Atherogenic lipoprotein profile associated with anthropometric indices of obesity and their association with cardiometabolic risk markers: a cross-sectional study in community

Background

Obesity, especially abdominal fat accumulation, is strongly associated with various metabolic comorbidities. Whether simple anthropometric measures are independently associated with atherogenic lipoproteins is not completely clear.

Methods

We randomly recruited 505 participants (51.5% women; mean age: 48.8 years) from the Flemish community, who had undergone lipoprotein particle measurements by nuclear magnetic resonance spectroscopy and conventional lipid measurements. Each lipoprotein fraction was subgrouped into large, medium, and small subclass. Anthropometric measures included body mass index (BMI) and waist-to-hip ratio (WHR), and defined BMI obesity as BMI ≥30 kg/m2, and WHR obesity as WHR ≥0.85 (women) or 0.9 (men).

Results

In the multivariable logistic regression analysis, total very-low-density lipoprotein (VLDL) particle and its subclasses were positively associated with BMI obesity (adjusted odds ratio [OR] for total VLDL: 2.37; 95% confidence interval [CI]: 1.70–3.31) and WHR obesity (OR for total VLDL: 2.06 [95% CI: 1.55–2.73]). The level of total high-density lipoprotein (HDL) particle and its subclass was negatively associated with BMI (OR for total HDL: 0.63 [95% CI: 0.45–0.90), but not with WHR (P≥0.11). None of the low-density lipoprotein (LDL) particles was associated with the two types of obesity (P≥0.092). BMI was inversely associated with the size of LDL and HDL particles, whereas high WHR was significantly associated with smaller VLDL and HDL sizes. For conventional lipid measures, both BMI and WHR were independently associated with high triglyceride and remnant cholesterol, both mainly driven from VLDL particles, and low HDL cholesterol (P≤0.008). These associations were confirmed in multivariable linear regression analysis, except the association of BMI with HDL number and the association of WHR with HDL size. With partial least squares analysis, the lipoprotein profiles of BMI and WHR were significantly associated with a high 10-year cardiovascular disease risk score, the homeostasis model assessment-estimated insulin resistance (HOMA-IR), and C-reactive protein.

Conclusion

BMI and WHR were independently associated with high triglyceride-rich lipoproteins, decreased HDL cholesterol. The size of LDL and HDL was more consistently associated with BMI than WHR. The lipoprotein alterations may link obesity with high cardiometabolic risk.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): The European Research Council; the European Research Area Net for Cardiovascular Diseases

Association of fatal and non-fatal adverse health outcomes with urinary peptides reflecting collagen I turnover

Background

Imbalance of collagen I (COL1) turnover, featured by increased synthesis and decreased degradation of collagen fibers, is a hallmark of fibrosis in the heart and blood vessels that associates with poor cardiovascular outcomes. Such as imbalance of COL1 turnover could be reflected in urine and serve as fingerprint for future adverse outcomes in general population, and high risk subjects.

Purpose

We hypothesize that imbalance of proteomic signatures of urinary peptides (UPs) reflecting COL1 turnover relate to adverse health outcomes in participants from a general population

Methods

We randomly recruited 776 participants (51.2% women; 50.5 years) from the Flemish Study on Environment, Genes and Health Outcomes cohort and measured UPs proteome by capillary electrophoresis coupled with mass spectrometry. Our analyses focused on 148 peptides of COL1 alpha-1 (COL1A1) chain that retained ≥70% signal in the whole sample. The primary endpoint included fatal and nonfatal cardiovascular endpoints. Secondary endpoints consisted of total mortality, fatal and nonfatal cardiac, coronary, and heart failure endpoints. Multivariate Cox proportional models, partial least squares analysis (PLS), log-likelihood test, and receiver operating characteristics (ROC) curve were applied.

Results

Over a median follow up of 12.4 years, 110 primary endpoints occurred, 61 participants died, 81, 41 and 24 experienced cardiac, coronary, and heart failure endpoints; respectively. In PLS analyses, upregulation of UPs signatures closer to C- and N-terminal locations of the COL1A1 chain whereas downregulation of mid-region UPs were associated with lower risk of adverse health outcomes. This pattern was inverted in subjects with cardiovascular disease, as upregulation of terminal and downregulation of mid region UPs increased risk. Adding UPs to a basic model including sex, age and usual cardiovascular risk factors significantly improved model performance between 2.54% to 4.93% (P≤0.001) for prediction of adverse health outcomes. In ROC plots, adding UPs to the basic model increased the area under the curve up to 4.00% (P<0.012).

Conclusions

UPs reflecting COL1 turnover predicted adverse health outcomes. The inverted up- and down regulations of UPs in between participants with and without previous cardiovascular diseases might be explained by a shift in the UPs signatures of COL1 fragments linked to distinct fibrotic processes. Urinary proteomic might have clinical importance in documenting the extent of collagen accumulation that relates to adverse health outcomes. In patients at high cardiovascular risk, modification of collagen I fibers turnover might be a potential treatment target

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): The European Union the European Research Council and the European Research Area Net for Cardiovascular Diseases.

Management of edoxaban in patients undergoing multiple procedures: a subanalysis of the EMIT-AF/VTE program

Funding Acknowledgements

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

Background

Patients with atrial fibrillation (AF) or venous thromboembolism (VTE) receiving long-term direct oral anticoagulant (DOAC) therapy undergo diagnostic or therapeutic procedures at a rate of approximately 10% annually. The prospective Global EMIT-AF/VTE program (Edoxaban Management in Diagnostic and Therapeutic Procedures; NCT02950168, NCT02951039) demonstrated that physician-guided periprocedural management of the DOAC edoxaban in these patients was associated with low bleeding and thromboembolic event rates. It is unclear whether the experience of a previous (index) procedure influences the periprocedural management of subsequent procedures.

Purpose

To analyze differences in periprocedural edoxaban management in patients on chronic anticoagulation therapy undergoing multiple diagnostic or therapeutic procedures.

Methods

Baseline characteristics were recorded in patients enrolled in the EMIT-AF/VTE program who underwent multiple procedures. Details of periprocedural edoxaban interruption were collected from patients who underwent two procedures of the same European Heart Rhythm Association (EHRA) bleeding risk level or procedural type. Only data from the index and second procedure of the same category were included in this analysis; procedures conducted less than 7 days apart were excluded. All analyses are exploratory and descriptive in nature.

Results

Among 227 patients who underwent multiple procedures, the most common types were vascular and gastrointestinal (GI) procedures. Patients had a mean ± standard deviation age of 72.1 ± 9.8 years, a CHA2DS2-VASc score of 3.2 ± 1.6, a HAS-BLED score of 1.9 ± 1.0, and were mostly male (67.0%). Patients who underwent low/minor risk procedures were less likely to undergo edoxaban interruption with their second procedure compared with their index procedure (Figure 1A), and the median interruption duration was shorter for the second procedure (Table 1). A second high risk procedure was associated with a higher rate of both pre- and postprocedural edoxaban interruption compared with a patient’s index procedure, but treatment resumed earlier (Figure 1B). Patients who underwent vascular procedures had a lower rate of pre- and postprocedural interruption and a shorter interruption time with their second procedure (Table 1). Conversely, patients who underwent GI procedures experienced pre- and postprocedural interruption more often for their second procedure. The median interruption duration was longer for GI procedures than for vascular procedures (Table 1).

Conclusion

Overall, periprocedural edoxaban interruption varied by procedural bleeding risk and type. Edoxaban interruption patterns differed between index and second procedures, indicating that periprocedural edoxaban management may be influenced by the experience of previous procedures.

The novel proteomic signature for the detection of cardiac allograft vasculopathy

Background

Cardiac allograft vasculopathy (CAV) is the major long-term complications after heart transplantation, leading to mortality and re-transplantation. As available noninvasive biomarkers are scarce for CAV screening, we aimed to identify a proteomic signature for CAV detection.

