Elevated Lipoprotein(a) levels increase Major Adverse Limb Event

Background

High lipoprotein(a) levels are involved in the development of cardiovascular events, as particularly in myocardial infarction, stroke, and peripheral artery disease. Studies assessing prognostic values of lipoprotein(a) levels on the lower limbs are lacking.

Purpose

The aim of our study was to look after a relationship between the lipoprotein(a) level and the incidence of major adverse limb events (MALE) defined as major amputation, peripheral artery endovascular revascularization or peripheral artery bypass.

Methods

We included 16,513 patients with lipoprotein(a) measurements from our clinical information system. Normal lipoprotein(a) level was under 50 mg/dL and we defined: high lipoprotein(a) level as a lipoprotein(a) level between 50 mg/dL and 134 mg/dL and very high lipoprotein(a) level as a lipoprotein(a) levels over 134 mg/dL, i.e the 95th percentile in this cohort. Accelerated Failure Time models were used to assess the relationship between the lipoprotein(a) level and the incidence of MALE retrieved from the patient's electronic record during a median (interquartile range) follow-up of 3.74 (1.07; 7.30) years after the lipoprotein(a) measurement. MALE was defined as the occurrence of one of the following during follow-up: aortofemoral bypass surgery, limb bypass surgery, percutaneous transluminal angioplasty revascularization of the iliac, or infrainguinal arteries; or major amputation above the forefoot. Secondary outcomes included individual components of the primary

Results

Median lipoprotein(a) level was 24 mg/dL (10; 60), with 70.3%; 24.7%; and 5.0% within normal; high and very high lipoprotein(a) level respectively. The 1-year MALE incidence was 2.2% [95% CI: 1.96; 2.51]; 2.60% [95% CI: 2.09; 3.10] and 4.54% [95% CI: 3.08; 5.98] among the normal, high and very high lipoprotein(a) level patients respectively. High and very high lipoprotein(a) levels were independently associated with an increased risk of MALE (adjusted Accelerated Failure Time Exponential Estimate) 0.43 [95% CI: 0.24; 0.78], p=0.01 and 0.17 [95% CI: 0.07; 0.40], p<0.001, respectively.

Conclusion

In this large cohort of unselected real-world hospital inpatients, higher lipoprotein(a) levels were independently associated with an increased risk of MALE. Though, lipoprotein(a) measurement shall be taken into account not only to refine the cardiovascular risk but also the lower limb risk of revascularization or amputation.

Funding Acknowledgement

Type of funding sources: None.

Place of the Advanced Practice Registered Nurse within the vascular team: a qualitative study of vascular medicine physicians and nurses caring for patients with peripheral artery disease

Introduction

Advanced Practice Registered Nurses (APRNs) treat and diagnose diseases, counsel the public about health problems, manage chronic diseases, and participate in continuing education. In the cardiovascular field, Peripheral Arterial Disease (PAD), one of the manifestations of atherosclerotic cardiovascular disease, is archetypal in combining multiple cardiovascular risk factors (hypertension, hyperlipidemia, diabetes mellitus smoking). Vascular medicine faces the challenge of improving their care and quality of life, but some goals cannot be achieved with all patients. Patients with PAD should benefit from APRN care, but to date there is little published on the place of APRN in vascular medicine worldwide, and none in France.

Objective

It appeared important to us to assess the perception of their role by physicians and nurses in vascular medicine. As the status of APRN in France has only been enacted by law in 2018, we aim to investigate physicians and nurses working with patients suffering from PAD, to gather their opinions and draw the cooperation outlines these practitioners could have with an APRN.

Methods

Multicentre exploratory qualitative study by semi-directive interview conducted until data saturation and thematic analysis carried out with healthcare practitioners taking care of patients with PAD: 10 physicians working either in private practice setting or hospital setting or both, and 8 nurses in a vascular unit for hopsitalised patients.

Results

Three main themes emerged from responders' verbatims: a specific organization of vascular medicine with its inherent challenges, particularly regarding patients with PAD (specific psychosocial profile of patients, lack of therapeutic education, time, knowledge of non-specialist physicians, tedious follow-up outside hospitals, complex care trajectory, and lack of medical-surgical collaboration). Second, a role for APRN, particularly in consultation as part of patient follow-up, with expected benefits for the patient and the care team. The APRN is wanted to fill part of this gap. The expected benefits include a smoother care pathway and increased capacity for cardiovascular education and prevention, especially during consultations. Third, there are certain pitfalls that need to be clarified to integrate these new practitioners into the vascular teams already in place. In particular, the need to inform the vascular medicine teams about this new profession, and the indispensable presence of the conditions necessary for the development of a relationship of trust.

Conclusion

APRN could be the missing link in a Vascular team by creating a continuum in the care of patients with PAD, ensuring clinical assessment, nursing supervision, adverse event screening, and renewing drug prescriptions with the necessary adjustments, while ensuring an essential part of therapeutic education personalized to each PAD patient.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of Takayasu's arteritis activity by ultrasound localization microscopy

Objectives

Use of sulphur hexafluoride microbubbles (MB) with ultrasound can provide arterial wall enhancement. The use of ultrafast imaging with MB super-localization offers the possibility of ultrasound localization microscopy (ULM) and thus a visualization of in vivo carotid vasa vasorum. We aim to perform in vivo Vasa vasorum imaging in the carotid wall in Takayasu's arteritis and to provide a correlation with the disease's activity.

