Proteomic profiling for biomarker discovery in heparin-induced thrombocytopenia

New analytical techniques can assess hundreds of proteins simultaneously with high sensitivity, facilitating the observation of their complex interplay and role in disease mechanisms. We hypothesized that proteomic profiling targeting proteins involved in thrombus formation, inflammation, and the immune response would identify potentially new biomarkers for heparin-induced thrombocytopenia (HIT). Four existing panels of the Olink proximity extension assay covering 356 proteins involved in thrombus formation, inflammation, and immune response were applied to randomly selected patients with suspected HIT (confirmed HIT, n=32; HIT ruled-out, n=38; positive heparin/PF4 [H/PF4] antibodies, n=28). The relative difference in protein concentration was analyzed using a linear regression model adjusted for sex and age. To confirm the test results, soluble P-selectin was determined using ELISA in above mentioned patients and an additional second dataset (n=49). HIT was defined as a positive heparin-induced platelet aggregation test (HIPA; washed platelet assay). Among 98 patients of the primary dataset, the median 4Ts score was 5 in patients with HIT, 4 in patients with positive heparin/PF4 antibodies, and 3 in patients without HIT. The median OD of a polyspecific heparin/PF4 ELISA was 3.0, 0.9, and 0.3, respectively. Soluble P-selectin remained statistically significant after multiple test adjustments. The area under the receiver-operating-characteristics-curve was 0.81 for Olink and 0.8 for ELISA. Future studies shall assess the diagnostic and prognostic value of soluble P-selectin in the management of HIT.

Cardiovascular multimodality imaging in women: a scientific statement of the European Association of Cardiovascular Imaging of the European Society of Cardiology

Cardiovascular diseases (CVD) represent an important cause of mortality and morbidity in women. It is now recognized that there are sex differences regarding the prevalence and the clinical significance of the traditional cardiovascular (CV) risk factors as well as the pathology underlying a range of CVDs. Unfortunately, women have been under-represented in most CVD imaging studies and trials regarding diagnosis, prognosis, and therapeutics. There is therefore a clear need for further investigation of how CVD affects women along their life span. Multimodality CV imaging plays a key role in the diagnosis of CVD in women as well as in prognosis, decision-making, and monitoring of therapeutics and interventions. However, multimodality imaging in women requires specific consideration given the differences in CVD between the sexes. These differences relate to physiological changes that only women experience (e.g. pregnancy and menopause) as well as variation in the underlying pathophysiology of CVD and also differences in the prevalence of certain conditions such as connective tissue disorders, Takotsubo, and spontaneous coronary artery dissection, which are all more common in women. This scientific statement on CV multimodality in women, an initiative of the European Association of Cardiovascular Imaging of the European Society of Cardiology, reviews the role of multimodality CV imaging in the diagnosis, management, and risk stratification of CVD, as well as highlights important gaps in our knowledge that require further investigation.

Accuracy of Diagnosing Heparin-Induced Thrombocytopenia

Importance

Heparin-induced thrombocytopenia (HIT) is a life-threatening condition that requires urgent diagnostic clarification. However, knowledge of the diagnostic utility of the recommended diagnostic tests is limited in clinical practice.

Objective

To evaluate the current diagnostic practice for managing the suspicion of HIT.

Design, Setting, and Participants

This prospective diagnostic study was conducted from January 2018 to May 2021 among consecutive patients with suspected HIT from 11 study centers in Switzerland, Germany, and the United States. Detailed clinical data and laboratory information were recorded. Platelet factor 4/heparin antibodies were quantified using an automated chemiluminescent immunoassay (CLIA). A washed-platelet heparin-induced platelet activation (HIPA) test was used as a reference standard to define HIT.

Exposures

Suspicion of HIT.

Main Outcomes and Measures

The primary outcome was the diagnostic accuracy of the 4Ts score, the CLIA, and the recommended algorithm serially combining both tests.

Results

Of 1448 patients included between 2018 and 2021, 1318 were available for the current analysis (median [IQR] age, 67 [57-75] years; 849 [64.6%] male). HIPA was positive in 111 patients (prevalence, 8.4%). The most frequent setting was intensive care unit (487 [37.0%]) or cardiovascular surgery (434 [33.0%]). The 4Ts score was low risk in 625 patients (46.8%). By 2 × 2 table, the numbers of patients with false-negative results were 10 (9.0%; 4Ts score), 5 (4.5%; CLIA), and 15 (13.5%; recommended diagnostic algorithm). The numbers of patients with false-positive results were 592 (49.0%; 4Ts score), 73 (6.0%; CLIA), and 50 (4.1%; recommended diagnostic algorithm), respectively.

Conclusions and Relevance

In this diagnostic study of patients suspected of having HIT, when the recommended diagnostic algorithm was used in clinical practice, antibody testing was required in half the patients. A substantial number of patients were, however, still misclassified, which could lead to delayed diagnosis or overtreatment. Development of improved diagnostic algorithms for HIT diagnosis should be pursued.

Historic characteristics and mortality of patients in the Swiss Amyloidosis Registry

AIMS OF THE STUDY

Systemic amyloidoses are rare protein-folding diseases with heterogeneous, often nonspecific clinical presentations. To better understand systemic amyloidoses and to apply state-of-the-art diagnostic pathways and treatment, the interdisciplinary Amyloidosis Network was founded in 2013 at University Hospital Zurich. In this respect, a registry was implemented to study the characteristics and life expectancy of patients with amyloidosis within the area covered by the network. Patient data were collected retrospectively for the period 2005-2014 and prospectively from 2015 onwards.

METHODS

Patients aged 18 years or older diagnosed with any subtype of systemic amyloidosis were eligible for inclusion if they were treated in one of the four referring centres (Zurich, Chur, St Gallen, Bellinzona). Baseline data were captured at the time of diagnosis. Follow-up data were assessed half-yearly for the first two years, then annually.

RESULTS

Between January 2005 and March 2020, 247 patients were screened, and 155 patients with confirmed systemic amyloidosis were included in the present analysis. The most common amyloidosis type was light-chain (49.7%, n = 77), followed by transthyretin amyloidosis (40%, n = 62) and amyloid A amyloidosis (5.2%, n = 8). Most patients (61.9%, n = 96) presented with multiorgan involvement. Nevertheless, single organ involvement was seen in all types of amyloidosis, most commonly in amyloid A amyloidosis (75%, n = 6). The median observation time of the surviving patients was calculated by the reverse Kaplan-Meier method and was 3.29 years (95% confidence interval [CI] 2.33-4.87); it was 4.87 years (95% CI 3.14-7.22) in light-chain amyloidosis patients and 1.85 years (95% CI 1.48-3.66) in transthyretin amyloidosis patients, respectively. The 1-, 3- and 5-year survival rates were 87.0% (95% CI 79.4-95.3%), 68.5% (95% CI 57.4-81.7%) and 66.0% (95% CI 54.6-79.9%) respectively for light-chain amyloidosis patients and 91.2% (95% CI 83.2-99.8%), 77.0% (95% CI 63.4-93.7%) and 50.6% (95% CI 31.8-80.3%) respectively for transthyretin amyloidosis patients. There was no significant difference between the two groups (p = 0.81).

CONCLUSION

During registry set-up, a more comprehensive work-up of our patients suffering mainly from light-chain amyloidosis and transthyretin amyloidosis was implemented. Survival rates were remarkably high and similar between light-chain amyloidosis and transthyretin amyloidosis, a finding which was noted in similar historic registries of international centres. However, further studies are needed to depict morbidity and mortality as the amyloidosis landscape is changing rapidly.