Methods

Urinary proteome was measured by capillary electrophoresis coupled to mass spectrometry in 217 heart transplantation recipients. Participants were further randomly and evenly divided into the derivation cohort and validation cohort. The proteomic signature for CAV was identified by decision tree-based machine learning in the derivation cohort and further tested in the validation cohort. The pathway analysis was investigated with Reactome Pathway Database.

Results

We identified a proteomic signature with 27 urinary peptides, which yielded areas under the curve (AUC) of 0.83 and 0.71 in the derivation and validation cohort, respectively. In the validation cohort, it had a sensitivity of 68.4%, specificity of 73.2%, accuracy of 71.6%, negative predictive value of 81.3%. Including the proteomic signature into the basic model further improved the diagnostic accuracy with an relative integrated discrimination improvement of 25.9% and the continuous net reclassification improvement of 83.3% (p≤0.023). The pathways analysis on revealed that collagen turnover, platelet aggregation and coagulation, cell adhesion and motility might involve in the pathogenesis of CAV.

Conclusions

The proteomic signature might be valuable for the surveillance of CAV thereby reduce the frequency of invasive procedures after HTx. Moreover, the highlighted pathways might provide insights in the potential novel treatment targets for CAV.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Research Council Advanced Researcher Grant and Proof-of-Concept Grant ROC curves of the urinary proteomicThe 25 highlighted enrichment pathways

The urinary proteomic profile of arterial stiffness in the general population

Background

Although arterial stiffness is an independent predictor of cardiovascular outcomes, its physiopathology remains unclear.

Purpose

This study aimed to investigate the urinary proteomic profile of aortic stiffness and provide insights into pathogenetic processes of arterial stiffness by pathway analysis.

Methods

In 669 participants (mean age, 50.5 years; 48.9% men) randomly recruited from the Flemish population, we measured carotid-femoral pulse wave velocity (PWV) by applanation tonometry. The proteomics of urine samples was quantified by using capillary electrophoresis coupled mass spectrometry. The proteomic data were analysed by the orthogonal projections to latent structures, a supervised dimensional reduction statistic method and summarised as a urinary proteomic (UP) score.

Results

The mean values were 7.56±2.02 m/s for PWV and 7.59±1.95 unit for the UP score. PWV was significantly associated with the UP score before and after adjustment for the potential covariates (β coefficient: 0.81 and 0.75, respectively; p<0.001). The significant proteins in the urinary proteomic profile consisted of 43 kinds of proteins, including collagen I, II and III, fibrinogen, matrix Gla-protein, apolipoprotein A-I and A-VI. The pathways annotated by the significant proteins mainly involved in fibrosis, signal conduction, platelet activation and aggregation.

Conclusions

In conclusion, the urinary proteomic profile could be a new biomarker of aortic stiffness and the altered proteins may link to the underlying mechanisms and holds the potential to discover novel therapeutic targets for arterial stiffness.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Internal Funds KU Leuven (STG-18-00379) Distribution and CorrelationThe Enrichment Pathways

Periprocedural anticoagulation management in edxoaban patients undergoing catheter-based cardiovascular procedures: analyses of the noninterventional global EMIT study

Funding Acknowledgements

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

Background

 The optimal periprocedural management of direct oral anticoagulants (DOAC), including edoxaban, in patients undergoing catheter-based cardiovascular procedures is unknown, and mainly based on physician opinion and experience.

Purpose

To assess real-world management of edoxaban in patients undergoing cardiovascular procedures, and to report their clinical events.

Methods

Global EMIT-AF/VTE is a prospective study of periprocedural management in edoxaban-treated patients undergoing diagnostic and therapeutic procedures. We report the data from patients undergoing cardiovascular procedures. Timing and duration of edoxaban interruption were at the treating physician’s discretion. Outcomes were collected from 5 days before until 30 days post procedure. Primary outcome was the incidence of major bleeding (MB); secondary outcomes included incidence of clinically relevant non-major bleeding (CRNMB) and acute thromboembolic events (ATE).

Results

Data was collected from 301 and 311 procedures with arterial or venous access, respectively. Baseline characteristics are shown in Table 1. Edoxaban was not interrupted in 36.9% of arterial and 52.7% of venous procedures. Edoxaban was interrupted pre-procedure in 41% of arterial and 32.8% of venous procedures. The median periprocedural interruption was 2 days. The overall incidence of bleeding was very low. Any bleeding was reported in 8 patients undergoing arterial and 10 patients undergoing venous procedures (2.7% and 3.2%). MB or CRNMB occurred in 2 arterial and 3 venous procedures (0.7% and 1.0%) and ATE occurred in 5 arterial and 1 venous procedure (1.7% and 0.3%, Table 1).

Conclusions

In this study, the periprocedural risks of bleeding and thrombotic events were low. About a third of arterial access procedures and half of venous access procedures were performed without edoxaban interruption. Arterial(n = 301) Venous(n = 311) Baseline characteristics Age, year, mean (SD)Male, n (%)Weight (kg), mean (SD) 71.9 (8.5)211 (70.1%)80.8 (16.7) 64.6 (11.1)215 (69.1%)84.1 (17.4) CrCL (mL/min), mean (SD) CHA2DS2-VASc score, mean (SD)HAS-BLED score, mean (SD) 73.5 (29.8) 3.3 (1.5)2.0 (1.0) 88.9 (35.5) 2.2 (1.5)1.3 (1.0) Edoxaban 60 mg / 30 mg, % 73% / 26% 88% / 26% Coronary heart disease, n (%) Congestive heart failure, n (%) 101 (33.6%) 58 (19.3%) 51 (16.4%) 33 (10.6%) Interruption of edoxaban, n (%) No interruption Pre-procedure only Post-procedure only Pre- and post-procedure 111 (36.9%)125 (41.5%)12 (4.0%)53 (17.6%) 164 (52.7%)102 (32.8%)8 (2.6%)37 (11.9%) Clinical events, n (%) MB or CRNMBACSStroke/Transient ischemic attackCV mortalityAll-cause mortality 2 (0.7%)2 (0.7%)3 (1.0%)1 (0.3%)2 (0.7%) 3 (1.0%) 01 (0.3%)00

Periprocedural management of patients on edoxaban undergoing pacemaker and cardiac monitoring device implantation - a sub-analysis of the EMIT-AF/VTE study

Funding Acknowledgements

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

Background

 Periprocedural management of patients on direct oral anticoagulants undergoing insertion of permanent pacemaker (PPM) and cardiac monitoring devices is mainly based on pharmacokinetic considerations, clinical experience, and expert opinion.

Purpose

 To describe the characteristics, periprocedural management, and events of edoxaban patients undergoing implantation of PPM/monitoring devices. 

Methods

From the global EMIT-AF/VTE registry, which includes edoxaban patients undergoing any diagnostic or therapeutic procedures, those with PPM/cardiac monitoring device implantation were observed from five days prior to 30 days post procedure. Events documented included the incidence of International Society on Thrombosis and Haemostasis defined Major Bleeding, Clinically Relevant Non-Major Bleeding (CRNMB), acute thromboembolic events (ATE) and perioperative edoxaban interruption times.

Results

  PPM or invasive cardiac monitoring devices were implanted in 136 patients. Conformance with European Heart Rhythm Association Guidance for the interruption of anticoagulation was variable: of the cardiac monitoring patients, 62.5% had interruption of treatment, whereas in PPM procedures 23.4% had no interruption. One case of CRNMB and two cases of minor bleeding were documented. All bleedings seem non procedure-related since they occurred > three days post procedure. There were no ATE.

