Pragmatic Trial of Hospitalization Rate in Chronic Kidney Disease.

BACKGROUND: Despite the availability of effective therapies for patients with chronic kidney disease, type 2 diabetes, and hypertension (the kidney-dysfunction triad), the results of large-scale trials examining the implementation of guideline-directed therapy to reduce the risk of death and complications in this population are lacking. METHODS: In this open-label, cluster-randomized trial, we assigned 11,182 patients with the kidney-dysfunction triad who were being treated at 141 primary care clinics either to receive an intervention that used a personalized algorithm (based on the patient's electronic health record [EHR]) to identify patients and practice facilitators to assist providers in delivering guideline-based interventions or to receive usual care. The primary outcome was hospitalization for any cause at 1 year. Secondary outcomes included emergency department visits, readmissions, cardiovascular events, dialysis, and death. RESULTS: We assigned 71 practices (enrolling 5690 patients) to the intervention group and 70 practices (enrolling 5492 patients) to the usual-care group. The hospitalization rate at 1 year was 20.7% (95% confidence interval [CI], 19.7 to 21.8) in the intervention group and 21.1% (95% CI, 20.1 to 22.2) in the usual-care group (between-group difference, 0.4 percentage points; P = 0.58). The risks of emergency department visits, readmissions, cardiovascular events, dialysis, or death from any cause were similar in the two groups. The risk of adverse events was also similar in the trial groups, except for acute kidney injury, which was observed in more patients in the intervention group (12.7% vs. 11.3%). CONCLUSIONS: In this pragmatic trial involving patients with the triad of chronic kidney disease, type 2 diabetes, and hypertension, the use of an EHR-based algorithm and practice facilitators embedded in primary care clinics did not translate into reduced hospitalization at 1 year. (Funded by the National Institutes of Health and others; ICD-Pieces ClinicalTrials.gov number, NCT02587936.).

Predicting renal function response to renal artery stenting.

OBJECTIVE: The Cardiovascular Outcomes in Renal Atherosclerotic Lesions Trial found no benefit of renal artery stenting (RAS) over medical therapy, although it was underpowered to detect a benefit among patients with chronic kidney disease (CKD). A post hoc analysis demonstrated improved event-free survival after RAS for patients whose renal function improved by 20% or more. A significant obstacle to achieving this benefit is the inability to predict which patients' renal function will improve from RAS. The objectives of the current study were to identify predictors of renal function response to RAS. METHODS: The Veteran Affairs Corporate Data Warehouse was queried for patients who underwent RAS between 2000 and 2021. The primary outcome was improvement in renal function (estimated glomerular filtration rate [eGFR]) after stenting. Patients were categorized as responders if the eGFR at 30 days or greater after stenting increased by 20% or more compared with before stenting. All others were nonresponders. RESULTS: The study cohort included 695 patients with a median follow-up of 7.1 years (interquartile range, 3.7-11.6 years). Based on postoperative change in eGFR, 202 stented patients (29.1%) were responders, and the remainder (n = 493 [70.9%]) were nonresponders. Before RAS, responders had a significantly higher mean serum creatinine, lower mean eGFR, and higher rate of decline of preoperative GFR in the months before stenting. After stenting, responders had a 26.1% increase in eGFR, compared with before stenting (P < .0001), which remained stable during follow-up. In contrast, nonresponders had a progressive 5.5% decrease in eGFR after stenting. Logistic regression analysis identified three predictors of renal function response to stenting: (1) diabetes (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.44-0.91; P = .013), (2) CKD stages 3b or 4 (OR, 1.80; 95% CI, 1.26-2.57; P = .001), and (3) rate of decline in preoperative eGFR per week before stenting (OR, 1.21; 95% CI, 1.05-1.39; P = .008). CKD stages 3b and 4 and the rate of decline in preoperative eGFR are positive predictors of renal function response to stenting, whereas diabetes is a negative predictor. CONCLUSIONS: Based on our data, patients in CKD stages 3b and 4 (eGFR 15-44 mL/min/1.73 m2) are the only subgroups with a significant probability of improved renal function after RAS. The rate of decline of preoperative eGFR over the months before stenting is a powerful discriminator of patients who are most likely to benefit from RAS. Specifically, patients with a more rapid decrease in eGFR before stenting have a significantly greater probability of improved renal function with RAS. In contrast, diabetes is a negative predictor of improved renal function, so interventionalists should be circumspect about RAS in diabetic patients.