Two-stage laparoscopic transversus abdominis plane block as an equivalent alternative to thoracic epidural anaesthesia in bowel resection-an explorative cohort study

PURPOSE

We evaluated the effect of the two-stage laparoscopic transversus abdominis plane block (TS-L-TAPB) in comparison to thoracic epidural anaesthesia (TEA) and a one-stage L-TAPB (OS-L-TAPB) in patients who underwent elective laparoscopic bowel resection.

METHODS

We compared a TS-L-TAPB (266 mg bupivacaine), which was performed bilaterally at the beginning and end of surgery, with two retrospective cohorts. These were patients who had undergone a TEA (ropivacaine/sufentanil) or an OS-L-TAPB (200 mg ropivacaine) at the beginning of surgery. Oral and i.v. opiate requirements were documented over the first 3 postoperative days (POD).

RESULTS

Patients were divided into three groups TEA (n = 23), OS-L-TAPB (n = 75), and TS-L-TAPB (n = 49). By the evening of the third POD, patients with a TEA had a higher cumulative opiate requirement with a median of 45.625 mg [0; 202.5] than patients in the OS-L-TAPB group at 10 mg [0; 245.625] and the TS-L-TAPB group at 5.625 mg [0; 215.625] (p = 0.1438). One hour after arrival in the recovery room, significantly more patients in the TEA group (100%) did not need oral and i.v. opioids than in the TS-L-TAPB (78%) and OS-L-TAPB groups (68%) (p = 0.0067).This was without clinical relevance however as the median in all groups was 0 mg. On the third POD, patients in the TEA group had a significantly higher median oral and i.v. opioid dose at 40 mg [0; 80] than the TS-L-TAPB and OS-L-TAPB groups, both at 0 mg [0; 80] (p = 0.0009).

CONCLUSION

The TS-L-TAP showed statistically significant and clinically meaningful benefits over TEA and OS-L-TAP in reducing postoperative opiate requirements.

Distribution of normalized pulmonary transit time per pathology in a population of routine CMR examinations

Pulmonary transit time (PTT), defined as the time taken for a contrast agent bolus to pass from the right ventricle to the left ventricle, is a surrogate for non-invasive assessment of preload. It is used in several imaging modalities: pulmonary angiography, echocardiography and cardiac magnetic resonance (CMR). Many recent studies have highlighted the prognostic value of PTT. Therefore, we sought to evaluate PTT in a consecutive cohort of patients undergoing CMR. We retrospectively evaluated PTT normalised for heart rate in 278 patients (66% male, mean age 58 ± 11 years) who underwent CMR between August 2017 and November 2021 with a diagnosis of dilated cardiomyopathy, infarct, hypertrophy, valvular, myocarditis, other pathology or no pathology ("normal"). Normalised pulmonary transit time (nPTT) was higher in men than in women (8.4 ± 1.3 beats vs 7.5 ± 1.1 beats, p = 0.002) in the "normal" group. nPTT was moderately correlated with left ventricular end-diastolic volume (LVEDV) (r2 = 0.19; p < 0.001), left ventricular end-systolic volume (LVESV) (r2 = 0.34; p < 0.001) and left ventricular ejection fraction (LVEF) (r2 = 0.29; p < 0.001). nPTT was significantly higher in patients with dilated cardiomyopathy (11.3 ± 5.4 beats; p < 0.001), infarct (9.5 ± 2.9 beats; p < 0.001) or valvular heart disease (9.5 ± 3.1 beats; p = 0.006) than in patients included in the "normal" group (7.9 ± 1.3 beats). The nPTT is an important marker of pathology. Its value depends on sex and type of pathology, but it is not specific for any type of pathology.

Amyloid detection and typing yield of skin biopsy in systemic amyloidosis and polyneuropathy

OBJECTIVE

Disease-modifying therapies are available for amyloidosis but are ineffective if end-organ damage is severe. As small fiber neuropathy is an early and common feature of amyloidosis, we assessed detection and typing yield of skin biopsy for amyloid in patients with confirmed systemic amyloidosis and neuropathic symptoms.

METHODS

In this case-control study, patients with transthyretin and light chain amyloidosis (ATTRv, ATTRwt, and AL) were consecutively recruited. They were sex and age-matched to three control groups (1) non-neuropathic controls (NNC), (2) monoclonal gammopathy of undetermined significance (MGUS), and (3) other neuropathic disease controls (ONC). Patients underwent a double 3 mm skin biopsy in proximal and distal leg. Amyloid index and burden, protein typing by immuno-electron microscopy, intraepidermal nerve fiber density, electroneuromyography, and clinical characteristics were analyzed.

RESULTS

We studied 15 subjects with confirmed systemic amyloidosis, 20 NNC, 18 MGUS, and 20 ONC. Amyloid was detected in 100% of patients with amyloidosis (87% in ankle and 73% in thigh). It was not detected in any of the control groups. A small fiber neuropathy was encountered in 100% of amyloidosis patients, in 80% of MGUS, and in 78% of ONC. Amyloid burden was higher in ATTRv, followed by AL and ATTRwt. The ultrastructural examination allowed the identification of the precursor protein by immunotyping in most of the cases.

INTERPRETATION

Skin biopsy is a minimally invasive test with optimal sensitivity for amyloid. It allows amyloid typing by electron microscope to identify the precursor protein. The diagnostic work up of systemic amyloidosis should include a skin biopsy.

Mean platelet volume: a prognostic marker in heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) is associated with high burden of comorbidities known to increase the mean platelet volume (MPV). This parameter has been associated with morbidity and mortality in HF. However, the role of platelets and the prognostic relevance of MPV in HFpEF remain largely unexplored. We aimed to evaluate the clinical usefulness of MPV as a prognostic marker in HFpEF. We prospectively enrolled 228 patients with HFpEF (79 ± 9 years; 66% females) and 38 controls of similar age and gender (78 ± 5 years; 63% females). All subjects underwent two-dimensional echocardiography and MPV measurements. Patients were followed-up for a primary end point of all-cause mortality or first HF hospitalization. The prognostic impact of MPV was determined using Cox proportional hazard models. Mean MPV was significantly higher in HFpEF patients compared with controls (MPV: 10.7 ± 1.1fL vs. 10.1 ± 1.1fL, p = .005). HFpEF patients (n = 56) with MPV >75th percentile (11.3 fL) displayed more commonly a history of ischemic cardiomyopathy. Over a median follow-up of 26 months, 136 HFpEF patients reached the composite endpoint. MPV >75th percentile was a significant predictor of the primary endpoint (HR: 1.70 [1.08; 2.67], p = .023) adjusted for NYHA class, chronic obstructive pulmonary disease, loop diuretics, renal function, and hemoglobin. We demonstrated that MPV was significantly higher in HFpEF patients compared with controls of similar age and gender. Elevated MPV was a strong and independent predictor of poor outcome in HFpEF patients and may be relevant for clinical use.

Prevalence of amyloid in ligamentum flavum of patients with lumbar spinal stenosis

BACKGROUND

Transthyretin (ATTR) amyloidosis is often diagnosed in an advanced stage, when irreversible cardiac damage has occurred. Lumbar spinal stenosis (LSS) may precede cardiac ATTR amyloidosis by many years, offering the opportunity to detect ATTR already at the time of LSS surgery. We prospectively assessed the prevalence of ATTR in the ligamentum flavum by tissue biopsy in patients aged >50 years undergoing surgery for LSS.

METHODS

Ligamentum flavum thickness was assessed pre-operatively on axial T2 magnetic resonance imaging (MRI) slices. Tissue samples from ligamentum flavum were screened centrally by Congo red staining and immunohistochemistry (IHC).

