Assessment of Price Variation in Coronary Artery Bypass Surgery at US Hospitals

BACKGROUND

Little is known about hospital pricing for coronary artery bypass grafting (CABG). Using new price transparency data, we assessed variation in CABG prices across US hospitals and the association between higher prices and hospital characteristics, including quality of care.

METHODS AND RESULTS

Prices for diagnosis related group code 236 were obtained from the Turquoise database and linked by Medicare Facility ID to publicly available hospital characteristics. Univariate and multivariable analyses were performed to assess factors predictive of higher prices. Across 544 hospitals, median commercial and self-pay rates were 2.01 and 2.64 times the Medicare rate ($57 240 and $75 047, respectively, versus $28 398). Within hospitals, the 90th percentile insurer-negotiated price was 1.83 times the 10th percentile price. Across hospitals, the 90th percentile commercial rate was 2.91 times the 10th percentile hospital rate. Regional median hospital prices ranged from $35 624 in the East South Central to $84 080 in the Pacific. In univariate analysis, higher inpatient revenue, greater annual discharges, and major teaching status were significantly associated with higher prices. In multivariable analysis, major teaching and investor-owned status were associated with significantly higher prices (+$8653 and +$12 200, respectively). CABG prices were not related to death, readmissions, patient ratings, or overall Centers for Medicare and Medicaid Services hospital rating.

CONCLUSIONS

There is significant variation in CABG pricing, with certain characteristics associated with higher rates, including major teaching status and investor ownership. Notably, higher CABG prices were not associated with better-quality care, suggesting a need for further investigation into drivers of pricing variation and the implications for health care spending and access.

Use of Human-Centered Design Methodology to Develop a Digital Toolkit to Optimize Heart Failure Guideline-Directed Medical Therapy

BACKGROUND

Guideline-directed medical therapies (GDMTs) improve quality of life and health outcomes for patients with heart failure (HF). However, GDMT utilization is suboptimal among patients with HF.

OBJECTIVE

The aims of this study were to engage key stakeholders in semistructured, virtual human-centered design sessions to identify challenges in GDMT optimization posthospitalization and inform the development of a digital toolkit aimed at optimizing HF GDMTs.

METHODS

For the human-centered design sessions, we recruited (a) clinicians who care for patients with HF across 3 hospital systems, (b) patients with HF with reduced ejection fraction (ejection fraction ≤ 40%) discharged from the hospital within 30 days of enrollment, and (c) caregivers. All participants were 18 years or older, English speaking, with Internet access.

RESULTS

A total of 10 clinicians (median age, 37 years [interquartile range, 35-41], 12 years [interquartile range, 10-14] of experience caring for patients with HF, 80% women, 50% White, 50% nurse practitioners) and three patients and one caregiver (median age 57 years [IQR: 53-60], 75% men, 50% Black, 75% married) were included. Five themes emerged from the clinician sessions on challenges to GDMT optimization (eg, barriers to patient buy-in). Six themes on challenges (eg, managing medications), 4 themes on motivators (eg, regaining independence), and 3 themes on facilitators (eg, social support) to HF management arose from the patient and caregiver sessions.

CONCLUSIONS

The clinician, patient, and caregiver insights identified through human-centered design will inform a digital toolkit aimed at optimizing HF GDMTs, including a patient-facing smartphone application and clinician dashboard. This digital toolkit will be evaluated in a multicenter, clinical trial.

Abstract P398: Using Human-Centered Design Methodology to Identify Challenges and Inform the Development of a Digital Toolkit to Optimize Heart Failure Guideline-Directed Medical Therapy From Diverse Clinician, Patient, and Patient Health Partner Perspectives

Introduction: Despite overwhelming evidence that guideline-directed medical therapies (GDMT) for heart failure (HF) can reduce mortality and improve quality of life, significant gaps in treatment optimization persist. GDMT initiation and up-titration are especially critical for improving patient outcomes post-hospitalization.

Objective: Identify challenges encountered post-hospitalization in optimizing GDMT for HF management by engaging key stakeholders in human-centered design (HCD) to guide the development of a digital toolkit to increase HF GDMT optimization.

Methods: HCD is used to solve complex problems by soliciting input from stakeholders. We recruited: a) clinicians (physicians and advanced practice providers) who provide care to patients with HF across three health systems, b) patients with HF with Reduced Ejection Fraction (HFrEF, EF < 40%) discharged from the hospital within 30 days of enrollment, and c) patient health partners when available. We conducted separate virtual sessions for clinicians and patients/health partners using semi-structured interview guides to identify challenges, motivators and themes.

Results: We enrolled 10 clinicians, 10 patients, and 2 patient health partners. The clinicians had a median age of 37 years (IQR: 35-41) and 12 years (IQR: 14-9) experience caring for patients with HF; 80% (8/10) were women, and 50% (5/10) were physicians. Patients had a median age of 53 years (IQR: 48-64); 40% (4/10) were women, 60% (6/10) were a racial/ethnic minority, and 50% (5/10) were married. Top challenges to HF GDMT optimization (e.g. number of medications) and digital toolkit features identified during the clinician HCD sessions are reported in Figure 1.

Conclusions: The clinician and patient/health partner HCD findings will inform the development of the digital toolkit, including a patient-facing smartphone application and clinician dashboard, for HF GDMT optimization. We will also conduct HCD sessions in Brazil to further co-design the digital toolkit for low resource settings.

