Abstract Objective Substantial controversy surrounds the choice between a mechanical versus bioprosthetic prosthesis for aortic valve replacement (AVR), based on age. This study aims to investigate ...national trends and in-hospital outcomes of the 2 prosthesis choices. Methods All patients aged >18 years in the National Inpatient Sample who received an AVR between 1998 and 2011 were considered. Valve-type use was examined by patient, procedural, and hospital characteristics, after which we matched patients based on their propensity score for receiving a bioprosthetic valve and compared their in-hospital outcomes. Results Bioprosthetic valves comprised 53.3% of 767,375 implanted valves, an increase in use from 37.7% in the period 1998 to 2001 to 63.6% in the period 2007 to 2011. The median age was 74 years for patients receiving bioprosthetic valves, and 67 years for those receiving mechanical valves. Use of bioprosthetic valves increased across all age groups, most markedly in patients age 55 to 64 years. Compared with patients receiving mechanical valves, these patients had a higher incidence of renal disease (8.0% vs 4.2%), coronary artery disease (58.5% vs 50.5%), concomitant coronary artery bypass grafting (46.7% vs 41.9%), and having surgery in a high-volume (>250 cases per year) center (31.3% vs 18.5%). Patients receiving bioprosthetic valves had a higher occurrence of in-hospital complications (55.9% vs 48.6%), but lower in-hospital mortality (4.4% vs 4.9%) than patients receiving mechanical valves. This difference was confirmed in propensity-matched analyses (complications: 52.7% vs 51.5%; mortality: 4.3% vs 5.2%). Conclusions Use of bioprosthetic valves in AVR increased dramatically from 1998 to 2011, particularly in patients age 55 to 64 years. Prosthesis selection varied significantly by facility, with low-volume facilities favoring mechanical valves. Aortic valve replacement with a bioprosthetic valve, compared with a mechanical valve, was associated with lower in-hospital mortality.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Superhydrophobic surfaces, as indicated in the name, are highly hydrophobic and readily repel water. With contact angles greater than 150° and sliding angles less than 10°, water droplets flow easily ...and hardly wet these surfaces. Superhydrophobic materials and coatings have been drawing increasing attention in medical fields, especially on account of their promising applications in blood-contacting devices. Superhydrophobicity controls the interactions of cells with the surfaces and facilitates the flowing of blood or plasma without damaging blood cells. The antibiofouling effect of superhydrophobic surfaces resists adhesion of organic substances, including blood components and microorganisms. These attributes are critical to medical applications such as filter membranes, prosthetic heart valves, extracorporeal circuit tubing, and indwelling catheters. Researchers have developed various methods to fabricate blood-compatible or biocompatible superhydrophobic surfaces using different materials. In addition to being hydrophobic, these surfaces can also be antihemolytic, antithrombotic, antibacterial, and antibiofouling, making them ideal for clinical applications. In this review, the authors summarize recent developments of blood-compatible superhydrophobic surfaces, with a focus on methods and materials. The expectation of this review is that it will support the biomedical research field by providing current trends as well as future directions.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The aim of this study was to assess the impact of individual operator experience on transfemoral transcatheter aortic valve replacement (TAVR) outcomes.
TAVR volume-outcome relationships have not ...been evaluated at the individual operator level.
New York Statewide Planning and Research Cooperative System data from 8,771 transfemoral TAVR procedures performed by 207 operators between 2012 and 2016 were analyzed. Operator volume was defined as the number of TAVR procedures performed during 1 year prior to the index procedure. Hierarchical and restrictive cubic spline regression models were used to evaluate the impact of individual operator experience on risk-adjusted in-hospital outcomes. The primary outcome was a composite of in-hospital mortality, stroke, and/or acute myocardial infarction. Secondary outcomes were the individual components of the primary outcome.