RESULTS

Amyloid in the ligamentum flavum was detected in 74/94 patients (78.7%). IHC revealed ATTR in 61 (64.9%), whereas amyloid subtyping was inconclusive in 13 (13.8%). Mean thickness of ligamentum flavum was significantly higher at all levels in patients with amyloid (p < .05). Patients with amyloid deposits were older (73.1 ± 9.2 vs. 64.6 ± 10.1 years, p = .01). No differences in sex, comorbidities, previous surgery for carpal tunnel syndrome or LSS were observed.

CONCLUSIONS

Amyloid, mostly of the ATTR subtype, was found in four out of five patients with LSS and is associated with age and ligamentum flavum thickness. Histopathological work-up of ligamentum flavum might inform future decision making.

Repurposing the β3-Adrenergic Receptor Agonist Mirabegron in Patients With Structural Cardiac Disease: The Beta3-LVH Phase 2b Randomized Clinical Trial

Importance

Left ventricular (LV) hypertrophy contributes to the onset and progression of heart failure (HF), particularly for patients with pre-HF (stage B) for whom no treatment has yet proven effective to prevent transition to overt HF (stage C). The β3-adrenergic receptors (β3ARs) may represent a new target, as their activation attenuates LV remodeling.

Objective

To determine whether activation of β3ARs by repurposing a β3AR agonist, mirabegron, is safe and effective in preventing progression of LV hypertrophy and diastolic dysfunction among patients with pre- or mild HF.

Design, Setting, and Participants

The Beta3-LVH prospective, triple-blind, placebo-controlled phase 2b randomized clinical trial enrolled patients between September 12, 2016, and February 26, 2021, with a follow-up of 12 months. The trial was conducted at 10 academic hospitals in 8 countries across Europe (Germany, Poland, France, Belgium, Italy, Portugal, Greece, and the UK). Patients aged 18 years or older with or without HF symptoms (maximum New York Heart Association class II) were screened for the presence of LV hypertrophy (increased LV mass index [LVMI] of ≥95 g/m2 for women or ≥115 g/m2 for men) or maximum wall thickness of 13 mm or greater using echocardiography. Data analysis was performed in August 2022.

Intervention

Participants were randomly assigned (1:1) to mirabegron (50 mg/d) or placebo, stratified by the presence of atrial fibrillation and/or type 2 diabetes, for 12 months.

Main Outcomes and Measures

The primary end points were LVMI determined using cardiac magnetic resonance imaging and LV diastolic function (early diastolic tissue Doppler velocity [E/e'] ratio assessed using Doppler echocardiography) at 12 months. Patients with at least 1 valid measurement of either primary end point were included in the primary analysis. Safety was assessed for all patients who received at least 1 dose of study medication.

Results

Of the 380 patients screened, 296 were enrolled in the trial. There were 147 patients randomized to mirabegron (116 men [79%]; mean [SD] age, 64.0 [10.2] years) and 149 to placebo (112 men [75%]; mean [SD] age, 62.2 [10.9] years). All patients were included in the primary intention-to-treat analysis. At 12 months, the baseline and covariate-adjusted differences between groups included a 1.3-g/m2 increase in LVMI (95% CI, -0.15 to 2.74; P = .08) and a -0.15 decrease in E/e' (95% CI, -0.69 to 0.4; P = .60). A total of 213 adverse events (AEs) occurred in 82 mirabegron-treated patients (including 31 serious AEs in 19 patients) and 215 AEs occurred in 88 placebo-treated patients (including 30 serious AEs in 22 patients). No deaths occurred during the trial.

Conclusions

In this study, mirabegron therapy had a neutral effect on LV mass or diastolic function over 12 months among patients who had structural heart disease with no or mild HF symptoms.

Trial Registration

ClinicalTrials.gov Identifier: NCT02599480.

Enoxaparin for symptomatic COVID-19 managed in the ambulatory setting: An individual patient level analysis of the OVID and ETHIC trials

BACKGROUND

Antithrombotic treatment may improve the disease course in non-critically ill, symptomatic COVID-19 outpatients.

METHODS

We performed an individual patient-level analysis of the OVID and ETHIC randomized controlled trials, which compared enoxaparin thromboprophylaxis for either 14 (OVID) or 21 days (ETHIC) vs. no thromboprophylaxis for outpatients with symptomatic COVID-19 and at least one additional risk factor. The primary efficacy outcome included all-cause hospitalization and all-cause death within 30 days from randomization. Both studies were prematurely stopped for futility. Secondary efficacy outcomes were major symptomatic venous thromboembolic events, arterial cardiovascular events, or their composite occurring within 30 days from randomization. The same outcomes were assessed over a 90-day follow-up. The primary safety outcome was major bleeding (ISTH criteria).

RESULTS

A total of 691 patients were randomized: 339 to receive enoxaparin and 352 to the control group. Over 30-day follow-up, the primary efficacy outcome occurred in 6.0 % of patients in the enoxaparin group vs. 5.8 % of controls for a risk ratio (RR) of 1.05 (95%CI 0.57-1.92). The incidence of major symptomatic venous thromboembolic events and arterial cardiovascular events was 0.9 % vs. 1.8 %, respectively (RR 0.52; 95%CI 0.13-2.06). Most cardiovascular thromboembolic events were represented by symptomatic venous thromboembolic events, occurring in 0.6 % vs. 1.5 % of patients, respectively. A similar distribution of outcomes between the treatment groups was observed over 90 days. No major bleeding occurred in the enoxaparin group vs. one (0.3 %) in the control group.

CONCLUSIONS

We found no evidence for the clinical benefit of early administration of enoxaparin thromboprophylaxis in outpatients with symptomatic COVID-19. These results should be interpreted taking into consideration the relatively low occurrence of events.

Limited concordance of heparin/platelet factor 4 antibody assays for the diagnosis of heparin-induced thrombocytopenia: an analysis of the TORADI-HIT study

BACKGROUND

Anecdotal reports suggest that the correlation between heparin/platelet factor 4 (PF4) antibody assays for the diagnosis of heparin-induced thrombocytopenia (HIT) is limited.

OBJECTIVES

To investigate the correlation between widely used assays and examine possible factors contributing to variability.

METHODS

This is a large, prospective cohort study with 10 participating tertiary care hospitals including 1393 patients with suspected HIT in clinical practice. HIT was defined by a positive heparin-induced platelet activation (HIPA) assay (washed platelet reference standard test). Three different immunoassays were used to measure heparin/PF4 antibodies: chemiluminescent immunoassay, enzyme-linked immunosorbent assay, and particle gel immunoassay. Various factors that could influence the assays were examined: sex (male or female), age (<65 years or ≥65 years), unfractionated heparin exposure, presence of thrombosis, cardiovascular surgery, and intensive care unit. Spearman's correlation coefficients were calculated. Z-scores and diagnostic odds ratios were determined in the aforementioned subgroups of patients.

RESULTS

Among 1393 patients, 119 were classified as HIT-positive (prevalence, 8.5%). The median 4Ts score was 5 (IQR, 4-6) in patients with HIT compared with 3 (IQR, 2-4) in patients without HIT. Correlations (rs) between immunoassays were weak (0.53-0.65). Inconsistencies between immunoassays could not be explained by further analyses of z-scored test results and diagnostic odds ratios in subgroups of patients.

CONCLUSION

The correlation between widely used heparin/PF4 antibody assays was weak, and key factors could not explain this variability. Standardization of immunoassays is requested to improve comparability.

