Analysis of a multicenter registry on evaluation of transit-time flow in coronary artery disease surgery.

Objective: The Evaluation of Transit-Time Flow in Coronary Artery Disease Surgery (EFCAD) registry aims to assess the influence of transit-time flow measurement (TTFM) in daily practice. Methods: EFCAD is a prospective, multicenter study involving 9 centers performing TTFM during isolated coronary artery bypass grafting. Primary end point was occurrence and risk factors of major adverse cardiac events, including perioperative myocardial infarction, urgent postoperative coronary angiogram and/or revascularization, and hospital mortality. Secondary end points were rate of graft revision during surgery and factors affecting graft flow. We respected the limit values set by the experts: mean graft flow >15 mL/minute and pulsatility index ≤5. Results: Between May 2017 and March 2021, 1616 patients were registered in the EFCAD database. After review, 1414 were included for analyses. Of those, 1176 were eligible for primary end point analysis. Graft revision, mainly due to inadequate TTFM values, occurred in 2% (29 patients). The primary end point occurred in 46 (3.9%) patients, and it was related with left anterior descending artery graft flow ≤15 mL/minute (odds ratio, 3.64; P < .001). Graft flow was related with number of grafts (3 vs 1-2, ß = -1.6; 4-6 vs 1-2, ß = -4.1; P < .001; ß > 0 indicates higher flow), and graft origin (aorta vs Y, ß = 9.2; in situ left internal thoracic artery vs Y, ß = 3.2; in situ right internal thoracic artery vs Y, ß = 2.3; P < .001). Conclusions: Data from EFCAD study suggest that TTFM is reliable to evaluate graft flow, and acceptance of inadequate flow on left anterior descending artery anastomosis influence postoperative outcomes. In our opinion, TTFM assessment should be routinely used in coronary artery bypass procedures, even if interpretation depends on learning curves.

Flow dynamics of surgical and transcatheter aortic valves: Past to present.

Objective: To perform an in vitro characterization of surgical aortic valves (SAVs) and transcatheter aortic valves (TAVs) to highlight the development of the flow dynamics depending on the type of valve implanted and assess the basic differences in the light of flow turbulence and its effect on blood damage likelihood and hemodynamic parameters that shed light on valve performance. Methods: A Starr-Edwards ball and cage valve of internal diameter 22 mm, a 23-mm Medtronic Hancock II SAV, a 23-mm St Jude Trifecta SAV, a 23-mm St Jude SJM (mechanical valve) SAV, a 26-mm Medtronic Evolut TAV, and a 26-mm Edwards SAPIEN 3 TAV were assessed in a pulse duplicator under physiological conditions. Particle image velocimetry was performed for each valve. Pressure gradient and effective orifice area (EOA) along with velocity flow field, Reynolds shear stress (RSS), and viscous shear stress (VSS) were calculated. Results: The SJM mechanical valve exhibited the greatest EOA (1.96 ± 0.02 cm2), showing superiority of efficiency compared with the same-size Trifecta (1.87 ± 0.07 cm2) and Hancock II (1.05 ± 0.01 cm2) (P < .0001). The TAVs show close EOAs (2.10 ± 0.06 cm2 with Evolut and 2.06 ± 0.03 cm2 with SAPIEN 3; P < .0001). The flow characteristics and behavior downstream of the valves differed depending on the valve type, design, and size. The greater the RSS and VSS the more turbulent the downstream flow. Hancock II displays the greatest range of RSS and VSS magnitudes compared with the same-size Trifecta and SJM. The Evolut displays the greatest range of RSS and VSS compared with the SAPIEN 3. Conclusions: The results of this study shed light on numerous advancements in the design of aortic valve replacement prosthesis and the subsequent hemodynamic variations. Future surgical and transcatheter valve designs should aim at not only concentrating on hemodynamic parameters but also at optimizing downstream flow properties.

Increased complications of COVID-19 in people with cardiovascular disease: Role of the renin-angiotensin-aldosterone system (RAAS) dysregulation.

