[Human immunodeficiency virus and venous thromboembolism: Role of direct oral anticoagulants]

Nowadays, thanks to highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV) infection is transforming into a chronic disease. The life expectancy of people living with HIV (PWH) has increased, as well as their risk of developing several co-morbidities, in particular cardiovascular diseases. In addition, the incidence of venous thromboembolism (VTE) is increased in PWH with a 2 to 10 times higher incidence when compared to the general population. Over the last decade, direct oral anticoagulants (DOACs) have been widely used in the treatment and prevention of VTE and non-valvular atrial fibrillation. DOACs are characterized by a rapid onset of activity, a predictable response and a relatively wide therapeutic window. Nevertheless, drug interactions exist between HAART and DOACs, exposing PWH to a theoretically increased bleeding or thrombotic risk. DOACs are substrates of the transport protein P-glycoprotein and/or of isoforms of cytochromes P450 pathway, which can be affected by some antiretroviral drugs. Limited guidelines are available to assist physicians with the complexity of those drug-drug interactions. The aim of this paper is to provide an updated review on the evidence of the high risk of VTE in PWH and the place of DOAC therapy in this population.

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

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.

Respiratory mechanics and gas exchanges in the early course of COVID-19 ARDS: a hypothesis-generating study

Rationale

COVID-19 ARDS could differ from typical forms of the syndrome.

Objective

Pulmonary microvascular injury and thrombosis are increasingly reported as constitutive features of COVID-19 respiratory failure. Our aim was to study pulmonary mechanics and gas exchanges in COVID-2019 ARDS patients studied early after initiating protective invasive mechanical ventilation, seeking after corresponding pathophysiological and biological characteristics.

Methods

Between March 22 and March 30, 2020 respiratory mechanics, gas exchanges, circulating endothelial cells (CEC) as markers of endothelial damage, and D-dimers were studied in 22 moderate-to-severe COVID-19 ARDS patients, 1 [1–4] day after intubation (median [IQR]).

Measurements and main results

Thirteen moderate and 9 severe COVID-19 ARDS patients were studied after initiation of high PEEP protective mechanical ventilation. We observed moderately decreased respiratory system compliance: 39.5 [33.1–44.7] mL/cmH₂O and end-expiratory lung volume: 2100 [1721–2434] mL. Gas exchanges were characterized by hypercapnia 55 [44–62] mmHg, high physiological dead-space (V_D/V_T): 75 [69–85.5] % and ventilatory ratio (VR): 2.9 [2.2–3.4]. V_D/V_T and VR were significantly correlated: r² = 0.24, p = 0.014. No pulmonary embolism was suspected at the time of measurements. CECs and D-dimers were elevated as compared to normal values: 24 [12–46] cells per mL and 1483 [999–2217] ng/mL, respectively.

Conclusions

We observed early in the course of COVID-19 ARDS high V_D/V_T in association with biological markers of endothelial damage and thrombosis. High V_D/V_T can be explained by high PEEP settings and added instrumental dead space, with a possible associated role of COVID-19-triggered pulmonary microvascular endothelial damage and microthrombotic process.

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

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.