Experimental and theoretical investigation of waveguided plasmonic surface lattice resonances.

Plasmonic nanostructures are good candidates for refractive index sensing applications through the surface plasmon resonance due to their strong dependence on the surrounding dielectric media. However, typically low quality-factor limits their application in sensing devices. To improve the quality-factor, we have experimentally and theoretically investigated two-dimensional gold nanoparticle gratings situated on top of a waveguide. The coupling between the localized surface plasmon and waveguide modes results in Fano-type resonances, with high quality-factors, very similar to plasmonic surface lattice resonances. By combining plasmonic surface lattice resonance and waveguide theory, we present a theoretical framework describing the structures. By immersing the fabricated samples in three different media we find a sensitivity of ∼50 nm/RIU and figure of merit of 8.9, and demonstrate good agreement with the theory presented. Further analysis show that the sensitivity is very dependent on the waveguide parameters, grating constant and the dielectric environment, and by tuning these parameters we obtain a theoretical sensitivity of 887 nm/RIU.

Photon-counting MCP/Timepix detectors for soft X-ray imaging and spectroscopic applications.

Detectors with microchannel plates (MCPs) provide unique capabilities to detect single photons with high spatial (<10 µm) and timing (<25 ps) resolution. Although this detection technology was originally developed for applications with low event rates, recent progress in readout electronics has enabled their operation at substantially higher rates by simultaneous detection of multiple particles. In this study, the potential use of MCP detectors with Timepix readout for soft X-ray imaging and spectroscopic applications where the position and time of each photon needs to be recorded is investigated. The proof-of-principle experiments conducted at the Advanced Light Source demonstrate the capabilities of MCP/Timepix detectors to operate at relatively high input counting rates, paving the way for the application of these detectors in resonance inelastic X-ray scattering and X-ray photon correlation spectroscopy (XPCS) applications. Local count rate saturation was investigated for the MCP/Timepix detector, which requires optimization of acquisition parameters for a specific scattering pattern. A single photon cluster analysis algorithm was developed to eliminate the charge spreading effects in the detector and increase the spatial resolution to subpixel values. Results of these experiments will guide the ongoing development of future MCP devices optimized for soft X-ray photon-counting applications, which should enable XPCS dynamics measurements down to sub-microsecond timescales.

Effect of silica-core gold-shell nanoparticles on the kinetics of biohydrogen production and pollutant hydrogenation via organic acid photofermentation over enhanced near-infrared illumination.

A biological photoinduced fermentation process provides an alternative to traditional hydrogen productions. In this study, biohydrogen production was investigated at near IR region coupled to a near-field enhancement by silica-core gold-shell nanoparticles (NPs) over a range of acetate concentrations (5-40 mM) and light intensities (11-160 W/m2). The kinetic data were modeled using modified Monod equations containing light intensity effects. The yields of H2 and CO2 produced per acetate were determined as 2.31 mol-H2/mol-Ac and 0.83 mol-CO2/mol-Ac and increased to 4.38 mmol-H2/mmol-Ma and 2.62 mmol-CO2/mmol-Ma when malate was used. Maximum increases in H2 and CO2 productions by 115% and 113% were observed by adding NPs without affecting the bacterial growth rates (6.1-8.2 mg-DCM/L/hour) while the highest hydrogen production rate was determined as 0.81 mmol/L/hour. Model simulations showed that the energy conversion efficiency increased with NPs concentration but decreased with the intensity. Complete hydrogenation application was demonstrated with toxic 2-chlorobiphenyl using Pd catalysts.

The effect of lifelong endurance exercise on cardiovascular structure and exercise function in women.