Recommendations for the use of andexanet alfa in the management of bleeding in patients on oral factor Xa inhibitors in Switzerland: Guideline from the Working Party Hemostasis of the Swiss Society of Hematology

Anticoagulants are essential in preventing and treating thrombosis. Unfortunately, their use is accompanied by an enhanced risk of bleeding. Since the introduction of direct oral anticoagulants (DOACs), the risk of major bleeding has been reduced but not eliminated. Major bleeding events related to the use of factor Xa inhibitors can be challenging to manage. In recent years, four-factor prothrombin complex concentrates have been used in patients with severe bleeding taking oral direct factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). Andexanet alfa (OndexxyaTM, AstraZeneca AG) is a specially designed recombinant version of human factor Xa that acts as a decoy receptor to reverse the effects of factor Xa inhibitors. Since 2 December 2020, andexanet alfa has been used in Switzerland for adult patients receiving apixaban or rivaroxaban when reversal of anticoagulation is required because of life-threatening or uncontrolled bleeding. However, the use of andexanet alfa remains a challenge owing to its cost, the reported thrombotic complications and the fact that its efficacy mainly relates to intracranial haemorrhage. Moreover, the use of nonspecific reversal agents together with andexanet alfa is controversial. The present recommendations on the use of andexanet alfa in the management of bleeding in patients on factor Xa inhibitors in Switzerland were developed by a group of Swiss experts from the Working Party Hemostasis of the Swiss Society of Hematology. These recommendations aim to provide support to clinicians in their decision-making in the management of patients with major bleeding receiving factor Xa inhibitors.

Cardiac atrial metabolism quantitative assessment with analog and digital time of flight-PET/computed tomography

BACKGROUND

Evaluation of left atrium (LA) remodeling is becoming increasingly relevant in understanding several pathological cardiac conditions. 18 F-FDG-PET/computed tomography (CT), the current gold standard for metabolic evaluation of the left ventricle, could be extended to LA using the latest PET technologies. We sought to perform a phantom study to optimize the reconstruction algorithm in this context.

METHODS

The liver, heart cavity and walls of an anthropomorphic phantom were filled with typical patient 18 F-FDG activity concentrations. Acquisitions were performed on an analog and on a digital TOF-PET/CT, and reconstructed with and without resolution recovery (RR). The Richardson-Lucy RR method was used, either through a third-party software or through the PET/CT manufacturer algorithm. Activity recoveries in the atria and ventricles and signal-to-noise ratios were evaluated to identify the best reconstruction and RR parameters. The same methodology was applied on a patient cardiac study.

RESULTS

Analog PET/CT with the third-party RR cannot improve the activity recovery without markedly degrading the image quality. For the digital PET/CT, the optimal algorithm was the manufacturer RR reconstruction using four iterations and 15 subsets combined with five RR iterations. This reconstruction improved the LA activity recovery from 58% to 70% while preserving images of diagnostic quality. Similar results were obtained for the patient study.

CONCLUSION

The digital TOF-PET/CT with the identified optimal reconstruction can be used to quantitatively analyze the LA uptake in 18 F-FDG cardiac studies while still preserving image reading quality. This may lead to more precise cardiovascular disease status evaluation, especially when atria are concerned.

Determination of Anti-Xa Inhibitor Plasma Concentrations Using a Universal Edoxaban Calibrator

A universal calibrator for the determination of all anti-Xa inhibitors would support laboratory processes. We aimed to test the clinical performance of an anti-Xa assay utilizing a universal edoxaban calibrator to determine clinically relevant concentrations of all anti-Xa inhibitors. Following a pilot study, we enrolled 553 consecutive patients taking rivaroxaban, edoxaban, or apixaban from nine study centers in a prospective cross-sectional study. The Technochrom^® anti-Xa assay was conducted using the Technoview^® edoxaban calibrator. Using ultra-high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), anti-Xa inhibitor drug concentrations were determined. Sensitivities and specificities to detect three clinically relevant drug concentrations (30 µgL^-1, 50 µgL^-1, 100 µgL^-1) were determined. Overall, 300 patients treated with rivaroxaban, 221 with apixaban, and 32 with edoxaban were included. The overall correlation coefficient (r_s) was 0.95 (95% CI 0.94, 0.96). An area under the receiver operating characteristic curve of 0.96 for 30 µgL^-1, 0.98 for 50 µgL^-1, and 0.99 for 100 µgL^-1 was found. The sensitivities were 92.3% (95% CI 89.2, 94.6), 92.7% (89.4, 95.1), and 94.8% (91.1, 97.0), respectively (specificities 82.2%, 93.7%, and 94.4%). In conclusion, the clinical performance of a universal, edoxaban-calibrated anti-Xa assay was solid and most drug concentrations were predicted correctly.

Tricuspid annular dynamics, not diameter, predicts tricuspid regurgitation after mitral valve surgery: Results from a prospective randomized trial

Objective

Current guidelines advise using prophylactic tricuspid valve annuloplasty during mitral valve surgery, especially in the presence of annular diameter enlargement. However, several retrospective studies and a prospective randomized study from our department could not confirm that diameter enlargement is predictive of late regurgitation. We examined whether 2- and 3-dimensional echocardiographic and clinical characteristics could identify patients who will develop moderate or severe recurrent tricuspid regurgitation.

Methods

Patients with less than severe functional tricuspid regurgitation (FTR) were randomized not to receive tricuspid annuloplasty, and 11 of 53 of them were excluded from the study because 3-dimensional echocardiographic analysis was not possible. Cox regression was used to estimate the model-based probability of moderate or severe FTR (vena contracta ≥3 mm) or progression of TR and FTR regression using valve dimensions (annulus area, diameter perimeter, nonplanar angle, and sphericity index), dynamics (annulus contraction, annulus displacement, and displacement velocity), and clinical parameters as possible predictors.

Results

At a median follow-up of 3.8 years (range, 3-5.6 years), 17 patients had moderate or severe FTR or progression, and 13 had FTR regression. Our models identified annular displacement velocity as a significant predictor for FTR recurrence and nonplanar angle as a significant predictor for FTR regression.

Conclusions

Annular dynamics, not the dimension, predict recurrence and regression of FTR. Annular contraction should be systematically investigated as a possible surrogate of right ventricle function to prophylactically treat the tricuspid valve.

Acquired haemophilia A in southern Switzerland from 2013 to 2019: a case series

AIMS OF THE STUDY: Acquired haemophilia A is a rare disease with an annual incidence of 1.48 per million. Based on clinical observations, we suspect a higher incidence in southern Switzerland, and aimed at providing local epidemiological data, and clinical information regarding diagnosis, treatment and outcome in our region. METHODS: All adult patients with acquired haemophilia A treated between 2013 and 2019 in our facility were included in the present retrospective analysis. RESULTS: We treated 11 patients with acquired haemophilia A between 2013 and 2019, resulting in an annual incidence of 4.5 per million (95% confidence interval [CI] 0–9.0). Median delay from first symptoms to diagnosis was 4.5 days, and the median age at diagnosis was 79 years (range 23–87). Possible causative conditions were: pregnancy (n = 1), polyarteritis nodosa (n = 1), myelodysplastic syndrome (n = 1), chronic human immunodeficiency virus (HIV) (n = 1), and HIV postexposure prophylaxis (n = 1). In five patients no underlying or associated condition was identified. Median activated partial thromboplastin time (aPTT)) at baseline was 79 seconds (65–117; ref. value <38 sec), and FVIII:C 2.15% (<1–3.75%). A FVIII:C <1% was present in 4/10 patients. Median FVIII-inhibitor titre was 10.3 BU/ml (2.4–75.0 BU/ml). All patients had bleeding symptoms, 5/10 patients had major bleedings, and 7/10 patients were treated with bypassing agents. All patients received corticosteroids; 7/10 patients received immunosuppressive combination therapy. FVIII levels of ≥50% were achieved after a median of 40 days (8–62). One patient had a severe immunosuppressive therapy-related infection. An 87-years-old woman died for reasons not related to acquired haemophilia A or immunosuppressive therapy. CONCLUSIONS: Acquired haemophilia A is a rare disease, but manageable despite the advanced patient age and comorbidities. Its incidence in Southern Switzerland is higher than previously suspected.

