Background
Rapid ventricular pacing (RVP) is an established technique to temporarily reduce left ventricular output during transcatheter aortic valve implantation (TAVI). The purpose of this study ...was to evaluate the impact of RVP on microvascular tissue perfusion (MTP) in patients undergoing TAVI.
Methods and results
We studied 42 patients (mean age 81.8 ± 6.9 years,
n
= 18 females. EuroSCORE 33 ± 12 %) during TAVI. MTP was analyzed using Sidestream–Darkfield imaging, of the sublingual microvasculature. Microvascular flow index (MFI) was continuously measured in small (10–25 μm)- and medium (26–50 μm)-sized vessels, starting 10 s before and ending 12 s after RVP. Further, perfused capillary density, total vessel density and the proportion of perfused vessels were assessed. After a mean RVP duration of 14.3 s (range 6–29), mean arterial pressure decreased from 68 ± 05 to 40 ± 7 mmHg (
p
< 0.001). This was associated with a significant decrease of MFI in small- and medium-sized vessels from 2.29 ± 0.64 and 2.36 ± 0.6 to 0.87 ± 0.66 (
p
< 0.001) and 1.0 ± 0.83 (
p
< 0.001), respectively. MFI remained significantly below baseline values (small: 1.75 ± 0.8,
p
= 0.001 vs. baseline; medium: 1.77 ± 0.85;
p
= 0.005 vs. baseline) at 12 s after end of RVP.
Conclusions
The study demonstrates a time-dependent effect of RVP on microflow, leading to 50 and 25 % of baseline at 8 and 18 s of RVP, respectively. In a substantial proportion of patients, RVP is associated with microcirculatory arrest and a delayed recovery of microflow. Although the impact of these findings on outcome is yet unclear, TAVI operators should be aware of the potentially adverse effects of even short periods of RVP.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Methods Plaque assessment consisted of: (a) plaque count of each subtype according to international consensus, (b) plaque volume, (c) luminal surface area was calculated using the Shoelace formula ...(Fig. left) which determines areas as simple polygons "projected" at the luminal surface, and (d) cap thickness.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
BACKGROUND—In this randomized trial, strut coverage and neointimal proliferation of a therapy of bare metal stents (BMSs) postdilated with the paclitaxel drug-eluting balloon (DEB) was compared with ...everolimus drug-eluting stents (DESs) at 6-month follow-up using optical coherence tomography. We hypothesized sufficient stent coverage at follow-up.
METHODS AND RESULTS—A total of 105 lesions in 90 patients were treated with either XIENCE V DES (n=51) or BMS postdilated with the SeQuent Please DEB (n=54). At follow-up, comparable results on the primary optical coherence tomography end point (percentage uncovered struts 5.64±9.65% in BMS+DEB versus 4.93±9.29% in DES; P=0.366) were found. Thus, BMS+DEB achieved the prespecified noninferiority margin of 5% uncovered struts versus DES (difference between treatment means, 0.71%; one-sided upper 95% confidence interval, 4.14%; noninferiority P=0.04). Optical coherence tomography analysis showed significantly more global neointimal proliferation in the BMS+DEB group (15.7±7.8 versus 11.0±5.2 mm proliferation volume/cm stent length; P=0.002). No significant focal in-stent stenosis analyzed with angiography (percentage diameter stenosis at follow-up, 22.8±11.9 versus 16.9±10.4; P=0.014) and optical coherence tomography (peak local area stenosis, 39.5±13.8% versus 36.8±15.6%; P=0.409) was found.
CONCLUSIONS—Good stent strut coverage of >94% was found in both therapy groups. Despite greater suppression of global neointimal growth in DES, both DES and BMS+DEB effectively prevented clinically relevant focal restenosis at 6-month follow-up.
CLINICAL TRIAL REGISTRATION—URLhttp://www.clinicaltrials.gov. Unique identifierNCT01056744.
Background
Accurate assessment of the aortic annulus is crucial for successful transcatheter aortic valve replacement (TAVR), in particular to prevent paravalvular regurgitation (PVR). We compared ...aortic annular sizing using multidetector computed tomography (MDCT) and three-dimensional transoesophageal echocardiography (3-D TEE) to determine the predictive value of MDCT.
Methods and results
All patients admitted for transfemoral TAVR
n
= 227; 48.9% balloon expandable (Edwards Sapien 3); 51.1% self-expandable (Core Valve, Evolut R) at our institution from January 2015 until December 2016 were analysed retrospectively. Aortic annular parameters were obtained either by MDCT or 3-D TEE. Additionally, we included a cohort of patients (
n
= 27) assessed by both MDCT and 3D TEE between October 2017 and April 2018 to enable intra-individual comparison of the two methods. Indications for TAVR were severe degenerative aortic stenosis (AS; 94.7%) or re-stenosis after surgical AVR (5.3%). 74.4% were classified as high-gradient AS. The mean age was 80 (37–94) years and 75.8% presented with NYHA III/IV. STS risk of mortality was intermediate (3.5 ± 2.3). MDCT and 3-D TEE were performed in 116 and 111 patients for aortic annulus sizing, respectively. Significantly larger implants were chosen in the CT group irrespective of prosthesis type or post-dilatation. Follow-up (median at 79 days) revealed significantly less PVR in the MDCT compared to 3-D TEE group (absence of PVR in 59.3% and 40.7%,
p
= 0.016), without differences in mortality. Patients without PVR or mild PVR had a better clinical performance according to NYHA class (
p
= 0.016).