The rapid spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19), has had a dramatic negative impact on public health and economies worldwide. Recent studies on COVID-19 complications and mortality rates suggest that there is a higher prevalence in cardiovascular diseases (CVD) patients. Past investigations on the associations between pre-existing CVDs and susceptibility to coronavirus infections including SARS-CoV and the Middle East Respiratory Syndrome coronavirus (MERS-CoV), have demonstrated similar results. However, the underlying mechanisms are poorly understood. This has impeded adequate risk stratification and treatment strategies for CVD patients with SARS-CoV-2 infections. Generally, dysregulation of the expression of angiotensin-converting enzyme (ACE) and the counter regulator, angiotensin-converting enzyme 2 (ACE2) is a hallmark of cardiovascular risk and CVD. ACE2 is the main host receptor for SARS-CoV-2. Although further studies are required, dysfunction of ACE2 after virus binding and dysregulation of the renin-angiotensin-aldosterone system (RAAS) signaling may worsen the outcomes of people affected by COVID-19 and with preexisting CVD. Here, we review the current knowledge and outline the gaps related to the relationship between CVD and COVID-19 with a focus on the RAAS. Improved understanding of the mechanisms regulating viral entry and the role of RAAS may direct future research with the potential to improve the prevention and management of COVID-19.

Transverse isotropic modelling of left-ventricle passive filling: Mechanical characterization for epicardial biomaterial manufacturing.

Biomaterials applied to the epicardium have been studied intensively in recent years for different therapeutic purposes. Their mechanical influence on the heart, however, has not been clearly identified. Most biomaterials for epicardial applications are manufactured as membranes or cardiac patches that have isotropic geometry, which is not well suited to myocardial wall motion. Myocardial wall motion during systole and diastole produces a complex force in different directions. Membrane or cardiac patches that cannot adapt to these specific directions will exert an inappropriate force on the heart, at the risk of overly restricting or dilating it. Accurately characterizing the mechanical properties of the myocardial wall is thus essential, through analysis of muscle orientation and elasticity. In this study, we investigated the Hertz contact theory for characterizing cardiac tissue, using nanoindentation measurements to distinguish different patterns in the local myocardium. We then evaluated the predictive accuracy of this model using Finite Element Analysis (FEA) to mimic the diastolic phase of the heart. Our results, extracted from instrumented nanoindentation experiments in a liquid environment using five pig hearts, revealed variations in elasticity according to the local orientation of the myocardial tissue. In addition, applying the Finite Element Method (FEM) in our model based on transverse isotropy and local tissue orientation proved able to accurately simulate the passive filling of a left ventricle (LV) in a representative 3D geometry. Our model enables improved understanding of the underlying mechanical properties of the LV wall and can serve as a guide for designing and manufacturing biomedical material better adapted to the local epicardial tissue.

Stem cell-based approaches in cardiac tissue engineering: controlling the microenvironment for autologous cells.

Cardiovascular disease is one of the leading causes of mortality worldwide. Cardiac tissue engineering strategies focusing on biomaterial scaffolds incorporating cells and growth factors are emerging as highly promising for cardiac repair and regeneration. The use of stem cells within cardiac microengineered tissue constructs present an inherent ability to differentiate into cell types of the human heart. Stem cells derived from various tissues including bone marrow, dental pulp, adipose tissue and umbilical cord can be used for this purpose. Approaches ranging from stem cell injections, stem cell spheroids, cell encapsulation in a suitable hydrogel, use of prefabricated scaffold and bioprinting technology are at the forefront in the field of cardiac tissue engineering. The stem cell microenvironment plays a key role in the maintenance of stemness and/or differentiation into cardiac specific lineages. This review provides a detailed overview of the recent advances in microengineering of autologous stem cell-based tissue engineering platforms for the repair of damaged cardiac tissue. A particular emphasis is given to the roles played by the extracellular matrix (ECM) in regulating the physiological response of stem cells within cardiac tissue engineering platforms.

Outbreak of SARS-CoV-2: challenge for diagnosis and medical management in patients with left ventricular assist device: a case series.