Conclusions

Relevant complications for edoxaban treated patients undergoing PPM or invasive cardiac monitoring procedures were rare. This population of patients is apparently well managed in routine practice, but further investigation of risk factors is justified. TablePatient characteristics Parameter All subjectsN = 136 All pacemakerN = 128 Insertion first pacemakerN = 89 Change pacemakerN = 39 Monitoring deviceN = 8 Age, mean (SD)Male, n (%) 75.1 (10.1)85 (62.5) 75.0 (10.3)83 (64.8) 75.7 (9.9)57 (64.0) 73.5 (11.2)26 (66.7) 76.3 (4.3)2 (25.0) BMI, mean (SD) 27.1 (5.5) 27.2 (5.6) 27.2 (6.0) 27.3 (4.5) 25.2 (4.3) AF, n (%)‡ 135 (99.3) 127 (99.2) 89 (100.0) 38 (97.4) 8 (100.0) VTE, n (%)‡ 3 (2.2) 3 (2.3) 1 (1.1) 2 (5.1) 0 CrCL, mean (SD) 63.8 (26.4) 64.1 (26.7) 62.3 (26.2) 68.3 (27.9) 58.9 (21.8) CrCL, ≤50, n (%) 43 (31.6) 41 (32.0) 33 (37.1) 8 (20.5) 2 (25.0) HAS-BLED Score, mean (SD) 2.0 (1.2) 1.9 (1.2) 1.9 (1.0) 2.1 (1.6) 2.6 (0.5) CHA2DS2-VASc Score, mean (SD) 3.7 (1.6) 3.7 (1.6) 3.7 (1.5) 3.8 (1.9) 3.1 (0.6) Edoxaban 30 mg/day, n (%) 49 (36.0) 46 (35.9) 32 (36.0) 14 (35.9) 3 (37.5) Edoxaban 60 mg/day, n (%) 86 (63.2) 81 (63.3) 56 (62.9) 25 (64.1) 5 (62.5) AF, atrial fibrillation; BMI, body mass index; CrCL, creatinine clearance; VTE, venous thromboembolism. ‡Two patients had both AF and VTE.

Correction to: Elderly patients with atrial fibrillation in routine clinical practice: peri-procedural management of edoxaban oral anticoagulation therapy is associated with a low risk of bleeding and thromboembolic complications: a subset analysis of the prospective, observational, multinational EMIT-AF study

An amendment to this paper has been published and can be accessed via the original article.

Comparative clinical prognosis of massive and non-massive pulmonary embolism: A registry-based cohort study

AIMS

Little is known about the prognosis of patients with massive pulmonary embolism (PE) and its risk of recurrent venous thromboembolism (VTE) compared with non-massive PE, which may inform clinical decisions. Our aim was to compare the risk of recurrent VTE, bleeding, and mortality after massive and non-massive PE during anticoagulation and after its discontinuation.

METHODS AND RESULTS

We included all participants in the RIETE registry who suffered a symptomatic, objectively confirmed segmental or more central PE. Massive PE was defined by a systolic hypotension at clinical presentation (<90 mm Hg). We compared the risks of recurrent VTE, major bleeding, and mortality using time-to-event multivariable competing risk modeling. There were 3.5% of massive PE among 38 996 patients with PE. During the anticoagulation period, massive PE was associated with a greater risk of major bleeding (subhazard ratio [sHR] 1.72, 95% confidence interval [CI] 1.28-2.32), but not of recurrent VTE (sHR 1.15, 95% CI 0.75-1.74) than non-massive PE. An increased risk of mortality was only observed in the first month after PE. After discontinuation of anticoagulation, among 11 579 patients, massive PE and non-massive PE had similar risks of mortality, bleeding, and recurrent VTE (sHR 0.85, 95% CI 0.51-1.40), but with different case fatality of recurrent PE (11.1% versus 2.4%, P = .03) and possibly different risk of recurrent fatal PE (sHR 3.65, 95% CI 0.82-16.24).

CONCLUSION

In this large prospective registry, the baseline hemodynamic status of the incident PE did not influence the risk of recurrent VTE, during and after the anticoagulation periods, but was possibly associated with recurrent PE of greater severity.

Characteristics of patients with atrial fibrillation prescribed edoxaban in Belgium and the Netherlands: insights from the ETNA-AF-Europe study

Background

Studies on the use of non-vitamin K antagonist oral anticoagulants in unselected patients with atrial fibrillation (AF) show that clinical characteristics and dosing practices differ per region, but lack data on edoxaban.

Methods

With data from Edoxaban Treatment in routiNe clinical prActice for patients with AF in Europe (ETNA-AF-Europe), a large prospective observational study, we compared clinical characteristics (including the dose reduction criteria for edoxaban: creatinine clearance 15–50 ml/min, weight ≤60 kg, and/or use of strong p‑glycoprotein inhibitors) of patients from Belgium and the Netherlands (BeNe) with those from other European countries (OEC).

Results

Of all 13,639 patients in ETNA-AF-Europe, 2579 were from BeNe. BeNe patients were younger than OEC patients (mean age: 72.3 vs 73.9 years), and had lower CHA₂DS₂-VASc (mean: 2.8 vs 3.2) and HAS-BLED scores (mean: 2.4 vs 2.6). Patients from BeNe less often had hypertension (61.6% vs 80.4%), and/or diabetes mellitus (17.3% vs 23.1%) than patients from OEC. Moreover, relatively fewer patients in BeNe were prescribed the reduced dose of 30 mg edoxaban (14.8%) than in OEC (25.4%). Overall, edoxaban was dosed according to label in 83.1% of patients. Yet, 30 mg edoxaban was prescribed in the absence of any dose reduction criteria in 36.9% of 30 mg users (5.5% of all patients) in BeNe compared with 35.5% (9.0% of all patients) in OEC.

Conclusion

There were several notable differences between BeNe and OEC regarding clinical characteristics and dosing practices in patients prescribed edoxaban, which are relevant for the local implementation of dose evaluation and optimisation.

Trial registration

NCT02944019; Date of registration 24 October 2016

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01518-7) contains supplementary material, which is available to authorized users.

Correction to: A randomized, open-label, adaptive, proof-of-concept clinical trial of modulation of host thromboinflammatory response in patients with COVID-19: the DAWn-Antico study

An amendment to this paper has been published and can be accessed via the original article.

A randomized, open-label, adaptive, proof-of-concept clinical trial of modulation of host thromboinflammatory response in patients with COVID-19: the DAWn-Antico study

BACKGROUND

The peak of the global COVID-19 pandemic has not yet been reached, and many countries face the prospect of a second wave of infections before effective vaccinations will be available. After an initial phase of viral replication, some patients develop a second illness phase in which the host thrombotic and inflammatory responses seem to drive complications. Severe COVID-19 disease is linked to high mortality, hyperinflammation, and a remarkably high incidence of thrombotic events. We hypothesize a crucial pathophysiological role for the contact pathway of coagulation and the kallikrein-bradykinin pathway. Therefore, drugs that modulate this excessive thromboinflammatory response should be investigated in severe COVID-19.

METHODS

In this adaptive, open-label multicenter randomized clinical trial, we compare low molecular weight heparins at 50 IU anti-Xa/kg twice daily-or 75 IU anti-Xa twice daily for intensive care (ICU) patients-in combination with aprotinin to standard thromboprophylaxis in hospitalized COVID-19 patients. In the case of hyperinflammation, the interleukin-1 receptor antagonist anakinra will be added on top of the drugs in the interventional arm. In a pilot phase, the effect of the intervention on thrombotic markers (D-dimer) will be assessed. In the full trial, the primary outcome is defined as the effect of the interventional drugs on clinical status as defined by the WHO ordinal scale for clinical improvement.

DISCUSSION

In this trial, we target the thromboinflammatory response at multiple levels. We intensify the dose of low molecular weight heparins to reduce thrombotic complications. Aprotinin is a potent kallikrein pathway inhibitor that reduces fibrinolysis, activation of the contact pathway of coagulation, and local inflammatory response. Additionally, aprotinin has shown in vitro inhibitory effects on SARS-CoV-2 cellular entry. Because the excessive thromboinflammatory response is one of the most adverse prognostic factors in COVID-19, we will add anakinra, a recombinant interleukin-1 receptor antagonist, to the regimen in case of severely increased inflammatory parameters. This way, we hope to modulate the systemic response to SARS-CoV-2 and avoid disease progressions with a potentially fatal outcome.