After adjusting for hospital and physician characteristics, patients undergoing TAVR performed by high-volume physicians (≥80/year) had a significantly lower risk for death, stroke, or acute myocardial infarction (odds ratio: 0.59; 95% confidence interval: 0.37 to 0.93) compared with those treated by low-volume physicians (<24/year). Being treated by operators who performed 200 procedures during the prior year was associated with significantly lower risks for post-procedural stroke (odds ratio: 0.41; 95% confidence interval: 0.17 to 0.97) and composite events (odds ratio: 0.45; 95% confidence interval: 0.26 to 0.78). This relationship was nonlinear, and a sensitivity analysis excluding the first 10, 20, and 30 procedures for each operator mitigated the effect of the initial learning curve.
Increased TAVR experience of operators is associated with improved risk-adjusted in-hospital outcomes. These results have potentially important implications for individual training and hospital programs in TAVR.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Extracorporeal membrane oxygenation (ECMO) is a life-saving modality increasingly used in the management cardiopulmonary failure. However, ECMO itself is not without major complications. Mortality ...remains high, and morbidity such as stroke, renal failure, and acute limb threatening ischemia (ALI) are common among surviving patients. We analyzed the effect of one of these complications, ALI, on the survival of patients receiving venoarterial ECMO (VA ECMO) with femoral cannulation.
Patients with cardiopulmonary failure supported by VA ECMO inserted through femoral cannulation at two institutions from December 2010 to December 2017 were enrolled in this study. Data were collected retrospectively. Our primary outcome was ALI and its effect on hospital mortality. Secondary outcomes included six-month mortality, length of hospital stay, and other complications (stroke and renal failure); multivariate logistic regression analysis was used to identify predictors of ALI and hospital mortality.
There were 71 patients included in this study. The overall VA ECMO hospital mortality was 53.5%. ALI was seen in 14 (19.7%) patients. Of these, four (5.6%) patients had fasciotomy, four patients (5.6%) had thrombectomy, and one underwent arterial repair (1.4%). Five additional patients (7.0%) with ALI expired and had no vascular intervention. None of the demographic and clinical characteristics significantly correlated with ALI except for stroke and renal failure requiring new-onset hemodialysis (HD). The rate of hospital and 6-month mortality in patients with and without vascular complications were 78.6%, 92.3% and 47.4%, 57.4%, respectively (P = 0.042 and P = 0.023). Multivariate analysis correlated hospital and six-month mortality with ALI, stroke, and new-onset HD.
ALI correlates with higher mortality in VA ECMO patients with femoral cannulation. Although some of the contributing factors to mortality in these patients are related to the consequences of cardiopulmonary failure, strong efforts should be made to avoid ALI after femoral VA ECMO cannulation.
Constant-voltage time-dependent dielectric breakdown (TDDB) measurements are performed on recently manufactured commercial 1.2 kV 4H-SiC power metal-oxide-semiconductor (MOS) field-effect transistors ...(MOSFETs) from three vendors. Abrupt changes of the electric field acceleration parameters (<inline-formula> <tex-math notation="LaTeX">\gamma </tex-math></inline-formula>) are observed at oxide electric fields (<inline-formula> <tex-math notation="LaTeX">E_{ox} </tex-math></inline-formula>) around 8.5 MV/cm to 9 MV/cm for all commercial MOSFETs. Gate leakage currents and threshold voltage shifts are also monitored under different oxide fields (<inline-formula> <tex-math notation="LaTeX">E_{ox}= {\mathrm {8 MV/cm}} </tex-math></inline-formula> and 10 MV/cm). The results suggest the failure mode under high oxide electric field is modified by impact ionization or Anode Hole Injection (AHI) induced hole trapping. This observation agrees with previously published oxide reliability studies on SiC MOSFETs and suggests that constant-voltage TDDB measurements need to be carefully performed under low oxide fields to avoid lifetime overestimation caused by hole trapping. The extrapolated <inline-formula> <tex-math notation="LaTeX">t_{63\%} </tex-math></inline-formula> lifetimes (times to 63% failures) from TDDB measurements performed at <inline-formula> <tex-math notation="LaTeX">E_{ox} < {\mathrm {8.5 MV/cm}} </tex-math></inline-formula> are longer than 10 8 hours at 150°C for all vendors. The predicted lifetimes at <inline-formula> <tex-math notation="LaTeX">E_{ox}= {\mathrm {4 MV/cm}} </tex-math></inline-formula> demonstrate more than 10 5 times increases than the oxide lifetimes reported a decade ago, showing promising progress in SiC technology.
