Association between arterial oxygen and mortality across critically ill patients with hematologic malignancies: results from an international collaborative network

PURPOSE

Patients with hematological malignancies are at high risk for life-threatening complications. To date, little attention has been paid to the impact of hyperoxemia and excess oxygen use on mortality. The aim of this study was to investigate the association between partial pressure of arterial oxygen (PaO2) and 28-day mortality in critically ill patients with hematologic malignancies.

METHODS

Data from three international cohorts (Europe, Canada, Oceania) of patients who received respiratory support (noninvasive ventilation, high-flow nasal cannula, invasive mechanical ventilation) were obtained. We used mixed-effect Cox models to investigate the association between day one PaO2 or excess oxygen use (inspired fraction of oxygen ≥ 0.6 with PaO2 > 100 mmHg) on day-28 mortality.

RESULTS

11,249 patients were included. On day one, 5716 patients (50.8%) had normoxemia (60 ≤ PaO2 ≤ 100 mmHg), 1454 (12.9%) hypoxemia (PaO2 < 60 mmHg), and 4079 patients (36.3%) hyperoxemia (PaO2 > 100 mmHg). Excess oxygen was used in 2201 patients (20%). Crude day-28 mortality rate was 40.6%. There was a significant association between PaO2 and day-28 mortality with a U-shaped relationship (p < 0.001). Higher PaO2 levels (> 100 mmHg) were associated with day-28 mortality with a dose-effect relationship. Subgroup analyses showed an association between hyperoxemia and mortality in patients admitted with neurological disorders; however, the opposite relationship was seen across those admitted with sepsis and neutropenia. Excess oxygen use was also associated with subsequent day-28 mortality (adjusted hazard ratio (aHR) [95% confidence interval (CI)]: 1.11[1.04-1.19]). This result persisted after propensity score analysis (matched HR associated with excess oxygen:1.31 [1.20-1.1.44]).

CONCLUSION

In critically-ill patients with hematological malignancies, exposure to hyperoxemia and excess oxygen use were associated with increased mortality, with variable magnitude across subgroups. This might be a modifiable factor to improve mortality.

Long-term survival and functional outcomes of critically ill patients with hematologic malignancies: a Canadian multicenter prospective study

PURPOSE

Patients with hematologic malignancy (HM) commonly develop critical illness. Their long-term survival and functional outcomes have not been well described.

METHODS

We conducted a prospective, observational study of HM patients admitted to seven Canadian intensive care units (ICUs) (2018-2020). We followed survivors at 7 days, 6 months and 12 months following ICU discharge. The primary outcome was 12-month survival. We evaluated functional outcomes at 6 and 12 months using the functional independent measure (FIM) and short form (SF)-36 as well as variables associated with 12-month survival.

RESULTS

We enrolled 414 patients including 35% women. The median age was 61 (interquartile range, IQR: 52-69), median Sequential Organ Failure Assessment (SOFA) score was 9 (IQR: 6-12), and 22% had moderate-severe frailty (clinical frailty scale [CFS] ≥ 6). 51% had acute leukemia, 38% lymphoma/multiple myeloma, and 40% had received a hematopoietic stem cell transplant (HCT). The most common reasons for ICU admission were acute respiratory failure (50%) and sepsis (40%). Overall, 203 (49%) were alive 7 days post-ICU discharge (ICU survivors). Twelve-month survival of the entire cohort was 21% (43% across ICU survivors). The proportion of survivors with moderate-severe frailty was 42% (at 7 days), 14% (6 months), and 8% (12 months). Median FIM at 7 days was 80 (IQR: 50-109). Physical function, pain, social function, mental health, and emotional well-being were below age- and sex-matched population scores at 6 and 12 months. Frailty, allogeneic HCT, kidney injury, and cardiac complications during ICU were associated with lower 12- month survival.

CONCLUSIONS

49% of all HM patients were alive at 7 days post-ICU discharge, and 21% at 12 months. Survival varied based upon hematologic diagnosis and frailty status. Survivors had important functional disability and impairment in emotional, physical, and general well-being.