TRIAL REGISTRATION

The EU Clinical Trials Register 2020-001739-28 . Registered on April 10, 2020.

Elderly patients with atrial fibrillation in routine clinical practice-peri-procedural management of edoxaban oral anticoagulation therapy is associated with a low risk of bleeding and thromboembolic complications: a subset analysis of the prospective, observational, multinational EMIT-AF study

Background

Annually > 10% of patients with atrial fibrillation on oral anticoagulation undergo invasive procedures. Optimal peri-procedural management of anticoagulation, as judged by major bleeding and thromboembolic events, especially in the elderly, is still debated.

Methods

Procedures from 1442 patients were evaluated. Peri-procedural edoxaban management was guided only by the experience of the attending physician. The primary safety outcome was the rate of major bleeding. Secondary outcomes included the peri-procedural administration of edoxaban, other bleeding events, and the main efficacy outcome, a composite of acute coronary syndrome, non-hemorrhagic stroke, transient ischemic attack, systemic embolic events, deep vein thrombosis, pulmonary embolism, and mortality.

Results

Of the 1442 patients, 280 (19%) were < 65, 550 (38%) were 65–74, 514 (36%) 75–84, and 98 (7%) were 85 years old or older. With increasing age, comorbidities and risk scores were higher. Any bleeding complications were uncommon across all ages, ranging from 3.9% in patients < 65 to 4.1% in those 85 years or older; major bleeding rates in any age group were ≤ 0.6%. Interruption rates and duration increased with advancing age. Thromboembolic events were more common in the elderly, with all nine events occurring in those > 65, and seven in patients aged > 75 years.

Conclusion

Despite increased bleeding risk factors in the elderly, bleeding rates were small and similar across all age groups. However, there was a trend toward more thromboembolic complications with advancing age. Further efforts to identify the optimal management to reduce ischemic complications are needed.

Trial registration: NCT# 02950168, October 31, 2016

Heparin is more effective than apixaban in inhibiting in vitro contact activated coagulation

Introduction

Contact of blood with artificial surfaces such as mechanical support devices, catheters, and mechanical heart valves activates the contact activation (CA) pathway of coagulation. Furthermore, recent animal data and clinical studies suggest a more important contribution of CA in pathological thrombus formation in other cardiovascular diseases. Direct oral anticoagulants (DOACs) are recommended as first-line treatment in most patients who require long-term anticoagulation. However, because DOACs directly inhibit a single downstream coagulation factor (thrombin (fXIIa) or factor Xa (fXa)), it has been suggested that their efficacy could be reduced in the presence of strong activation of the CA pathway as compared to anticoagulants that target multiple, more upstream located coagulation factors.

Purpose

To compare the efficacy of a DOAC (apixaban) and heparin to suppress thrombin generation in the presence of strong CA pathway activation.

Methods

Pooled platelet-poor plasma was spiked with either apixaban (dissolved in DMSO and PBS) or unfractionated heparin to achieve therapeutic plasma levels. SynthASil, a commercially available mixture of phospholipids and silica, was used to stimulate the CA pathway in two different dilutions (1–80 and 5–80). Downstream coagulation was accessed by Thrombin Generation Test using Thrombinoscope by Stago and associated Thrombin Calibrator (activity 640 nM). The endogenous thrombin potential (area under the thrombin generation curve; ETP), peak thrombin generation (PTG), time to peak (ttPeak) and time to start (ttStart) were accessed.

Results

With decreasing concentrations of apixaban, stimulation with the lower dose SynthASil reveals an increasing ETP and PTG. As expected, ttPeak and ttStart decreased. Even supratherapeutic levels of apixaban (i.e. 1120 ng/mL) could not inhibit thrombin from being generated, in striking contrast with UFH where no thrombin was formed. Using a five times higher dose of SynthASil showed comparable ETP for all concentrations of apixaban, allocated around the control value. PTG, however, slightly increased with decreasing concentrations of apixaban. ttPeak and ttStart slightly decreased. Except for the subtherapeutic UFH concentration of 0,114 IU/mL, no thrombin was generated with UFH.

Conclusion

UFH is more effective in inhibiting downstream thrombin generation compared to apixaban as a response to activation of the CA pathway in vitro. These findings could help explain why direct inhibitors were not able to show non-inferiority in patients with mechanical heart valves and support the development of specific CA pathway inhibitors for patients with conditions that activate the CA pathway.

Thrombin generation curves

Funding Acknowledgement

Type of funding source: None

Efficacy and safety of low-dose rivaroxaban on top of aspirin in patients with polypharmacy and multimorbidity: an analysis from the COMPASS trial

Background

In patients with coronary or peripheral artery disease, intensified antithrombotic therapy with aspirin plus low dose rivaroxaban reduced cardiovascular outcomes compared with aspirin alone. Polypharmacy and multimorbidity are frequent in patients with vascular disease and are often perceived as barriers to more intensive pharmacotherapy by both patients and physicians.

Purpose

To report cardiovascular outcomes and the efficacy, safety, and net benefit of low dose rivaroxaban plus aspirin in patients with stable vascular disease by the number of concomitant cardiovascular drugs and by the number of comorbidities.

Methods

We reported ischemic events (cardiovascular death, stroke, or MI), major bleeding (ISTH modified criteria), and a prespecified net clinical outcome in participants from the randomised, double-blind COMPASS study by number of cardiovascular medications (0–2, 3, 4, 5–7) and by number of concomitant medical conditions. We compared rates and hazard ratios of patients treated with rivaroxaban plus aspirin vs aspirin alone by category of number of medications and concomitant conditions and tested for interaction between polypharmacy and multimorbidity and antithrombotic regimen.

Results

Although patients with polypharmacy and multimorbidity have a higher risk of cardiovascular events (Figure) those who required many cardiovascular drugs derived the largest absolute reduction in the net clinical outcome when adding rivaroxaban on top of aspirin. The relative efficacy, safety, and net clinical benefit of adding low-dose rivaroxaban to aspirin in patients with stable vascular diseases were not affected by the number of cardiovascular drugs or by the number of comorbidities. Multimorbidity, but not polypharmacy, was related with a higher risk of major bleeding.

Conclusion

Addition of low-dose rivaroxaban conveyed a benefit irrespective of the number of concomitant drugs or comorbid conditions. Multiple comorbidities and/or polypharmacy should not dissuade the addition of low-dose rivaroxaban to aspirin in otherwise eligible patients.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): The COMPASS trial was funded by Bayer AG.

CHA2DS2-VASc and CHADS2 scores for risk stratification of major adverse cardiovascular events in the COMPASS trial

Background

The COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) trial demonstrated that the combination therapy of rivaroxaban and aspirin reduced major adverse cardiovascular events (MACE) compared to aspirin alone in patients with chronic coronary artery disease (CAD) and/or peripheral artery disease (PAD).

Purpose

We assessed whether the CHA2DS2-VASc (congestive heart failure (CHF), hypertension, age ≥75 years, diabetes, stroke/transient ischemic attack (TIA)/thromboembolism, vascular disease, age 65–75 years, and sex category) and CHADS2 (CHF, hypertension, age ≥75 years, diabetes, stroke/TIA) scores used to predict the risk of stroke in patients with atrial fibrillation, can be used identify vascular patients at highest risk of recurrent events who may derive greatest benefits of treatment.

Methods

In COMPASS patients, the predictive accuracy of CHA2DS2-VASc and CHADS2 scores were assessed for MACE, bleeding and net clinical benefit using Cox proportional hazards model. Kaplan-Meier estimates of cumulative risk and absolute risk differences were used to examine the effects of rivaroxaban plus aspirin compared with aspirin alone over 30 months according to risk score categories.