KEY POINTS: The beneficial effects of sustained or lifelong (>25 years) endurance exercise on cardiovascular structure and exercise function have been largely established in men. The current findings indicate that committed (≥4 weekly exercise sessions) lifelong exercise results in substantial benefits in exercise capacity ( V̇O2max ), cardiovascular function at submaximal and maximal exercise, left ventricular mass and compliance, and blood volume compared to similarly aged or even younger (middle-age) untrained women. Endurance exercise training should be considered a key strategy to prevent cardiovascular disease with ageing in women as well as men. ABSTRACT: This study was a retrospective, cross-sectional analysis of exercise performance and left ventricular (LV) morphology in 70 women to examine whether women who have performed regular, lifelong endurance exercise acquire the same beneficial adaptations in cardiovascular structure and function and exercise performance that have been reported previously in men. Three groups of women were examined: (1) 35 older (>60 years) untrained women (older untrained, OU), (2) 13 older women who had consistently performed four or more endurance exercise sessions weekly for at least 25 years (older trained, OT), and (3) 22 middle-aged (range 35-59 years) untrained women (middle-aged untrained, MU) as a reference control for the appropriate age-related changes. Oxygen uptake ( V̇O2 ) and cardiovascular function (cardiac output ( Q̇ ); stroke volume (SV) acetylene rebreathing) were examined at rest, steady-state submaximal exercise and maximal exercise (maximal oxygen uptake, V̇O2max ). Blood volume (CO rebreathing) and LV mass (cardiac magnetic resonance imaging), plus invasive measures of static and dynamic chamber compliance were also examined. V̇O2max (p < 0.001) and maximal exercise Q̇ and SV were larger in older trained women compared to the two untrained groups (∼17% and ∼27% for Q̇ and SV, respectively, versus MU; ∼40% and ∼38% versus OU, all p < 0.001). Blood volume (mL kg-1 ) and LV mass index (g m-2 ) were larger in OT versus OU (∼11% and ∼16%, respectively, both P ≤ 0.015) Static LV chamber compliance was greater in OT compared to both untrained groups (median (25-75%): MU: 0.065 (0.049-0.080); OU: 0.085 (0.061-0.138); OT: 0.047 (0.031-0.054), P ≤ 0.053). Collectively, these findings indicate that lifetime endurance exercise appears to be extremely effective at preserving or even enhancing cardiovascular structure and function with advanced age in women.

Impact of Prolonged Spaceflight on Orthostatic Tolerance During Ambulation and Blood Pressure Profiles in Astronauts.

BACKGROUND: Astronauts returning to earth usually demonstrate reduced orthostatic tolerance when assessed on a tilt table or quiet standing, but no studies have evaluated postflight orthostatic tolerance during activities of daily living, when it is most clinically relevant. Ambulatory blood pressure (BP) variability also is associated with orthostatic intolerance in certain patient populations and can capture clinically significant orthostatic hypotension during activities of daily living, especially when measured on a beat-to-beat basis. We evaluated the impact of prolonged spaceflight on orthostatic tolerance and BP profiles in astronauts. METHODS: Ambulatory beat-to-beat BP was recorded using a portable device for multiple 24-hour time periods before, during, and after 6 months of spaceflight in 12 astronauts (4 women; age 48±5 [mean±SD] years). BP variability in the time domain was calculated as the SD. Systolic BP distribution during activities of daily living was characterized by skewness and kurtosis. RESULTS: In contrast with results from previous studies that used tilt tables or stand tests, no astronaut experienced orthostatic intolerance/hypotension during activities of daily living before or after spaceflight. Also, 24-hour systolic BP decreased in space (120±10 mm Hg before spaceflight versus 106±9 mm Hg during spaceflight; P<0.01), but it returned to normal upon landing (122±13 mm Hg). Diastolic BP was unchanged during and after spaceflight. Systolic and diastolic BP variability remained the same before, during, and after spaceflight (both P>0.05). The skewness of systolic BP increased in space (0.74±0.51 versus 1.43±1.00; P=0.001), indicating that signal fluctuations became asymmetrical; however, it returned to preflight levels after landing (0.51±0.42). The kurtosis increased in space (5.01±7.67 versus 11.10±11.79; P=0.010), suggesting that fluctuations concentrated around the mean with a narrow distribution; however, it also returned to preflight levels (2.21±2.56) after return to earth. CONCLUSIONS: Given current countermeasures including in-flight exercise training and volume resuscitation on return, no astronauts experienced orthostatic hypotension or intolerance during routine (for landing day) activities in the initial 24 hours after landing following 6 months in space. Prolonged exposure to spaceflight had little impact on systolic BP variability and its distribution, although the latter showed a transient change in space (accompanied by mild relative hypotension), all of which returned to preflight values after return to earth.