Methods

Patients with Takayasu arteritis were consecutively included in the national referral centre. Assessment of activity was performed by NIH activity index, with measurement of biological inflammation, morphological evaluation by computed tomography (CT) angiography, and 18-fluorodeoxyglucose CT scan. Ultrafast ultrasound imaging was performed with a 7 MHz central frequency linear probe. A dedicated contrast imaging sequence (plane waves with 8 angles, frame rate 500 Hz, voltage 8 V, duration of 8 s), coupled with the intravenous injection of sulphur hexafluoride MB allow us to store the raw radio frequency data of the MB passage. After a pre-processing step to accumulate frames properly including a frames selection and a movement correction, the MB were localized then tracked, allowing reconstruction of the vasa vasorum. The inflammation was quantified through MB tracked and normalized for inter acquisition comparison.

Results

16 patients were included. 5 patients (median age 35.8 [24.5–46.0] years, 3 women) had active disease and 11 patients (37.2 [31.7–47.3] years, 9 women) had quiescent disease. The passage of MB allowed the visualisation of microvessels within the arterial wall for active cases. The number of MB detected per second in the wall was 118 [80–169] for active cases vs. 13 [10–15] for quiescent cases (p=0.0005).

Conclusion

ULM allows visualization of microvessels within the carotid wall, with significantly greater MB passage in active Takayasu arteritis. ULM provides for the first time a precise visualization in vivo of the vasa vasorum and gives access to quantification of the vascularity of the arterial wall.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Société française de cardiologie

Relationship between kalemia and intensive care unit admission or death in hospitalized COVID-19 patients: A cohort study

Background

Methods

Results

Conclusion

Carotid plaque vulnerability assessed by combined shear wave elastography and ultrafast doppler compared to histology: the UF-plaque study

Purpose

New biomarkers are needed to assess the vulnerability of carotid plaque to guide carotid surgery decision. Ultrafast Ultrasound Imaging (UUI) provides an estimation of plaque stiffness by Shear Wave Elastography (SWE) and the quantification of wall shear stress (WSS) by ultrafast Doppler. We aimed at evaluating the plaque stiffness and WSS applied on the plaque as potential biomarkers of plaque vulnerability.

Methods

Patients were referred for carotid endarterectomy because of symptomatic or asymptomatic carotid stenosis. Their plaques were evaluated by UUI within 48 hours before surgery. For each plaque, WSS and SWE were obtained on a longitudinal view at the stenosis. After endarterectomy, gross analysis and histology were performed on each removed plaque.

Results

46 plaques with SWE data and 29 with WSS data were analysed. Histological analysis revealed 29 vulnerable and 17 stable plaques. Analysis of the Gray Scale Median by B mode, mean and standard deviation of stiffness by SWE were not helpful in identifying vulnerable plaques. Figure 1 presents the SWE acquisition on one plaque (A) and the distribution of plaque's stiffness average over all plaques showing the 4 ranges of stiffness (B). SWE analysis revealed that the percentage of stiffness range of [3–5] m/s was significantly increased in vulnerable plaques (p=0.048) (Figure 2A). WSS alone showed no significant difference between stable and vulnerable plaques regardless of which segment of the plaque was analysed. A multiparametric score using maximal WSS at the peak of the plaque associated with SWE texture analysis parameters was created by a stepwise analysis, leading to a score with a sensitivity of 80% and a specificity of 78%. The ROC curve of this score found an AUC of 0.85 (Figure 2B).

Conclusions

Multiparameter scoring including plaque stiffness and flow analysis using ultrafast ultrasound imaging allows an effective identification of histologically vulnerable carotid plaques.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Fédération Française de cardiologieSociété Française de Cardiologie Figure 1Figure 2

Twelve-months safety of valvosoft non-invasive ultrasound therapy (NIUT) in patients with severe symptomatic aortic valve stenosis: a first-in-human study

Background

Despite overall favourable outcome of surgical and transcatheter aortic valve replacement (SAVR/TAVR) in patients with severe calcific aortic stenosis (CAS), not all patients are eligible for an invasive treatment1 because of too high predicted mortality and complications.

Cardiawave© has developed a novel non-invasive ultrasound therapy (NIUT) device called Valvosoft to treat calcific aortic stenosis (CAS). Based on preclinical results2,3, a prospective first-in-human study was conducted in two centres in 10 patients in 2019 and a second one in 4 patients in 2020. All patients had symptomatic severe CAS and were not eligible for aortic valve replacement according to local heart teams.

Methods

Fourteen patients with severe symptomatic CAS not eligible for valve replacement were enrolled. Transthoracic therapeutic ultrasound was delivered by the Valvosoft transducer coupled with an echocardiographic phased-array probe for real-time monitoring. Clinical and echocardiographic evaluation were performed at baseline, discharge, 1-, 3-, 6- and 12-months follow-up. Additionally, the 4 patients of the second study had a brain-MRI performed before and after treatment to rule out silent cerebrovascular events.