An Update on Gender Disparity in Critical Care Conferences

This commentary's objective was to identify whether female representation at critical care conferences has improved since our previous publication in 2018. We audited the scientific programs from three international (International Symposium on Intensive Care and Emergency Medicine [ISICEM], European Society of Intensive Care Medicine [ESICM], and Society of Critical Care Medicine [SCCM]) and two national (State of the Art [SOA] and Critical Care Canada Forum) critical care conferences from the years 2017 to 2022. We collected data on the number of female faculty members and categorized them into physicians, nurses, allied health professions (AHPs), and other. Across all conferences, there was an increased representation of females as speakers and moderators over the 6 years. However, at each conference, male speakers outnumbered female speakers. Only two conferences achieved gender parity in speakers, SCCM in 2021 (48% female) and 2022 and SOA in 2022 (48% female). These conferences also had the highest representation of female nursing and AHP speakers (25% in SCCM, 2021; 19% in SOA, 2022). While there was a statistically significant increase in female speakers (p < 0.01) in 2022 compared with 2016, there was a persistent gender gap in the representation of men and female physicians. While the proportion of female moderators increased in each conference every year, the increase was statistically only significant for ISICEM, ESICM, and SCCM (p < 0.05). The proportion of female nurses and AHP speakers increased in 2022 compared with 2016 (p < 0.0001) but their overall representation was low with the highest proportion (25%) in the 2022 SCCM conference and the lowest (0.5%) in the 2017 ISICEM conference. This follow-up study demonstrates a narrowing but persisting gender gap in the studied critical care conferences. Thus, a commitment toward minimizing gender inequalities is warranted.

Pharmacological agents for procedural sedation and analgesia in the emergency department and intensive care unit: a systematic review and network meta-analysis of randomised trials

BACKGROUND

We aimed to evaluate the comparative effectiveness and safety of various i.v. pharmacologic agents used for procedural sedation and analgesia (PSA) in the emergency department (ED) and ICU. We performed a systematic review and network meta-analysis to enable direct and indirect comparisons between available medications.

METHODS

We searched Medline, EMBASE, Cochrane, and PubMed from inception to 2 March 2023 for RCTs comparing two or more procedural sedation and analgesia medications in all patients (adults and children >30 days of age) requiring emergent procedures in the ED or ICU. We focused on the outcomes of sedation recovery time, patient satisfaction, and adverse events (AEs). We performed frequentist random-effects model network meta-analysis and used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to rate certainty in estimates.

RESULTS

We included 82 RCTs (8105 patients, 78 conducted in the ED and four in the ICU) of which 52 studies included adults, 23 included children, and seven included both. Compared with midazolam-opioids, recovery time was shorter with propofol (mean difference 16.3 min, 95% confidence interval [CI] 8.4-24.3 fewer minutes; high certainty), and patient satisfaction was better with ketamine-propofol (mean difference 1.5 points, 95% CI 0.3-2.6 points, high certainty). Regarding AEs, compared with midazolam-opioids, respiratory AEs were less frequent with ketamine (relative risk [RR] 0.55, 95% CI 0.32-0.96; high certainty), gastrointestinal AEs were more common with ketamine-midazolam (RR 3.08, 95% CI 1.15-8.27; high certainty), and neurological AEs were more common with ketamine-propofol (RR 3.68, 95% CI 1.08-12.53; high certainty).

CONCLUSION

When considering procedural sedation and analgesia in the ED and ICU, compared with midazolam-opioids, sedation recovery time is shorter with propofol, patient satisfaction is better with ketamine-propofol, and respiratory adverse events are less common with ketamine.

Virtual urgent care is here to stay: driving toward safe, equitable, and sustainable integration within emergency medicine

BACKGROUND

Virtual care in Canada rapidly expanded during the COVID-19 pandemic in a low-rules environment in response to pressing needs for ongoing access to care amid public health restrictions. Emergency medicine specialists now face the challenge of advising on which virtual urgent care services ought to remain as part of comprehensive emergency care. Consideration must be given to safe, quality, and appropriate care as well as issues of equitable access, public demand, and sustainability (financial and otherwise). The aim of this project was to summarize current literature and expert opinion and formulate recommendations on the path forward for virtual care in emergency medicine.

METHODS

We formed a working group of emergency medicine physicians from across Canada working in a variety of practice settings. The virtual care working group conducted a scoping review of the literature and met monthly to discuss themes and develop recommendations. The final recommendations were circulated to stakeholders for input and subsequently presented at the 2023 Canadian Association of Emergency Physicians (CAEP) Academic Symposium for discussion, feedback, and refinement.

RESULTS

The working group developed and reached unanimity on nine recommendations addressing the themes of system design, equity and accessibility, quality and patient safety, education and curriculum, financial models, and sustainability of virtual urgent care services in Canada.