Impact of Lifelong Exercise Training Dose on Ventricular-Arterial Coupling.

BACKGROUND: The dynamic Starling mechanism, as assessed by beat-by-beat changes in stroke volume and left ventricular end-diastolic pressure, reflects ventricular-arterial coupling. It deteriorates with age, and is preserved in highly trained masters athletes. Currently, it remains unclear how much exercise over a lifetime is necessary to preserve efficient ventricular-arterial coupling. The purpose of this study was to assess the dose-dependent relationship between lifelong exercise training and the dynamic Starling mechanism in healthy seniors. METHODS: One hundred two seniors were recruited and stratified into 4 groups based on 25 years of exercise training history: sedentary subjects (n=27, <2 sessions/week), casual exercisers (n=25, 2-3 sessions/week), committed exercisers (n=25, 4-5 sessions/week), and competitive Masters Athletes (n=25, 6-7 sessions/week). The dynamic Starling mechanism was estimated by transfer function gain between beat-by-beat changes in diastolic pulmonary artery pressure, a surrogate for left ventricular end-diastolic pressure, and stroke volume index. RESULTS: The transfer function gain of pulmonary artery pressure-stroke volume index was markedly enhanced in committed and competitive exercisers compared with more sedentary seniors and correlated with higher peak oxygen uptake (Vo2) and lower left ventricular stiffness. The power spectral density of pulmonary artery pressure was greater in sedentary adults than in committed and competitive exercisers, whereas the power spectral density of stroke volume index was greater in competitive exercisers than in the other groups. CONCLUSIONS: There is a graded, dose-dependent improvement in ventricular-arterial coupling with increasing amounts of lifelong regular exercise in healthy older individuals. Our data suggest that the optimal dose of lifelong endurance exercise to preserve ventricular-arterial coupling with age appears to be at least 4 to 5 sessions per week.

The effect of lifelong exercise frequency on arterial stiffness.

KEY POINTS: This study examined the effect of different 'doses' of lifelong (>25 years) exercise on arterial stiffening (a hallmark of vascular ageing) in older adults. There are clear dose-dependent effects of lifelong exercise training on human arterial stiffness that vary according to the site and size of the arteries. Similar to what we have observed previously with ventricular stiffening, 4-5 days week-1 of committed exercise over a lifetime are necessary to preserve 'youthful' vascular compliance, especially of the large central arteries. Casual exercise training of two to three times per week may be sufficient for middle-sized arteries like the carotid to minimize arterial stiffening with ageing. However, there is little effect of exercise training on the small-sized peripheral arteries at any dose. ABSTRACT: Central arterial stiffness increases with sedentary ageing. While near-daily, vigorous lifelong (>25 years) endurance exercise training prevents arterial stiffening with ageing, this rigorous routine of exercise training over a lifetime is impractical for most individuals. The aim was to examine whether a less frequent 'dose' of lifelong exercise training (four to five sessions per week for > 30 min) that is consistent with current physical activity recommendations elicits similar benefits on central arterial stiffening with ageing. A cross-sectional examination of 102 seniors (>60 years old) who had a consistent lifelong exercise history was performed. Subjects were stratified into four groups based on exercise frequency as an index of exercise 'dose': sedentary: fewer than two sessions per week; casual exercisers: two to three sessions per week; committed exercisers: four to five sessions per week; and Masters athletes: six to seven sessions per week plus regular competitions. Detailed measurements of arterial stiffness and left ventricular afterload were collected. Biological aortic age and central pulse wave velocity were younger in committed exercisers and Masters athletes compared to sedentary seniors. Total arterial compliance index (TACi) was lower, while carotid ß-stiffness index and effective arterial elastance were higher in sedentary seniors compared to the other groups. There appeared to be a dose-response threshold for carotid ß-stiffness index and TACi. Peripheral arterial stiffness was not significantly different among the groups. These data suggest that four to five weekly exercise sessions over a lifetime is associated with reduced central arterial stiffness in the elderly. A less frequent dose of lifelong exercise (two to three sessions per week) is associated with decreased ventricular afterload and peripheral resistance, while peripheral arterial stiffness is unaffected by any dose of exercise.