A machine-learning model for reducing misdiagnosis in heparin-induced thrombocytopenia: A prospective, multicenter, observational study

BACKGROUND

Diagnosing heparin-induced thrombocytopenia (HIT) at the bedside remains challenging, exposing a significant number of patients at risk of delayed diagnosis or overtreatment. We hypothesized that machine-learning algorithms could be utilized to develop a more accurate and user-friendly diagnostic tool that integrates diverse clinical and laboratory information and accounts for complex interactions.

METHODS

We conducted a prospective cohort study including 1393 patients with suspected HIT between 2018 and 2021 from 10 study centers. Detailed clinical information and laboratory data were collected, and various immunoassays were conducted. The washed platelet heparin-induced platelet activation assay (HIPA) served as the reference standard.

FINDINGS

HIPA diagnosed HIT in 119 patients (prevalence 8.5%). The feature selection process in the training dataset (75% of patients) yielded the following predictor variables: (1) immunoassay test result, (2) platelet nadir, (3) unfractionated heparin use, (4) CRP, (5) timing of thrombocytopenia, and (6) other causes of thrombocytopenia. The best performing models were a support vector machine in case of the chemiluminescent immunoassay (CLIA) and the ELISA, as well as a gradient boosting machine in particle-gel immunoassay (PaGIA). In the validation dataset (25% of patients), the AUROC of all models was 0.99 (95% CI: 0.97, 1.00). Compared to the currently recommended diagnostic algorithm (4Ts score, immunoassay), the numbers of false-negative patients were reduced from 12 to 6 (-50.0%; ELISA), 9 to 3 (-66.7%, PaGIA) and 14 to 5 (-64.3%; CLIA). The numbers of false-positive individuals were reduced from 87 to 61 (-29.8%; ELISA), 200 to 63 (-68.5%; PaGIA) and increased from 50 to 63 (+29.0%) for the CLIA.

INTERPRETATION

Our user-friendly machine-learning algorithm for the diagnosis of HIT (https://toradi-hit.org) was substantially more accurate than the currently recommended diagnostic algorithm. It has the potential to reduce delayed diagnosis and overtreatment in clinical practice. Future studies shall validate this model in wider settings.

FUNDING

Swiss National Science Foundation (SNSF), and International Society on Thrombosis and Haemostasis (ISTH).

Enoxaparin for outpatients with COVID-19: 90-day results from the randomised, open-label, parallel-group, multinational, phase III OVID trial

INTRODUCTION

The benefits of early thromboprophylaxis in symptomatic COVID-19 outpatients remain unclear. We present the 90-day results from the randomised, open-label, parallel-group, investigator-initiated, multinational OVID phase III trial.

METHODS

Outpatients aged 50 years or older with acute symptomatic COVID-19 were randomised to receive enoxaparin 40 mg for 14 days once daily vs. standard of care (no thromboprophylaxis). The primary outcome was the composite of untoward hospitalisation and all-cause death within 30 days from randomisation. Secondary outcomes included arterial and venous major cardiovascular events, as well as the primary outcome within 90 days from randomisation. The study was prematurely terminated based on statistical criteria after the predefined interim analysis of 30-day data, which has been previously published. In the present analysis, we present the final, 90-day data from OVID and we additionally investigate the impact of thromboprophylaxis on the resolution of symptoms.

RESULTS

Of the 472 patients included in the intention-to-treat population, 234 were randomised to receive enoxaparin and 238 no thromboprophylaxis. The median age was 57 (Q1-Q3: 53-62) years and 217 (46 %) were women. The 90-day primary outcome occurred in 11 (4.7 %) patients of the enoxaparin arm and in 11 (4.6 %) controls (adjusted relative risk 1.00; 95 % CI: 0.44-2.25): 3 events per group occurred after day 30. The 90-day incidence of cardiovascular events was 0.9 % in the enoxaparin arm vs. 1.7 % in controls (relative risk 0.51; 95 % CI: 0.09-2.75). Individual symptoms improved progressively within 90 days with no difference between groups. At 90 days, 42 (17.9 %) patients in the enoxaparin arm and 40 (16.8 %) controls had persistent respiratory symptoms.

CONCLUSIONS

In adult community patients with COVID-19, early thromboprophylaxis with enoxaparin did not improve the course of COVID-19 neither in terms of hospitalisation and death nor considering COVID-19-related symptoms.

Prognostic implications of paradoxical low gradient severe aortic stenosis: a comprehensive analysis from a large multicentric registry

Background

Up to 40% of patients with severe aortic stenosis (SAS; indexed aortic valve area (AVAi) &lt;0.6 cm2/m2) present with low transvalvular mean gradient (MG) despite a normal left ventricular ejection fraction (EF). There is intense debate about the prognostic significance of such entity, with some referring to it as an advanced form of the disease, others as an intermediate form between a moderate and a severe form.

Objectives

To compare outcome of patients with paradoxical low gradient SAS (PLG-SAS; i.e., mean gradient &lt;40 mmHg and AVAi &lt;0.6 cm2/m2) vs. moderate aortic stenosis (MAS; i.e. mean gradient &lt;40 mmHg and AVAi &gt;0.6 cm2/m2) and high gradient SAS (HG-SAS; i.e. mean gradient &gt;40 mmHg and AVAi &lt;0.6 cm2/m2).

Methods

2582 consecutive patients with aortic stenosis (PLG-SAS, n=933; MAS, n=876 and HG-SAS, n=773) and a preserved EF (&gt;50%) from an international multicentric registry were studied. Five years mortality between groups was compared using Kaplan Meier analysis. Inverse probability weighting was used to adjust for clinical and imaging baseline characteristics. Additionally, to explore the impact of MG (&lt;40 mmHg vs. &gt;40 mmHg) in patients with AVAi &lt;0.6 cm2/m2 (PLG-SAS vs. HG-SAS) and to explore the impact of AVAi (&lt;0.6 cm2/m2 vs. &gt;0.6 cm2/m2) in patients with MG &lt;40 mmHg (PLG-SAS vs MAS) we performed 2 different propensity score analyses. Patients were censored at the time of surgery.

Results

Overall, during 23 [IQR,10–47] months of follow-up 1003 patients died and 770 patients underwent aortic valve replacement. IPW-adjusted natural history was significantly better in patients with MAS, intermediate for patients with PLG-SAS and worst in patients with HG-SAS (59 vs. 47 vs. 41%, p&lt;0.001, see Figure 1A). Furthermore, at equal MG (448 pairs), survival was significantly better in patients with MAS compared with PLG-SAS (54% vs. 39% p&lt;0.001, see Figure 1B) and at equal AVAi (377 pairs), survival was significantly better in patients with PLG-SAS compared with HG-SAS (43% vs. 32% p&lt;0.001, see Figure 1C).

Conclusions

In this large multicentric cohort, survival of PLG-SAS patients was better than that of HG-SAS patients and worse than that of MAS patients. Furthermore, with a comparable mean gradient, the smaller the calculated AVAi, the worse the prognosis whereas with a comparable AVAi, the higher the mean gradient, the worse the prognosis. Taking together, these data demonstrate that PLG-SAS is an intermediate form in the disease continuum, HG-SAS being the most malignant form of AS.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Fonds National de la Recherche Scientifique (F.R.S.–FNRS)

Clinical use of mean platelet volume and neutrophil-to-lymphocyte ratio to predict prognosis in heart failure with preserved ejection fraction patients

Background

Over the last decade, a new paradigm for heart failure with preserved ejection (HFpEF) development has been proposed. High burden of comorbidities would lead to a systemic inflammatory state and enhanced platelet activation. High platelet reactivity could be associated with higher mean platelet volume (MPV) due increased circulating immature platelets. Moreover, neutrophil-to-lymphocyte (NLR) reflects systemic inflammation. Both parameters have been associated with morbidity and mortality in heart failure (HF). However, data in HFpEF are limited.