CONCLUSION

Virtual urgent care has become an established service in the Canadian health care system. Emergency medicine specialists are uniquely suited to provide leadership and guidance on the optimal delivery of these services to enhance and complement emergency care in Canada.

Association between Patient Race and Ethnicity and Use of Invasive Ventilation in the United States

Rationale: Outcomes for people with respiratory failure in the United States vary by patient race and ethnicity. Invasive ventilation is an important treatment initiated based on expert opinion. It is unknown whether the use of invasive ventilation varies by patient race and ethnicity. Objectives: To measure 1) the association between patient race and ethnicity and the use of invasive ventilation; and 2) the change in 28-day mortality mediated by any association. Methods: We performed a multicenter cohort study of nonintubated adults receiving oxygen within 24 hours of intensive care admission using the Medical Information Mart for Intensive Care IV (MIMIC-IV, 2008-2019) and Phillips eICU (eICU, 2014-2015) databases from the United States. We modeled the association between patient race and ethnicity (Asian, Black, Hispanic, White) and invasive ventilation rate using a Bayesian multistate model that adjusted for baseline and time-varying covariates, calculated hazard ratios (HRs), and estimated 28-day hospital mortality changes mediated by differential invasive ventilation use. We reported posterior means and 95% credible intervals (CrIs). Results: We studied 38,258 patients, 52% (20,032) from MIMIC-IV and 48% (18,226) from eICU: 2% Asian (892), 11% Black (4,289), 5% Hispanic (1,964), and 81% White (31,113). Invasive ventilation occurred in 9.2% (3,511), and 7.5% (2,869) died. The adjusted rate of invasive ventilation was lower in Asian (HR, 0.82; CrI, 0.70-0.95), Black (HR, 0.78; CrI, 0.71-0.86), and Hispanic (HR, 0.70; CrI, 0.61-0.79) patients compared with White patients. For the average patient, lower rates of invasive ventilation did not mediate differences in 28-day mortality. For a patient on high-flow nasal cannula with inspired oxygen fraction of 1.0, the odds ratios for mortality if invasive ventilation rates were equal to the rate for White patients were 0.97 (CrI, 0.91-1.03) for Asian patients, 0.96 (CrI, 0.91-1.03) for Black patients, and 0.94 (CrI, 0.89-1.01) for Hispanic patients. Conclusions: Asian, Black, and Hispanic patients had lower rates of invasive ventilation than White patients. These decreases did not mediate harm for the average patient, but we could not rule out harm for patients with more severe hypoxemia.

Physicians' beliefs and perceived importance of traumatic brain injury-associated agitation in critically ill patients: a survey of Canadian intensivists

PURPOSE

Agitation is a common behavioural problem following traumatic brain injury (TBI). Intensive care unit (ICU) physicians' perspectives regarding TBI-associated agitation are unknown. Our objective was to describe physicians' beliefs and perceived importance of TBI-associated agitation in critically ill patients.

METHODS

Following current standard guidance, we built an electronic, self-administrated, 42-item survey, pretested it for reliability and validity, and distributed it to 219 physicians working in 18 ICU level-1 trauma centres in Canada. We report the results using descriptive statistics.

RESULTS

The overall response rate was 93/219 (42%), and 76/93 (82%) respondents completed the full survey. Most respondents were men with ten or more years of experience. Respondents believed that pre-existing dementia (90%) and regular recreational drug use (86%) are risk factors for agitation. Concerning management, 91% believed that the use of physical restraints could worsen agitation, 90% believed that having family at the bedside reduces agitation, and 72% believed that alpha-2 adrenergic agonists are efficacious for managing TBI agitation. Variability was observed in beliefs on epidemiology, sex, gender, age, socioeconomic status, and other pharmacologic options. Respondents considered TBI agitation frequent enough to justify the implementation of management protocols (87%), perceived the current level of clinical evidence on TBI agitation management to be insufficient (84%), and expressed concerns about acute and long-term detrimental outcomes and burden to patients, health care professionals, and relatives (85%).

CONCLUSION

Traumatic brain injury-associated agitation in critically ill patients was perceived as an important issue for most ICU physicians. Physicians agreed on multiple approaches to manage TBI-associated agitation although agreement on epidemiology and risk factors was variable.

