Polymyxin B hemoperfusion in endotoxemic septic shock patients without extreme endotoxemia: a post hoc analysis of the EUPHRATES trial

PURPOSE

The EUPHRATES trial examined the impact of polymyxin B hemoperfusion (PMX) on mortality in patients with septic shock and endotoxemia, defined as EAA ≥ 0.60. No difference was found in 28-day all-cause mortality. However, the trial showed that in some patients with septic shock the burden of endotoxin activity was extreme (EAA ≥ 0.9). In a post hoc analysis, we evaluated the impact of PMX use in patients with septic shock and endotoxin activity measured between 0.6-0.89.

METHODS

Post-hoc analysis of the EUPHRATES trial for the 194 patients with EAA ≥ 0.6-0.89 who completed two treatments (PMX or sham). The primary end point was mortality at 28 days adjusted for APACHE II score and baseline mean arterial pressure (MAP). Additional end points included changes in MAP, cumulative vasopressor index (CVI), median EAA reduction, ventilator-free days (VFD), dialysis-free days (DFD) and hospital length of stay. Subpopulations analyzed were site and type of infection and those with norepinephrine dose > 0.1 mcg/kg/min at baseline.

RESULTS

At 28 days, 23 patients of 88 (26.1%) in the PMX group died versus 39 of 106 (36.8%) in the sham group [risk difference 10.7%, OR 0.52, 95% CI (0.27, 0.99), P = 0.047]. When unadjusted for baseline variables, P = 0.11. The 28-day survival time in the PMX group was longer than for the sham group [HR 0.56 (95% CI 0.33, 0.95) P = 0.03]. PMX treatment compared with sham showed greater change in MAP [median (IQR) 8 mmHg (- 0.5, 19.5) vs. 4 mmHg (- 4.0, 11) P = 0.04] and VFD [median (IQR) 20 days (0.5, 23.5) vs. 6 days (0, 20), P = 0.004]. There were no significant differences in other end points. There was a significant difference in mortality in PMX-treated patients with no bacterial growth on culture [PMX, 6/30 (20%) vs. sham, 13/31 (41.9%), P = 0.005]. The median EAA change in the population was - 12.9% (range: increase 49.2%-reduction 86.3%). The mortality in the above median EAA change group was PMX: 6/38 (15.7%) vs. sham 15/49 (30.6%), P = 0.08.

CONCLUSIONS

These hypothesis-generating results, based on an exploratory post hoc analysis of the EUPHRATES trial, suggest measurable responses in patients with septic shock and an EAA ≥ 0.6 to 0.89 on changes in mean arterial pressure, ventilator-free days and mortality.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT01046669. Funding Spectral Medical Incorporated.

Crossover between liquidlike and gaslike behavior in CH_{4} at 400 K

We report experimental evidence for a crossover between a liquidlike state and a gaslike state in fluid methane (CH_{4}). This crossover is observed in all of our experiments, up to a temperature of 397 K, 2.1 times the critical temperature of methane. The crossover has been characterized with both Raman spectroscopy and x-ray diffraction in a number of separate experiments, and confirmed to be reversible. We associate this crossover with the Frenkel line-a recently hypothesized crossover in dynamic properties of fluids extending to arbitrarily high pressure and temperature, dividing the phase diagram into separate regions where the fluid possesses liquidlike and gaslike properties. On the liquidlike side the Raman-active vibration increases in frequency linearly as pressure is increased, as expected due to the repulsive interaction between adjacent molecules. On the gaslike side this competes with the attractive van der Waals potential leading the vibration frequency to decrease as pressure is increased.

Abstract P119: Hypertension Trends in Florida Stroke Patients. The Florida Puerto Rico Collaboration to Reduce Stroke Disparities

Aim: To describe hypertension prevalence (HTN) in a race diverse stroke registry and investigate associated presentation in patients admitted for acute ischemic stroke (AIS) and hemorrhagic stroke in Florida hospitals participating in the Florida Collaboration to Reduce Stroke Disparities (CReSD).

Background: HTN affects about 30% of U.S. adults and this prevalence doubles among stroke survivors. HTN is a major risk factor for incident stoke and recurrent stroke. Quantifying the prevalence of HTN in stroke survivors is important to guide secondary stroke prevention.