BACKGROUND: The outbreak of coronavirus disease 2019 (COVID-19) exposes vulnerable patients to high risk of mortality. Patients with left ventricular assist device (LVAD) usually have symptoms such as cough, fever, and shortness of breath because of their cardiac condition and comorbidity, therefore these related symptoms challenge the correct diagnosis in time within the COVID-19 pandemic. CASE SUMMARY: We report two case studies of patients with LVAD in whom COVID-19 related symptoms were overlapped by their cardiac status and comorbidities. In the first case, the patient was admitted for suspicion of COVID-19 due to cough and shortness of breath for 1 month. The blood test evocated a high index of suspicion of COVID-19. The nasopharyngeal test for COVID-19 performed on admission and at Day 2 was inconclusive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the test obtained on Day 3 of admission was positive, whereas computed tomography confirmed the diagnosis of COVID-19. This patient developed acute respiratory distress syndrome (ARDS) and nasal epistaxis within 48 h during hospitalization. The ARDS was treated by non-invasive ventilation and probabilistic antibiotics for 3 days and resulted significant improvement. The nasal epistaxis due to international normalized ratio increase was treated by nasal packing and vitamin K antagonist was switched to parenteral heparin infusion. The patient was kept hospitalized for 1 month for further supportive treatment. In the second case, the patient was admitted for recurrent anaemia due to melaena, the patient was tested for COVID-19 because of new-onset symptoms of cough and rhinorrhoea. The first nasopharyngeal test was positive, and sudden increase of anticoagulation status was noted in the setting of gastrointestinal bleeding. The anticoagulation status was controlled by parenteral heparin infusion, and the melaena was disappeared at Day 3. The moderate dyspnoea of the patient was quickly improved with nasal oxygen delivery for 4 days. The patient was discharged at Day 5. DISCUSSION: COVID-19 specific symptoms are challenging to distinguish in patients with LVADs, although radiological evidence can be beneficial in the COVID-19 diagnosis. We also observed the need for precise anticoagulation control to avoid bleeding or thrombotic events in these patients.

The hemodynamics of transcatheter aortic valves in transcatheter aortic valves.

BACKGROUND: The durability of transcatheter aortic valves (TAVs) remains their greatest disadvantage, given that fixed tissue leaflets are not immune to structural degeneration from calcification and thrombosis. Therefore, a second intervention is necessary, especially given that TAV in low-risk patients has shown noninferior outcomes compared with surgery. This study aimed to assess the hemodynamic and turbulent properties of the flow downstream with different TAV-in-TAV configurations, to offer basic hemodynamic guidance for future interventions when currently implanted valves structurally degrade. METHODS: Six TAV-in-TAV configurations were chosen: 23 mm Evolut-in-26 mm Evolut, 23 mm Evolut-in-23 mm SAPIEN 3, 26 mm Evolut-in-26 mm Evolut, 26 mm Evolut-in-23 mm SAPIEN 3, 23 mm SAPIEN3-in-26 mm Evolut, and 23 mm SAPIEN3-in-23 mm SAPIEN 3. Their hemodynamic performance was assessed in a pulse duplicator for 100 cycles. High-speed imaging and particle image velocimetry were performed to assess turbulence. Effective orifice area (EOA), pinwheeling index (PI), and Reynolds shear stress (RSS) were evaluated. RESULTS: The largest mean EOA was obtained with 23 mm SAPIEN-in-26 mm Evolut (2.07 ± 0.06 cm2), and the smallest was obtained with 23 mm Evolut-in-23 mm SAPIEN (1.50 ± 0.04 cm2) (P < .001). The highest mean PI was obtained with SAPIEN-in-SAPIEN (26.5 ± 2.00%), and the lowest was obtained with 26 mm Evolut-in-26 mm Evolut (7.5 ± 1.6%) (P < .01). At peak systole, the least detrimental RSS range was obtained with 23 mm Evolut-in-26 mm Evolut (up to ∼340 Pa), and the most detrimental RSS range was obtained with 23 mm Evolut-in-SAPIEN (∼900 Pa) (P < .01). CONCLUSIONS: This study shows that best hemodynamic parameters are TAV-specific (implanted and to be implanted). In addition, it shows that RSS levels, which are indicative of turbulence levels and associated with blood damage, are 2- to 3-fold higher after TAV-in-TAV.

Isolated tricuspid valve surgery after congenital versus left heart-disease surgery: mid-term outcomes.