Treatment Differences in Medical Therapy for Heart Failure With Reduced Ejection Fraction Between Sociodemographic Groups

BACKGROUND

There are sociodemographic disparities in outcomes of heart failure with reduced ejection fraction (HFrEF), but disparities in guideline-directed medical therapy (GDMT) remain poorly characterized.

OBJECTIVES

This study aimed to analyze GDMT treatment rates in eligible patients with recently diagnosed HFrEF, and to determine how rates vary by sociodemographic characteristics.

METHODS

This retrospective cohort study included patients diagnosed with HFrEF at Veterans Affairs (VA) hospitals from 2013 to 2019. The authors analyzed GDMT treatment rates and doses, excluding patients with contraindications. Therapies of interest were evidence-based beta-blockers (BBs), renin-angiotensin system inhibitors (RASIs), angiotensin receptor-neprilysin inhibitors (ARNIs), and mineralocorticoid antagonists (MRAs). The authors compared adjusted treatment rates by race and ethnicity, neighborhood social vulnerability, rurality, distance to medical care, and sex.

RESULTS

The cohort comprised 126,670 VA patients with recently diagnosed HFrEF. The study found that racial and ethnic minorities had similar or higher treatment rates than White patients. Patients residing in socially vulnerable neighborhoods had 3.4% lower ARNI (95% CI: 1.9%-5.0%) treatment rates. Patients residing farther from specialty care had similar rates of GDMT therapy overall, but were less likely to be taking at least 50% of the target doses of either BBs (4.0% less likely; 95% CI: 3.1%-5.0%) or RASIs (5.0% less likely; 95% CI: 4.1%-6.0%) compared with those closer to care.

CONCLUSIONS

Among VA patients with recently diagnosed HFrEF, the authors did not find that racial and ethnic minority patients were less likely to receive GDMT. However, appropriate dose up-titration may occur less frequently in more remote patients.

Variation in Cost of Echocardiography Within and Across U.S. Hospitals

BACKGROUND

While transthoracic echocardiography (TTE) is responsible for more Medicare spending than any other cardiovascular imaging procedure, little is known about its commercial cost footprint. The 2021 Hospital Price Transparency Final Rule mandated that U.S. hospitals publish their insurer-negotiated and self-pay prices for services. This study sought to characterize and assess factors contributing to variation in TTE prices.

METHODS

We used a commercial database containing hospital-disclosed prices to characterize variation in TTE prices within and across hospitals. We linked these price data to hospital and regional characteristics using Medicare Facility IDs.

RESULTS

A total of 1,949 hospitals reported commercial prices. Among reporting hospitals, median commercial and self-pay prices were 2.93 and 3.06 times greater than the median Medicare price ($1,313 and $1,422, respectively, vs $464). Within hospitals, the 90th percentile payer-negotiated rate was 2.78 (interquartile range, 1.80-5.09) times the 10th percentile rate (within-center ratio). Across hospitals within the same hospital referral region, the median price at the 90th percentile hospital was 2.47 (interquartile range, 1.69-3.75) times that at the 10th percentile hospital (across-center ratio). On univariate analysis, for-profit (P = .04), teaching (P < .01), investor-owned (P < .01), and higher-rated hospitals (P < .01) charged higher prices, whereas rural referral centers (P = .01) and disproportionate share hospitals (P < .01) charged less. On multivariate analysis, the association between these characteristics and TTE prices persisted, except for investor ownership and rural referral centers.

CONCLUSIONS

Self-pay and commercial TTE prices were higher than Medicare prices and varied significantly within and across hospitals. For-profit, teaching, and higher-rated hospitals had higher prices, in contrast to DSH hospitals. A better understanding of the relationship between this cost variation and quality of care is critical given the impact of cost on health care access and affordability.

The patient-reported outcome measurement in heart failure clinic trial: Rationale and methods of the PRO-HF trial

BACKGROUND

Among patients with heart failure (HF), patient-reported health status provides information beyond standard clinician assessment. Although HF management guidelines recommend collecting patient-reported health status as part of routine care, there is minimal data on the impact of this intervention.

STUDY DESIGN

The Patient-Reported Outcomes in Heart Failure Clinic (PRO-HF) trial is a pragmatic, randomized, implementation-effectiveness trial testing the hypothesis that routine health status assessment via the Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12) leads to an improvement in patient-reported health status among patients treated in a tertiary health system HF clinic. PRO-HF has completed randomization of 1,248 participants to routine KCCQ-12 assessment or usual care. Patients randomized to the KCCQ-12 arm complete KCCQ-12 assessments before each HF clinic visit with the results shared with their treating clinician. Clinicians received education regarding the interpretation and potential utility of the KCCQ-12. The primary endpoint is the change in KCCQ-12 over 1 year. Secondary outcomes are HF therapy patterns and health care utilization, including clinic visits, testing, hospitalizations, and emergency department visits. As a sub-study, PRO-HF will also evaluate the impact of routine KCCQ-12 assessment on patient experience and the accuracy of clinician-assessed health status. In addition, clinicians completed semi-structured interviews to capture their perceptions on the trial's implementation of routine KCCQ-12 assessment in clinical practice.

CONCLUSIONS

PRO-HF is a pragmatic, randomized trial based in a real-world HF clinic to determine the feasibility of routinely assessing patient-reported health status and the impact of this intervention on health status, care delivery, patient experience, and the accuracy of clinician health status assessment.

Catheter ablation for atrial fibrillation in adult congenital heart disease: an international registry study

Background

Life expectancies for patients with congenital heart disease (CHD) have dramatically increased in recent years, accompanied by a rise in atrial fibrillation (AF) prevalence. Data on AF ablation strategy and outcomes are limited in CHD.