Frequency of Adequate Endometrial Biopsy in Evaluation of Postmenopausal Women With Benign Endometrial Cells on Pap Test.

OBJECTIVE: The aim of the study was to determine the frequency that endometrial biopsies (EMBs) performed on postmenopausal (PMP) women with benign endometrial cells (BECs) on Pap test are adequate for assessing malignancy or hyperplasia. METHODS: This is a case series including all PMP women older than 55 years at a single academic institution between January 2008 and September 2015 with a Pap test result including BEC. Patients were identified via an internal cytology database. Patient data, the ability to obtain an EMB, and the result of the EMB were collected. An adequate EMB was defined as the presence of glands and stroma sufficient to assess for endometrial hyperplasia and/or malignancy. Descriptive statistics were performed, and then univariable and logistic regression analyses were used to evaluate associations of patient factors and adequacy of EMB. RESULTS: One hundred sixteen women met inclusion criteria. One hundred seven had an EMB scheduled (92%) and of those 91 EMBs were obtained (85%). Of the obtained biopsies, 63 were inadequate to rule out the diagnosis of hyperplasia and/or malignancy (69%). Of these, 19 patients underwent pelvic ultrasound (30%), 12 followed up with repeat Pap test (19%), and 4 underwent dilation and curettage (6%). Of the adequate biopsies, 5 had a diagnosis of hyperplasia (18%) and 5 with malignancy (18%). CONCLUSIONS: In PMP women with BEC on Pap test, adequate EMB was only obtained in 31% of patients. Most patients without an adequate biopsy had no further workup of their abnormal Pap test.

Long-term outcomes with first- vs. second-generation drug-eluting stents in saphenous vein graft lesions.

BACKGROUND: As compared with bare metal stents, first-generation drug-eluting stents (DES) improved post-procedural outcomes in aortocoronary saphenous vein graft (SVG) lesions, but there is limited information on outcomes after use of second-generation DES in SVGs. METHODS: We compared the outcomes of patients who received first- (n = 81) with those who received second-generation (n = 166) DES in SVG lesions at our institution between 2006 and 2013. Major adverse cardiac events (MACE) were defined as the composite of all-cause death, myocardial infarction, and target vessel revascularization. RESULTS: Mean age was 66.0 ± 8.1 years and 97.6% of the patients were men. Mean SVG age was 11.1 ± 0.4 years. First-generation DES were sirolimus-eluting (n = 17) and paclitaxel-eluting (n = 64) stents. Second-generation DES were everolimus-eluting (n = 115) and zotarolimus-eluting (n = 51) stents. Median follow-up was 41 months. At 2-years post-procedure, patients with first- and second-generation DES had similar rates of death (20.91% vs. 20.27%, P = 0.916), target lesion revascularization (16.39% vs. 20.00%, P = 0.572), target vessel revascularization (20.97% vs. 23.16%, P = 0.747), myocardial infarction (26.15% vs. 23.00%, P = 0.644), and MACE (43.5% vs. 40.87%, P = 0.707), respectively. CONCLUSIONS: Outcomes with first- and second-generation DES in SVGs are similar. Novel stent designs are needed to further improve the clinical outcomes in this challenging patient and lesion subgroup. © 2015 Wiley Periodicals, Inc.

Transient Ischemic Dilatation during Stress Echocardiography: An Additional Marker of Significant Myocardial Ischemia.