Venous thromboembolism in critically ill adult patients with hematologic malignancy: a population-based cohort study

PURPOSE

The aim of this study was to describe the incidence of venous thromboembolism (VTE) and major bleeding among hospitalized patients with hematologic malignancy, assessing its association with critical illness and other baseline characteristics.

METHODS

We conducted a population-based cohort study of hospitalized adults with a new diagnosis of hematologic malignancy in Ontario, Canada, between 2006 and 2017. The primary outcome was VTE (pulmonary embolism or deep venous thrombosis). Secondary outcomes were major bleeding and in-hospital mortality. We compared the incidence of VTE between intensive care unit (ICU) and non-ICU patients and described the association of other baseline characteristics and VTE.

RESULTS

Among 76,803 eligible patients (mean age 67 years [standard deviation, SD, 15]), 20,524 had at least one ICU admission. The incidence of VTE was 3.7% in ICU patients compared to 1.2% in non-ICU patients (odds ratio [OR] 3.08; 95% confidence interval [CI] 2.77-3.42). The incidence of major bleeding was 7.6% and 2.4% (OR 3.33; 95% CI 3.09-3.58), respectively. The association of critical illness and VTE remained significant after adjusting for potential confounders (OR 2.92; 95% CI 2.62-3.25). We observed a higher incidence of VTE among specific subtypes of hematologic malignancy and patients with prior VTE (OR 6.64; 95% CI 5.42-8.14). Admission more than 1 year after diagnosis of hematologic malignancy (OR 0.64; 95% CI 0.56-0.74) and platelet count ≤ 50 × 109/L at the time of hospitalization (OR 0.63; 95% CI 0.48-0.84) were associated with a lower incidence of VTE.

CONCLUSION

Among patients with hematologic malignancy, critical illness and certain baseline characteristics were associated with a higher incidence of VTE.

Interprofessional intensive care unit (ICU) team perspectives on physical restraint practices and minimization strategies in an adult ICU: A qualitative study of contextual influences

BACKGROUND

Guidelines advocate for minimization of physical restraint (PR) use in intensive care units (ICU). Interprofessional team perspectives on PR practices can inform the design and implementation of successful PR minimization interventions.

AIM

To identify ICU staff perspectives of contextual influences on PR practices and minimization strategies.

STUDY DESIGN

A qualitative descriptive study in a single ICU in Toronto, Canada. One-on-one semi-structured interviews were conducted with 14 ICU staff. A deductive content analysis of interviews was undertaken using the integrated-Promoting Action on Research Implementation in Health Services (i-PARIHS) framework.

RESULTS

Five themes were developed: risk-averse culture, leadership, practice monitoring and feedback processes, environmental factors, and facilitation. Participants described a risk-averse culture where prophylactic application of PR for intubated patients was used to prevent unplanned extubation thereby avoiding blame from colleagues. Perceived absence of leadership and interprofessional team involvement situated nurses as the primary decision-maker for restraint application and removal. Insufficient monitoring of restraint practices, lack of access to restraint alternatives, and inability to control environmental contributors to delirium and agitation further increased PR use. Recommendations as to how to minimize restraint use included a nurse facilitator to advance leadership-team collaboration, availability of restraints alternatives, and guidance on situations for applying and removing restraints.

CONCLUSIONS

This analysis of contextual influences on PR practices and minimization using the i-PARIHS framework revealed potentially modifiable barriers to successful PR minimization, including a lack of leadership involvement, gaps in practice monitoring, and collaborative decision-making processes. A team approach to changing behaviour and culture should be considered for successful implementation and sustainability of PR minimization.

RELEVANCE TO PRACTICE

The establishment of an interprofessional facilitation team that addresses risk-averse culture and promotes collaboration among ICU stakeholders will be crucial to the success of any approach to restraint minimization.

Ketamine sedation in the intensive care unit: a survey of Canadian intensivists

PURPOSE

We sought to understand the beliefs and practices of Canadian intensivists regarding their use of ketamine as a sedative in critically ill patients and to gauge their interest in a randomized controlled trial (RCT) examining its use in the intensive care unit (ICU).

METHODS

We designed and validated an electronic self-administered survey examining the use of ketamine as a sedative infusion for ICU patients. We surveyed 400 physician members of the Canadian Critical Care Society (CCCS) via email between February and April 2022 and sent three reminders at two-week intervals. The survey was redistributed in January 2023 to improve the response rate.