Purpose

We aimed to investigate the characteristics of CHD patients presenting for AF ablation and their outcomes.

Methods

A multicenter, retrospective analysis was performed of CHD patients undergoing AF ablation between 2004 and 2020 at 13 participating centers. The severity of CHD was classified using the 2014 PACES/HRS guidelines. Clinical data were collected including ablation strategy and follow up. One-year procedural success was defined as freedom from AF in the absence of antiarrhythmic drugs (AADs, complete) or including previously failed AADs (partial).

Results

Of 240 patients, 127 (53.4%) had persistent AF, 62.5% were male, and mean age was 55.2±0.9 years. CHD complexity categories included 147 (61.3%) simple, 69 (28.8%) intermediate and 25 (10.4%) severe. The most common CHD type was atrial septal defect (n=78). More complex CHD conditions included transposition of the great arteries (n=14), anomalous pulmonary veins (n=13), tetralogy of Fallot (n=8), cor triatriatum (n=7), single ventricle physiology (n=2), among others. The majority (71.3%) of patients had AF despite at least one AAD. 46 patients (22.1%) had a reduced systemic ventricular ejection fraction &lt;50%, and the mean left atrial diameter was 44.1±0.7 mm. PV isolation (PVI) was performed in 227 patients (94.6%); additional ablation strategies included left atrial linear ablations (25.4%), CFAE (19.2%), and cavotricuspid isthmus ablation (40.8). One-year complete and partial success rates were 45.0% and 20.5%, respectively, with no significant difference in the rate of complete success between complexity groups. Overall, 38 patients (15.8%) required more than one ablation procedure. There were 3 (1.3%) major and 13 (5.4%) minor procedural complications.

Conclusion

AF ablation in this complex population was safe and resulted in AF control in the majority of patients. Future work should address the most appropriate ablation targets in the challenging population.

Funding Acknowledgement

Type of funding sources: None.

1060 Surgical Currency - the Link Between Skill Fade and Safe Practice

Aim

Surgical currency refers to the operating time required per year before a surgeon's skill fade could negatively affect patient outcomes. Increased surgical experience and volume of operating hours directly improves patient outcomes. There is no clear guidance from the NHS or Defence Medical Services on amount of experience needed to maintain current. This paper highlights the importance of surgical currency, investigates if skill fade occurs faster than knowledge, and looks to ensure surgeons are not deployed beyond the point of currency. It explores methods to prevent skill fade and reintegrate surgeons following absence.

Method

A thorough literature search was performed. Currency protocols across Royal Colleges, healthcare systems and other industries were studied, including systems installed to mitigate skill fade during COVID-19.

Results

An average deployment for a military surgeon will be three months, but pre-deployment training can make this six. The AMRC states an absence over three months affects medical knowledge. Skill fade occurs more rapidly than knowledge, but research remains limited for how long a well-practiced skill is retained. The aviation industry clearly stipulates a pilot's currency, and simulator training is provided following absence. US surgical simulator training proved effective in maintaining skills during the pandemic. Health Education England and Royal College of Surgeons Edinburgh provides return programs for trainees but not consultants.

Conclusions

Careful consideration should be given before extending surgical deployments. Surgical simulation could be used while deployed to maintain currency. Return-to-work programs should be available to consultants. Further research should be done on currency and prevention of skill fade.

Raman Interferometry between Autoionizing States to Probe Ultrafast Wave-Packet Dynamics with High Spectral Resolution

Photoelectron interferometry with femtosecond and attosecond light pulses is a powerful probe of the fast electron wave-packet dynamics, albeit it has practical limitations on the energy resolution. We show that one can simultaneously obtain both high temporal and spectral resolution by stimulating Raman interferences with one light pulse and monitoring the modification of the electron yield in a separate step. Applying this spectroscopic approach to the autoionizing states of argon, we experimentally resolved its electronic composition and time evolution in exquisite detail. Theoretical calculations show remarkable agreement with the observations and shed light on the light-matter interaction parameters. Using appropriate Raman probing and delayed detection steps, this technique enables highly sensitive probing and control of electron dynamics in complex systems.

Autoionizing Polaritons in Attosecond Atomic Ionization

Light-induced states and Autler-Townes splitting of laser-coupled states are common features in the photoionization spectra of laser-dressed atoms. The entangled light-matter character of metastable Autler-Townes multiplets, which makes them autoionizing polaritons, however, is still largely unexplored. We employ attosecond transient-absorption spectroscopy in argon to study the formation of polariton multiplets between the 3s^{-1}4p and several light-induced states. We measure a controllable stabilization of the polaritons against ionization, in excellent agreement with ab initio theory. Using an extension of the Jaynes-Cummings model to autoionizing states, we show that this stabilization is due to the destructive interference between the Auger decay and the radiative ionization of the polaritonic components. These results give new insights into the optical control of electronic structure in the continuum and unlock the door to applications of radiative stabilization in metastable polyelectronic systems.

POS0838 EPIDEMIOLOGY AND TRENDS IN SURVIVAL OF SYSTEMIC SCLEROSIS IN OLMSTED COUNTY: A POPULATION-BASED STUDY (1980-2018)

Background:

Systemic sclerosis (SSc) is a complex immune-mediated disease with heterogeneous manifestations, which is characterized by vasculopathy and fibrosis of the skin and visceral organs. Mortality associated with SSc exceeds that of other rheumatic diseases, though population-based studies assessing recent trends in survival are lacking.

