Single versus double Perclose techniques for vascular closure during transfemoral transcatheter aortic valve replacement.

INTRODUCTION: The preferred approach for transcatheter aortic valve replacement (TAVR) is transfemoral. There has been widespread adoption of the Perclose ProglideTM device for vascular closure. Typically, two devices are deployed before upsizing the access sheath in the "preclose technique." Prior investigations have compared the use of a single device versus double device technique, but none have shown significant clinical benefit to either approach. METHODS: Five hundred and six patients underwent transfemoral TAVR (TF-TAVR) with single or double Perclose devices for vascular closure from July 2015 to February 2020. A retrospective review was conducted, and propensity-matched analyses were used to account for differences in baseline characteristics. RESULTS: In the matched analysis, there were 251 patients in the single Perclose group and 238 in the double. There was a statistically significant improvement in overall procedural success using the single closure device (94.6% vs. 88.5%, p = 0.009) This was defined as intraprocedural hemostatic control, lack of contrast extravasation, arterial dissection, occlusion, or stenosis >50% in the final crossover angiogram, as well as unimpaired limb perfusion without claudication throughout the index hospitalization. There was also a significant improvement in arterial dissection rates (0.6% vs. 4.6%, p = 0.004), stenosis >50% (1.3% vs. 4.4%, p = 0.028), and Valve Academic Research Consortium major vascular complications (1.8% vs. 4.9%, p = 0.038). CONCLUSION: A single Perclose device is a safe means of vascular closure during TF-TAVR and may have important clinical benefits compared to the commonly used two-device technique.

Fractional Flow Reserve in End-Stage Liver Disease.

Fractional flow reserve (FFR) determines the functional significance of epicardial stenoses assuming negligible venous pressure (Pv) and microvascular resistance. However, these assumptions may be invalid in end-stage liver disease (ESLD) because of fluctuating Pv and vasodilation. Accordingly, all patients with ESLD who underwent right-sided cardiac catheterization and coronary angiography with FFR as part of their orthotopic liver transplantation evaluation between 2013 and 2018 were included in the present study. Resting mean distal coronary pressure (Pd)/mean aortic pressure (Pa), FFR, and Pv were measured. FFR accounting for Pv (FFR - Pv) was defined as (Pd - Pv)/(Pa - Pv). The hyperemic effect of adenosine was defined as resting Pd/Pa - FFR. The primary outcome was all-cause mortality at 1 year. In 42 patients with ESLD, 49 stenoses were interrogated by FFR (90% were <70% diameter stenosis). Overall, the median model for ESLD score was 16.5 (10.8 to 25.5), FFR was 0.87 (0.81 to 0.94), Pv was 8 mm Hg (4 to 14), FFR-Pv was 0.86 (0.80 to 0.94), and hyperemic effect of adenosine was 0.06 (0.02 to 0.08). FFR-Pv led to the reclassification of 1 stenosis as functionally significant. There was no significant correlation between the median model for ESLD score and the hyperemic effect of adenosine (R = 0.10). At 1 year, 13 patients had died (92% noncardiac in etiology), and patients with FFR ≤0.80 had significantly higher all-cause mortality (73% vs 17%, p = 0.001. In conclusion, in patients with ESLD who underwent orthotopic liver transplantation evaluation, Pv has minimal impact on FFR, and the hyperemic effect of adenosine is preserved. Furthermore, even in patients with the predominantly angiographically-intermediate disease, FFR ≤0.80 was an independent predictor of all-cause mortality.

Mechanical circulatory support in acute myocardial infarction and cardiogenic shock: Challenges and importance of randomized control trials.

BACKGROUND: Acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) is associated with significant morbidity and mortality. METHODS: We provide an overview of previously conducted studies on the use of mechanical circulatory support (MCS) devices in the treatment of AMI-CS and difficulties which may be encountered in conducting such trials in the United States. RESULTS: Well powered randomized control trials are difficult to conduct in a critically ill patient population due to physician preferences, perceived lack of equipoise and challenges obtaining informed consent. CONCLUSIONS: With growth in utilization of MCS devices in patients with AMI-CS, efforts to perform well-powered, randomized control trials must be undertaken.