Purpose

We aim to investigate the use of MPV and NLR to predict clinical outcome in HFpEF patients.

Methods

We prospectively enrolled 228 patients with HFpEF (79±9 years, 66% female patients) and 38 controls of similar age and gender (78±5, 63% female patients). All subjects underwent a complete two-dimensional echocardiography. Mean platelet volume and NLR were measured at baseline. Patients were followed over time for a primary end point of all-cause mortality or first HF hospitalization. The prognosis impact of MPV and NLR were determined with Cox proportional hazard models.

Results

Mean MPV and median NLR were significantly higher in HFpEF patients compared to controls (MPV: 11.7±1.1 fL vs 10.0±1.1 fL, p=0.005; NLR: 3.3 [2.2; 5.0] vs 2.2 [1.9; 2.9], p&lt;0.001). HFpEF patients with MPV &gt;75th percentile (n=56) had more frequently a history of ischemic cardiomyopathy (46%, p=0.04). HFpEF patients with NLR &gt;75th percentile (n=57) were more frequently in New York Heart Association functional (NYHA) III or IV class (58%, p=0.02) and had higher levels of NT-proBNP (2152 [1336; 6397] pg/mL vs 1690 [705; 3304] pg/mL, p=0.02). Over a median follow-up of 26 months [11.5–56.7 months], 136 HFpEF patients (60%) reached the composite end point (87 deaths and 107 hospitalizations for HF). In univariate Cox regression analysis for the primary end point, MPV &gt;75th percentile (HR: 1.45 [0.99; 2.13], p=0.05) and NLR &gt;75th percentile (HR: 1.59 [1.11; 2.28], p=0.01) were predictors of the primary composite endpoint. In multivariate Cox regression analysis, mean platelet volume &gt;75th percentile (χ2=8.11, P=0.004), continuous MPV (χ2=4.64, P=0.03) provided significant additional prognostic value over a baseline model created using independent predictors of the primary composite end point: body mass index (BMI), NYHA class III or IV, chronic obstructive pulmonary disease (COPD), loop diuretics, estimated glomerular filtration rate (eGFR) and NT-proBNP. By contrast, NLR did not provide any additional information (Figure 1 and 2).

Conclusion

MPV level and NLR were significantly higher in HFpEF patients compared with controls of similar age and gender. Elevated MPV offers an additional prognostic indication for clinicians and more interestingly it supports the hypothesis that of platelet activation could be involved in disease pathophysiology in HFpEF.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Fondation Saint-Luc

Impact of recent 2021 ESC guideline changes on postoperative survival of patients with severe aortic regurgitation: insights from the AVIATOR registry

Background

Until 2021, the strongest guidelines on surgical correction of severe aortic regurgitation (AR) focused on the left ventricular systolic function (LVEF) and the presence of symptoms. However, those situations lead to an outcome penalty, even after surgical correction. Left ventricle end-systolic diameter (LVESD) gained in strength in 2021 European guidelines. Moreover, more inclusive cut-off values are now recommended (class IIb) in patients at low surgical risk, reflecting the will to recommend surgery before developing heart failure and its consequences on post-operative outcome.

Purpose

We sought to evaluate the impact of guidelines triggers and their recent changes on postoperative survival of patients with severe AR from a large multicentric international registry.

Method and results

Postoperative overall survival of 1899 patients operated for severe and chronic AR (mean age 49±15 years, 85% male) in the international multicenter surgery registry for aortic valve surgery, AVIATOR, was evaluated over a median of 37 months. Twelve patients (0.6%) died postoperatively, and 68 within 10 years. By multivariable Cox analysis, presence of heart failure symptoms (HR 2.60; 95% CI [1.20–5.66]; p=0; 016), and either LVESD &gt;50 mm or &gt;25 mm/m2 (HR 1.64; 95% CI [1.05–2.55]; p=0.029) predicted survival independently over and above age (HR 2.25 per SD, 95% CI [1.67–3.03], p&lt;0.001), female gender and bicuspid phenotype. Therefore, patients operated on when meeting either old or new 2021 class I triggers had worse adjusted survival (respectively 86±2% and 87±2%) than patients operated on without meeting triggers (97±2%, p&lt;0.01). However asymptomatic patients operated on while meeting new 2021 ESC class IIb triggers (ie LVESD &gt;20 mm/m2 or LVEF between 50–55%, 10-year survival 97±3%). Moreover, the sub-group of patients having a dilated LVESD &gt;50 mm or &gt;25 mm/m2 but a preserved LVEF &gt;50% had excellent survival (10-year survival 95±3%).

Conclusions

In severe AR, patients operated on when meeting any class I trigger have postoperative survival penalty. Asymptomatic patients operated on earlier have better survival. This supports early surgery in AR as encouraged by the recent ESC/EACTS guidelines.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Fondation Nationale de la Recherche Scientifique of the Belgian Government

Enoxaparin for primary thromboprophylaxis in symptomatic outpatients with COVID-19 (OVID): a randomised, open-label, parallel-group, multicentre, phase 3 trial

Background

COVID-19 is a viral prothrombotic respiratory infection. Heparins exert antithrombotic and anti-inflammatory effects, and might have antiviral properties. We aimed to investigate whether thromboprophylaxis with enoxaparin would prevent untoward hospitalisation and death in symptomatic, but clinically stable outpatients with COVID-19.

Methods

OVID was a randomised, open-label, parallel-group, investigator-initiated, phase 3 trial and was done at eight centres in Switzerland and Germany. Outpatients aged 50 years or older with acute COVID-19 were eligible if they presented with respiratory symptoms or body temperature higher than 37·5°C. Eligible participants underwent block-stratified randomisation (by age group 50–70 vs >70 years and by study centre) in a 1:1 ratio to receive either subcutaneous enoxaparin 40 mg once daily for 14 days versus standard of care (no thromboprophylaxis). The primary outcome was a composite of any untoward hospitalisation and all-cause death within 30 days of randomisation. Analysis of the efficacy outcomes was done in the intention-to-treat population. The primary safety outcome was major bleeding. The study was registered in ClinicalTrials.gov (NCT04400799) and has been completed.

Findings

At the predefined formal interim analysis for efficacy (50% of total study population), the independent Data Safety Monitoring Board recommended early termination of the trial on the basis of predefined statistical criteria having considered the very low probability of showing superiority of thromboprophylaxis with enoxaparin for the primary outcome under the initial study design assumptions. Between Aug 15, 2020, and Jan 14, 2022, from 3319 participants prescreened, 472 were included in the intention-to-treat population and randomly assigned to receive enoxaparin (n=234) or standard of care (n=238). The median age was 57 years (IQR 53–62) and 217 (46%) were women. The 30-day risk of the primary outcome was similar in participants allocated to receive enoxaparin and in controls (8 [3%] of 234 vs 8 [3%] of 238; adjusted relative risk 0·98; 95% CI 0·37–2·56; p=0·96). All hospitalisations were related to COVID-19. No deaths were reported during the study. No major bleeding events were recorded. Eight serious adverse events were recorded in the enoxaparin group versus nine in the control group.

Interpretation

These findings suggest thromboprophylaxis with enoxaparin does not reduce early hospitalisations and deaths among outpatients with symptomatic COVID-19. Futility of the treatment under the initial study design assumptions could not be conclusively assessed owing to under-representation of older patients and consequent low event rates.