BACKGROUND: Left heart involvement might be a differential factor in the physiopathology and prognosis of severe tricuspid regurgitation (TR) following cardiac surgery. We aimed to compare the outcomes of isolated tricuspid valve surgery (ITVS) after congenital versus left heart-disease surgery. METHODS: We retrospectively studied and followed up 58 patients who underwent ITVS for TR following cardiac surgery in our center from January 2012 to December 2017. According to the different etiologies of TR, the participants were divided into one group of TR following surgery for congenital heart diseases (CHD) (pCHD group, n=24), and another group of TR following surgery for left heart disease (pVHD group, n=34). RESULTS: Compared to the pCHD group, the pVHD group presented with a more advanced age (P<0.001), higher model for end-stage liver disease (MELD) score calculation (P=0.04), and higher EuroSCORE II calculation (P=0.01). In the post-operative course, the pVHD group showed a longer mechanical ventilation time (P<0.001) and longer intensive care unit stay (P=0.001). However, there was no significant difference between the two groups in in-hospital mortality (8.8% vs. 0, P=0.26), or the incidence of major adverse cardiac and cerebrovascular events (MACCE) (20.6% vs. 12.5%, P=0.47) at follow-up. CONCLUSIONS: Severe TR following surgery for left heart disease is associated with higher surgical risks and a remarkable frailty as compared to that following surgery for CHDs; however, with the development of surgical techniques and peri-operative management, ITVS can be safely performed in both conditions with promising contemporary mid-term outcomes.

Sinus Hemodynamics After Transcatheter Aortic Valve in Transcatheter Aortic Valve.

BACKGROUND: This study evaluated the effect of transcatheter aortic valve (TAV)-in-TAV on sinus hemodynamics and washout. With TAV becoming the standard procedure for aortic valve replacement and with the limited valve durability, a second intervention is necessary (TAV-in-TAV) after first TAV failure. METHODS: Six arrangements of TAV-in-TAV were chosen for this study as follows: (1) Evolut 23 (Medtronic, Minneapolis, MN) in Evolut 26, (2) Evolut 23 in SAPIEN 3 23 (Edwards Lifesciences, Irvine, CA), (3) Evolut 26 in Evolut 26, (4) Evolut 26 in SAPIEN 23, (5) SAPIEN 3 23 in Evolut 26, and (6) SAPIEN 3 23 in SAPIEN 3 23. These TAV-in-TAV configurations were assessed in a pulse duplicator. Particle image velocimetry was performed. RESULTS: During systole, (1) the highest velocity was found with SAPIEN-in-SAPIEN (0.7 m/s) and the lowest was with Evolut 26-in-Evolut 26 (0.2 m/s); (2) the highest shear stress magnitude near the leaflet was with Evolut 23-in-SAPIEN (1.45 Pa) and the lowest was with Evolut 26-in-Evolut 26 (0.55 Pa); and (3) washout was almost equal in all sinuses of these cases (<2.5 cycles). CONCLUSIONS: This study shows that TAV-in-TAV is highly dependent on the valve that is originally implanted and the valve to be implanted. Washout is not significantly degraded after TAV-in-TAV compared with valve-in-valve and TAV replacement. Further studies are needed to optimize valve size and selection.

Prognostic influence of acute decompensated heart failure in patients planned for transcatheter aortic valve implantation.

OBJECTIVE: The aim of our study was to evaluate the outcome of patients with severe aortic stenosis presenting with acute decompensated heart failure (ADHF) and planned for transcatheter aortic valve implantation (TAVI) and to study the variables influencing their prognosis. METHODS: Our retrospective study included 801 patients planned for TAVI in our center. Seven hundred and fifty-six underwent TAVI and were categorized according to ADHF as the initial clinical presentation into two groups: ADHF group (n = 261) and no-ADHF group (n = 495). Pre as well as periprocedural outcomes and 1 year mortality were analyzed. RESULTS: Among the patients planned for the TAVI procedure, 45 patients remained untreated: 35 patients died while waiting to undergo TAVI which represented 20% of all deaths in our study, ADHF was observed in 23 of 45 (51%) these untreated patients. The 1-year all-cause mortality rate was significantly higher in the ADHF group versus the no-ADHF group (27% vs. 15%, p < .0001). In multivariate analysis, male gender (odds ratio [OR] =2.5, 95% confidence interval [CI]: 1.37-4.57, p = .03), body mass index <25 kg/m2 (OR = 2.76, 95% CI: 1.51-5.04, p = .0009), and logistic EuroSCORE II ≥20% (OR = 3.04, 95% CI: 1.56-5.94, p = .001) were associated with a higher 1-year mortality in the ADHF group. CONCLUSION: The patients eligible for TAVI presenting with ADHF were associated with a higher mortality for both: while on the waiting list for TAVI as well as at 1-year follow-up and thus asking for clearer criteria to prioritize action in this high-risk TAVI patients.