RESULTS

We received 87/400 (22%) completed questionnaires. Most respondents reported they rarely use ketamine as a continuous infusion for sedation or analgesia in the ICU (52/87, 58%). Physicians reported the following conditions would make them more likely to use ketamine: asthma exacerbation (73/87, 82%), tolerance to opioids (68/87, 77%), status epilepticus (44/87, 50%), and severe acute respiratory distress syndrome (33/87, 38%). Concern for side-effects that limited respondents' use of ketamine include adverse psychotropic effects (61/87, 69%) and delirium (47/87, 53%). The majority of respondents agreed there is need for an RCT to evaluate ketamine as a sedative infusion in the ICU (62/87, 71%).

CONCLUSION

This survey of Canadian intensivists illustrates that use of ketamine as a continuous infusion for sedation is limited, and is at least partly driven by concerns of adverse psychotropic effects. Canadian physicians endorse the need for a trial investigating the safety and efficacy of ketamine as a sedative for critically ill patients.

Accuracy of Heart Rate Measurement with Wrist-Worn Wearable Devices in Various Skin Tones: a Systematic Review

BACKGROUND

Wearable consumer technology allows for the collection of a growing amount of personal health data. Through the analysis of reflected LED light on the skin, heart rate measurement and arrhythmia detection can be performed. Given that melanin alters skin light absorption, this study seeks to summarize the accuracy of cardiac data from wrist-worn wearable devices for participants of varying skin tones.

METHODS

We conducted a systematic review, searching Embase, MEDLINE, CINAHL, and Cochrane for original studies that stratified heart rate and rhythm data for consumer wearable technology according to participant race and/or skin tone.

RESULTS

A total of 10 studies involving 469 participants met inclusion criteria. The frequency-weighted Fitzpatrick score for skin tone was reported in six studies (n = 293), with a mean participant score of 3.5 (range 1-6). Overall, four of the ten studies reported a significant reduction in accuracy of heart rate measurement with wearable devices in darker-skinned individuals, compared to participants with lighter skin tones. Four studies noted no effect of user skin tone on accuracy. The remaining two studies showed mixed results.

CONCLUSIONS

Preliminary evidence is inconclusive, but some studies suggest that wearable devices may be less accurate for detecting heart rate in participants with darker skin tones. Higher quality evidence is necessary, with larger sample sizes and more objective stratification of participants by skin tone, in order to characterize potential racial bias in consumer devices.

Gender equity of authorship in pulmonary medicine over the past decade

BACKGROUND

Gender disparity in authorship broadly persists in medical literature, little is known about female authorship within pulmonary medicine.

METHODS

A bibliometric analysis of publications from 2012 to 2021 in 12 journals with the highest impact in pulmonary medicine was conducted. Only original research and review articles were included. Names of the first and last authors were extracted and their genders were identified using the Gender-API web. Female authorship was described by overall distribution and distribution by country/region/continent and journal. We compared the article citations by gender combinations, evaluated the trend in female authorship, and forecasted when parity for first and last authorship would be reached. We also conducted a systematic review of female authorship in clinical medicine.

RESULTS

14,875 articles were included, and the overall percentage of female first authors was higher than last authors (37.0% vs 22.2%, p<0.001). Asia had the lowest percentage of female first (27.6%) and last (15.2%) authors. The percentages of female first and last authors increased slightly over time, except for a rapid increase in the COVID-19 pandemic periods. Parity was predicted in 2046 for the first authors and 2059 for the last authors. Articles with male authors were cited more than articles with female authors. However, male-male collaborations significantly decreased, whereas female-female collaborations significantly increased.

CONCLUSIONS

Despite the slow improvement in female authorship over the past decade, there is still a substantial gender disparity in female first and last authorship in high-impact medical journals in pulmonary medicine.

Radiation Therapy Knowledge and Health Literacy among Culturally Diverse Patients with Prostate Cancer Treated at a Safety-Net Hospital

PURPOSE/OBJECTIVE(S)

Shared decision making is integral to the physician-patient relationship for radiotherapy (RT) patients. It is implicit that patients both comprehend and retain information explained during consultation. However, quality and quantity of patient knowledge following this visit is unknown. The purpose of this study was to evaluate post-consultation RT knowledge and health literacy among a diverse group of patients.