Results

Patients were advanced in age (82.4±5.3 years) with severe comorbidities (57% with heart failure and 50% with coronary heart disease) and severe CAS. No adverse events occurred during the procedure other than isolated ventricular extrasystoles. No device- or procedure-related SAEs were reported at 1-month follow-up as adjudicated by the Clinical Event Committee (CEC). No death, stroke or TIAs or deterioration of neurological status were observed at 1-month follow-up for all 14 patients.

During 12-months follow-up, 5 out of the 14 patients died (from 2 to 7 months after the procedure). All deaths were adjudicated as non-procedure related. The survival rate was higher (100%, 93%, 79%, 64% at 1-, 3-, 6- and 12-months) comparing to the natural evolution of the disease on an equivalent studied population4 (94%, 73%, 73%, 54% at 1, 3, 6 and 12-months). No abnormality was detected in any of the 4 patients who had a brain-MRI before and after treatment.

Conclusions

NIUT seemed feasible and safe and in a small first cohort of very frail patients with severe comorbidities suffering from severe symptomatic CAS. Brain-MRIs performed before and after treatment ruled out silent cerebrovascular events. The survival comparison of the studied population contrasted to the natural evolution of the disease suggests that NIUT is beneficial for these patients with no other medical option.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This study has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement 829492 and is supported by the French Government, managed by the National Research Agency (ANR) under the program “Investissements d'avenir” with the reference ANR-16-RHUS-0003 and ANR VALVOSOFT-17-CE19-0019-02.

Smart ultrasound device for real-time myocardial stiffness quantification of the human heart

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ERC

Introduction

Myocardial stiffness (MS) is crucial to understand cardiac biomechanics and evaluate cardiac function. We recently demonstrated that shear wave imaging using acoustic radiation force can provide quantitative end-diastolic MS in human patients [1] . However, the dependence of shear wave velocity with myofiber orientation remained a limitation and required to perform Shear Wave Velocity (SWV) estimations from different probe orientations which is challenging in clinical practice. We propose a new approach to provide real-time quantitative assessment of MS without dependence of the probe orientation based on a dedicated smart ultrasound (US) device.

Methods

A new US probe was designed and manufactured to generate acoustic radiation force along the central axis and track the SWV simultaneously along three different orientations to obtain an elliptic profile of SWS. The probe was connected to dedicated electronics and software to provide real-time end-diastolic MS with ECG gating. Validation was performed on 4 in-vitro calibrated phantoms (0.92 – 1.49 – 2.58 – 3.49 m/s) and on ex vivo porcine hearts. MS along and across the fibers were compared to the values measured by conventional shear wave imaging with a linear probe mounted on a rotation motor (angular step of 10°) (Aixplorer, Supersonic imaging). Finally, the in vivo feasibility and reproducibility of measuring MS of the antero-septal wall and of the right ventricular (RV) wall was assessed transthoracically on four human volunteer .

Results

In vitro results on phantoms showed a good agreement with calibrated value (r2 = 0.98, std = 4.8%). Elliptic profiles on ex-vivo porcine heart showed good agreement with Aixplorer measurements acquired at different angles, with a relative difference along the long axis (LA) of: Δ=7.0%, Δ=7.1%, Δ=9% respectively for left ventricle (LV), right ventricle (RV) and septum. Finally, myocardial SWV assessment in human volunteers was obtained successfully on the RV and on the septum in late diastole. The mean MS was 1.79+/- 0.15 m/s along the fiber direction, the  fractional anisotropy (FA) was 0.25 +/- 0.06 on septal wall  in good agreement with previous results [1] and 1.06 +/- 0.11 m/s along fibers orientation and a FA of 0.27 +/- 0.08 on RV.  Finally the beat to beat reproducibility of MS measurement was estimated to be 8.22%.

Conclusion

The new smart US device allowed non-invasive quantification of anisotropic myocardial tissues in real time. Results showed the accuracy of the methods. This approach could offer a new clinical tool for the evaluation of the myocardium in cardiomyopathies and in heart failure patients.

Abstract Figure. SWV on myocardium human volonteer

Ergotism with acute limb ischemia, provoked by HIV protease inhibitors interaction with ergotamine, rescued by multisite transluminal balloon angioplasty

Acute limb ischemia induced by arterial vasospasm remains an exceptional situation, favoured by the use of arterial vasoconstrictors. The risk of these substances is largely underestimated in the general population, especially with the co-administration of strong cytochrome inhibitors like human immunodeficiency virus (HIV) protease inhibitors. A 33-year-old woman, who used to take dihydroergotamine for orthostatic hypotension, was prescribed a post-exposure HIV prophylaxis including lopinavir and ritonavir. One day later, she presented an acute bilateral limb ischemia with a sudden pain in both calves, initially while walking and then at rest with bilateral ischemic toes. Angiography confirmed diffuse arterial vasospasm of the lower limb arteries. A first-line therapy with isosorbide dinitrate and amlodipine was ineffective, with rapid clinical worsening. A combination of intra-arterial injections and intra-venous infusions of vasodilators, transluminal balloon angioplasty and bilateral 4-Compartment fasciotomies permitted rapid improvement and finally resulted in both lower limbs rescue. This case and literature review illustrate ergotism due to ergotamine overdose after taking HIV protease inhibitors. It also demonstrates the benefit of an interventional procedure besides medical therapy with vasodilators in severe arterial vasospasm. All along the lower limb arterial tree, transluminal balloon angioplasty restored the blood flow, without vasospasm recurrence. CONCLUSION: In case of ergotism with acute lower limbs ischemia, combining medical vasodilator therapy with interventional procedure can restore the arterial blood flow, thus allowing to save lower limbs.