Strategic implementation of phosphorus repletion strategy in continuous two-stage cultivation of Chlorella sp. HS2: Evaluation for biofuel applications.

Lipid production in microalgae under nitrogen (N) starved condition can be enhanced by excess phosphorus (P) supply in the second stage of two-stage cultivation strategy. However, implementing two-stage cultivation is difficult in large-scale cultivation system as it requires high energy of transferring large algal biomass from first stage to second stage. To address this problem, we have optimized a continuous two-stage (CTS) cultivation strategy using Chlorella sp. HS2, where nitrogen in the growth environment is depleted naturally via consumption. To enhance both biomass and lipid productivity this strategy explored supplementation of additional P from 50% to 2500% of the initial concentration at the start of N-limited second stage of growth. The results of the optimization study in photobioreactor (PBR) showed that supplementing 500% of initial P and 100% of initial other nutrients (O) (N0-P500-O100) on 5th day showed the maximum biomass productivity of 774.4 mg L-1 d-1. It was observed that Chlorella sp. HS2 grown in PBR yielded higher biomass (3.8 times), lipid (6.1 times) and carbohydrate (5.5 times) productivity in comparison to the open raceway ponds (ORP) study, under optimum nutrient and carbon supply condition. The maximum lipid (289.6 mg L-1 d-1) and carbohydrate (219.2 mg L-1 d-1) productivities were obtained in TPBR-3, which were 1.9 and 1.3 times higher than that of TPBR-2 (+ve control) and 9.6 and 3.7 times higher than that of TPBR-1 (-ve control), respectively. Fatty acid mainly composed of C16/C18 (84.5%-85.7%), which makes the microalgal oil suitable for biofuel production. This study concluded that feeding excess amount of P is an effective and scalable strategy to improve the biomass and lipid productivity of CTS cultivation.

Application of transcatheter valves for aortic valve replacement in pediatric patients: A case series.

OBJECTIVES: To describe our initial experience with pediatric transcatheter aortic valve replacement. BACKGROUND: Transcatheter aortic valve replacement (TAVR) has been approved and used to treat calcific aortic stenosis in adult patients. Select pediatric patients with congenital heart disease (CHD) who are poor candidates for conventional surgical aortic valve replacement can benefit from TAVR. METHODS: A retrospective review was performed to identify and describe pediatric patients with CHD who underwent transcatheter or hybrid aortic valve replacement using a Melody Valve (Medtronic, Minneapolis, MN), or Sapien S3/XT valve (Edwards Life sciences LLC, Irvine, CA). Patients in whom transcatheter valves were implanted on cardiopulmonary bypass were included. Imaging data, procedural elements, and clinical follow-up data were collected to evaluate acute and short-term results. RESULTS: A total of eight pediatric patients underwent treatment of aortic valvular disease using balloon expandable valves and delivery systems. Two patients had Melody valve implantation and six received a Sapien valve (one XT/five S3). In one patient, a Melody valve was placed surgically, failed, and was replaced with a Sapien valve 2 years later. Two patients were treated using a standard transfemoral route, four had the valve delivered on cardiopulmonary bypass via a median sternotomy, one was placed with a transapical approach, and one via a carotid cut down. Patients were followed for an average 16 months (range 1-208 weeks). There were no early or late deaths in this cohort. There were no embolic events, and all valves worked well in the immediate postoperative period. Both Melody implants developed moderate to severe regurgitation at 2 years and 4 years, respectively, and both required replacement at that time. One Sapien 3 valve developed a paravalvular leak that required reintervention within 6 months of implantation. CONCLUSIONS: Transcatheter valves offer a reasonable alternative to traditional surgical aortic valve replacement in certain pediatric patients who are suboptimal surgical candidates. Hybrid approaches and valve delivery on cardiopulmonary bypass has been used in smaller patients. Long-term performance of these valves in young patients has not been studied.

Optimization of heterotrophic cultivation of Chlorella sp. HS2 using screening, statistical assessment, and validation.