Objectives:

We aimed to determine the incidence and prevalence of physician-diagnosed SSc in a population-based cohort over a 39-year time period, and assess for trends in survival over time.

Methods:

Medical records of patients with a diagnosis or suspicion of SSc in a geographically well-defined area from Jan 1, 1980 to Dec 31, 2018 were reviewed to identify incident cases of SSc. Cases were defined by physician diagnosis of SSc, and fulfillment of the 2013 ACR/EULAR classification criteria was ascertained. Prevalent cases of SSc on Jan 1, 2015 were also identified. Incidence and prevalence rates were age- and sex-adjusted to the 2010 U.S. white population. Survival rates were compared with expected rates in the general population.

Results:

85 incident cases of SSc (91% female, mean age 55.4 ± 16 y) and 49 prevalent cases on Jan 1, 2015 were identified. Patients had a mean 11.7 (SD 9.4) years of follow-up available. The overall age and sex adjusted annual incidence for 1980-2018 was 2.5 (95% CI: 2.0-3.1) per 100,000 population, with no change in incidence over time (p=0.32). The age-adjusted incidence was 4.4 (95% CI: 3.4-5.4) for females, and 0.56 (95% CI: 0.16-0.96) for males per 100,000 population. The age- and sex-adjusted prevalence on Jan 1, 2015 was 43.6 (95% CI: 31.3-55.8) per 100,000 population.

77 (91%) patients fulfilled the 2013 classification criteria; 38 (45%) fulfilled 1980 criteria. 70 (82%) had limited cutaneous involvement, 12 (14%) had diffuse cutaneous involvement, and 3 (4%) had sine scleroderma. At SSc diagnosis, 80 (94%) patients had Raynaud’s, 43 (51%) had sclerodactyly, 39 (46%) had telangiectasias, 14/48 (29%) had abnormal nailfold capillaries, 16/35 (46%) had digital ulcers or fingertip scarring, 8 (9%) had interstitial lung disease (ILD), and 7 (8%) had pulmonary arterial hypertension (PAH). 77/82 patients (91%) had a positive antinuclear antibody. 44 (52%) had a known SSc-related autoantibody: 32 (73%) with anti-centromere, 9 (20%) with anti-Scl-70, and 4 (9%) with anti-RNA-polymerase III.

Survival was 77% (95% CI: 69-87) at 5 years, 66% (95% CI: 56-78) at 10 years, and 42% (95% CI: 30-57) at 20 years, with no evidence of improved survival over time (p=0.46). Age (Hazard ratio [HR]: 1.49 per 10 year increase; 95% CI 1.19-1.88), smoking at time of diagnosis (HR: 2.37; 95% CI: 1.05-5.34), digital ischemia (HR: 2.54; 95% CI: 1.33-4.87), ILD (HR: 4.00; 95% CI: 2.11-7.59), and PAH (HR: 4.30; 95% CI: 2.24-8.25) had significant associations with mortality. Survival of patients with SSc was poorer than the general population (standardized mortality ratio: 2.48; 95% CI: 1.76-3.39).

Conclusion:

The average incidence of SSc in this population-based cohort spanning 39 years was 2.5 per 100,000 population, with no change in incidence over time. Age, smoking, digital ischemia, ILD and PAH were risk factors for poorer survival. Overall survival for patients with SSc is worse than that of the general population and shows no improvement over time, suggesting continued need for improved diagnostic and treatment measures.

Figure 1.

Survival of 85 Olmsted County residents with SSc compared with expected survival rates from Minnesota lifetables (observed: solid line, expected: dashed line).

Disclosure of Interests:

None declared

POS0836 CONDUCTION AND RHYTHM DISORDERS AMONG PATIENTS WITH SYSTEMIC SCLEROSIS: A US POPULATION BASED STUDY

Background:

Systemic sclerosis (SSc) can impact multiple areas of the heart through fibrotic and vascular processes; leading to variable cardiac involvement including electrocardiogram (ECG) abnormalities. Conduction and rhythm disorders are associated with worse prognosis in patients with SSc. (1, 2)

Objectives:

To study the incidence, risk factors and outcomes of conduction and rhythm disorders in a US population-based cohort of patients with SSc and non-SSc comparators from the same geographic area.

Methods:

A previously identified incident cohort of SSc patients (1980-2016) in a well-defined geographic area was compared to a randomly selected 2:1 cohort of age- and sex-matched non-SSc subjects from the same population base. Demographics, disease characteristics, cardiovascular risk factors and laboratory tests were abstracted by manual record review. ECGs and Holter ECGs were reviewed to determine the occurrence of any conduction or rhythm abnormalities. The need for cardiac interventions was also abstracted.

Results:

78 incident SSc cases and 156 non-SSc comparators were identified [age 56 years± 15.7, 91% female]. Prevalence of any conduction disorders before SSc diagnosis compared to non-SSc comparators was 15% vs. 7% (p=0.06), and any rhythm disorder was 18% vs. 13% (p=0.33). During a median follow up of 10.5 years in patients with SSc and 13.0 years in non-SSc comparators, conduction disorders developed in 25 SSc patients with a cumulative incidence (ci) of 20.5% (95% CI: 12.4-34.1%) compared to 28 non-SSc patients with ci of 10.4% (95% CI: 6.2-17.4%) (HR: 2.57; 95% CI: 1.48-4.45), while rhythm disorders developed in 27 SSc patients with ci of 27.3% (95% CI: 17.9-41.6%) vs 43 non-SSc patients with ci of 18.0% (95% CI: 12.3-26.4%) (HR: 1.62; 95% CI: 1.00-2.64). (Figure 1).