Results

In 27,395 participants with CAD and/or PAD, a high CHA2DS2-VASc score (6–9) was associated with 3 times greater absolute risk of MACE compared to a low score (1–2) (hazard ratio=3.39, 95% CI: 2.54–4.51, p&lt;0.0001). The effects of combination therapy with rivaroxaban and aspirin on MACE, bleeding and net clinical benefit were consistent across CHA2DS2-VASc and CHADS2 score categories, with the greatest benefit in those with the highest risk scores (Figure 1). The greatest reduction in MACE with rivaroxaban and aspirin compared to aspirin only was observed in patients treated for 30 months with highest CHA2DS2-VASc score (6–9) (23 events per 1000 patients prevented) or highest CHADS2 score (3–6) (25 events per 1000 patients prevented). There was increased bleeding in patients with higher CHA2DS2-VASc and CHADS2 scores, but net clinical benefit was preserved across all risk categories and was greatest in those with the highest risk scores.

Conclusion

The CHA2DS2-VASc or CHADS2 scores can be used in patients with chronic CAD and/or PAD to identify patients who are at highest risk of MACE, and therefore likely to achieve the greatest benefit of dual pathway inhibition with the combination of rivaroxaban and aspirin compared with aspirin alone.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): This study was sponsored by Bayer AG.

Differentiation of hypertensive heart disease and hypertrophic cardiomyopathy with myocardial stiffness measurements: a shear wave imaging study using ultra-high frame rate echocardiography

Background

Recently, cardiac shear wave (SW) elastography, based on high frame rate (HFR) echocardiography, has been proposed as new non-invasive technique for assessing myocardial stiffness. As myocardial stiffness increases with increasing wall stress, differences in measured operating myocardial stiffness do not necessarily reflect differences in intrinsic myocardial properties, but can also be caused by mere changes in loading or chamber geometry. This complicates myocardial stiffness interpretation for different types of pathologic hypertrophy.

Purpose

To explore the relationship between myocardial stiffness and underlying pathological substrates for cardiac hypertrophy.

Methods

We included 20 patients with hypertension (HT) and myocardial remodelling (59±14 years, 75% male), 20 patients with hypertrophic cardiomyopathy (HCM) (59±16 years, 60% male) and 20 healthy controls (56±14 years, 75% male). Left ventricular (LV) parasternal long axis views were acquired with an experimental HFR scanner at 1293±362 frames per seconds. Propagation velocity of SW occurring after mitral valve closure in the interventricular septum (IVS) served as measure of operating myocardial stiffness (Figure A). To compare myocardial stiffness among hearts with differing loading conditions and chamber geometry, SW velocities were normalized to end-diastolic wall stress, estimated at IVS from regional wall thickness, longitudinal and circumferential regional radii of curvature, and non-invasively estimated LV end-diastolic pressure (EDP).

Results

SW velocities differed significantly between groups (p&lt;0.001). The controls had the lowest SW velocities (4.02±0.97 m/s), whereas values between HT and HCM group were comparable (6.46±0.99 m/s vs. 7.00±2.10 m/s; p=0.738). Considering end-diastolic wall stress, HCM patients had the same SW velocity at lower wall stress compared to HT (Figure B), indicating higher myocardial stiffness in the HCM group. SW velocities normalized for wall stress indicated significantly different myocardial stiffness among all groups (p&lt;0.001) (Figure C). In a multiple linear regression model, the underlying pathological substrate independently influenced SW velocity (beta 1.37, 95% CI (0.78–1.96); p&lt;0.001), while wall stress did not significantly affect its value (p=0.479).

Conclusions

Our study demonstrated that SW elastography can detect differences in myocardial stiffness in hypertensive heart and hypertrophic cardiomyopathy. Additionally, our results suggest that SW velocity is dominated by underlying myocardial tissue properties. We hypothesize that differential changes in cardiomyocytes and/or the extracellular matrix contribute to the differential myocardial stiffening in different pathologic entities of LV hypertrophy. Thus, SW elastography could provide useful novel diagnostic information in the evaluation of LV hypertrophy.

Figure A, B, C

Funding Acknowledgement

Type of funding source: None

D-dimer levels and risk of recurrence following provoked venous thromboembolism: findings from the RIETE registry

BACKGROUND

Patients with venous thromboembolism (VTE) secondary to transient risk factors may develop VTE recurrences after discontinuing anticoagulation. Identifying at-risk patients could help to guide the duration of therapy.

METHODS

We used the RIETE database to assess the prognostic value of d-dimer testing after discontinuing anticoagulation to identify patients at increased risk for recurrences. Transient risk factors were classified as major (postoperative) or minor (pregnancy, oestrogen use, immobilization or recent travel).

RESULTS

In December 2018, 1655 VTE patients with transient risk factors (major 460, minor 1195) underwent d-dimer measurements after discontinuing anticoagulation. Amongst patients with major risk factors, the recurrence rate was 5.74 (95% CI: 3.19-9.57) events per 100 patient-years in those with raised d-dimer levels and 2.68 (95% CI: 1.45-4.56) in those with normal levels. Amongst patients with minor risk factors, the rates were 7.79 (95% CI: 5.71-10.4) and 3.34 (95% CI: 2.39-4.53), respectively. Patients with major risk factors and raised d-dimer levels (n = 171) had a nonsignificantly higher rate of recurrences (hazard ratio [HR]: 2.14; 95% CI: 0.96-4.79) than those with normal levels. Patients with minor risk factors and raised d-dimer levels (n = 382) had a higher rate of recurrences (HR: 2.34; 95% CI: 1.51-3.63) than those with normal levels. On multivariate analysis, raised d-dimers (HR: 1.74; 95% CI: 1.09-2.77) were associated with an increased risk for recurrences in patients with minor risk factors, not in those with major risk factors.

CONCLUSIONS

Patients with raised d-dimer levels after discontinuing anticoagulant therapy for VTE provoked by a minor transient risk factor were at an increased risk for recurrences.

417 Can myocardial stiffness measurements distinguish the underlying pathology in hearts with thick walls? A shear wave imaging study using ultra-high frame rate echocardiography

Background

Different pathophysiologic pathways in the development of left ventricular (LV) hypertrophy may alter passive myocardial stiffness differently. Recently, cardiac shear wave (SW) elastography has been proposed as new non-invasive technique for assessing myocardial stiffness.

Purpose

To explore the relationship between myocardial stiffness and the underlying pathological substrates for cardiac hypertrophy.

Methods

We included 17 patients with cardiac amyloidosis (AML) (69 ± 10 years, 41% male), 17 patients with hypertrophic cardiomyopathy (HCM) (59 ± 16 years, 65% male) matched for interventricular septum (IVS) thickness and 17 hypertensive patients (HT) with prominent myocardial remodelling (56 ± 15 years, 71% male). LV parasternal long axis views were acquired with an experimental ultrasound scanner at 1255 ± 354 frames per seconds. Myocardial acceleration maps were created from the HFR-datasets and an anatomical M-mode line was drawn along the midline of the IVS (Figure A). The propagation velocity of natural SWs occurring at mitral valve closure (MVC) was measured on these M-modes in order to assess operating myocardial stiffness. To compare myocardial stiffness among hearts with differing loading conditions and chamber geometry, SW velocities were normalized to operating end-diastolic wall stress. The end-diastolic wall stress was estimated at the IVS from regional wall thickness, longitudinal and circumferential regional radii of curvature, and noninvasively estimated left ventricular end-diastolic pressure (EDP).

Results

IVS thickness was significant different among groups (AML: 1.63 ± 0.33 cm, HCM: 1.69 ± 0.21 cm, HT: 1.48 ± 0.14 cm; p = 0.037). HT patients had significant higher septal radius of curvature compared to other two groups (p &lt; 0.05), while the AML patients had the highest estimated EDP (p &lt; 0.05). All groups had comparable, elevated SW velocities at MVC (AML: 6.49 ± 1.00 m/s, HCM: 6.46 ± 1.45 m/s, HT: 6.22 ± 0.96 m/s; p = 0.752). Considering end-diastolic wall stress, HT patients had the same SW velocity at higher wall stress compared to AML and HCM (Figure B), indicating lower myocardial stiffness in the HT group. SW velocities normalized for wall stress indicated significantly different myocardial stiffness among groups (p = 0.003) (Figure C). The HT group had the lowest normalized myocardial stiffness, whereas values of the AML group overlapped with the HCM group (p = 1.00).