The heterotrophic cultivation of microalgae has a number of notable advantages, which include allowing high culture density levels as well as enabling the production of biomass in consistent and predictable quantities. In this study, the full potential of Chlorella sp. HS2 is explored through optimization of the parameters for its heterotrophic cultivation. First, carbon and nitrogen sources were screened in PhotobioBox. Initial screening using the Plackett-Burman design (PBD) was then adopted and the concentrations of the major nutrients (glucose, sodium nitrate, and dipotassium phosphate) were optimized via response surface methodology (RSM) with a central composite design (CCD). Upon validation of the model via flask-scale cultivation, the optimized BG11 medium was found to result in a three-fold improvement in biomass amounts, from 5.85 to 18.13 g/L, in comparison to a non-optimized BG11 medium containing 72 g/L glucose. Scaling up the cultivation to a 5-L fermenter resulted in a greatly improved biomass concentration of 35.3 g/L owing to more efficient oxygenation of the culture. In addition, phosphorus feeding fermentation was employed in an effort to address early depletion of phosphate, and a maximum biomass concentration of 42.95 g/L was achieved, with biomass productivity of 5.37 g/L/D.

Biological Carbon Recovery from Sugar Refinery Washing Water into Microalgal DHA: Medium Optimization and Stress Induction.

Sugar refinery washing water (SRWW) contains abundant levels of carbon sources and lower levels of contaminants than other types of wastewater, which makes it ideal for heterotrophic cultivation of microalgae. Here, carbon sources in SRWW were utilized for conversion into the form of value-added docosahexaenoic acid (DHA) using Aurantiochytrium sp. KRS101. Since SRWW is not a defined medium, serial optimizations were performed to maximize the biomass, lipid, and DHA yields by adjusting the nutrient (carbon, nitrogen, and phosphorus) concentrations as well as the application of salt stress. Optimum growth performance was achieved with 30% dilution of SRWW containing a total organic carbon of 95,488 mg L-1. Increasing the nutrient level in the medium by supplementation of 9 g L-1 KH2PO4 and 20 g L-1 yeast extract further improved the biomass yield by an additional 14%, albeit at the expense of a decrease in the lipid content. Maximum biomass, lipid, and DHA yields (22.9, 6.33, and 2.03 g L-1, respectively) were achieved when 35 g L-1 sea salt was applied on a stationary phase for osmotic stress. These results demonstrate the potential of carbon-rich sugar refinery washing water for DHA production using Aurantiochytrium sp. KRS101 and proper cultivation strategy.

Efficient microalgae removal from aqueous medium through auto-flocculation: investigating growth-dependent role of organic matter.

This study investigated the growth-dependent role of algal organic matters (AOMs) to achieve high removal efficiency (R.E) of microalgae. The results showed that the microalgae cells produced 96 ± 2% of total AOMs as loose bound AOMSS (LB-AOMs) and 4 ± 1% as cell-bound (CB-AOMs) in exponential phase. In stationary phase, LB-AOMs and CB-AOMs were 46 ± 0.7percentage and 54 ± 0.2 percentage, respectively. The R.Es in exponential and stationary phase were 83 ± 2.6% and 66 ± 1.2%, respectively. It is found that the difference of biomass concentration (between exponential and stationary phase) had no significant impact on the R.E (P > 0.01). Further investigations revealed that LB-AOMs inhibit flocculation in exponential and CB-AOMs in stationary phase; however, CB-AOMs showed stronger inhibition than the LB-AOMs (P < 0.01). The provision of calcium (17 ± 0.9 mg/L) to the culture reduced the AOMs inhibition and improved the R.E from 66 ± 1.2% (in control) to 90 ± 4.2%. An increase in R.E was attributed to the interaction of calcium with AOMs and subsequently acting as a flocculant. The findings of this study can be valuable to improve the performance of auto-flocculation technology, which is mainly limited by the presence of AOMs. Graphical Abstract.

Isolation and Characterization of Novel Chlorella Species with Cold Resistance and High Lipid Accumulation for Biodiesel Production.