Funding

SNSF (National Research Programme COVID-19 NRP78: 198352), University Hospital Zurich, University of Zurich, Dr-Ing Georg Pollert (Berlin), Johanna Dürmüller-Bol Foundation.

Prothrombinase-Induced Clotting Time to Measure Drug Concentrations of Rivaroxaban, Apixaban, and Edoxaban in Clinical Practice: A Cross-Sectional Study

Prothrombinase-induced clotting time (PiCT) is proposed as a rapid and inexpensive laboratory test to measure direct oral anticoagulant (DOAC) drug levels. In a prospective, multicenter cross-sectional study, including 851 patients, we aimed to study the accuracy of PiCT in determining rivaroxaban, apixaban, and edoxaban drug concentrations and assessed whether clinically relevant drug levels could be predicted correctly. Citrated plasma samples were collected, and the Pefakit^® PiCT was utilized. Ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to measure drug concentrations. Cut-off levels were established using receiver-operating characteristics curves. We calculated sensitivities and specificities with respect to clinically relevant drug concentrations. Spearman’s correlation coefficient between PiCT and drug concentrations was 0.85 in the case of rivaroxaban (95% CI 0.82, 0.88), 0.66 for apixaban (95% CI 0.60, 0.71), and 0.78 for edoxaban (95% CI 0.65, 0.86). The sensitivity to detect clinically relevant drug concentrations was 85.1% in the case of 30 µg L⁻¹ (95% CI 82.0, 87.7; specificity 77.9; 72.1, 82.7), 85.7% in the case of 50 µg L⁻¹ (82.4, 88.4; specificity 77.3; 72.5, 81.5), and 85.1% in the case of 100 µg L⁻¹ (80.9, 88.4; specificity 73.2%; 69.1, 76.9). In conclusion, the association of PiCT with DOAC concentrations was fair, and the majority of clinically relevant drug concentrations were correctly predicted.

Role of Cardiovascular Magnetic Resonance in Native Valvular Regurgitation: A Comprehensive Review of Protocols, Grading of Severity, and Prediction of Valve Surgery

Valvular regurgitation is common in developed countries with an increasing prevalence due to the aging of the population and more accurate diagnostic imaging methods. Echocardiography is the gold standard method for the assessment of the severity of valvular heart regurgitation. Nonetheless, cardiovascular magnetic resonance (CMR) has emerged as an additional tool for assessing mainly the severity of aortic and mitral valve regurgitation in the setting of indeterminate findings by echocardiography. Moreover, CMR is a valuable imaging modality to assess ventricular volume and flow, which are useful in the calculation of regurgitant volume and regurgitant fraction of mitral valve regurgitation, aortic valve regurgitation, tricuspid valve regurgitation, and pulmonary valve regurgitation. Notwithstanding this, reference values and optimal thresholds to determine the severity and prognosis of valvular heart regurgitation have been studied lesser by CMR than by echocardiography. Hence, further larger studies are warranted to validate the potential prognostic relevance of the severity of valvular heart regurgitation determined by CMR. The present review describes, analyzes, and discusses the use of CMR to determine the severity of valvular heart regurgitation in clinical practice.

Prognostic factors in dogs with common causes of proteinuria

INTRODUCTION

Little is known about the prognostic value of increased urine protein to creatinine ratios (UPC) comparing different underlying diseases in dogs. Therefore, between 2014 and 2015, dogs with a UPC of 2,0 or higher measured were retrospectively analysed at least once. They were divided into groups of the most common underlying diseases, namely primary glomerulopathy, Cushing's disease, leishmaniasis and in a group of different diseases. Possible prognostic factors, like UPC at time of diagnosis, creatinine, urine specific gravity, albumin and haematocrit, were assessed. Eighty-nine dogs with severe proteinuria were included in the study. Median time of survival was 42 days. UPC and time of survival did not differ significantly between the groups. Among the dogs with primary glomerulopathy, identified significant risk factors for death included increased UPC (p=0,03), increased creatinine (p.

Accuracy of a Single, Heparin-Calibrated Anti-Xa Assay for the Measurement of Rivaroxaban, Apixaban, and Edoxaban Drug Concentrations: A Prospective Cross-Sectional Study

Background

Applying a single anti-Xa assay, calibrated to unfractionated heparin to measure rivaroxaban, apixaban, and edoxaban would simplify laboratory procedures and save healthcare costs.

Aim

We hypothesized that a heparin-calibrated anti-Xa assay would accurately measure rivaroxaban, apixaban, and edoxaban drug concentrations and correctly predict clinically relevant drug levels.

Methods

This analysis is part of the Simple-Xa study, a prospective multicenter cross-sectional study conducted in clinical practice. Patients treated with rivaroxaban, apixaban, or edoxaban were included. Anti-Xa activity was measured using the Siemens INNOVANCE^® Heparin assay. Drug concentrations were determined using ultra-high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Cut-off levels were determined in a derivation dataset (50% of patients) and sensitivities and specificities were calculated in a verification dataset (50% of patients).

Results

Overall, 845 patients were available for analysis. Correlation coefficients (r _s ) between the heparin-calibrated anti-Xa assay and drug concentrations were 0.97 (95% CI 0.97, 0.98) for rivaroxaban, 0.96 (0.96, 0.97) for apixaban, and 0.96 (0.94, 0.99) for edoxaban. The area under the receiver operating characteristics curve (ROC) was 0.99 for all clinically relevant drug concentrations. In the verification dataset, the sensitivity was 94.2% (95% CI 90.8-96.6) for 30 μg L^-1, 95.8% (92.4-98.0) for 50 μg L^-1, and 98.7% (95.5-99.9) for 100 μg L^-1. Specificities were 86.3% (79.2-91.7), 89.8% (84.5-93.7), and 88.7% (84.2-92.2), respectively.

Conclusion

In a large prospective study in clinical practice, a strong correlation of heparin-calibrated anti-Xa measurements with LC-MS/MS results was observed and clinically relevant drug concentrations were predicted correctly.

Anti-PD-L1 monoclonal antibody for the management of chronic disseminated intravascular coagulation secondary to a urothelial carcinoma: a case report

Background

Thrombocytopenia is often considered a risk factor for bleeding, but conversely may be associated with an increased thrombotic risk in several clinical situations. Here we present a patient with arterial thrombosis and chronic disseminated intravascular coagulation caused by metastatic urothelial carcinoma. As the treatment for a disseminated intravascular coagulation caused by a neoplasia is the treatment of the underlying disease itself, our case highlights a new therapeutic approach—immunotherapy—in a patient prone to hematological complications due to conventional chemotherapy.

Clinical case

A 74-year-old Caucasian male patient with a history of urothelial carcinoma of the bladder and moderate thrombocytopenia had multiple arterial thrombotic events despite antiplatelet therapy and anticoagulation. A diagnosis of chronic disseminated intravascular coagulation in the setting of a metastatic bladder urothelial carcinoma was made. The patient was treated with an anti-PD-L1 monoclonal antibody, and achieved a rapid response with subsequent reversal of the disseminated intravascular coagulation.

Conclusion

Unexplained arterial or venous thrombosis despite adequate thromboprophylaxis should be investigated, especially in the setting of thrombocytopenia. Chronic disseminated intravascular coagulation is a possible, life-threatening reason for this clinical picture, and should prompt rapid identification of the underlying disease. To the best of our knowledge, this is the second case of chronic disseminated intravascular coagulation due to neoplastic disease treated with immunotherapy.