Conclusions

Our study demonstrated that shear wave elastography can detect differences in myocardial stiffness in hearts with thick walls. Considering the effect of wall stress, our results suggest that factors other than chamber geometry and loading condition mediate myocardial stiffness in hearts with thick walls. We hypothesize that differential changes in cardiomyocytes and/or the extracellular matrix contribute to the differential myocardial stiffening in different pathologic entities of LV hypertrophy.

Abstract 417 Figure.

Tranexamic acid to reduce bleeding after dental extraction in patients treated with non-vitamin K oral anticoagulants: design and rationale of the EXTRACT-NOAC trial

Bleeding after dental extraction in patients treated with non-vitamin K oral anticoagulants (NOAC) may lead to unplanned reinterventions and interruption of anticoagulation, thereby exposing patients to a risk of thromboembolism. We have designed a study (EXTRACT-NOAC) to investigate whether tranexamic acid (TXA) mouthwash decreases bleeding after extraction in such patients. The study is a randomised, double-blind, placebo-controlled trial. We plan to randomise 236 patients listed for dental extraction and treated with NOAC to 10% TXA mouthwash or placebo. Patients are instructed to use the mouthwash before the dental extraction, and three times a day for three days thereafter. The primary outcome is oral bleeding. Secondary outcomes include type of bleeding, procedural bleeding score, number of reinterventions after oral bleeding, and number of interruptions in NOAC treatment. Any bleeding from sources other than the mouth, and thrombotic events, are recorded as safety outcomes. Patients are followed-up for seven days. This study will provide evidence to guide the management of patients taking NOAC who need teeth extracted.

4112Risk factors and clinical outcomes in chronic CAD and PAD: an analysis of the randomized, double-blind COMPASS trial

Background

Patients with coronary artery disease (CAD) and peripheral artery disease (PAD) are at high risk for cardiovascular death and ischemic events. Secondary prevention requires both optimal control of modifiable cardiovascular risk factors and antithrombotic therapy. The COMPASS study showed a reduction in ischemic events in patients treated with the combination of low-dose rivaroxaban and aspirin, compared with aspirin alone. However, the impact of intensifying antithrombotic therapy by baseline risk factor control is not well studied.

Objective

To study the association between baseline risk factor status and outcomes, and the effects of treatment with low-dose rivaroxaban and aspirin compared with aspirin alone according to baseline risk factors, in a large contemporary population of patients with CAD or PAD.

Methods

We studied ischemic events (cardiovascular death, stroke, or MI) in participants from the randomised, double blind COMPASS trial in relation to baseline blood pressure, smoking status, cholesterol level, presence of diabetes, body mass index, and level of physical activity, as well as by the number of cardiovascular risk factors (0–1, 2, 3, 4, or 5–6). Within each risk factor category, we compared rates and hazard ratios of patients treated with rivaroxaban plus aspirin vs aspirin alone and tested for interaction between the treatment effect of rivaroxaban and risk factor status.

Results

Baseline information on all six risk factors was available in 27,117 (99%) patients. Each risk factor was associated with increased risk of ischemic events (Figure 1, panel A). Patients with 5 or 6 risk factors had more than 2-fold higher rates of ischemic events (HR 2.36; 95% CI: 1.80–3.10) and of cardiovascular death (HR 2.22; 1.48–3.33) compared with patients with 0 or 1 risk factor. The addition of low-dose rivaroxaban on top of aspirin reduced event rates independently of number of risk factors (p for interaction 0.93) (Figure 1, panel B). The largest absolute benefit of low-dose rivaroxaban was seen in patients with the greatest number of risk factors.

Figure 1

Conclusion

More favourable baseline risk factor status and the use of low-dose rivaroxaban were both independently associated with lower risk of ischemic events. Patients at highest risk, based on number of baseline risk factors, derive the largest absolute benefit of the combination of rivaroxaban and aspirin.

Acknowledgement/Funding

The COMPASS trial was sponsored by Bayer AG. The sponsor did not influence the analysis plan, drafting of abstract, or the decision to submit

P3660Investigating the role of neutrophils and NETs in staphylococcus aureus endocarditis

Background/Introduction

Infective endocarditis (IE) remains one of the deadliest cardiac diseases. Despite optimal antibiotic and surgical treatment, still one in three patients do not survive Staphylococcus aureus (S. aureus) IE. In order to cause this disease, bacteria need to first overcome shear stress and adhere to cardiac valves. Secondly, they need be able to progress into a complex lesion. Previously, we have shown that S. aureus adheres to cardiac valves via platelets and von Willebrand factor. However, the process of progression from initial bacterial adhesion to a complex vegetation, particularly how bacteria bypass the immune system and thrive in the host environment, remains unclear.

Purpose

We aimed to determine the role of neutrophils and neutrophil extracellular traps (NETs) in IE progression using a novel mouse model.

Methods

We intravenously injected mice with S. aureus and locally stimulated the endothelium with histamine, resulting in IE lesions that originate on inflamed heart valves. After three days we determined the development of IE on the aortic valves with Gram staining and echocardiography. We investigated the presence of NETs in 14 mice by immunostaining for citrullinated histone H3 (H3Cit), extracellular DNA, and myeloperoxidase. Of these 14 mice, 9 developed endocarditis. In a separate set of experiments, we investigated the role of neutrophils in IE development by injecting a neutrophil-depleting or control antibody 24h before surgery.

Results

Echocardiography revealed real IE lesions attached on inflamed aortic valves. Mice with endocarditis had significantly (P=0.005) more detectable H3Cit (9/9) than those without (1/5). More specifically, four mice had H3Cit+ neutrophils within thrombi, indicating early NETosis. Seven mice had an extracellular H3Cit staining pattern within the thrombus. These extracellular H3Cit-positive regions were associated with DNA and myeloperoxidase, indicating the presence of a network of NETs. When we depleted neutrophils, mice developed significantly more endocarditis (7/16 vs. 1/15, P=0.03).

Conclusion

Endocarditis lesions contained NETs or neutrophils undergoing NETosis, and neutrophil depletion led to increased IE incidence. Further investigating these two players in IE could potentially provide new strategies to combat this deadly disease.

Acknowledgement/Funding

FWO SB

P5715Trends in indications and outcome in thrombolytic therapy: a retrospective single center study

Background

Thrombolytic therapy is used as a lifesaving treatment for a broad range of acute thrombotic events. The role of thrombolysis for its various indications has rapidly evolved.

Purpose

To provide a contemporary overview of current indications and outcome of thrombolytic therapy in clinical practice.

Methods

This retrospective single-center study analyzed indications, complications and short-term mortality of systemic thrombolytic therapy between 2010 and 2016 in a university hospital, totaling 763 cases. Major bleedings were defined using criteria published by the International Society on Thrombosis and Haemostasis (ISTH).

Results

Thrombolytic drugs were mostly used for ischemic strokes (66.6%) and peripheral arterial disease (16.9%). Acute coronary syndrome only represented a minority of cases (in this PCI-center). Overall seven- and thirty-day-mortality were 7.3% and 12.0%, respectively. Major bleeding occurred in 8.3% of patients and was fatal in 0.9% of all patients. Both major bleeding and mortality differed by the indication for thrombolysis. Thrombolytic therapy for pulmonary embolism and peripheral arterial disease were associated with the highest rates of major bleeding, 28.6% and 23.3% respectively. Short-term mortality was highest in patients receiving thrombolysis for pulmonary embolism. Predictors for major bleeding included use of antiplatelet and anticoagulation drugs prior to thrombolysis. Major bleedings, age and concomitant anticoagulation were associated with lower survival rates.