AIM: Left ventricular (LV) transient ischemic dilatation (TID) is not clear how it relates to inducible myocardial ischemia during stress echocardiography (SE). METHODS AND RESULTS: Eighty-eight SEs were examined from the site certification phase of the ISCHEMIA Trial. LV end-diastolic volume (EDV) and end-systolic volume (ESV) were measured at rest and peak stages and the percent change calculated. Moderate or greater ischemia was defined as ≥3 segments with stress-induced severe hypokinesis or akinesis. Optimum cut points in stress-induced percent EDV and ESV change that identified moderate or greater myocardial ischemia were analyzed. Analysis from percentage distribution identified a > 13% LV volume increase in EDV or a > 9% LV volume increase in ESV as the optimum cutoff points for moderate or greater ischemia. Using these definitions for TID, there were 27 (31%) with TIDESV and 12 (14%) with TIDEDV . By logistic regression analysis and receiver operating characteristic curves, the percent change in ESV had a stronger association with moderate or greater myocardial ischemia than that of EDV change. Compared to those without TIDESV , cases with TIDESV had larger extent of inducible wall-motion abnormalities, lower peak stress LVEF, and higher likelihood of moderate or grater ischemia. For moderate or greater myocardial ischemia detection, TIDESV had a sensitivity of 46%, specificity of 83%, positive predictive value of 70%, and negative predictive value of 64%. CONCLUSION: Transient ischemic dilatation by SE is a marker of extensive myocardial ischemia and can be used as an additional marker of higher risk.

Hemodynamic responses to rapid saline loading: the impact of age, sex, and heart failure.

BACKGROUND: Hemodynamic assessment after volume challenge has been proposed as a way to identify heart failure with preserved ejection fraction. However, the normal hemodynamic response to a volume challenge and how age and sex affect this relationship remain unknown. METHODS AND RESULTS: Sixty healthy subjects underwent right heart catheterization to measure age- and sex-related normative responses of pulmonary capillary wedge pressure and mean pulmonary arterial pressure to volume loading with rapid saline infusion (100-200 mL/min). Hemodynamic responses to saline infusion in heart failure with preserved ejection fraction (n=11) were then compared with those of healthy young (<50 years of age) and older (≥50 years of age) subjects. In healthy subjects, pulmonary capillary wedge pressure increased from 10±2 to 16±3 mm Hg after ~1 L and to 20±3 mm Hg after ~2 L of saline infusion. Older women displayed a steeper increase in pulmonary capillary wedge pressure relative to volume infused (16±4 mm Hg·L(-1)·m(2)) than the other 3 groups (P≤0.019). Saline infusion resulted in a greater increase in mean pulmonary arterial pressure relative to cardiac output in women compared with men regardless of age. Subjects with heart failure with preserved ejection fraction exhibited a steeper increase in pulmonary capillary wedge pressure relative to infused volume (25±12 mm Hg·L(-1)·m(2)) than healthy young and older subjects (P≤0.005). CONCLUSIONS: Filling pressures rise significantly with volume loading, even in healthy volunteers. Older women and patients with heart failure with preserved ejection fraction exhibit the largest increases in pulmonary capillary wedge pressure and mean pulmonary arterial pressure.

Forehead versus forearm skin vascular responses at presyncope in humans.

Facial pallor is commonly observed at presyncope in humans, suggestive of reductions in facial skin blood flow (SkBF). Yet, cutaneous vasoconstriction is usually minimal at presyncope when measured at the forearm. We tested the hypothesis that reductions in forehead SkBF at presyncope are greater than in the forearm. Forehead and forearm SkBF (laser-Doppler) and blood pressure (Finometer or radial artery catheterization) were measured during lower body negative pressure (LBNP) to presyncope in 11 normothermic and 13 heat-stressed subjects (intestinal temperature increased ∼1.4°C). LBNP reduced mean arterial pressure from 91 ± 5 to 57 ± 7 mmHg during normothermia (P ≤ 0.001) and from 82 ± 5 to 57 ± 7 mmHg during heat stress (P ≤ 0.001). During normothermia, LBNP decreased forehead SkBF 55 ± 14% compared with 24 ± 11% at the forearm (P = 0.002), while during heat stress LBNP decreased forehead SkBF 39 ± 11% compared with 28 ± 8% in the forearm (P = 0.007). In both conditions, most (≥68%) of the decreases in SkBF were due to decreases in blood pressure. However, a greater contribution of actively mediated reductions in SkBF was observed at the forehead, relative to the forearm during normothermia (32 ± 13% vs. 11 ± 11%, P = 0.031) and heat stress (30 ± 13% vs. 10 ± 13%, P = 0.004). These data suggest that facial pallor at presyncope is due to a combination of passive decreases in forehead SkBF secondary to reductions in blood pressure and to active decreases in SkBF, the latter of which are relatively greater than in the forearm.