Safety, feasibility and performance of Valvosoft non-invasive ultrasound therapy in patients with severe symptomatic calcific aortic valve stenosis. First-in-Man

Objectives

We recently developed a unique transthoracic non-invasive ultrasound therapy device called Valvosoft to treat aortic stenosis. The therapy consists in delivering trans-thoracically precisely focused and controlled short ultrasound pulses (<20μsec) at a high acoustic intensity to produce non-thermal mechanical tissue softening of the calcified aortic valve with the ultimate aim of improving the valve opening. Ultrasound imaging enables to follow valve movements in real-time and thus targets the ultrasound waves on the valve with great precision. After having validated this concept in pre-clinical studies, we aimed at applying this technique in human. The primary objectives were to assess the safety and feasibility of this novel technique along with its performance by evaluation of the valve leaflets mobility and valve opening area.

Methods

This is a multi-center, prospective, controlled first-in-man study. Ten patients with severe symptomatic calcific aortic stenosis and not eligible for SAVR/TAVR underwent a Valvosoft ultrasound therapy. The therapy consists of 6 sessions of ultrasound therapy. The Valvosoft transducer is applied on the patient's chest and coupled at its center with an echocardiography phased array probe to allow real-time control of the therapy (cavitation bubble detection). Preselection of the region of interest is performed by echo still frame before each session. Ultrasonic evaluation was performed by an independent core lab at baseline, discharge, 30-day and 3 month follow-up along with clinical follow up.

Results

Enrolled patients were advanced in age (84.1±6.5 yrs) with severe comorbidities (8 with heart failure, 5 with coronary heart disease and 5 with kidney failure). All had extensive aortic valve calcification (mean calcification volume of 687.28 mm3) with mean AVA of 0.61±0.17 cm2 and mean pressure gradient of 37.5±10.5 mmHg (6 patients had SV<35ml/m2). No adverse events were recorded during the procedures other than some benign ventricular extrasystoles. The mean treatment time was 52 minutes. At 3 months follow-up, one patient had died due to end stage heart failure not linked to the procedure (9 weeks post procedure) and another got finally TAVI (45 days post procedure). Of the other 8 patients, 6 experienced an improvement of their NYHA status. No device or procedure related major adverse events nor deterioration of neurological status were observed at 3 months follow-up. Of the 7 patients that had echo follow-up at 3 months (one patient refused to get echo evaluation), 5 increased the AVA (between 14% and 46%) and 4 patients decreased the mean pressure gradient (from 6% to 44%). No AI or EF deterioration occurred during follow up.

Conclusion

Non-invasive ultrasound therapy is feasible and safe in patients with severe aortic valve stenosis and is able to improve AVA and pressure gradient in some patient. Larger studies with longer follow up will need to be conducted.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Cardiawave SA, Paris, France

Management of cancer-related thrombosis in the era of direct oral anticoagulants: A comprehensive review of the 2019 ITAC-CME clinical practice guidelines. On behalf of the Groupe Francophone Thrombose et Cancer (GFTC)

Venous thromboembolism (VTE) is a common disease complication in cancer patients and the second cause of death after cancer progression. VTE management and prophylaxis are critical in cancer patients, but effective therapy can be challenging because these patients are at higher risk of VTE recurrence and bleeding under anticoagulant treatment. Numerous published studies report inconsistent implementation of existing evidence-based clinical practice guidelines (CPG), including underutilization of thromboprophylaxis, and wide variability in clinical practice patterns across different countries and various practitioners. This review aims to summarize the 2019 ITAC-CME evidence-based CPGs for treatment and prophylaxis of cancer-related VTE, which include recommendations on the use of direct oral anticoagulants specifically in cancer patients. The guidelines underscore the gravity of developing VTE in cancer and recommend the best approaches for treating and preventing cancer-associated VTE, while minimizing unnecessary or over-treatment. Greater adherence to the 2019 ITAC guidelines could substantially decrease the burden of VTE and improve survival of cancer patients.

419 Revisiting cardiac Doppler index with single heart beat 4D ultrafast echocardiography

Funding Acknowledgements

European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n° 311025 and the ANR-10-IDEX-00

Background

4D echocardiography has the strong potential to improve cardiac index quantification by providing reproducible and user independent measurements. Quantification of left ventricle volume and ejection fraction, for instance, have been shown to be more reliable using 4D echocardiography. However, Doppler index evaluation has not yet benefited from it, due to limited volume rates and single location estimation when assessing spectral Doppler.

Purpose

In this study, we propose to demonstrate the feasibility of performing semi-automatic evaluation of cardiac Doppler indices within a single heartbeat on three human hearts by performing 4D ultrafast echocardiography, a new technique allowing a drastic volume rate increase.