Conclusion
MDCT is superior to 3-D TEE in terms of sizing accuracy and clinical outcomes. Reduction of PVR after TAVR with MDCT is likely due to valve annulus undersizing by TEE.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Transcatheter aortic valve implantation (TAVI) is now a commonly used therapy in patients with severe aortic stenosis, even in those patients at low surgical risk. The indications for TAVI have ...broadened as the therapy has proven to be safe and effective. Most challenges associated with TAVI after its initial introduction have been impressively reduced; however, the possible need for post-TAVI permanent pacemaker implantation (PPI) secondary to conduction disturbances continues to be on the radar. Conduction abnormalities post-TAVI are always of concern given that the aortic valve lies in close proximity to critical components of the cardiac conduction system. This review will present a summary of noteworthy pre-and post-procedural conduction blocks, the best use of telemetry and ambulatory device monitoring to avoid unnecessary PPI or to recognize the need for late PPI due to delayed high-grade conduction blocks, predictors to identify those patients at greatest risk of requiring PPI, important CT measurements and considerations to optimize TAVI planning, and the utility of the MInimizing Depth According to the membranous Septum (MIDAS) technique and the cusp-overlap technique. It is stressed that careful membranous septal (MS) length measurement by MDCT during pre-TAVI planning is necessary to establish the optimal implantation depth before the procedure to reduce the risk of compression of the MS and consequent damage to the cardiac conduction system.
Endothelial microparticles (EMP) are small membrane vesicles that originate from activated or apoptotic endothelial cells. Although the exact mechanism of EMP function is still relatively unknown, it ...has been shown that they modulate inflammatory processes, coagulation and vascular function. In this study we hypothesized that transient hypoxia may act as a trigger for the release of EMP into circulation.
Fourteen healthy volunteers were subjected to transient normobaric hypoxia in an air-conditioned chamber simulating an oxygen concentration of a height of up to 5500 meters. Blood samples were evaluated for EMP using flow cytometry.
During the experiment oxygen concentration was adjusted to a value equivalent to a height of 5500 meters to achieve hypoxic conditions. Oxygen saturation decreased to 78% . At the final height a significant increase of CD31+/Annexin+ EMP levels was evident (increase from 0.03% ± 0.01% SEM to 0.12% ± 0.04% SEM, p = 0.0188).
These experimental results show that temporary hypoxic conditions can trigger the release of CD31+/ Annexin+ EMP also in healthy volunteers. In our previous studies we have shown that apoptotic bodies can confer pro-survival signals to cardiomyocytes during myocardial ischemia. Based on the experimental results of this current study we believe that the release of CD31+/Annexin+ EMP during hypoxia might act as an endogenous survival signal.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Background
Increased levels of endothelial cell microparticles (EMP) are known to reflect endothelial dysfunction (ED). In diabetes mellitus type 2 (T2DM), the expression of endothelin (ET)‐1 is ...increased. As treatment with an ET‐1 antagonist significantly inhibited atherosclerosis in animal models, we sought to investigate whether treatment with ET‐1 antagonists affects EMP levels in vitro and in vivo in patients with T2DM.
Materials and methods
In vitro study: Human umbilical vein endothelial cells (HUVEC) were stimulated with ET‐1 alone and ET‐1 in combination with a dual ET‐A and ET‐B endothelin receptor blocker. In vivo study: Patients with T2DM were randomized to treatment with the ET receptor antagonist bosentan or placebo. After 4 weeks, the patients were re‐examined and blood samples were obtained. EMP counts in supernatants and plasma samples were determined using flow cytometry.
Results
In vitro study: In supernatants of ET‐1‐stimulated HUVECs, the increased release of EMP was reduced significantly by co‐incubation with an ET‐1 receptor antagonist (e.g. CD31+/CD42b‐EMP decreased from 37·1% ± 2·8 to 31·5% ± 2·8 SEM, P = 0·0078). In vivo study: No changes in EMP levels in blood samples of patients with T2DM were found after 4 weeks of bosentan treatment (n = 36, P = ns).
Conclusions
Our in vitro results suggest that ET‐1 stimulates the release of EMP from HUVECs via a receptor‐dependent mechanism. Co‐incubation with an endothelin receptor blocker abolished ET‐1‐dependent EMP release. However, treatment with bosentan for 4 weeks failed to alter EMP levels in patients with T2DM. Other factors seem to have influenced EMP release in patients with T2DM independent of ET‐1 receptor‐mediated mechanisms.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
A novel 3D-OCT algorithm was applied to analyze strut apposition (incomplete stent apposition ISA volumes and surface areas), coverage, proliferation, vessel remodeling (remodeling volume = stented ...vessel volume-stent volume) and spatial distribution patterns.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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