Conduction disorders in patients with SSc during follow up included: 1st-degree atrioventricular block (AVB) (n=12), 2nd-degree AVB (n=1), 3rd-degree AVB (n=1), right bundle branch block (n=10), left bundle branch block (n=4), bifascicular block (n=6), and prolonged-QT (n=13). Rhythm disorders included: atrial fibrillation (n=10), atrial flutter (n=4), supraventricular tachycardia (n=4), ventricular tachycardia (n=1), and premature ventricular contractions (n=16).

Pulmonary hypertension (PHT) was the only significant risk factor identified for development of both conduction and rhythm disorders (HR=8.38, 95% CI: 1.32-53.40 and HR=8.07, 95% CI: 1.60-40.74, respectively). Current smoking significantly increased the risk for development of rhythm disorders (HR=2.91, 95% CI: 1.19-7.12). Conduction and rhythm disorders were associated with increased mortality among patients with SSc (HR=7.60, 95% CI: 3.49-16.55 and HR=4.87, 95% CI: 2.28-10.42, respectively, after adjusting for age, sex and calendar year of diagnosis).

Conclusion:

Patients with SSc have a significantly higher prevalence of conduction disorders at disease onset than non-SSc comparators. During the course of their disease, their risk of developing conduction disorders is 2.6-fold, and risk of rhythm disorders is 1.6-fold increased, compared to non-SSc subjects.

PHT was significantly associated with increased risk of developing conduction and rhythm disorders among patients with SSc, a finding that should warrant increased vigilance and screening for ECG abnormalities in this population.

References:

[1]Tyndall A.J. et al. Ann Rheum Dis, 2010. 69(10): p. 1809-15.

[2]Desai C.S. et al. Curr Opin Rheumatol, 2011. 23(6): p. 545-54.

Figure 1.

Cumulative incidence of any conduction or any rhythm disorder in SSc (solid line) vs non-SSc comparators (dashed line).

Disclosure of Interests:

None declared

A134 A MULTI-CENTRE RANDOMIZED CONTROLLED TRIAL TO COMPARE TWO BOWEL CLEANSING REGIMENS AFTER A COLONOSCOPY WITH INADEQUATE BOWEL PREPARATION

Aims

Failed bowel preparation is common during colonoscopy, yet the optimal purgative regimen to use for the next attempt is unknown. The objective of this study was to compare the efficacy, tolerability, and safety of two regimens at supratherapeutic doses for use after failed bowel preparation.

Methods

A multi-centre phase III endoscopist blinded randomized controlled trial (NCT02976805) was conducted in patients who failed bowel preparation, using the US Multi-Society Task Force (USMSTF) definition of inability to exclude polyps &gt;5 mm in size and requiring a shortened interval to next colonoscopy. Regimen A consisted of 15 mg of bisacodyl and 2 + 2 L of split dose polyethylene glycol electrolyte solution (PEG) and Regimen B consisted of 15 mg of bisacodyl and 4 + 2 L of split dose PEG. The primary outcome was adequate bowel preparation, defined as a Boston Bowel Preparation Scale (BBPS) total score ≥ 6 with all segment scores ≥ 2. Secondary outcomes were adequate bowel preparation using the USMSTF definition, median BBPS, adenoma detection (ADR), advanced adenoma detection (aADR), sessile serrated polyp detection (SSPDR), and cecal intubation (CIR). Adverse events were assessed at the time of the colonoscopy and 14 days later.

Results

Between February 2017 and December 2019, 250 subjects were screened at four academic centres in Canada, of which 195 were randomized: 96 to Regimen A and 99 to Regimen B. The mean (SD) age was 60.6 (11.4) years, 87 (45.1%) were female, and the median (IQR) total BBPS score at previous failed colonoscopy was 3 (1,4). Regimen B was not superior to Regimen A in achieving adequate bowel preparation using the BBPS definition (87.6% vs. 91.1%, p=0.45) or the USMSTF definition (85.4% vs 91.1%, p=0.24), nor was it superior with respect to the median BBPS score (7 vs 7, p=0.50), mean ADR (31.5% vs 37.8%, p=0.37), aADR (11.2% vs 18.9%, p=0.15), SSPDR (5.6% vs 8.9%, p=0.40) or CIR (92.1% vs 96.7%, p=0.19). Regimen A had a higher adherence rate (88.2% vs. 74.7%, p=0.02) and greater willingness to undergo the bowel preparation again (91.2% vs. 66.2%, p&lt;0.001). The only serious adverse event occurred in a patient randomized to Regimen B who was admitted to hospital for vomiting after colonoscopy.

Conclusions

Split dose 4L PEG with 15mg of bisacodyl is highly efficacious, well tolerated, and can be used for patients who previously failed first line bowel preparations. The additional 2L of PEG in Regimen B did not improve bowel preparation and was not as well tolerated.

Funding Agencies

AMOSO Opportunities Grant, Pharmascence Inc.

Clinical outcomes after faecal microbiota transplant by retention enema in both immunocompetent and immunocompromised patients with recurrent Clostridioides difficile infections at an academic medical centre

BACKGROUND

Recurrent Clostridioides difficile infection (CDI) is one of the most common and challenging infections to treat in healthcare facilities. Faecal microbiota transplantation (FMT) is recommended as a definitive treatment option.