Impact of BASILICA on Sinus and Neo-Sinus Hemodynamics after Valve-in-Valve with and without Coronary Flow.

BACKGROUND/PURPOSE: This study aims at evaluating the impact of BASILICA on neo-sinus and sinus hemodynamics with and without coronary flow. Leaflet thrombosis after valve-in-valve (ViV) may compromise not only leaflet mobility but also affect valve durability and performance. METHODS/MATERIALS: In a 23 mm transparent surgical aortic valve model, a 23 mm Edwards SAPIEN 3 and a 26 mm Medtronic Evolut were deployed before and after leaflet laceration, in models with and without coronary flow. Neo-sinus and sinus hemodynamics were evaluated in the aortic position of a pulse duplicator and particle image velocimetry was performed in order to quantify sinus flow hemodynamics along with sinus and neo-sinus washout. RESULTS: BASILICA-type leaflet laceration procedure led to (a) an increase in the velocities in the sinus and the neo-sinus by 50% for Evolut ViV with and without coronary flow, 70% for non-coronary SAPIEN 3 ViV and 10% for coronary SAPIEN 3 ViV, and (b) an improvement in overall washout up to 2 cycles in the neo-sinus and 0.5 cycles in the sinus. CONCLUSIONS: A BASILICA-type leaflet laceration approach may improve sinus and neo-sinus hemodynamics through decreasing flow stasis and enabling less confined blood flow. BASILICA confers coronary sinus flow patterns to the non-coronary sinus.

A turbulence in vitro assessment of On-X and St Jude Medical prostheses.

OBJECTIVE: The objective of this study was to investigate and compare the hemodynamic and turbulence characteristics upon implantation of St Jude Medical (SJM) (St Jude Medical, St Paul, Minn) and On-X (On-X Life Technologies, Kennesaw, Ga) bileaflet mechanical valves. Both valves are considered highly successful bileaflet mechanical valves characterized by good clinical outcomes despite their numerous design differences. Although thromboembolism remains the main disadvantage of bileaflet mechanical valves, On-X valves have been shown to need less anticoagulation therapy. METHODS: Hemodynamic assessment of a 23-mm On-X bileaflet mechanical valve and a 23-mm bileaflet SJM valve implanted in an aortic root was performed under pulsatile physiologic conditions. Time-resolved and phase-locked particle-image-velocimetry images and high-speed imaging data were acquired. Pressure gradients, effective orifice areas, dimensionless area index, leaflet position tracking, velocity, and principal Reynolds shear stress were calculated. RESULTS: Pressure gradient for the On-X valve was 4.15 ± 0.099 mm Hg versus 4.75 ± 0.048 mm Hg for SJM (P < .001). Effective orifice area for the On-X valve was 2.61 ± 0.045 cm2 versus 2.36 ± 0.022 cm2 for SJM (P < .001). Area index was higher with SJM (0.87 ± 0.008) than with On-X (0.73 ± 0.013) (P < .001). On-X showed fluctuating leaflet behavior during systole, whereas SJM leaflets were stable. At peak systole, the maximal velocity with On-X was 1.86 m/s versus 2.33 m/s with SJM. Reynolds shear stress was higher with On-X compared with SJM at peak systole (95 vs 72 Pa). Higher velocity fluctuation was noted with the On-X valve. CONCLUSIONS: This study shows that despite the design differences that characterize the On-X valve, the hemodynamic and turbulence parameters were not necessarily improved compared with SJM.

Impact of Leaflet Laceration on Transcatheter Aortic Valve-in-Valve Washout: BASILICA to Solve Neosinus and Sinus Stasis.