Chlorella spp. are green algae that are found across wide-ranging habitats from deserts to arctic regions, with various strains having adapted to survive under diverse environmental conditions. In this study, two novel Chlorella strains (ABC-002, ABC-008) were isolated from a freshwater lake in South Korea during the winter season and examined for possible use in the biofuel production process. The comparison of ABC-002 and ABC-008 strains with Chlorella vulgaris UTEX265 under two different temperatures (10°C, 25°C) revealed their cold-tolerant phenotypes as well as high biomass yields. The maximum quantum yields of UTEX25, ABC- 002, and ABC-008 at 10°C were 0.5594, 0.6747, and 0.7150, respectively, providing evidence of the relatively higher cold-resistance capabilities of these two strains. Furthermore, both the biomass yields and lipid content of the two novel strains were found to be higher than those of UTEX265; the overall lipid productivities of ABC-002 and ABC-008 were 1.7 ~ 2.8 fold and 1.6 ~ 4.2 fold higher compared to that of UTEX265, respectively. Thus, the high biomass and lipid productivity over a wide range of temperatures indicate that C. vulgaris ABC-002 and ABC-008 are promising candidates for applications in biofuel productions via outdoor biomass cultivation.

Exploration of two-stage cultivation strategies using nitrogen starvation to maximize the lipid productivity in Chlorella sp. HS2.

In this work, the two-stage cultivation of Chlorella sp. HS2 for enhancing the lipid productivity was optimized by adjusting the duration of nitrogen-replete (N+) and -deplete (N-) stages within a 9 day period using urea as nitrogen source. The highest lipid content of 36.7% and productivity of 216.9 mg L-1 d-1 were obtained under five days of N+ followed by four days of N- conditions. Replenishing phosphorus and other nutrients (N-P+O+) at the beginning of the nutrient-starvation resulted in 1.55 and 1.68-folds improvement in lipid productivities compared to the single stage and zero nutrient controls (N-P-O-), respectively. The estimated biodiesel properties based on the fatty acid profiles met all criteria of international standards. The findings of this study indicate that properly adjusting the period of nitrogen availability as well as the presence of other nutrients is highly important in order to maximize the biofuel productivity in two-stage microalgal cultivation.

Transcatheter aortic valve replacement outcomes in bicuspid compared to trileaflet aortic valves.

AIM: TAVR in patients with bicuspid aortic valves (BAV) is more challenging compared to individuals with trileaflet aortic valves (TAV). BAV have been excluded from the large randomized clinical trials assessing transcatheter aortic valve replacements (TAVR) and has been considered as a relative contraindication to TAVR. To report the outcomes of TAVR in BAV and compare them to TAV in the National Inpatient Sample (NIS). METHODS AND RESULTS: TAVR procedures were identified between 2011 and 2014 in the NIS dataset. Endpoints assessed included in-hospital mortality, periprocedural complications, length of stay and cost. Of 40,604 identified TAVR procedures, 407 (1%) were BAV and the 40,197 (99%) were TAV. Patients with BAV were younger and had a lower comorbidity burden. In hospital mortality (4.89% vs 4.17%, OR: 1.71, 95%CI: 0.57-5.12, P = 0.21), AMI (3.49% vs 3.58%, OR: 1.12, 95%CI: 0.36-3.54, P = 0.85), stroke and TIA (2.49% vs 3.55%, OR: 0.75, 95%CI: 0.18-3.16, P = 0.70), vascular complications (2.39% vs 5.58%, OR:0.47, 95%CI: 0.11-1.93, P = 0.29), major bleeding (16.96% vs 23.50%, OR: 0.63, 95%CI: 0.34-1.17, P = 0.15) and rates of permanent pacemaker (PPM) (9.88% vs 10.88%, OR: 1.19, 95%CI: 0.57-2.51, P = 0.64) were similar in both cohorts. CONCLUSIONS: With multimodality imaging and further improvement in technology, our study demonstrates off-label TAVR should not be considered prohibitive and can be successfully performed for BAV with similar peri-procedural outcomes compared to those with TAV. However, there is a need for robust large prospective studies.