Methods

A 4D ultrafast echocardiography scanner prototype connected to a matrix probe was developed to image the human heart. The probe was positioned on the apical 4-chamber view of N = 3 volunteers. High volume rate (5200 volume/s) acquisitions were performed three times by two different trained cardiologists. 4D color flow and tissue Doppler imaging were computed from the each single heartbeat acquisition. Spectral Doppler were derived at each voxel of the volumes. Region of interest such as LV outflow tract, mitral inflow or basal inferoseptal locations were automatically detected. Doppler index were derived from Doppler spectra and tissue velocity curves at these locations, and were compared against indices obtained using a clinical procedure based on 2D echocardiography.

Results

For each acquisition and the three volunteers, major Doppler indices: E, A, E/A, S, e’, a’, e’/a’, s’, E/e’, cardiac output were successfully assessed during a single heartbeat. A high degree of similarity between the indices assessed by 4D ultrafast echocardiography and clinical 2D measurements were found.(p > 0.05 for each index).

Conclusions

4D ultrafast echocardiography can quantify the major cardiac Doppler indices in a single heart beat acquisition. It promises to improve patient care by accelerating examination time and to improve results reproducibility by removing most of the operator dependency. It also offers a unique feature by enabling E/e’ index assessment in the same heart beat which could be of a great interest for atrial fibrillation patients.

Abstract 419 Figure.

3041Wall shear stress measurement by ultrafast vector flow imaging for atherosclerotic carotid stenosis

Background

Carotid plaque vulnerability assessment is an important factor in guiding the decision to treat significant carotid stenosis. Ultrafast Ultrasound Imaging (UF) offers the possibility of evaluating local flow velocities over an entire 2D image, allowing access to velocity measurements in contact with the arterial wall and to measure the wall shear stress (WSS).

Purpose

To evaluate the feasibility of WSS measurement in a prospective series of patients with carotid stenosis.

Methods

A 7.5 MHz linear probe of an Aixplorer scanner was used. UF acquisitions had 3 tilted plane waves transmits (−10; 0; 10°) and an effective frame rate of 5000Hz. We evaluated the flow velocity in 5 areas of the carotid wall: common carotid artery (1), plaque ascent (2), plaque peak (3), plaque descent (4), internal carotid artery (5) (Figure). WSS was computed with the vector field speed using the following formula, WSS=μ·δn·v with v the blood velocity, n the normal vector to the vessel wall and μ, the blood viscosity, calculated from the hematocrit value for each patient. WSS measurement method was first validated using a laminar flow phantom and known viscosity. And then, 33 patients were then prospectively evaluated, with a median carotid stenosis degree of 80% [75–85].

Results

Significant correlation was found between in vitro measurement and the theoretical WSS values (R2=0.95; p<0.001).In patients,the maximum WSS value over the cardiac cycle follows the shape of the plaque with an increase during the ascend, reaching its maximum value of 3.57 Pa [2.47–4.45] at the peak of the plaque, and a fall after passing the peak (0.99 Pa [0.8–1.32]) lower than the WSS values in the non-stenotic areas (1.55 Pa [1.13–1.90] for the common carotid artery) (Table).

Table 1 Wall's area Wall shear stress (Pa) Min Max Delta 1. Common carotid artery 0.14 [0.05–0.27] 1.55 [1.13–1.90] 0.73 [0.55–0.96] 2. Plaque's ascent 0.39 [0.24–0.59] 2.63 [1.89–3.28] 1.20 [0.89–1.79] 3. Plaque's peak 0.60 [0.32–0.89] 3.57 [2.47–4.45] 1.78 [1.44–2.46] 4. Plaque's descent 0.16 [0.13–0.22] 0.99 [0.80–1.32] 0.52 [0.34–0.73] 5. Internal carotid artery 0.17 [0.13–0.35] 1.37 [1.04–1.75] 0.72 [0.50–0.87] Results are median [25th–75th percentile].

Figure 1

Conclusion

UF provide reliable WSS values. High WSS was present at the peak of the plaque, whereas lowest WSS values were found at the post-stenotic zone. WSS evaluation may help to better characterize the carotid plaque vulnerability.

P2765Efficacy of venous recanalization by noninvasive pulsed cavitational ultrasound therapy on swine model of acute deep venous thrombosis

Background

Post thrombotic syndrome is a frequent complication of deep venous thrombosis and is associated with high morbidity and hospitalization. Treatments currently available are invasive, involve use of endovenous procedures with stents and balloons, and frequently require general anesthesia. Pulsed cavitational ultrasound therapy (PCUT) emerged recently as a new technique to destroy remotely soft tissue. We recently demonstrated that PCUT was able to recanalize non-invasively in in vitro model of acute venous thrombosis (human blood clot).

Purpose

We aim to test the safety and efficacy of venous recanalization by noninvasive PCUT in vivo swine model of acute venous thrombosis.