Low molecular weight dextran provides similar optical coherence tomography coronary imaging compared to radiographic contrast media.

BACKGROUND: Optical coherence tomography (OCT) coronary imaging requires displacement of red blood cells from the vessel lumen. This is usually accomplished using radiographic contrast. Low molecular weight dextran has low cost and is safe in low volumes. In the present study, we compared dextran with contrast for coronary OCT imaging. METHODS: Fifty-one vessels in 26 patients were sequentially imaged using manual injection of radiographic contrast (iodixanol) and dextran. OCT images were analyzed at 1 mm intervals to determine the image clarity (defined as a visible lumen border > 270°) and to measure the lumen area and lumen diameter. To correct for the refractive index of dextran, the dextran area measurements were multiplied by 1.117 and the dextran length measurements were multiplied by 1.057. RESULTS: A total of 3,418 cross-sections (1,709 with contrast and 1,709 with dextran) were analyzed. There were no complications related to OCT imaging or to contrast or dextran administration. Clear image segments were observed in 97.0% vs. 96.7% of the cross-sections obtained with contrast and dextran, respectively (P = 0.45). The mean lumen areas were also similar: 6.69 ± 1.95 mm(2) with iodixanol vs. 7.06 ± 2.06 mm(2) with dextran (correlation coefficient 0.984). CONCLUSIONS: The image quality and measurements during OCT image acquisition are similar for dextran and contrast. Dextran could be used instead of contrast for OCT imaging, especially in patients in whom contrast load minimization is desired.

Prevalence and management of coronary chronic total occlusions in a tertiary Veterans Affairs hospital.

OBJECTIVES: We sought to determine the contemporary prevalence and management of coronary chronic total occlusions (CTO) in a veteran population. BACKGROUND: The prevalence and management of CTOs in various populations has received limited study. METHODS: We collected clinical and angiographic data in consecutive patients that underwent coronary angiography at our institution between January 2011 and December 2012. Coronary artery disease (CAD) was defined as ≥50% diameter stenosis in ≥1 coronary artery. CTO was defined as total coronary artery occlusion of ≥3 month duration. RESULTS: Among 1,699 patients who underwent angiography during the study period, 20% did not have CAD, 20% had CAD and prior coronary artery bypass graft surgery (CABG), and 60% had CAD but no prior CABG. The prevalence of CTO among CAD patients with and without prior CABG was 89 and 31%, respectively. Compared to patients without CTO, CTO patients had more co-morbidities, more extensive CAD and were more frequently referred for CABG. Percutaneous coronary intervention (PCI) to any vessel was performed with similar frequency in patients with and without CTO (50% vs. 53%). CTO PCI was performed in 30% of patients without and 15% of patients with prior CABG with high technical (82 and 75%, respectively) and procedural success rates (80 and 73%, respectively). CONCLUSIONS: In a contemporary veteran population, coronary CTOs are highly prevalent and are associated with more extensive co-morbidities and higher likelihood for CABG referral. PCI was equally likely to be performed in patients with and without CTO.

Plaque regression and progenitor cell mobilization with intensive lipid elimination regimen (PREMIER) trial design.

Progression of lipid rich necrotic core elements of atherosclerotic vulnerable plaque (VP) or its rupture leads to a majority of cardiovascular events. Endothelial progenitor cells (EPC) contribute to vascular healing and play a crucial role in repair following ischemic injury primarily by endothelialization of VP and neovascularization of ischemic myocardium. We present the rationale and design of the Plaque Regression and Progenitor Cell Mobilization with Intensive Lipid Elimination Regimen or the PREMIER Trial, which is designed to address the question for the very first time whether a highly intensive low-density lipoprotein (LDL)-lowering therapy with LDL-apheresis could lead to a more rapid and detectable reduction in coronary atheroma volume, along with a robust mobilization of EPC compared to standard statin therapy, in patients selected for percutaneous coronary intervention for an acute coronary syndrome.

Risk factors for preeclampsia in twin pregnancies.