MAPK/ERK and JNK pathways regulate lipid synthesis and cell growth of Chlamydomonas reinhardtii under osmotic stress, respectively.

Microalgae have great potential for the production of biofuels due to the ability of the organism to accumulate large quantities of storage lipids under stress conditions. Mitogen activated protein kinase (MAPK) signaling cascades are widely recognized for their role in stress response signal transduction in eukaryotes. To assess the correlation between MAPK activation and lipid productivity, Chlamydomonas reinhardtii was studied under various concentrations of NaCl. The results demonstrated that C. reinhardtii exhibits elevated levels of extracellular-signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) activities after undergoing osmotic stress, as well as an increase in cellular lipid content. To establish a more direct causal link between both kinases and lipid productivity, C. reinhardtii was subjected to biochemically induced regulation of ERK and JNK pathways. Activating the MEK-ERK pathway via C6 ceramide treatment increased ERK activation and lipid production simultaneously, while PD98059 mediated inhibition of the pathway yielded opposite results. Interestingly, suppression of the JNK pathway with SP600125 resulted in a substantial decrease in cell viability under osmotic stress. These results suggest that ERK and JNK MAP kinases have important roles in microalgal lipid accumulation and cell growth under osmotic stress, respectively.

Radial haemostasis is facilitated with a potassium ferrate haemostatic patch: the Statseal with TR Band assessment trial (STAT).

AIMS: Haemostasis is a limiting factor for discharge after uncomplicated transradial procedures. The purpose of this study was to determine whether a potassium ferrate haemostatic patch (PFHP) could serve as an adjunct to the air-bladder TR Band (TRB) to facilitate implementation of a rapid deflation protocol. METHODS AND RESULTS: This was a prospective multicentre randomised controlled trial comparing radial haemostatic protocols. Deflation of the TRB was attempted at 40 minutes with PFHP and at 120 minutes without the PFHP. The primary outcome was time to full deflation of the TRB with haemostasis. At four US sites, 180 patients were enrolled after receiving a minimum of 5,000 units of unfractionated heparin or bivalirudin. Interventions comprised 30% of procedures. Successful TRB deflation occurred at 43±14 minutes with PFHP and 160±43 minutes without PFHP (p<0.001). Minor haematomas occurred in nine (10.3%) of the TRB patients and 16 (17.2%) of the PFHP patients (p=0.20). Radial artery occlusion occurred in 2% of patients in the PFHP group (p=NS). Outpatients randomised to PFHP were discharged 51±83.5 minutes earlier than control. CONCLUSIONS: The PFHP haemostatic patch facilitated early deflation of the TRB with a non-significant increase in forearm haematomas. Use of the PFHP may improve patient throughput and allow earlier discharge following transradial procedures.

Vascular Complications in the Sapien 3 Era: Continued Role of Transapical Approach to Transcatheter Aortic Valve Replacement.

With the introduction of the latest generation Sapien 3 (S3) transcatheter aortic valve, there has been a reduction in the usage of transapical (TA) approach for transcatheter aortic valve replacements in many centers. However, despite the smaller sheath size and the more streamlined delivery system, vascular complications continue to occur, especially in patients with peripheral vascular disease. Thus, our institution has maintained a stringent TA protocol aiming to prevent these complications. We hypothesize that this protocol has helped to reduce vascular complications and improve outcomes at our institution even in the S3 era. All transcatheter aortic valve replacement procedures done at our institution were considered for analysis. Patients were grouped according to whether their procedure was done before (Pre-S3 era) or after (S3 era) the introduction of the S3 valve, as well as whether they underwent a TA or a transfemoral (TF) approach. A femoral artery intraluminal diameter of <7.5 mm in the Pre-S3 era and <5.5 mm in the S3 era with circumferential calcifications triggered TA approach consideration. Vascular complications included vascular perforation, dissection, flow-limiting stenosis, unplanned vascular surgery, significant postprocedural bleeding, hematoma at the access site, and retroperitoneal bleed. The Welch t test of unequal variance and chi-squared test were used as appropriate. An alpha of <0.05 was considered significant. A total of 275 patients were included in the analysis (121 Pre-S3 era and 154 S3 era). The TA approach was utilized in 45% in the Pre-S3 era vs 15% in the S3 era (P < 0.001). Within the S3 era, 131 underwent the TF approach compared with 23 who underwent the TA approach. TA and TF patients were similar in all preoperative characteristics except hypertension. Mortality was significantly lower in the S3 era (0% vs 4% in the pre-S3 era, P = 0.02). Overall rates of vascular complications were similar between the Pre-S3 and the S3 eras (16% vs 14%, P = 0.63). Overall adverse outcomes were similar between the TA and the TF groups. TA patients saw significantly longer intensive care unit stay and total hospital stay. Our results show that despite a smaller sheath size, vascular complications continue at a similar rate into the S3 era. This occurred in the setting of an ongoing aggressive TA utilization in select patients, specifically those with peripheral vascular disease. Maintaining this approach is likely a large contributor to both our current success and reduced mortality.