Methods

All the experiments were performed on White large X Landrace swine. We induced an acute femoral deep venous thrombosis by using occlusive balloons introduced from jugular and popliteal vein combined with local injection of 50 IU of human thrombin. A 3 cm length occlusive thrombosis was obtained after 2 hours. Swines were divided in three groups: one with PCUT without follow-up (n=11), one with PCUT and follow-up at 14 days (n=8), and a control group also followed for 14 days (n=5). Acutely and during the follow up all swines received curative anticoagulation. To achieve PCUT, a 2.25 MHz transducer centered by a linear probe was used and cavitation was obtained in the center of the vein (Figure). After manual determination of thrombus location, a robotic arm was used to automatically move the transducer along the thrombus. Effectiveness of recanalization was evaluated by echo-Doppler and phlebography. Safety was assessed by Doppler ultrasound of the insonified area (artery, veins and surrounding tissue) and by histological analysis (local femoral vein and artery and lungs for pulmonary embolism).

Results

Among the 24 swines, we obtained 22 occlusive venous thromboses and 2 partial. The median length of the thrombus was 26±4.4 mm with vein diameter of 8.5±1.6 mm. Acutely, thrombosis recanalization was systematically obtained among the 19 swine with PCUT with median treatment duration of 33 minutes with residual diameter of 2.9±0.9 mm. No extravasation of contrast material or hematoma was observed after the therapy. After a 14-day follow-up, 75% of recanalisation remain permeable vs. 0% of vein permeable in the no therapy group (p=0.008). Residual diameter was 2.6±1.2 mm, which correspond to 50% of the venous diameter. No vein or artery damage and no embolism or pulmonary infarction was observed in all pigs.

Figure 1

Conclusion

We have demonstrated in vivo the safety and the efficacy of PCUT for non-invasive venous recanalization, persistent after 2 weeks.

Acknowledgement/Funding

French society of cardiology

P3110Tyrosine kinase inhibitor nilotinib increases atherosclerosis burden in ApoE knock-out mice

Background

In 2001, imatinib, the 1st generation tyrosine kinase inhibitor (TKI), dramatically improved the treatment and survival of the patients with chronic myeloid leukemia (CML). However, the emergence of imatinib-resistant patients led to the development of 2nd generation TKIs. Nilotinib demonstrated increased efficacy to control CML disease over imatinib and is now recommended as first-line therapy. But arterial occlusive adverse events (AOE) occurs in patients treated with nilotinib and not with imatinib. Mechanisms leading to AOE with nilotinib is not well understood. AOE are dominated by ischemic heart disease and lower extremity arterial disease. Moreover, we demonstrated that CML patients with cardiovascular risk factors are at high risk to rapidly develop AOE with nilotinib.

Purpose

To evaluate the impact of nilotinib in a pre-clinical model of atherosclerosis.

Methods

ApoE Knock-Out mice (8-week-old) were treated with either placebo (N=10), imatinib (IMA) 200mg/kg/day (N=10) or nilotinib (NILO) 100mg/kg/day (N=10) by daily feeding and a high-fat diet for 12 weeks. Heart and aorta were harvested after sacrifice, for histology staining and immunochemistry. Splenocytes were cultured from collected spleens, and Interleukin (IL) 12p70 and IL10 measured by ELISA.

Results

Mice treated with nilotinib showed an increase of atherosclerotic plaque size at the aortic sinus level: 462.1x103 μm2 vs. 344.4x103 μm2 with imatinib or 394.9x103 μm2 with placebo (p<0.05) and at the thoracoabdominal aorta level (p<0.05). Plaques had greater infiltration of macrophages: 33.0±3.4% with nilotinib vs. 7.3±1.3% with imatinib and 12.6±1.1% with placebo (p<0.001) and a larger necrotic nucleus 33.0±3.4% with nilotinib vs. 7.3±1.3% with imatinib or 12.6±1.1% with placebo (p<0.001). Nilotinib modulated the systemic immune response by increasing IL-12p70 and by decreasing IL-10 production by splenocytes after stimulation by LPS-IFNγ whereas IL10 increase was observed with imatinib.

Plaque size (aortic sinus)

Conclusion

Nilotinib has a pro-atherogenic effect in a pre-clinical model of atherosclerosis and increases the monocyte/macrophage pro-inflammatory response. Further experiments are required to identify pathways activated by nilotinib.

P1823Aortic walls elastic properties assessment with ultrafast ultrasound imaging in case of bicuspid aortic valve

Background

Magnetic resonance imaging allows evaluation of aortic stiffness by the maximum rate of systolic distension (MRSD) a new prognosis factor of aortic dilatation in patients with bicuspid aortic valve (BAV). MRSD requires a continuous monitoring of the aortic diameter during the cardiac cycle, not accessible to conventional echocardiography contrary to ultrafast ultrasound imaging (UF).

Purpose

To develop specific aortic sequences in ultrafast ultrasound imaging (UF) to provide access to the aortic MRSD

Methods

Tissue Doppler allowed a precise estimation of the movement of each wall and the fine variation of the aortic diameter. To automatically track the anterior and posterior aortic walls during the cardiac cycle, we developed in the laboratory a specific interface (Figure). MRSD was the maximum of the derivative of the diameter chande over time. To assess this new technique, 24 patients (10 BAV patients and 14 controls, mean age 45.8 vs. 40.7 years, p=0.464, respectively) were consecutively included at a reference center for BAV. The ascending aorta was evaluated at the sinus of Valsalva, the tubular aorta and the aortic arch with a phased array probe (Supersonic Imagine) and dedicated sequences at 2000 frames/s.