Methods: 121,333 stroke cases were analyzed from 69 FL hospitals participating in the AHA Get With the Guidelines-Stroke Program and FL CReSD Stroke Registry. Hypertension was defined as systolic blood pressure >140mmHg. Demographics and CV risk factors were collected at admission. We investigated the differences in HTN prevalence between race groups: white (65%), black (20%) and Hispanic (15%) as well as between age groups: 18-60, 61-80 and >80 years old. Temporal trends of HTN prevalence were also analyzed from 2010 to 2016.

Results: In our stroke population, mean age was 70±15 and 60,667 were women (50%). HTN prevalence was 65% (78,553/121,333). Patients with HTN were significantly older (mean age 72±14 vs. 67±16 in non-HTN patients) and presented significantly higher prevalence of other CV risk factors such as diabetes, hyperlipidemia and had more previous stroke/TIAs. Women had greater prevalence of HTN (66% vs. 64% in males) in all age groups. Greater HTN prevalence was in blacks (70%) compared to white (64%) and Hispanics (58%) in all age groups. Interestingly, a significantly higher prevalence of HTN was found in AIS compared to hemorrhagic stroke but a higher SBP was observed in hemorrhagic strokes compared to AIS. Prevalence of HTN decreased of 8% from 2010 to 2016. Largest decline was observed among women (9%) and blacks (13%).

Conclusions: In our large Stroke Registry we observed higher prevalence of HTN in women, blacks and AIS. We also observe a decreasing trend over the past 7 years, especially among women and minorities (blacks and Hispanics). These findings provide an opportunity to design and implement interventions to reduce disparities in HTN and improve stroke outcome.

Disparities and Trends in Door-to-Needle Time: The FL-PR CReSD Study (Florida-Puerto Rico Collaboration to Reduce Stroke Disparities)

BACKGROUND AND PURPOSE

In the United States, about half of acute ischemic stroke patients treated with tPA (tissue-type plasminogen activator) receive treatment within 60 minutes of hospital arrival. We aimed to determine the proportion of patients receiving tPA within 60 minutes (door-to-needle time [DTNT] ≤60) and 45 minutes (DTNT ≤45) of hospital arrival by race/ethnicity and sex and to identify temporal trends in DTNT ≤60 and DTNT ≤45.

METHODS

Among 65 654 acute ischemic stroke admissions in the National Institute of Neurological Disorders and Stroke-funded FL-PR CReSD study (Florida-Puerto Rico Collaboration to Reduce Stroke Disparities) from 2010 to 2015, we included 6181 intravenous tPA-treated cases (9.4%). Generalized estimating equations were used to determine predictors of DTNT ≤60 and DTNT ≤45.

RESULTS

DTNT ≤60 was achieved in 42% and DTNT ≤45 in 18% of cases. After adjustment, women less likely received DTNT ≤60 (odds ratio, 0.81; 95% confidence interval, 0.72-0.92) and DTNT ≤45 (odds ratio, 0.73; 95% confidence interval, 0.57-0.93). Compared with Whites, Blacks less likely had DTNT ≤45 during off hours (odds ratio, 0.68; 95% confidence interval, 0.47-0.98). Achievement of DTNT ≤60 and DTNT ≤45 was highest in South Florida (50%, 23%) and lowest in West Central Florida (28%, 11%).

CONCLUSIONS

In the FL-PR CReSD, achievement of DTNT ≤60 and DTNT ≤45 remains low. Compared with Whites, Blacks less likely receive tPA treatment within 45 minutes during off hours. Treatment within 60 and 45 minutes is lower in women compared with men and lowest in West Central Florida compared with other Florida regions and Puerto Rico. Further research is needed to identify reasons for delayed thrombolytic treatment in women and Blacks and factors contributing to regional disparities in DTNT.

Knotted fields and explicit fibrations for lemniscate knots

We give an explicit construction of complex maps whose nodal lines have the form of lemniscate knots. We review the properties of lemniscate knots, defined as closures of braids where all strands follow the same transverse (1, ℓ) Lissajous figure, and are therefore a subfamily of spiral knots generalizing the torus knots. We then prove that such maps exist and are in fact fibrations with appropriate choices of parameters. We describe how this may be useful in physics for creating knotted fields, in quantum mechanics, optics and generalizing to rational maps with application to the Skyrme-Faddeev model. We also prove how this construction extends to maps with weakly isolated singularities.