OBJECTIVES: The aim of this study was to evaluate any potential leaflet washout benefits after bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (BASILICA) in transcatheter valve-in-valve (ViV) in the context of leaflet thrombosis. BACKGROUND: Leaflet thrombosis after transcatheter aortic valve replacement is secondary to flow stasis in both the sinus and neosinus. Strategies to improve washout and ameliorate neosinus and sinus flow velocities may have the potential to mitigate the occurrence of clinical and subclinical leaflet thrombosis. METHODS: A 23-mm Edwards SAPIEN 3 and a 26-mm Medtronic Evolut were deployed in a 23-mm transparent surgical aortic valve model before and after leaflet laceration. The valves were placed in the aortic position of a pulse duplicator flow loop. Particle image velocimetry was performed to quantify sinus flow hemodynamic status. A tracing fluorescent dye was injected to evaluate the number of cycles to washout in both regions of interest. RESULTS: The leaflet laceration procedure led to an increase in the velocities in the sinus and the neosinus by 50% for Evolut ViV and 61.9% for SAPIEN 3 ViV. In addition, leaflet laceration led to a reduction in overall cycles to washout in the neosinus by at least 56% with the Evolut and 54.5% with the SAPIEN 3 and in the sinus by at least 16.7% with the Evolut and 60.8% with the SAPIEN. CONCLUSIONS: Leaflet laceration using a BASILICA-type approach may hold the potential to mitigate neosinus and sinus flow stasis. Controlled in vivo trials are necessary to establish the potential benefit of BASILICA to reduce the occurrence of leaflet thrombosis.

An in vitro evaluation of turbulence after transcatheter aortic valve implantation.

BACKGROUND: This study aimed at assessment of post-transcatheter aortic valve (TAV) replacement hemodynamics and turbulence when a same-size SAPIEN 3 (Edwards Lifesciences Corp, Irvine, Calif) and Medtronic Evolut (Minneapolis, Minn) were implanted in a rigid aortic root with physiological dimensions and in a representative root with calcific leaflets obtained from patient computed tomography scans. METHODS: TAV hemodynamics were studied by placing a SAPIEN 3 26-mm and an Evolut 26-mm in rigid aortic roots and representative root with calcific leaflets under physiological conditions. Hemodynamics were assessed using high-fidelity particle image velocimetry and high-speed imaging. Transvalvular pressure gradients (PGs), pinwheeling indices, and Reynolds shear stress (RSS) were calculated. RESULTS: (1) PGs obtained with the Evolut and the SAPIEN 3 were comparable among the different models (10.5 ± 0.15 mm Hg vs 7.76 ± 0.083 mm Hg in the rigid model along with 13.9 ± 0.19 mm Hg vs 5.0 ± 0.09 mm Hg in representative root with calcific leaflets obtained from patient computed tomography scans respectively); (2) more pinwheeling was found in the SAPIEN 3 than the Evolut (0.231 ± 0.057 vs 0.201 ± 0.05 in the representative root with calcific leaflets and 0.366 ± 0.067 vs 0.122 ± 0.045 in the rigid model); (3) higher rates of RSS were found in the Evolut (161.27 ± 3.45 vs 122.84 ± 1.76 Pa in representative root with calcific leaflets and 337.22 ± 7.05 vs 157.91 ± 1.80 Pa in rigid models). More lateral fluctuations were found in representative root with calcific leaflets. CONCLUSIONS: (1) Comparable PGs were found among the TAVs in different models; (2) pinwheeling indices were found to be different between both TAVs; (3) turbulence patterns among both TAVs translated according to RSS were different. Rigid aortic models yield more conservative estimates of turbulence; (4) both TAVs exhibit peak maximal RSS that exceeds platelet activation 100 Pa threshold limit.

Transcarotid transcatheter aortic valve implantation: multicentre experience in France.