Genetic and phenotypic attributes of splenic marginal zone lymphoma

Splenic marginal zone B-cell lymphoma (SMZL) is a heterogeneous clinico-biological entity. The clinical course is variable, multiple genes are mutated with no unifying mechanism, and essential regulatory pathways and surrounding microenvironments are diverse. We sought to clarify the heterogeneity of SMZL by resolving different subgroups and their underlying genomic abnormalities, pathway signatures, and microenvironment compositions to uncover biomarkers and therapeutic vulnerabilities. We studied 303 SMZL spleen samples collected through the IELSG46 multicenter international study (NCT02945319) by using a multiplatform approach. We carried out genetic and phenotypic analyses, defined self-organized signatures, validated the findings in independent primary tumor metadata and in genetically modified mouse models, and determined correlations with outcome data. We identified 2 prominent genetic clusters in SMZL, termed NNK (58% of cases, harboring NF-κB, NOTCH, and KLF2 modules) and DMT (32% of cases, with DNA-damage response, MAPK, and TLR modules). Genetic aberrations in multiple genes as well as cytogenetic and immunogenetic features distinguished NNK- from DMT-SMZLs. These genetic clusters not only have distinct underpinning biology, as judged by differences in gene-expression signatures, but also different outcomes, with inferior survival in NNK-SMZLs. Digital cytometry and in situ profiling segregated 2 basic types of SMZL immune microenvironments termed immune-suppressive SMZL (50% of cases, associated with inflammatory cells and immune checkpoint activation) and immune-silent SMZL (50% of cases, associated with an immune-excluded phenotype) with distinct mutational and clinical connotations. In summary, we propose a nosology of SMZL that can implement its classification and also aid in the development of rationally targeted treatments.

Eyes on amyloidosis: microvascular retinal dysfunction in cardiac amyloidosis

Aims

Methods and results

Conclusions

Prevalence and risk factors for venous thromboembolic events in critically ill patients with SARS-CoV-2 infection: a prospective observational study

BACKGROUND

The majority of prevalence studies on deep vein thrombosis (DVT) in severe COVID-19 patients are retrospective with DVT assessment based on clinical suspicion. Our aim was to prospectively and systematically estimate the occurrence of DVT in critically-ill mechanically-ventilated patients, and to identify potential risk factors for DVT occurrence and mortality.

METHODS

All patients with COVID-19 admitted to our 45 beds in the Intensive Care Unit (ICU) between March 6, 2020, and April 18, 2020, requiring invasive ventilatory support were daily screened for DVT with lower extremities and jugular veins ultrasonography. Univariate and multivariable logistic regression models were performed in order to identify predictors of DVT and mortality.

RESULTS

Seventy-six patients were included in the final analysis (56 men, mean age 67 years, median SOFA=7 points, median SAPS II=41 points, median PaO<inf>2</inf>/Fi0<inf>2</inf>=10.8 kPa). The period prevalence of DVT was 40.8%. Thirty-one DVTs were diagnosed. Twenty-five DVTs (80.6% of total DVTs) were catheter-related, mainly in the jugular veins. Twenty-six DVTs (83.9%) occurred in patients receiving enhanced antithrombotic prophylaxis. No independent variable was predictive of DVT occurrence. Twenty-eight patients (36.8%) died during the ICU stay. Age and SOFA score were independently associated with mortality.

CONCLUSIONS

A high number of critically-ill mechanically-ventilated COVID-19 patients developed a DVT. The majority of DVTs were catheter-related and occurred under intensive prophylactic anticoagulation. Routine ultrasound of the jugular veins should be suggested in this patient population, and in particular in presence of a central venous catheter.

Management of transthyretin amyloidosis

Transthyretin amyloidosis (ATTR amyloidosis) is a disease caused by deposition of transthyretin fibrils in organs and tissues, which causes their dysfunction. The clinical heterogeneity of ATTR amyloidosis and the variable presentation of symptoms at early disease stages, historically meant treatment delays. Diagnostic tools and therapy options of ATTR amyloidosis have markedly improved in recent years. The first Swiss Amyloidosis Network (SAN) meeting (Zurich, Switzerland, January 2020) aimed to define a consensus statement regarding the diagnostic work-up and treatment for systemic amyloidosis, tailored to the Swiss healthcare system. A consortium of 45 clinicians and researchers from all Swiss regions and universities was selected by the SAN committee to represent all sub-specialty groups involved in care of patients with amyloidosis. A steering committee conducted the literature search and analysis, wrote the critical synthesis and elaborated a list of statements that were evaluated by all the participants. These recommendations will improve outcomes and quality of life for patients with ATTR amyloidosis. A global review of these guidelines is planned every 3 years with a formal meeting of all the involved experts.

Automated Thrombin Generation Assay for Rivaroxaban, Apixaban, and Edoxaban Measurements

Background: The thrombin generation assay (TG) is a promising approach to measure the degree of anticoagulation in patients treated with direct oral anticoagulants (DOAC). A strong association with plasma drug concentrations would be a meaningful argument for the potential use to monitor DOAC. Objectives: We aimed to study the correlation of TG with rivaroxaban, apixaban, and edoxaban drug concentrations in a large, prospective multicenter cross-sectional study. Methods: Five-hundred and fifty-nine patients were included in nine tertiary hospitals. The Technothrombin® TG was conducted in addition to an anti-Xa assay; LC-MS/MS was performed as the reference standard. Results: Correlation (r_s) between thrombin generation measurements and drug concentrations was -0.72 for peak thrombin generation (95% confidence interval, CI, -0.77, -0.66), -0.55 for area under the curve (AUC; 95% CI -0.61, -0.48), and 0.80 for lag time (95% CI 0.75, 0.84). In contrast, r_s was 0.96 with results of the anti-Xa activity (95% CI 0.95-0.97). Sensitivity with regard to the clinically relevant cut-off value of 50 μgL^-1 was 49% in case of peak thrombin generation (95% CI, 44, 55), 29% in case of AUC (95% CI, 24, 34), and 64% in case of lag time (95% CI, 58, 69). Sensitivity of the anti-Xa assay was 95% (95% CI, 92, 97). Conclusions: The correlation of thrombin generation measurements with DOAC drug concentrations was weak, and clinically relevant drug levels were not predicted correctly. Our results do not support an application of TG in the monitoring of DOAC.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

A universal anti-Xa assay for rivaroxaban, apixaban, and edoxaban measurements: method validation, diagnostic accuracy and external validation

A universal anti‐Xa assay for the determination of rivaroxaban, apixaban and edoxaban drug concentrations would simplify laboratory procedures and facilitate widespread implementation. Following two pilot studies analysing spiked samples and material from 698 patients, we conducted a prospective multicentre cross‐sectional study, including 867 patients treated with rivaroxaban, apixaban or edoxaban in clinical practice to comprehensively evaluate a simple, readily available anti‐Xa assay that would accurately measure drug concentrations and correctly predict relevant levels in clinical practice. Anti‐Xa activity was measured by an assay calibrated with low‐molecular‐weight heparin (LMWH) in addition to ultra‐high performance liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). As an external validation, LMWH‐calibrated anti‐Xa activity was also determined in nine external laboratories. The LMWH‐calibrated anti‐Xa activity correlated strongly with rivaroxaban, apixaban or edoxaban drug levels [r_s = 0·98, 95% confidence interval (CI) 0·98–0·98]. The sensitivity for the clinically relevant cut‐off levels of 30, 50 and 100 µg/l was 96·2% (95% CI 94·4–97·4), 96·4% (95% CI 94·4–97·7) and 96·7% (95% CI 94·3–98·1) respectively. Concordant results were obtained in the external validation study. In conclusion, a universal, LMWH‐calibrated anti‐Xa assay accurately measured rivaroxaban, apixaban and edoxaban concentrations and correctly predicted relevant drug concentrations in clinical practice.