Abstract TP2: Disparities in Delivery of Endovascular Therapy: Who Gets it and Where? The Florida Puerto Rico Collaboration to Reduce Stroke Disparities Study

Background and Purpose: Endovascular thrombectomy improves functional outcome in select ischemic stroke patients. In the NINDS-funded CReSD Registry we sought to determine the clinical, hospital and regional characteristics associated with use of this therapy in patients presenting with acute ischemic stroke.

Methods: Ischemic stroke patients within 24 hours of onset were prospectively included from 82 sites in Florida and Puerto Rico from January 2010 to April 2016. Independent predictors of endovascular therapy were evaluated using multivariable logistic regression with generalized estimating equations.

Results: Among 58,204 patients with acute ischemic stroke (50% male, 65% white, 15% black, 20% Hispanic, mean age±SD 71±14 yrs), 2105 (3.6%) received endovascular thrombectomy (50.9% men, 62.3% white, 13.7% black, 24% Hispanic, mean age±SD 70±15yrs) with (35.2%) or without intravenous thrombolysis. Patients who received endovascular therapy had a significantly lower risk of vascular risk factors except for Afib (33.7% vs 19.0%), more severe strokes (median NIHSS 15 vs. 5) and were more likely to arrive quickly (126 min vs. 210 min), via EMS (70.4% vs. 59.6%) or as a transfer from another hospital (20.8% vs 5.8%,) during working hours (47.7% vs. 45.6%), to large hospitals (≥ 680 beds) (48.3% vs 28.8%), and treated in South Florida (47.3% vs. 35.9%) as compared to those not receiving this treatment. In multivariable analysis; age (OR 0.97, 95% CI 0.96- 0.98), Blacks (OR 0.68, 95% CI 0.56-2.28) vs. White, off-hour presentation (OR 0.76, 95% CI 0.66- 0.96), to regions other than South Florida (North OR 0.40, 95% CI 0.17-0.93, Panhandle OR 0.12, 95% CI 0.04-0.36) remained independently associated with lower use of endovascular therapy. In contrast, Hispanics (OR 1.28, 95% CI 1.03- 1.69) vs. White and presenting to large hospital (OR 4.92, 95% CI 1.05- to 22.6) were associated with higher use of endovascular treatment.

Conclusions: There are significant race, regional and hospital disparities in delivery of endovascular care. Efforts should me made to improve access to endovascular treatment in patients presenting across the region to all stroke centers.

Abstract TMP81: Regional, Race-Ethnic and Sex Disparities in Lifestyle Interventions: Data from the Florida Puerto Rico Collaboration to Reduce Stroke Disparities (FL-PR CReSD) Study - the NINDS Stroke Prevention Intervention Research Program

Background: As key components of the AHA Life’s Simple 7 campaign, lifestyle modifications play an integral role in the prevention of vascular disease. Little is known about the prevalence of lifestyle modification counseling in patients with acute ischemic stroke (AIS). We sought to investigate disparities in the delivery of lifestyle interventions to AIS patients in the large NINDS-funded FL-PR CReSD Registry of Get With The Guidelines-Stroke (GWTG-S) data.

Methods: GWTG-S collects data on the provision of several lifestyle interventions including counseling on exercise/weight loss, Therapeutic Lifestyle Changes (TLC) diet, diabetes (DM) education and antihypertensive (low sodium) diet. 80,598 AIS cases were prospectively included from 82 sites (69 FL; 13 PR) from 2010-2016. Multilevel logistic regression models adjusted for age, race, and aphasia were used to evaluate differences in the provision of lifestyle interventions as indicated for patients prior to hospital discharge.

Results: Among AIS cases, 51% were men, 62% non-Hispanic White (NHW), 18% NH-Black (NHB), 13% FL-Hispanic (FLH), and 6% PR-Hispanic (PRH). Mean age was 71±14 years. The highest mean BMI was in PRH (29±7 kg/m 2 ), with the lowest in NHW (27±6 kg/m 2 ) and FLH (28±6 kg/m 2 ). Despite this, PRH were less likely to receive exercise/weight loss counseling compared to NHW (OR 0.43, 95% CI 0.20-0.90) and FLH (OR 0.46, 95% CI 0.22-0.97). PRH also had lower odds of receiving TLC diet counseling compared to NHW and FLH (OR 0.32, 95% CI 0.15-0.68). Though NHB presented with higher rates of DM compared to NHW (38% vs. 25%), they were less likely to receive DM education (OR 0.95, 95% CI 0.91-0.99). Women were less likely to receive TLC diet counseling (OR 0.94, 95% CI 0.90-0.98) and DM education (OR 0.94, CI 0.92-0.97) compared to men. Despite higher HTN frequency in women and NHB (67% and 69%), both were less likely to receive low sodium diet recommendations as compared to men (OR 0.94, 95% CI 0.92-0.97) and NHW (OR 0.95, 95% CI 0.91-0.99).