METHODS

We performed a retrospective review of 50 patients from January 2015 to December 2019 who underwent FMT for recurrent CDI. Primary outcome was recurrence of CDI within 12-weeks of FMT and secondary outcomes were the need for repeat FMT, serious adverse outcomes related to FMT and all-cause mortality.

RESULTS

Fifty charts were reviewed, of which 47 cases comprising 17 immunocompromised patients treated with FMT via retention enema were included in the study. The majority of the patients had ≥3 recurrent CDIs (62%). Nine (19%) patients failed to respond to the first FMT and five underwent repeat FMT within four to 12 weeks. The cure rate was 81% after the first FMT (38/47) and 91% after the second FMT treatment (43/47). Serious adverse events occurred in 2% and all-cause mortality was 2% at 90-day follow up.

CONCLUSION

Our study demonstrated the safety and efficacy of FMT administered via retention enema, a simple bedside procedure, for the treatment and prevention of recurrent non-severe and severe CDI with an overall cure rate of 91%.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

0614 Diurnal Patterning of Autonomic Measures in Sleep Apnea and Paroxysmal Atrial Fibrillation and Response to Continuous Positive Airway Pressure Therapy

Introduction

Diurnal patterning of autonomic function in paroxysmal atrial fibrillation (PAF) and sleep disordered breathing (SDB) is unknown. We hypothesize heart rate variability (HRV) as surrogates of autonomic function, exhibit diurnal differences in PAF relative to SDB severity and treatment.

Methods

We leveraged the Sleep Apnea and Atrial Fibrillation Biomarkers and Electrophysiologic Atrial Triggers (SAFEBEAT,NCT02576587) study focused on participants with PAF and SDB (apnea hypopnea index,AHI≥15,3% oxygen desaturation hypopnea). Attended 16-channel polysomnography (PSG) and continuous ECG monitoring (Heartrak Telemetry®) for 7-21 days was performed at baseline and after 3-months of continuous positive airway pressure (CPAP). Linear mixed-effects models (least square means,95%CI) were used to assess relationships between daily average HRV measures (frequency domain:LF,HF,LF/HF;time domain:MNN,RMSSD,SD1,SD ratio and novel non-linear:DFA-alpha measures) with SDB (AHI),%sleep time with SaO2&lt;90%(TRT&lt;90): per 5-unit increase),effect of 3-month CPAP relative to sleep-wake and statistical interaction of sleep-wake. Analyses were conducted using SAS version v.9.4, Cary, NC.

Results

The analytic sample was comprised of 33 cases with PAF and SDB:61.1±11.7 years,62.5% male, BMI:33.9±7.2kg/m2,75% Caucasian,AHI 15.1 (IQR: 4.4,29.4) and 68.8% on atrioventricular nodal blocking medications. AHI was associated with frequency (HF:0.08[0.01,0.16] and LF/HF:-0.11[-0.20, -0.01]), time (SD1:0.08[0.02,0.14] and SD ratio: 0.09[0.04,0.14]) and non-linear (DFA-alpha1: -0.02[-0.036,-0.003]) domain measures during wake, but not sleep. Significant sleep-wake and AHI as well as TRT&lt;90 interactions relative to HRV measures were observed (p≤0.001). Only SD ratio was associated with TRT&lt;90 (0.12[0.03,0.24]). Baseline to follow-up CPAP time domain measures were altered mainly during wake versus sleep with MNN increased 0.13: [0.08,0.19],p&lt;0.001; RMSSD increased 0.13 [0.08,0.19], p&lt;0.001; SD1 increased 30% [0.09,0.55], p=0.004; SD ratio increased 20% [0.01,0.43], p=0.033,and also frequency domain: HF increased 33%[0.03,0.72], p=0.028.

Conclusion

SDB defined by AHI--more so than nocturnal hypoxia--was associated with surrogate autonomic measures impacted by CPAP intervention during wake and not sleep in PAF. SDB-related autonomic influences in PAF appear to be more pronounced during wakefulness suggesting long-term potentiation-like influences.

Support

This study was supported by the National Heart, Lung and Blood Institute (NHLBI) [Grant R01 HL108493] and National Institutes of Health (NIH) National Center for Research Resources [Grant UL1 RR024989]

Determinants of Raised Blood Pressure in Urban Uganda: A Community-Based Case-Control Study

OBJECTIVE

Rapid urbanization is changing the epidemiology of non-communicable diseases in sub-Saharan Africa. We aimed to identify the determinants of raised blood pressure in urban Uganda to highlight targets for preventive interventions.

DESIGN

Case-control.

SETTING

Three community-based sites in Kampala, the capital of Uganda.

PARTICIPANTS

Participants were eligible to enroll if they were aged ≥18 years and not pregnant.

METHODS

450 cases with raised blood pressure were frequency matched by sex and age to 412 controls. Unconditional logistic regression was used to evaluate the association of socio-demographic, lifestyle, anthropometric, and laboratory variables with the outcome of raised blood pressure. Cases currently treated with antihypertensive medication and cases not treated with antihypertensive medication were analyzed separately.

RESULTS

Significantly increased odds of raised blood pressure were associated with overweight body mass index (BMI) (25 kg/m² ≤ BMI < 30 kg/m²), obese BMI (BMI ≥ 30 kg/m²) and hemoglobin A1c ≥ 6.5%. Significantly decreased odds of raised blood pressure were associated with moderate-to-vigorous work-related physical activity of >4 hours/week. No significant associations were found between raised blood pressure and marital status, education level, car or flush toilet ownership, dietary habits, alcohol consumption, smoking habits, moderate-to-vigorous leisure-related physical activity > 4 hours/week, waist-to-hip ratio, or total cholesterol levels.