Results

The lab-made interface allowed to track the aortic diameter and to calculate the MRSD from the UF acquisitions for each patient. We found lower MRSD at the sinus of Valsalva in case of BAV in accordance with previously demonstrated higher stiffness at this segment by our team (Table).

Table 1. UF Aortic parameters for BAV patients and controls BAV patients Controls p (Mann Whitney) Sinus of Valsalva Diameter (mm) 26.2 [22.4–32.5] 27.09 [23.5–29.5] 0.796 MRSD (s–1) 1.05 [0.73–1.19] 1.51 [1.28–1.99] 0.023 Tubular ascending aorta Diameter 31.4 [29.4–32.2] 28.9 [22.6–31.5] 0.328 MRSD 0.94 [0.59–1.27] 1.09 [0.87–1.41] 0.353 Aortic arch Diameter 24.2 [23.7–24.8] 24.2 [18.9–24.5] 0.673 MRSD 0.57 [0.35–1.07] 0.85 [0.76–1.02] 0.257 Results are median [25th–75th percentile].

Figure 1

Conclusion

UF allows evaluation of aortic stiffness by MRSD using dedicated sequence and interface. As echocardiography, UF is easily accessible and therefore deserves attention from cardiologists taking care of BAV patients to evaluate the segmental aortic remodeling associated with BAV.

P4490Safety and feasibility of non invasive transthoracic pulsed cavitational ultrasound therapy (PCUT) on a swine aortic valve model

Background

Aortic valve stenosis is associated with age and comorbidities, which require exploring less invasive therapeutic approach to improve patient outcome. We previously demonstrated in vitro and in vivo that pulsed cavitational ultrasound therapy (PCUT) can improve calcified bioprosthesis stenosis by softening leaflets remotely. To apply this technique noninvasively we aim to test PCUT transthoracicalyin a swine model targeting aortic valve. Because calcified aortic valve model doesn't exist, we tested this technique on a normal valve.

Objective

Primary objective was to estimate the feasibility and safety of PCUT. Secondary objectiveswere to evaluate occurrence, severity and evolution of cardiovascular side effects during therapy and within follow-up period (30±5 days) with and without double antithrombotic treatment.

Methods

All the experiments were performed on normal aortic valves (n=19) of swine. The system was composed of a high-power multi-element transducer with electronic steering and 2D echocardiographic probe embedded in the center. Swine were divided in three groups: one with PCUT and no anti thrombotic treatment (n=10), a second with PCUT and one-month treatment of aspirin and clopidogrel (n=5) and third group sham (n=4). All groups were followed up after 30 days.

Results

The primary feasibility endpoint was successful in 100% of tests performed (n=16). A maximal amplitude of 70 MPa and −19 MPa respectively for positive and negative peak pressure was found at the focus point. Survival at 30 days was 100% and no life-threatening arrhythmia was recorded and no sustained ventricular arrhythmia (SVT >30 s) was noticed. For the secondary safety objectives,we recorded acutely, at the time of procedure, NSVT in 7 pigs which corresponded to a cumulated duration of 2.1 out of the 485.3 min of the total US delivery (0.4% of time). Mean cycle of NSVT was slow 428.9 ms in average (139.6 bpm). The interruption or decrease of power of US delivery allowed immediate cessation of cardiac arrhythmia in all cases. There was no evidence of damage to the valve and no observation of impairment of valvular function by echocardiography. Only one animal showed side effects (RV dilatation) and the RV returned to normal after cessation of the therapy with no sequelae at follow up. At follow up no significant findings biology disturbance or valve thrombosis was observed (creatinine, CK MB, hemoglobin, hematocrit, haptoglobin or red blood cell numbers). Antithrombotic treatment didn't demonstrate any advantage at follow up.

Conclusion

We demonstrated in vivo feasibility and safety of transthoracic PCUT targeting aortic valve without any serious adverse event and no significant histopathology damage. We hope that this first-time transthoracic delivery of very focused ultrasound at high power will pave the way to new non invasive approach of valve softening in case of human aortic valve calcified stenosis.

4D simultaneous tissue and blood flow Doppler imaging: revisiting cardiac Doppler index with single heart beat 4D ultrafast echocardiography