OBJECTIVES: Transcatheter aortic valve implantation is a well-recognized treatment option for high-risk patients with aortic stenosis. The femoral approach is possible in 80% of cases and remains the access of choice. When this approach is not feasible, other alternative routes have been proposed such as transapical, transaortic and subclavian. Transcarotid aortic valve implantation has been proposed as another direct vascular access. Its use is relatively new and still under evaluation. METHODS: We successfully performed transcarotid aortic valve implantation in 145 consecutive patients through the left or right carotid artery in 3 different French sites over a 2-year period. Data were prospectively entered in the French transcatheter aortic valve implantation database. RESULTS: The mean age was 79.8 ± 8.7 years, with a mean logistic EuroSCORE of 20.7 ± 12.6%. The procedure was successful in all patients, and no conversion was necessary. Thirty-day survival was 93.7%, 8 (5.5%) patients presented either minor or major strokes and 1 patient had a localized asymptomatic carotid dissection. All patients were immediately extubated, and none presented respiratory complications. CONCLUSIONS: Transcarotid aortic valve implantation is a safe alternative to transfemoral transcatheter aortic valve implantation, with direct access to the aortic valve, which can be performed with limited incision.

Permanently Hypoxic Cell Culture Yields Rat Bone Marrow Mesenchymal Cells with Higher Therapeutic Potential in the Treatment of Chronic Myocardial Infarction.

BACKGROUND: The mismatch between traditional in vitro cell culture conditions and targeted chronic hypoxic myocardial tissue could potentially hamper the therapeutic effects of implanted bone marrow mesenchymal stem cells (BMSCs). This study sought to address (i) the extent of change to BMSC biological characteristics in different in vitro culture conditions and (ii) the effectiveness of permanent hypoxic culture for cell therapy in treating chronic myocardial infarction (MI) in rats. METHODS: rat BMSCs were harvested and cultured in normoxic (21% O2, n=27) or hypoxic conditions (5% O2, n=27) until Passage 4 (P4). Cell growth tests, flow cytometry, and Bio-Plex assays were conducted to explore variations in the cell proliferation, phenotype, and cytokine expression, respectively. In the in vivo set-up, P3-BMSCs cultured in normoxia (n=6) or hypoxia (n=6) were intramyocardially injected into rat hearts that had previously experienced 1-month-old MI. The impact of cell therapy on cardiac segmental viability and hemodynamic performance was assessed 1 month later by 2-Deoxy-2[18F]fluoro-D-glucose (18F-FDG) positron emission tomography (PET) imaging and pressure-volume catheter, respectively. Additional histomorphological examinations were conducted to evaluate inflammation, fibrosis, and neovascularization. RESULTS: Hypoxic preconditioning significantly enhanced rat BMSC clonogenic potential and proliferation without altering the multipotency. Different profiles of inflammatory, fibrotic, and angiogenic cytokine secretion were also documented, with a marked correlation observed between in vitro and in vivo proangiogenic cytokine expression and tissue neovessels. Hypoxic-preconditioned cells presented a beneficial effect on the myocardial viability of infarct segments and intrinsic contractility. CONCLUSION: Hypoxic-preconditioned BMSCs were able to benefit myocardial perfusion and contractility, probably by modulating the inflammation and promoting angiogenesis.

Incidence, indications and predicting factors of permanent pacemaker implantation after transcatheter aortic valve implantation: A retrospective study.

BACKGROUND: As the number of transcatheter aortic valve implantation (TAVI) procedures is constantly increasing, it is important to consider common complications, such as pacemaker (PM) implantation, and their specific risk factors. AIMS: Echocardiographic, computed tomography and electrocardiographic data were analysed to determine the predicting factors, if any, associated with PM implantation. METHODS: This retrospective study included patients referred to Nancy University Hospital for a TAVI procedure from January 2013 to December 2015. Both Medtronic CoreValve and Edwards SAPIEN valves were implanted. Patients with preprocedurally implanted PMs and/or referred from another institution were excluded. RESULTS: Of 208 TAVI patients, 23 had a pre-existing PM and were excluded. A new PM was required in 38 patients (20.5%). Pre-existing right bundle branch block (RBBB), the use of the Medtronic CoreValve and large prostheses were identified as predictors of PM implantation (P=0.0361, P=0.0004 and P=0.0019, respectively). Using logistic regression, predictors of PM implantation included first-degree atrioventricular block (odds ratio 3.7, 95% confidence interval 1.5-9.1; P=0.0054) and large aortic annulus diameter in echocardiography (odds ratio 1.2, 95% confidence interval 1-1.4; P=0.0447), with a threshold of 24.1mm. For the combination of preTAVI PR duration >220ms and QRS duration >120ms, the positive predictive value for PM implantation reached 80%. CONCLUSION: Use of the Medtronic CoreValve, RBBB and first-degree atrioventricular block are major risk factors for post-TAVI PM implantation. In addition, large aortic annulus and large valvular prosthesis are independent risk factors for PM implantation. The combination of preTAVI prolonged PR interval and increased QRS duration could be used as a marker for periprocedural PM implantation.