CONCLUSIONS

Targeted interventions are needed to address the key modifiable risk factors for raised blood pressure identified in this study, namely elevated BMI and regular physical activity, in order to reduce the burden of cardiovascular disease in urban Uganda.

High photosensitivity few-layered MoSe2 back-gated field-effect phototransistors

In this paper, we report on the fabrication and optoelectronic properties of high sensitive phototransistors based on few-layered MoSe2 back-gated field-effect transistors, with a mobility of 19.7 cm² V⁻¹ s⁻¹ at room temperature. We obtained an ultrahigh photoresponsivity of 97.1 AW⁻¹ and an external quantum efficiency (EQE) of 22 666% using 532 nm laser excitation at room temperature. The photoresponsivity was improved near the threshold gate voltage; however, the selection of the silicon dioxide as a gate oxide represents a limiting factor in the ultimate performance. Thanks to their high photoresponsivity and external quantum efficiency, the few-layered MoSe2-based devices are promising for photoelectronic applications.

Gate dependent Raman spectroscopy of graphene on hexagonal boron nitride

Raman spectroscopy, a fast and nondestructive imaging method, can be used to monitor the doping level in graphene devices. We fabricated chemical vapor deposition (CVD) grown graphene on atomically flat hexagonal boron nitride (hBN) flakes and SiO2 substrates. We compared their Raman response as a function of charge carrier density using an ion gel as a top gate. The G peak position, the 2D peak position, the 2D peak width and the ratio of the 2D peak area to the G peak area show a dependence on carrier density that differs for hBN compared to SiO2. Histograms of two-dimensional mapping are used to compare the fluctuations in the Raman peak properties between the two substrates. The hBN substrate has been found to produce fewer fluctuations at the same charge density owing to its atomically flat surface and reduced charged impurities.

Spinal 5-HT3 receptors facilitate behavioural hypersensitivity induced by elevated calcium channel alpha-2-delta-1 protein

BACKGROUND

Peripheral nerve injury induces up-regulation of the calcium channel alpha-2-delta-1 proteins in the dorsal root ganglia and dorsal spinal cord that correlates with neuropathic pain development. Similar behavioural hypersensitivity was also observed in injury-free transgenic (TG) mice over-expressing the alpha-2-delta-1 proteins in neuronal tissues. To investigate pathways regulating alpha-2-delta-1 protein-mediated behavioural hypersensitivity, we examined whether spinal serotonergic 5-HT3 receptors are involved similarly in the modulation of behavioural hypersensitivity induced by either peripheral nerve injury in a nerve injury model or neuronal alpha-2-delta-1 over-expression in the TG model.

METHODS

The effects of blocking behavioural hypersensitivity in these two models by intrathecal or systemic injections of 5-HT3 receptor antagonist, ondansetron, were compared.

RESULTS

Our data indicated that the TG mice displayed similar behavioural hypersensitivities to non-painful mechanical stimulation (tactile allodynia) and painful thermal stimulation (thermal hyperalgesia) as that observed in the nerve injury model. Interestingly, tactile allodynia and thermal hyperalgesia in both models can be blocked similarly by intrathecal, but not systemic, injection of ondansetron.

CONCLUSIONS

Our data suggest that spinal 5-HT3 receptors are likely to play a role in alpha-2-delta-1-mediated behavioural hypersensitivities through a descending serotonergic facilitation.

Prognostic value of cardiac troponins in elderly patients with hip fracture--a systematic review

Cardiac troponins can be elevated in cardiac ischemic conditions or other diseases such as pulmonary embolism or renal failure, where they may predict outcome. We hypothesized that cardiac troponins offer useful prognostic information regarding morbidity and mortality in elderly hip fracture patients undergoing surgical therapy. A literature review was conducted using PubMed and CINAHL plus with full text (EBSCOhost). Articles with original data relating troponins to prognosis in elderly hip fracture patients were reviewed. Studies with patients not undergoing surgery or undergoing elective or nonhip fracture surgery were excluded. Six papers met inclusion criteria. Troponin elevation was seen in 26.7-39% of patients, while myocardial infarction, cardiac complications, and cardiac death occurred in ≤35% troponin-positive patients in four of six studies. Several noncardiac factors were associated with elevated troponin including higher American Society of Anaesthesiologists score, current smoking, reduced mobility/activity level, lower hemoglobin, and living in residential care. Patients with elevated troponin had longer lengths of stay, increased risk for discharge to long-term care facilities, and higher mortality. Increased age, male sex, and higher American Society of Anaesthesiologists score were also associated with mortality. Elevated troponin can be used as a marker of increased morbidity/mortality in elderly hip fracture patients undergoing surgery, as hypothesized, even in the absence of cardiac complications. Perioperative troponin evaluation may be useful for risk stratification, but further studies are needed to clarify risks and benefits of such testing.

Telomere length in patients with systemic lupus erythematosus and its associations with carotid plaque

OBJECTIVE

To evaluate telomere length (TL) between patients with SLE and healthy controls and to test if TL is associated with carotid plaque.