Myocardial functional changes in transfemoral versus transapical aortic valve replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has greatly expanded the treatment options available for patients with severe aortic stenosis at high surgical risk. MATERIALS AND METHODS: We compared changes in myocardial function in TAVR with a transfemoral (TF) versus a transapical (TA) approach at a major tertiary hospital from 2012-2016. Traditional echocardiographic measures of cardiac structure and function were tracked, alongside the use of two-dimensional speckle tracking echocardiography to measure myocardial strain and strain rates. RESULTS: For the entire cohort with complete data at all time points (n = 42), between the pre-TAVR baseline (mean: 20.1 d) and the post-TAVR 1-mo follow-up (mean: 32.7 d), global longitudinal strain significantly increased (from -15.6% to -18.2%, P < 0.001). When comparing the TF (n = 31) and TA (n = 11) groups, TA patients showed persistently impaired apical longitudinal strain at the 1-mo follow-up (-15.9% versus -22.3%, P < 0.05). In terms of clinical outcomes, both groups (n = 131 for TF, n = 53 for TA) were similar in terms of 30-d mortality, readmission rate, and risk of post-TAVR acute kidney injury. However, TA patients experienced significantly longer length of hospitalization (7.58 versus 3.92 d, P = 0.02), intensive care unit hours (105.4 versus 47.1 h, P = 0.02), and were at a greater risk of long-term (>72 h) intensive care unit stay (45% versus 25%, P = 0.01). CONCLUSIONS: Patients undergoing TA-TAVR exhibit impaired apical longitudinal strain, although global myocardial function is similar to TF-TAVR otherwise. Myocardial strain measured by two-dimensional speckle tracking echocardiography appears to be a sensitive method to detect subtle cardiac remodeling after TAVR.

Ferumoxytol-enhanced MR Angiography for Vascular Access Mapping before Transcatheter Aortic Valve Replacement in Patients with Renal Impairment: A Step Toward Patient-specific Care.

Purpose To assess the technical feasibility of the use of ferumoxytol-enhanced (FE) magnetic resonance (MR) angiography for vascular mapping before transcatheter aortic valve replacement in patients with renal impairment. Materials and Methods This was an institutional review board-approved and HIPAA-compliant study. FE MR angiography was performed at 3.0 T or 1.5 T. Unenhanced computed tomographic (CT) images were used to overlay vascular calcification on FE MR angiographic images as composite fused three-dimensional data. Image quality of the subclavian and aortoiliofemoral arterial tree and confidence in the assessment of calcification were evaluated by using a four-point scale (4 = excellent vascular definition or strong confidence). Signal intensity nonuniformity as reflected by the heterogeneity index (ratio between the mean standard deviation of luminal signal intensity and the mean luminal signal intensity), signal-to-noise ratio, and consistency of luminal diameter measurements were quantified. Findings at FE MR angiography were compared with pelvic angiograms. Results Twenty-six patients underwent FE MR angiography without adverse events. A total of 286 named vascular segments were scored. The image quality score was 4 for 99% (283 of 286) of the segments (κ = 0.9). There was moderate to strong confidence in the ability to assess vascular calcific morphology in all studies with complementary unenhanced CT. The steady-state luminal heterogeneity index was low, and signal-to-noise ratio was high. Interobserver luminal measurements were reliable (intraclass correlation coefficient, 0.98; 95% confidence interval: 0.98, 0.99). FE MR angiographic findings were consistent with correlative pelvic angiograms in all 16 patients for whom the latter were available. Conclusion In patients with renal impairment undergoing transcatheter aortic valve replacement, FE MR angiography is technically feasible and offers reliable vascular mapping without exposure to iodine- or gadolinium-based contrast agents. Thus, the total cumulative dose of iodine-based contrast material is minimized and the risk of acute nephropathy is reduced. © RSNA, 2017 Online supplemental material is available for this article.

