1,901) exhibited a higher risk for the primary endpoint (10.2% vs. 7.6%; HR 1.36; 95% CI 1.02–1.81; p=0.034). Guided de-escalation was non-inferior to conventional treatment for the primary endpoint in both patients with single-vessel CAD (6.7% vs. 8.5%; pnon-inferiority = 0.001; Figure 1A) and multivessel CAD (9,5% vs. 10.9%; pnon-inferiority=0.041; Figure 1B). Moreover, there was no significant interaction in the prognostic value of guided de-escalation between single-vessel and multivessel CAD for both the primary (HR 0.78 [0.56–1.08]; p=0.137 in patients with single-vessel CAD vs. 0.86 [0.54–1.37; p=0.524 in patients with multivessel CAD; pinteraction=0.732) and combined ischemic endpoints (HR 0.80 [0.44–1.45]; p=0.456 in patients with single-vessel CAD vs. 0.71 [0.35–1. 46]; p=0.356 in patients with multivessel CAD; pinteraction=0.823).

Kaplan-Meier curves

Conclusion

A guided de-escalation of P2Y12-inhibitor appears to be safe and effective in ACS patients with both single-vessel and multivessel CAD.

Acknowledgement/Funding

Klinikum der Universität München, Roche Diagnostics, Eli Lilly, and Daiichi Sankyo.