A new cell topology named the dodecagonal (a polygon with twelve sides, short for Dod) cell is proposed to optimize the gate-to-drain capacitance (Cgd) and reduce the specific ON-resistance (Ron,sp) ...of 4H-SiC planar power MOSFETs. The Dod and the octagonal (Oct) cells are used in the layout design of the 650 V SiC MOSFETs in this work. The experimental results confirm that the Dod-cell MOSFET achieves a 2.2× lower Ron,sp, 2.1× smaller high-frequency figure of merit (HF-FOM), higher turn on/off dv/dt, and 29% less switching loss than the fabricated Oct-cell MOSFET. The results demonstrate that the Dod cell is an attractive candidate for high-frequency power applications.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
High-current 4H-SiC lateral BJTs for high-temperature monolithic integrated circuits are fabricated. The BJTs have three different sizes and the designs are optimized in terms of emitter finger width ...and length and the device layout to have higher current density (J C ), lower on-resistance (R ON ), and more uniform current distribution. A maximum current gain (β) of >53 at significantly high current density was achieved for different sizes of SiC BJTs. The BJTs are measured from room temperature to 500 °C. An open-base breakdown voltage (V CEO ) of >50 V is measured for the devices.
Background Robotic-assisted mitral valve repair is becoming more frequently performed in cardiac surgery. However, little is known about its utilization and safety at a national level. Methods ...Patients undergoing mitral valve repair in the United States from 2008 to 2012 were identified in the National Inpatient Sample. Inhospital mortality, complications, length of stay, and cost for patients undergoing robotic-assisted mitral valve repair were compared with patients undergoing nonrobotic procedures. Results We identified 50,408 isolated mitral valve repair surgeries, of which 3,145 were done with robotic assistance. In a propensity score matched analysis of 631 pairs of patients, we found no difference between patients undergoing robotic-assisted and nonrobotic-assisted mitral valve repair with respect to inhospital mortality, complications, or composite outcomes in unadjusted or multivariable analyses. Robotic-assisted mitral valve repair surgery was associated with a shorter median length of stay (4 versus 6 days, p < 0.001), and there was no difference in median total costs between the two procedures. Conclusions In our analysis of a large national database with its inherent limitations, robotic-assisted mitral valve repair was found to be safe, with an acceptable morbidity and mortality profile.
Pulmonary Embolism Response Teams (PERTs) have emerged to provide rapid multidisciplinary assessment and treatment of PE patients. However, descriptive institutional experience and preliminary ...outcomes data from such teams are sparse. PERT activations were identified through a retrospective review. Only confirmed submassive or massive PEs were included in the data analysis. In addition to baseline variables, the therapeutic intervention, length of stay (LOS), in-hospital mortality, and bleeding rate/severity were recorded. A total of 124 PERT activations occurred over 20 months: 43 in the first 10 months and 81 in the next 10. A total of 87 submassive (90.8%) and massive (9.2%) PE patients were included. The median age was 65 (51–75 IQR) years. Catheter-directed thrombolysis (CDT) was administered to 25 patients, systemic thrombolysis (ST) to six, and anticoagulation alone (AC) to 54. The median ICU stay and overall LOS were 6 (3–10 IQR) and 7 (4–14 IQR) days, respectively, with no association with any variables except a brain natriuretic peptide (BNP) >100 pg/mL (p=0.008 ICU LOS; p=0.047 overall LOS). Twelve patients (13.7%) died in the hospital, nine of whom had metastatic or brain cancer, with a median overall LOS of 13 (11–17 IQR) days. There were five major bleeds: one in the CDT group, one in the ST group, and three in the AC group. Overall, (1) PERT activations increased after the first 10 months; (2) BNP >100 pg/mL was associated with a longer LOS; (3) rates of mortality and bleeding did not correlate with treatment; and (4) the majority of in-hospital deaths occurred in patients with advanced cancer.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
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