MATERIALS/METHODS

Participants were patients ≥18 years old who received consultation for definitive or salvage RT to the prostate gland/fossa between April 2021 and January 2023 at an urban safety-net hospital. Following consultation, patients completed the Radiation Oncology Knowledge Assessment Survey (ROKAS), designed to measure patient understanding of proposed RT treatment (e.g., treatment frequency, length, safety) and possible short- and long-term side effects (SE). Additional measures included patients' health literacy, health numeracy (numerical medical concepts), acculturation (assimilation to the dominant culture), and socioeconomic factors. ROKAS was administered in both English and Spanish with Spanish-speaking patients offered medical translation if desired. Bivariate Pearson correlations were conducted to examine the relationships between independent variables and post-consultation RT knowledge. Two-sided t-tests were conducted to examine differences in patients' knowledge by language.

RESULTS

Overall, 39 ROKAS were completed by 24 English-speaking and 15 Spanish-speaking patients (mean age 64.4 [SD 6.8], range 52-79). The majority (93%) of patients 'agreed' or 'strongly agreed' that they understood all the RT information presented. However, only 70% of the RT questions were answered correctly with 26% of patients answering all RT questions correctly. Similarly, 95% of patients 'agreed' or 'strongly agreed' with knowing the side effects of their proposed treatment, but only 71% and 74% of short- and long-term SE questions, respectively, were answered correctly. Higher health literacy (p = 0.04) and health numeracy (p = 0.001) were significantly correlated with better understanding of short-term SE, but not with RT knowledge or long-term SE. Spanish-speaking patients had significantly lower scores of health literacy (p = 0.001) and understanding of long-term (p = 0.01), but not short-term SE.

CONCLUSION

There is a significant gap between perceived and measured knowledge of RT treatment and SE in patients who receive consultation for RT to the prostate gland/fossa. Health literacy was significantly associated with improved knowledge of RT and short-term SE. Spanish-speaking patients had poorer understanding of long-term SE than English-speaking patients. Efforts to identify gaps in patient health literacy are needed to target those at risk and ensure that culturally diverse patient populations can engage in shared decision making with their providers.

Contouring Analysis on Synthetic Contrast-Enhanced MR from GRMM-GAN and Implications on MR-Guide Radiation Therapy

PURPOSE/OBJECTIVE(S)

MR-guided linear accelerators have been commercialized making MR-only planning and adaptation an appealing alternative circumventing MR-CT registration. However, obtaining daily contrast-enhanced MR images can be prohibitive due to the increased risk of side effects from repeated contrast injections. In this work, we evaluate the quality of contrast-enhanced multi-modal MR image synthesis network GRMM-GAN (gradient regularized multi-modal multi-discrimination sparse-attention fusion generative adversarial network) for MR-guided radiation therapy.

MATERIALS/METHODS

With IRB approval, we trained the GRMM-GAN based on 165 abdominal MR studies from 65 patients. Each study included T2, T1 pre-contrast (T1pre), and T1 contrast enhanced (T1ce) images. The two pre-contrast MR modalities, T2 and T1pre images were adopted as inputs for GRMM-GAN, and the T1ce image at the portal venous phase was used as an output. Ten MR scans containing 21 liver tumors were selected for contouring analysis. A Turing test was first given to six radiation oncologists, in which 100 real T1ce and synthetic T1ce image slices are randomly given to the radiation oncologists to determine the authenticity of the synthesis. We then invited two radiation oncologists (RadOnc 1 and RadOnc2) to manually contour the 21 liver tumors independently on the real T1ce images. RadOnc2 then performed contouring on the respective synthetic T1ce MRs. DICE coefficient (defined as the intersection over the average of two volumes) and Hausdorff distance (HD, measuring how far two volumes are from each other) were used as analysis metrics. The DICE coefficients were calculated from the two radiation oncologists' contours on the real T1ce MR for each tumor. The DICE coefficients were also calculated from RadOnc 2's contours on real and synthetic MRs. Besides, tumor center shifts were extracted. The tumor center of mass coordinates was extracted from real and synthetic volumes. The difference in the coordinates indicated the shifts in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions between real and synthetic tumor volumes.

RESULTS

An average of 52.3% test score was achieved from the six radiation oncologists, which is close to random guessing. RadOnc 1 and RadOnc 2, who had participated in the contouring analysis, achieved an average DICE of 0.91±0.02 from tumor volumes drawn on the real T1ce MRs. This result sets the inter-operator uncertainty baseline in the real clinical setting. RadOnc 2 achieved an average DICE (real vs. synth) of 0.90±0.04 and HD of 4.76±1.82 mm. Only sub-millimeter (SI: 0.67 mm, RL: 0.41 mm, AP: 0.39 mm) tumor center shifts were observed in all three directions.