Indications in absolute numbers – 2010 – – 2011 – – 2012 – – 2013 – – 2014 – – 2015 – – 2016 – Ischemic Stroke 56 63 66 57 96 88 82 Peripheral Arterial Disease 21 23 21 28 14 16 6 Pulmonary Embolism 4 9 10 10 5 8 8 Deep Vein Thrombosis 2 1 2 0 2 3 3 Acute Coronary Syndrome 0 1 0 1 0 0 0 Mechanical Heart Valve Thrombosis 1 3 3 1 2 7 1 Other 5 8 3 10 2 5 6 TOTAL 89 108 105 107 121 127 106

Mortality and major bleeding in %

Conclusion

The use of thrombolytic therapy has evolved, with stroke now being the most frequent indication. Mortality and bleeding rates are significant and vary considerably per indication. Major bleedings, age and maintenance anticoagulant therapy were risk factors associated with lower survival rates, but the underlying disease and patient population seem to play a major role in survival as well.

P1501Can we measure the stiffening of hypertensive hearts non-invasively? A shear wave imaging study using ultra-high frame rate echocardiography

Background

Cardiac shear wave (SW) elastography is a novel technique based on high-frame-rate (HFR) echocardiography which has been shown to be related to myocardial stiffness. In this study we explore the relation between myocardial SW velocity and myocardial remodelling in remodelled hearts of patients with arterial hypertension (AH).

Methods

We prospectively included 33 treated AH patients with hypertrophic left ventricular (LV) remodelling (59±14 years, 55% male) and 26 aged matched healthy controls (55±15 years, 77% male). AH patients were further divided according to their LV geometric pattern into a concentric remodelling (CR) group (13 patients) and a concentric hypertrophy (CH) group (20 patients). LV parasternal long axis views were acquired with an experimental HFR ultrasound scanner (HD-PULSE) at 1266±317 frames per seconds. Myocardial acceleration maps were created from the HFR-datasets and an anatomical M-mode line was drawn along the midline of the interventricular septum (IVS). The propagation velocity of natural SWs occurring at mitral valve closure (MVC) was measured on these M-modes (Figure A) in order to assess passive myocardial stiffness. Standard echocardiography using a commercial scanner was performed to evaluate LV remodelling.

Results

SW velocities at MVC differed significantly between AH patients and controls (5.83±1.20 m/s vs. 4.04±0.96 m/s; p<0.001). Within the patient group, patients with CH had highest SW velocities at MVC (p<0.001), whereas values between controls and patients with CR were comparable (p=0.075) (Figure B). In AH patients, significant positive correlations were found between SW velocity at MVC and parameters of LV remodelling (IVS thickness: r=0.728, p<0.001; LV mass index: r=0.780, p<0.001, LV end-diastolic volume: r=0.604, p=0.008) (Figure C) and also parameters of diastolic function (E/e': r=0.495, p=0.005, left atrium diameter: r=0.866, p<0.001, left atrium volume index: r=0.661, p<0.001).

Figure A, B, C

Conclusions

SW velocity – and therefore myocardial stiffness – is higher in AH patients compared to healthy controls and increases with increasing severity of hypertensive heart disease. Patients with concentric remodelling have still close-to-normal passive myocardial properties while patients with concentric hypertrophy show significant stiffening. Echocardiographic shear wave elastography is a promising new technique for the non-invasive assessment of myocardial stiffness and might provide valuable new insights into myocardial function and the pathophysiology of myocardial disease.

Staphylococcus aureus, master manipulator of the human hemostatic system

The coagulation system does not only offer protection against bleeding, but also aids in our defense against invading microorganisms. The hemostatic system and innate immunity are strongly entangled, which explains why so many infections are complicated by either bleeding or thrombosis. Staphylococcus aureus (S. aureus), currently the most deadly infectious agent in the developed world, causes devastating intravascular infections such as sepsis and infective endocarditis. During these infections S. aureus comes in close contact with the host hemostatic system and proves to be a master in manipulating coagulation. The coagulases of S. aureus directly induce coagulation by activating prothrombin. S. aureus also manipulates fibrinolysis by triggering plasminogen activation via staphylokinase. Furthermore, S. aureus binds and activates platelets and interacts with key coagulation proteins such as fibrin(ogen), fibronectin and von Willebrand factor. By manipulating the coagulation system S. aureus gains a significant advantage over the host defense mechanisms. Studying the interplay between S. aureus and the hemostatic system can therefore lead to new innovative therapies for battling S. aureus infections.

Clumping factor A, von Willebrand factor-binding protein and von Willebrand factor anchor Staphylococcus aureus to the vessel wall

Essentials Staphylococcus aureus (S. aureus) binds to endothelium via von Willebrand factor (VWF). Secreted VWF-binding protein (vWbp) mediates S. aureus adhesion to VWF under shear stress. vWbp interacts with VWF and the Sortase A-dependent surface protein Clumping factor A (ClfA). VWF-vWbp-ClfA anchor S. aureus to vascular endothelium under shear stress.

SUMMARY

Objective When establishing endovascular infections, Staphylococcus aureus (S. aureus) overcomes shear forces of flowing blood by binding to von Willebrand factor (VWF). Staphylococcal VWF-binding protein (vWbp) interacts with VWF, but it is unknown how this secreted protein binds to the bacterial cell wall. We hypothesized that vWbp interacts with a staphylococcal surface protein, mediating the adhesion of S. aureus to VWF and vascular endothelium under shear stress. Methods We studied the binding of S. aureus to vWbp, VWF and endothelial cells in a micro-parallel flow chamber using various mutants deficient in Sortase A (SrtA) and SrtA-dependent surface proteins, and Lactococcus lactis expressing single staphylococcal surface proteins. In vivo adhesion of bacteria was evaluated in the murine mesenteric circulation using real-time intravital vascular microscopy. Results vWbp bridges the bacterial cell wall and VWF, allowing shear-resistant binding of S. aureus to inflamed or damaged endothelium. Absence of SrtA and Clumping factor A (ClfA) reduced adhesion of S. aureus to vWbp, VWF and activated endothelial cells. ADAMTS-13 and an anti-VWF A1 domain antibody, when combined, reduced S. aureus adhesion to activated endothelial cells by 90%. Selective overexpression of ClfA in the membrane of Lactococcus lactis enabled these bacteria to bind to VWF and activated endothelial cells but only in the presence of vWbp. Absence of ClfA abolished bacterial adhesion to the activated murine vessel wall. Conclusions vWbp interacts with VWF and with the SrtA-dependent staphylococcal surface protein ClfA. The complex formed by VWF, secreted vWbp and bacterial ClfA anchors S. aureus to vascular endothelium under shear stress.

Outcome of Patients with Venous Thromboembolism and Factor V Leiden or Prothrombin 20210 Carrier Mutations During the Course of Anticoagulation

BACKGROUND

Individuals with factor V Leiden or prothrombin G20210A mutations are at a higher risk to develop venous thromboembolism. However, the influence of these polymorphisms on patient outcome during anticoagulant therapy has not been consistently explored.

METHODS

We used the Registro Informatizado de Enfermedad TromboEmbólica database to compare rates of venous thromboembolism recurrence and bleeding events occurring during the anticoagulation course in factor V Leiden carriers, prothrombin mutation carriers, and noncarriers.

RESULTS

Between March 2001 and December 2015, 10,139 patients underwent thrombophilia testing. Of these, 1384 were factor V Leiden carriers, 1115 were prothrombin mutation carriers, and 7640 were noncarriers. During the anticoagulation course, 160 patients developed recurrent deep vein thrombosis and 94 patients developed pulmonary embolism (16 died); 154 patients had major bleeding (10 died), and 291 patients had nonmajor bleeding. On multivariable analysis, factor V Leiden carriers had a similar rate of venous thromboembolism recurrence (adjusted hazard ratio [HR], 1.16; 95% confidence interval [CI], 0.82-1.64), half the rate of major bleeding (adjusted HR, 0.50; 95% CI, 0.25-0.99) and a nonsignificantly lower rate of nonmajor bleeding (adjusted HR, 0.66; 95% CI, 0.43-1.01) than noncarriers. Prothrombin mutation carriers and noncarriers had a comparable rate of venous thromboembolism recurrence (adjusted HR, 1.00; 95% CI, 0.68-1.48), major bleeding (adjusted HR, 0.75; 95% CI, 0.42-1.34), and nonmajor bleeding events (adjusted HR, 1.10; 95% CI, 0.77-1.57).