Conclusion: Overall, disparities were identified in the provision of several lifestyle interventions in AIS patients. These interventions can benefit all and providers should continue counseling patients regarding modifiable risk factors to prevent future stroke.

Abstract 89: Differences in Acute Stroke Care in Primary and Comprehensive Stroke Centers in Florida: An Analysis of the Florida-Puerto Rico Collaboration to Reduce Stroke Disparities (FL-PR CReSD) Study- the NINDS Stroke Prevention Intervention Research Program

Introduction: Primary stroke center (PSC) and comprehensive stroke center (CSC) designation in Florida aims to improve delivery of care and outcomes for stroke patients. In line with the goals of the NINDS funded Florida-Puerto Rico Collaboration to Reduce Stroke Disparities (FL-PR CReSD) Study, we sought to compare ischemic stroke performance metrics by stroke center designation in participating Florida hospitals.

Methods: We analyzed 74,623 cases with acute ischemic stroke from 26 CSC and 40 PSC from January 2010-April 2016. We described patient demographics, comorbidities and Get With The Guidelines-Stroke performance metrics of defect free care (compliance with 7 pre-defined performance core measures), door to CT time (DTCT) ≤25 mins and door to needle time (DTN) ≤60 mins.

Results: Compared with PSC patients, CSC patients were younger (70 ± 15 vs. 71 ± 14 years, p<.0001), more likely male (51% vs. 50%, p=.0008), more likely Hispanic (17% vs. 10%, p<.0001) and Black (21% vs. 17%, p<.0001), had more severe strokes (NIHSS median 5 (IQR 2-12) vs. 4 (IQR 1-9); NIHSS ≥16, 12% vs. 9%, p <.0001), were more likely to have atrial fibrillation (19% vs. 17%, p<.0001), and were more likely to arrive by EMS (55% vs. 46%, p<.0001). CSC cases were more likely to have faster DTCT (44 vs. 48 mins, p=.0124 ; < 25 mins 33% vs. 31%, p<.0001). More patients in CSC received thrombolysis (12% vs. 9%, p<.0001), with faster DTN (59 vs. 71 min, p <.0001; ≤60 minutes 53% vs. 37%, p <.0001). Patients in CSC had greater rates of defect free care (85% vs. 82.4%, p<.0001). Blacks had longer median DTCT than Whites and Hispanics in both CSC (56 mins Blacks vs. 41 mins Whites and Hispanics) and PSC (60 mins Blacks, 44 mins Whites, 57 mins Hispanics). Blacks in CSC had longer median DTN (63 mins) than Whites (60 mins) and Hispanics (53 mins). Hispanics had longer median DTN (73 mins) in PSC than Blacks (70 mins) and Whites (70 mins).

Conclusion: Patients treated in CSC, compared with those treated in PSC, received better defect-free care and had lower DTCT and DTN times. Race-ethnic disparities in performance metrics are still evident in both CSC and PSC. Identification of these disparities is important to design interventions to reduce disparities and improve stroke quality of care for all.

Readmissions - can they be predicted on admission?

This paper looks at the development of logistic regression models to predict readmissions for medical patients on their initial admission to hospital. The design of our study was a retrospective analysis of a large dataset drawn from a range of secondary sources - medical, nursing, therapy and social care records. Three northern hospitals and related community health districts and social care organizations in the UK participated. Records of 1,192 patients discharged from medical wards during the period April 1992-March 1995 were analysed. Readmission within six weeks of discharge was the main outcome measure.Four logistic regression equations were produced. Three individual site equations were calculated and classification levels for readmission of 17-22 per cent were achieved. Component factors that differed in importance were age, GP contact, social services contact, marital status and living status. The weakest equation was the equation that encompassed patients from all three sites, which classified 7 per cent of readmissions. It is possible to develop equations that will explain readmission for a fifth of medical patients on admission to individual hospitals. Further exploratory work needs to be undertaken to explore reasons for differences between districts and develop more generalizable predictive equations.