Bilateral vs unilateral internal mammary revascularization in patients with left ventricular dysfunction.

AIM: To investigate the survival benefit of bilateral internal mammary artery (BIMA) grafts in patients with left ventricular dysfunction. METHODS: Between 1996 and 2009, we performed elective, isolated, primary, multiple cardiac arterial bypass grafting in 430 consecutive patients with left ventricular ejection fraction ≤ 40%. The early and long-term results were compared between 167 patients undergoing BIMA grafting and 263 patients using left internal mammary artery (LIMA)-saphenous venous grafting (SVG). RESULTS: The mean age of the overall population was 60.1 ± 15 years. In-hospital mortality was not different between the two groups (7.8% vs 10.3%, P = 0.49). Early postoperative morbidity included myocardial infarction (4.2% vs 3.8%, P = 0.80), stroke (1.2% vs 3.8%, P = 0.14), and mediastinitis (5.3% vs 2.3%, P = 0.11). At 8-year follow-up, Kaplan-Meier-estimated survival (74.2% vs 58.9%, P = 0.02) and Kaplan-Meier-estimated event-free survival (all cause deaths, myocardial infarction, stroke, target vessel revascularization, heart failure) (61.7% and 41.1%, P < 0.01) were significantly higher in the BIMA group compared with the LIMA-SVG group in univariate analysis. The propensity score matching analysis confirmed that BIMA grafting is a safe revascularization procedure but there was no long term survival (P = 0.40) and event-free survival (P = 0.13) in comparison with LIMA-SVG use. CONCLUSION: Our longitudinal analysis suggests that BIMA grafting can be performed with acceptable perioperative mortality in patients with left ventricular dysfunction.

Aortic sinus flow stasis likely in valve-in-valve transcatheter aortic valve implantation.

OBJECTIVE: Valve-in-valve procedures using transcatheter aortic valves are increasingly performed to treat degenerated bioprosthetic surgical aortic valves because they are less invasive than redo aortic valve replacement. The objective of this study is to quantify the changes in aortic sinus blood flow dynamics before and after a valve-in-valve procedure to gain insight into mechanisms for clinical and subclinical thrombosis of leaflets. METHODS: A detailed description of the sinus hemodynamics for valve-in-valve implantation was performed in vitro. A Medtronic Hancock II (Medtronic Inc, Minneapolis, Minn) porcine bioprosthesis was modeled as a surgical aortic valve, and Medtronic CoreValve and Edwards Sapien (Edwards Lifesciences, Irvine, Calif) valves were used as the transcatheter aortic valves. High-resolution particle image velocimetry was used to compare the flow patterns from these 2 valves within both the left coronary and noncoronary sinuses in vitro. RESULTS: Velocity and vorticity within the surgical valve sinuses reached peak values of 0.7 m/s and 1000 s-1, with a 70% decrease in peak fluid shear stress near the aortic side of the leaflet in the noncoronary sinus. With the introduction of transcatheter aortic valves, peak velocity and vorticity were reduced to approximately 0.4 m/s and 550 s-1 and 0.58 m/s and 653 s-1 without coronary flow and 0.60 m/s and 631 s-1 and 0.81 m/s and 669 s-1 with coronary flow for the CoreValve and Sapien valve-in-valve implantations, respectively. Peak shear stress was approximately 38% higher along the aortic side of the coronary versus noncoronary transcatheter aortic valve leaflet. CONCLUSIONS: Decreased flow and shear stress in valve-in-valve procedures indicate a higher risk of leaflet thrombosis secondary to flow stasis, perhaps more so in the noncoronary sinus.