CONCLUSIONS

During the anticoagulation course, factor V Leiden carriers had a similar risk for venous thromboembolism recurrence and half the risk for major bleeding compared with noncarriers. This finding may contribute to decision-making regarding anticoagulation duration in selected factor V Leiden carriers with venous thromboembolism.

The addition of idarucizumab to plasma samples containing dabigatran allows the use of routine coagulation assays for the diagnosis of hemostasis disorders

BACKGROUND

The anticoagulant effect of dabigatran can be approximated by its prolongation of routine coagulation assays. Consequently, dabigatran also interferes with thrombophilia screening or with diagnosing hemostasis disorders that have developed after the initiation of anticoagulant treatment, such as vitamin K deficiency or acquired hemophilia A.

OBJECTIVES

This study was carried out to determine whether idarucizumab, a humanized antibody fragment that binds dabigatran, could fully neutralize dabigatran in routine diagnostic coagulation assays conducted in vitro, thereby preventing false-positive or false-negative diagnostic readouts.

METHODS

Preliminary experiments identified coagulation assays that were sensitive to dabigatran, and identified a concentration of idarucizumab that neutralized the effects of dabigatran. These assays were then carried out with patient and control plasma samples spiked with dabigatran, with or without a molar excess of idarucizumab.

RESULTS

Dabigatran altered the prothrombin time, activated partial thromboplastin time and thrombin time, and the measurement of intrinsic and extrinsic factor levels. Screening and confirmation tests used for lupus anticoagulant detection were prolonged by dabigatran, falsely suggesting the presence of lupus anticoagulant. Conversely, the addition of dabigatran falsely corrected an abnormal activated protein C resistance ratio. Addition of idarucizumab completely normalized these measurements, and allowed the correct identification of normal and abnormal samples with these assays.

CONCLUSIONS

In vitro addition of idarucizumab to plasma samples containing dabigatran fully neutralizes the drug, and facilitates the use of routine coagulation assays to allow the diagnosis of hemostasis disorders that may be concurrently present in patients taking dabigatran.

Real-world variability in dabigatran levels in patients with atrial fibrillation

BACKGROUND

In clinical practice, physicians are given the choice of selecting one of two dabigatran doses based on patient characteristics, with the lower dose typically used in patients at a higher risk of bleeding.

OBJECTIVES

The objectives of the study were to (i) estimate the inter- and intra-patient variability in dabigatran levels with 110 mg (DE110) and 150 mg (DE150) doses, (ii) examine the effect of physicians' dose selection on levels in DE110 and DE150 subgroups, and (iii) explore whether a single trough measurement identifies patients with extreme levels on subsequent visits.

METHODS

In this prospective observational study of 100 patients with atrial fibrillation (AF), peak and trough levels of dabigatran were measured with the Hemoclot(®) assay at baseline and every 2 months thereafter (maximum four visits).

RESULTS

Inter-patient variability in dabigatran levels (geometric coefficient of variation [gCV], 51-64%) was greater than intra-patient variability (gCV, 32-40%). Similar medians and distributions of levels were observed in DE110 and DE150 subgroups. Patients receiving DE110 were older, had lower renal function and weighed less than those receiving DE150. Up to 40% of patients whose trough levels were in the upper extremes, and up to 80% of patients whose trough levels were in the lower extremes at baseline, showed subsequent levels that fell in the middle quartiles.

CONCLUSIONS

Our data support the practice of selecting the dabigatran dose based upon clinical characteristics because it results in similar levels of drug exposure in patients given DE110 or DE150. They do not support the concept that a single Hemoclot(®) measurement reliably identifies patients with consistently high or low values.

Pulmonary arterio-venous malformations in a patient with a novel mutation in exon 10 of the ACVRL1 gene

Mutations of the ACVRL1 gene are a cause of hereditary haemorrhagic telangiectasia (HHT) type 2. In this case report, we present a patient with isolated pulmonary arterio-venous malformations (PAVMs) without other diagnostic criteria for HHT and a novel mutation in exon 10 of the ACVRL1 gene. Other mutations in exon 10 of ACVRL1 have been linked to the development of pulmonary artery hypertension, but PAVMs are a rare manifestation of HHT associated with ACVRL1 mutations. A disrupted endothelial TGF-beta/BMP signaling cascade underlies the pathogenesis of HHT, but the exact mechanism of the disease remains unelucidated. In particular, the factors that influence the variable clinical presentation are not fully understood.

Antidote strategies to reverse anticoagulation with TB-402, a long-acting partial inhibitor of factor VIII

BACKGROUND

TB-402 is a partially inhibiting antibody of factor VIII that is under development as a long-acting anticoagulant.

PATIENTS AND METHODS

The reversibility of FVIII inhibition by TB-402 was evaluated in vitro after spiking with recombinant human FVIII (rhFVIII), human plasma-derived FVIII (hpdFVIII), recombinant activated human FVII (rhFVIIa), FVIII inhibitor bypassing activity (FEIBA), and prothrombin complex concentrate (PCC). Twelve subjects were randomized to placebo or 35 or 70 IU kg(-1) rhFVIII 48 h after a single dose of 620 μg kg(-1) TB-402. TB-402 concentrations, FVIII activity (FVIII:C), activated partial thromboplastin time (APTT) and thrombin generation were measured over a period of 8 weeks.

RESULTS

In spiked samples, TB-402 inhibited FVIII:C by 30%, prolonged APTT by 4.5 s, and reduced the peak height in the thrombin generation assay to 56% ± 13% of the control value. In the presence of 10 μg mL(-1) TB-402, rhFVIII restored FVIII:C and APTT to the values obtained in the absence of TB-402. The inhibitory effect of TB-402 on thrombin generation was entirely reversed by rhFVIII, hpdFVIII, rhFVIIa, FEIBA, and PCC. In men, the mean half-life (t(1/2) ) of TB-402 was 14.2 days. TB-402 lowered the endogenous thrombin potential by 23% for ~ 35 days. Infusion of 35 IU kg(-1) rhFVIII had a marginal effect, whereas 70 IU kg(-1) rhFVIII restored FVIII:C, reduced APTT back to baseline for 9 h, and restored thrombin generation for ~ 3 h.

CONCLUSIONS

TB-402 resulted in a stable long-term anticoagulant effect. rhFVIII and other procoagulants counteracted the effect of TB-402 temporarily, and may be effective antidotes for future clinical practice.

Inhibition of staphylothrombin by dabigatran reduces Staphylococcus aureus virulence

BACKGROUND

Staphylocoagulase and von Willebrand binding protein (VWbp) bind to prothrombin to form the staphylothrombin complex that converts fibrinogen into fibrin.

OBJECTIVES

To study the role of staphylothrombin and its inhibition by dabigatran on Staphylococcus aureus virulence.

METHODS

We studied the effect of staphylothrombin inhibition on bacterial attachment to polystyrene surfaces, leukocyte activation and bactericidal activity for S. aureus ATCC 25923, S. aureus Newman, and staphylocoagulase- and VWbp-negative S. aureus Newman mutants in the presence or absence of prothrombin and fibrinogen. We measured the abscess size after subcutaneous (s.c.) injection of S. aureus ATCC 25923 and S. aureus Newman, as well as an S. aureus Newman mutant strain lacking staphylocoagulase and VWbp, in mice treated with either dabigatran or placebo.

RESULTS

Staphylothrombin-mediated fibrin increased the association of S. aureus to polystyrene surfaces and reduced the bactericidal activity of leukocytes. The absence or inhibition of staphylothrombin decreased the bacterial association, enhanced leukocyte activation and reduced bacterial survival in vitro. Abscess size was smaller in mice treated with dabigatran or infected with a coagulase-negative mutant.

CONCLUSION

Inhibition or the absence of staphylothrombin reduced S. aureus virulence in in vitro and in vivo models.