The goal of this study was to demonstrate the feasibility of semi-automatic evaluation of cardiac Doppler indices in a single heartbeat in human hearts by performing 4D ultrafast echocardiography with a dedicated sequence of 4D simultaneous tissue and blood flow Doppler imaging. 4D echocardiography has the potential to improve the quantification of major cardiac indices by providing more reproducible and less user dependent measurements such as the quantification of left ventricle (LV) volume. The evaluation of Doppler indices, however, did not benefit yet from 4D echocardiography because of limited volume rates achieved in conventional volumetric color Doppler imaging but also because spectral Doppler estimation is still restricted to a single location. High volume rate (5200 volume s^-1) transthoracic simultaneous tissue and blood flow Doppler acquisitions of three human LV were performed using a 4D ultrafast echocardiography scanner prototype during a single heartbeat. 4D color flow, 4D tissue Doppler cineloops and spectral Doppler at each voxel were computed. LV outflow tract, mitral inflow and basal inferoseptal locations were automatically detected. Doppler indices were derived at these locations and were compared against clinical 2D echocardiography. Blood flow Doppler indices E (early filling), A (atrial filling), E/A ratio, S (systolic ejection) and cardiac output were assessed on the three volunteers. Simultaneous tissue Doppler indices e' (mitral annular velocity peak), a' (late velocity peak), e'/a' ratio, s' (systolic annular velocity peak), E/e' ratio were also estimated. Standard deviations on three independent acquisitions were averaged over the indices and was found to be inferior to 4% and 8.5% for Doppler flow and tissue Doppler indices, respectively. Comparison against clinical 2D echocardiography gave a p  value larger than 0.05 in average indicating no significant differences. 4D ultrafast echocardiography can quantify the major cardiac Doppler indices in a single heart beat acquisition.

Correction to: Percutaneous Deep Venous Arterialization for Severe Critical Limb Ischemia in Patients With No Option of Revascularization: Early Experience From Two European Centers

The fifth author's name was incorrectly published as "M. Messas". The correct name is "E. Messas". The original article has been corrected.

[Recanalization procedure of the common femoral vein following iatrogenic femoral chronic occlusion: 3 cases]

Common femoral vein occlusion (CFVO) is frequently found in patients with chronic venous insufficiency. The iatrogenic form, secondary to either central catheter or surgery, is very rare but highly symptomatic. Classical compression therapy barely improves the clinical status of these patients, making them suitable candidates for an interventional procedure for venous recanalization.

METHODS

We report here three consecutive cases of iatrogenic CFVO referred to our outpatient clinic because the disease had an impact on daily life activities. We detail the recanalization procedure, the Doppler control and the short-term outcome.

RESULTS

In each case, endovascular recanalization required rigid material (rigid guide or Colapinto needle) to cross the fibrous adhesions before angioplasty could be performed with stenting. The procedure required two attempts in each case, underlining its complexity, but eventually enabled effective recanalization. No major complication occurred per- or post-procedure. One month later, a duplex Doppler control confirmed the permeability of the common femoral vein. The patients had experienced rapid and significant symptom improvement.

CONCLUSION

Patients suffering from severe chronic venous insufficiency caused by iatrogenic CFVO can benefit from endovascular recanalization. Although these procedures may be complex due to the extensive fibrosis at the Scarpa and require specialized equipment, no major complications were observed. Patency of the recanalization persisted at least one month after the procedure. Symptom relief was good.

[Takayasu arteritis]

Takayasu arteritis is a chronic inflammatory vasculitis of unknown origin affecting large vessels, predominantly the aorta and its main branches. Vessel inflammation leads to wall thickening, fibrosis, and stenosis. The lesions are often asymptomatic leading to limb numbness, transient ischemic attack, cardiovascular event and renovascular hypertension. Treatment is based on corticosteroids, immunosuppressant and biologics if necessary. Endovascular treatment and open-surgery can be useful for end-organ ischemia relief.

[Management of deep-vein thrombosis: A 2015 update]

Deep vein thrombosis (DVT) is a frequent and multifactor disease, with two major complications, post thrombotic syndrome and pulmonary embolism. Both transient (surgery, plaster immobilization, bed rest/hospitalization) and chronic/persistent (age, cancer, clinical or biological thrombophilia…) risk factors modulate treatment duration. Diagnostic management relies on clinical evaluations, probability followed by laboratory tests or imaging. So far, compression ultrasound is the diagnostic test of choice to make a positive diagnosis of DVT. Anticoagulants at therapeutic dose for at least 3 months constitute the cornerstones of proximal (i.e. involving popliteal or more proximal veins) DVT therapeutic management. The arrival of new oral anticoagulants should optimize ambulatory management of DVT.

[Distal revascularization in diabetic patients with chronic limb ischemia]

Diabetes mellitus is an independent risk factor for peripheral artery disease. Life expectancy is 41 months for diabetic patients with an ischemic ulcer. The characteristics of diabetic arteriopathy make its treatment more difficult than in non-diabetic patients. Few data are available about the surgical treatment of arteriopathy in diabetic patients (including angioplasty or bypass), especially in case of distal arteriopathy. The choice of the procedure depends on multiple factors such as the disease localization, its extent, distal blood flow and vascular disease-related surgical risk. The principal aim of revascularisation is to restore direct flow to the foot in order to ensure wound healing and limb salvage. With percutaneous endoluminal angioplasty, limb salvage can be achieved in more than 80% of patients at 1-3 years. The percutaneous procedure is less invasive than open surgery, there are fewer complications, and morbidity and mortality rates are reduced; moreover, a second procedure remains possible in the future. With bypass surgery, the rate of limb salvage exceeds 80% at five years. Nevertheless, peri-operative mortality reaches 3% and arterial anatomy, patient-related risks factors or venous graft availability may be limitations. New endovascular techniques especially designed for the distal arteries of the lower limbs enable very distal revascularization with morbidity and mortality rates lower than with surgery.