OBJECTIVE: Twin pregnancy is associated with an increased incidence of preeclampsia. However, it is unknown if the risk factors for preeclampsia in twin pregnancies are the same as those in singleton pregnancies. METHODS: Case-control analysis of all twin pregnancies managed by one maternal-fetal medicine practice from 2005 to 2012. Patients with chronic hypertension were excluded, as were monochorionic-monoamniotic twins. We compared patient and pregnancy characteristics between patients who did and did not develop preeclampsia, according to standard American College of Obstetricians and Gynecologists definitions. Odds ratios, adjusted odds ratios (aORs), and 95% confidence intervals (CIs) were obtained using chi-square analysis and logistic regression. RESULTS: Of the patients with twin pregnancies, 513 were included, and 76 (14.8%) patients developed preeclampsia. On univariable analysis, the risk factors associated with preeclampsia in twin pregnancies were egg donation, nonwhite race, nulliparity, prepregnancy obesity, and gestational diabetes. On adjusted analysis, the risk factors independently associated with preeclampsia were egg donation (aOR 2.409, 95% CI 1.051, 5.524) and prepregnancy obesity (aOR 2.367, 95% CI 1.079, 5.192). CONCLUSIONS: In twin pregnancy, the risk factors independently associated with preeclampsia are egg donation and prepregnancy obesity.

Liquid phase electron-beam-induced deposition on bulk substrates using environmental scanning electron microscopy.

The introduction of gases, such as water vapor, into an environmental scanning electron microscope is common practice to assist in the imaging of insulating or biological materials. However, this capability may also be exploited to introduce, or form, liquid phase precursors for electron-beam-induced deposition. In this work, the authors report the deposition of silver (Ag) and copper (Cu) structures using two different cell-less in situ deposition methods--the first involving the in situ hydration of solid precursors and the second involving the insertion of liquid droplets using a capillary style liquid injection system. Critically, the inclusion of surfactants is shown to drastically improve pattern replication without diminishing the purity of the metal deposits. Surfactants are estimated to reduce the droplet contact angle to below ~10°.

The effect of exercise training on left ventricular relaxation and diastolic suction at rest and during orthostatic stress after bed rest.

A marked reduction in upright stroke volume (SV) contributes substantially to orthostatic intolerance after exposure to spaceflight or bed rest. It is unclear whether slowed left ventricular (LV) relaxation and diastolic suction contribute to the reduction in SV or whether these changes are influenced by exercise training while in bed. Twenty-seven healthy adults completed 5 weeks of -6 deg head-down bed rest (HDBR). During HDBR, nine subjects were sedentary (NOEX), while 18 performed near-daily rowing ergometry (EX). Left ventricular mass, SV, LV end-diastolic volume (LVEDV), pulmonary capillary wedge pressure and Doppler ultrasound indices of LV function were collected pre- and post-HDBR during supine rest (twice) and during reduced LV loading (lower body negative pressure; LBNP) and increased LV loading (saline infusion). Post-HDBR, LV mass increased in the EX group, but decreased in the NOEX group. The reduction in SV and LVEDV during supine rest and LBNP were greater with NOEX in comparison to EX after HDBR. Peak early mitral annular velocity, isovolumic relaxation time, early propagation velocity, a non-invasive index of early diastolic filling and ventricular diastolic suction, and peak global longitudinal early strain rate were slowed during supine rest after HDBR with NOEX; however, these variables were either unaltered or the reduction was less prominent with EX. Doppler ultrasound measures of early diastolic filling, ventricular relaxation and diastolic suction were not significantly affected during LV unloading by LBNP after HDBR in either group. All Doppler indices were restored to pre-HDBR levels in both groups during saline infusion to normalize LV filling pressure after HDBR. It is concluded that Doppler indices of dynamic LV filling were reduced in both groups after HDBR; however, these effects were more pronounced in the NOEX group. Irrespective of group, post-HDBR Doppler parameters were restored when LV filling pressure was increased to pre-HDBR levels during saline infusion. Therefore, the reduction in upright SV after HDBR is more influenced by changes in LV loading conditions, namely left atrial pressure in the setting of LV remodelling, rather than ventricular relaxation and diastolic suction.