3-D Electrochemical Impedance Spectroscopy Mapping of Arteries to Detect Metabolically Active but Angiographically Invisible Atherosclerotic Lesions.

We designed a novel 6-point electrochemical impedance spectroscopy (EIS) sensor with 15 combinations of permutations for the 3-D mapping and detection of metabolically active atherosclerotic lesions. Two rows of 3 stretchable electrodes circumferentially separated by 120° were mounted on an inflatable balloon for intravascular deployment and endoluminal interrogation. The configuration and 15 permutations of 2-point EIS electrodes allowed for deep arterial penetration via alternating current (AC) to detect varying degrees of lipid burden with distinct impedance profiles (Ω). By virtue of the distinctive impedimetric signature of metabolically active atherosclerotic lesions, a detailed impedance map was acquired, with the 15 EIS permutations uncovering early stages of disease characterized by fatty streak lipid accumulation in the New Zealand White rabbit model of atherosclerosis. Both the equivalent circuit and statistical analyses corroborated the 3-D EIS permutations to detect small, angiographically invisible, lipid-rich lesions, with translational implications for early atherosclerotic disease detection and prevention of acute coronary syndromes or strokes.

Improved costs and outcomes with conscious sedation vs general anesthesia in TAVR patients: Time to wake up?

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has become a commonplace procedure for the treatment of aortic stenosis in higher risk surgical patients. With the high cost and steadily increasing number of patients receiving TAVR, emphasis has been placed on optimizing outcomes as well as resource utilization. Recently, studies have demonstrated the feasibility of conscious sedation in lieu of general anesthesia for TAVR. This study aimed to investigate the clinical as well as cost outcomes associated with conscious sedation in comparison to general anesthesia in TAVR. METHODS: Records for all adult patients undergoing TAVR at our institution between August 2012 and June 2016 were included using our institutional Society of Thoracic Surgeons (STS) and American College of Cardiology (ACC) registries. Cost data was gathered using the BIOME database. Patients were stratified into two groups according to whether they received general anesthesia (GA) or conscious sedation (CS) during the procedure. No-replacement propensity score matching was done using the validated STS predicted risk of mortality (PROM) as a propensity score. Primary outcome measure with survival to discharge and several secondary outcome measures were also included in analysis. According to our institution's data reporting guidelines, all cost data is presented as a percentage of the general anesthesia control group cost. RESULTS: Of the 231 patients initially identified, 225 (157 GA, 68 CS) were included for analysis. After no-replacement propensity score matching, 196 patients (147 GA, 49 CS) remained. Overall mortality was 1.5% in the matched population with a trend towards lower mortality in the CS group. Conscious sedation was associated with significantly fewer ICU hours (30 vs 96 hours, p = <0.001) and total hospital days (4.9 vs 10.4, p<0.001). Additionally, there was a 28% decrease in direct cost (p<0.001) as well as significant decreases in all individual all cost categories associated with the use of conscious sedation. There was no difference in composite major adverse events between groups. These trends remained on all subsequent subgroup analyses. CONCLUSION: Conscious sedation is emerging as a safe and viable option for anesthesia in patients undergoing transcatheter aortic valve replacement. The use of conscious sedation was not only associated with similar rates of adverse events, but also shortened ICU and overall hospital stays. Finally, there were significant decreases in all cost categories when compared to a propensity matched cohort receiving general anesthesia.