METHODS

A pilot study of 154 patients with SLE and 152 controls was performed from the SOLVABLE (Study of Lupus Vascular and Bone Long-Term Endpoints) cohort. Demographic and cardiovascular disease (CVD) factors were collected at baseline. The presence or absence of plaque was evaluated by B-mode US. Genomic DNA was isolated from whole peripheral blood. TL was quantified using real-time quantitative PCR.

RESULTS

SLE women had a short TL compared with healthy controls (4.57 vs 5.44 kb, P = 0.03). SLE women showed shorter TL than controls across all age groups: <35 years (4.38 vs 6.37 kb), 35-44 years (4.52 vs 5.30 kb), 45-54 years (4.77 vs 5.68 kb) and ≥55 years (4.60 vs 4.71 kb). Among patients with SLE and carotid plaque there was a trend towards shorter TL at a younger age and it was significantly lower in the 35- to 44-year age group when compared with controls (P = 0.025). Multiple logistic regression analysis indicated a risk of carotid plaque with older age [odds ratio (OR) 1.09; 95% CI 1.06, 1.12] but not with TL (OR 1.05; 95% CI 0.97, 1.13).

CONCLUSION

SLE women had significantly shorter TL than controls. SLE women trended towards shorter TL at a younger age. When carotid plaque was identified, the younger SLE women had shorter TL. Only older age but not shorter TL was independently associated with carotid plaque. Additional studies are needed to confirm if TL is a novel biomarker for cardiovascular disease in SLE.

The safety and efficacy of antitumour necrosis factor-alpha therapy for inflammatory bowel disease in patients post liver transplantation: a case series

BACKGROUND

The role of antitumour necrosis factor-alpha (anti-TNF) therapy for inflammatory bowel disease (IBD) among liver transplant recipients is largely unknown given the rarity of this population and the paucity of literature on the subject.

AIM

To investigate the safety and efficacy of anti-TNF therapy for refractory IBD in the post liver transplant population.

METHODS

The liver transplant database at London Health Sciences Centre was searched to identify adult patients with IBD treated with anti-TNF therapy post transplantation.

RESULTS

Six patients (five men, one woman) were identified, aged 28-65. All patients had cadaveric orthotopic liver transplants. Four patients required transplantation due to primary sclerosing cholangitis, one due to autoimmune hepatitis, and one due to biliary atresia. Five patients suffered from Crohn's disease and the remaining patient from indeterminate colitis. All patients were treated with infliximab 5 mg/kg every 8 weeks after undergoing induction at weeks 0, 2 and 6, with the exception of one patient. The duration of infliximab therapy ranged from 8 weeks to 4 years. Four patients treated with infliximab experienced sustained improvement of their IBD symptoms post transplantation, as documented by Harvey-Bradshaw Index scores demonstrating clinical remission. Of the remaining two patients, neither had sustained improvement of their IBD with infliximab or subsequent adalimumab. One patient was diagnosed with systemic lupus erythematosus and another with colorectal adenocarcinoma following anti-TNF therapy. Otherwise, no side effects were attributed to anti-TNF therapy.

CONCLUSIONS

Based on this case series, anti-TNF therapy appears to be safe and effective for treating refractory IBD in patients post liver transplantation. These patients respond to anti-TNF therapy similar to those who have not been previously transplanted.

Abstract 189: Hypercholesterolemia Blunts Gender Differences in Vascular Endothelin-1 Activity in Middle-Aged Adults

Background: Compared with age-matched women, healthy middle-aged men have a higher vascular activity of the vasoconstrictor and proatherosclerotic peptide endothelin-1(ET-1). Hypercholesterolemia is a major atherosclerotic risk factor and is associated with increased ET-1 activity. Whether high cholesterol levels abrogate gender differences in vascular ET-1 activity has not been studied. This investigation has been conducted to test the hypothesis that hypercholesterolemia blunts the gender difference in ET-1 activity present in middle-aged men and women.

Methods: Forearm blood flow (FBF) responses were measured by strain-gauge plethysmography during the intra-arterial infusion of the selective ET A receptor blocker BQ-123 in 19 women and 21 men with hypercholesterolemia (total cholesterol >240 mg/dL).

Results: Baseline characteristics were similar between women and men (see table). BQ-123 administration resulted in a significant progressive vasodilator response in both the female and male group (p < 0.001 for both). When these responses were compared between the two gender groups, no significant differences were observed (p=NS).

Conclusions: Hypercholesterolemia increases the vascular activity of ET-1 in middle-aged women and men. The lack of difference in ET-1 activity between women and men suggests that hypercholesterolemia eliminates the gender differences in ET-1 vascular activity, potentially offsetting the advantage in cardiovascular risk of middle-aged women compared with middle-aged men.

Pulmonary artery sarcoma mimicking a pulmonary embolism

Sarcomas involving the lung are a rare occurrence, often a result of metastatic disease from primary malignancies involving the skin, liver, breast or heart. Primary pulmonary artery sarcomas are rarer still, with limited cases reported world-wide and consequently data regarding treatment modalities are sparse and largely experimental. These tumors are often mistaken for a pulmonary embolism and seemingly supported by radiological findings. Patients will often present without symptom resolution despite therapeutic anticoagulation. The following case illustrates how a soft tissue sarcoma of the pulmonary artery can mimic a pulmonary embolism, thus, resulting in both a diagnostic and therapeutic dilemma. A positron emission tomography scan was an invaluable tool in this case, showing increased radiotracer uptake and placing neoplasm at the top of the differential diagnosis. This ultimately led to a biopsy that was vimentin positive, cytokeratin negative and CD117 negative, thus consistent with soft tissue sarcoma.