CONCLUSION

The GRMM-GAN method has the potential for MR-guided liver radiation when contrast agents cannot be administered daily and provide synthetic contrast-enhanced MR for better tumor targeting. The network can produce synthetic MR images with satisfactory contour agreement and geometric integrity.

A Combined Phase 0/2 "Trigger" Trial Evaluating Pamiparib or Olaparib with Concurrent Radiotherapy in Patients with Newly-Diagnosed or Recurrent Glioblastoma

PURPOSE/OBJECTIVE(S)

This study evaluates the pharmacokinetic (PK) and pharmacodynamic (PD) profiles and clinical efficacy of PARP1/2 selective inhibitors, pamiparib and olaparib, in newly-diagnosed or recurrent glioblastoma (GBM) patients in combination with radiotherapy (RT).

MATERIALS/METHODS

In this combined phase 0/2 trial presumed newly-diagnosed (Arm A) or recurrent (Arm B) GBM patients received 4 days of pamiparib (60 mg BID) prior to resection either 2-4 or 8-12 hours following the final dose. Arm C enrolled patients with recurrent GBM to 4 days of olaparib (200 mg BID) prior to resection. Enhancing and nonenhancing tumor tissue, cerebrospinal fluid (CSF) and plasma were collected. Total and unbound drug concentrations were measured using validated LC-MS/MS methods. A PK 'trigger', defined as unbound drug and gt; 5-fold biochemical IC 50 in nonenhancing tumor, determined eligibility for the therapeutic expansion phase 2. PARP inhibition was assessed via ex vivo radiation and quantification of PAR levels compared to non-radiated control. Newly-diagnosed MGMT unmethylated GBMs and recurrent GBMs exceeding the PK threshold were eligible for an expansion phase of pamiparib (Arms A and B) or olaparib (Arm C) with concurrent RT followed by maintenance pamiparib or olaparib. RT was 60 Gy in 30 fractions in newly-diagnosed patients and 40 Gy in 15 fractions in recurrent patients, delivered using volumetric-modulated arc therapy (VMAT).

RESULTS

A total of 38 patients (Arm A, n = 16; Arm B, n = 16; Arm C, n = 6) were enrolled in the initial phase 0 study. The mean unbound concentrations of pamiparib in nonenhancing tumor region for Arm A and Arm B were 167.3 nM and 109.4 nM respectively, and in Arm C the mean unbound concentration of olaparib was 5.2 nM. All patients in the pamiparib arms (n = 32/32) but only 1 of 6 patients in the olaparib Arm C exceeded the PK threshold. Radiation-induced PAR expression was 2.44-fold in untreated control vs 1.16 in Arm A (p<0.05), 0.85 in Arm B (p<0.01) and 1.11 in Arm C patients, respectively. In Arm A, 11 patients had unmethylated tumors, and of those, 7 patients enrolled in phase 2. In Arm B, 9 of the 16 clinically eligible patients with positive PK results were enrolled in phase 2. At a median follow-up of 8.4 months [range: 1.3-15.7 months], the median progression-free survival (PFS) was 5.4, 6.0, and 3.8 months for Arms A (n = 7), B (n = 9), and C (n = 1), respectively. Grade 3+ toxicities related to pamiparib occurred in 4 patients, with 2 adverse events resulting in treatment discontinuation. No grade 3+ toxicities were documented in the olaparib arm.

CONCLUSION

Pamiparib achieved pharmacologically-relevant concentrations in nonenhancing GBM tissue and suppressed induction of PAR levels ex vivo post-radiation. The majority of patients with MGMT-unmethylated GBM advanced to the phase 2 portion of the trial, and pamiparib was generally well-tolerated in these patients.

A Combined Phase 0/2 "Trigger" Trial of Niraparib in Combination with Radiation in Patients with Newly-Diagnosed Glioblastoma

PURPOSE/OBJECTIVE(S)

Poly ADP-ribose (PAR) polymerase (PARP) mediates DNA damage response. Niraparib is an investigational PARP1/2-selective inhibitor. We conducted a combined phase 0/2 study to evaluate niraparib pharmacokinetics (PK) and pharmacodynamics (PD) in patients with newly-diagnosed glioblastoma (GBM), graduating patients to a phase 2 study evaluating a therapeutic regimen of niraparib with concurrent conventionally-fractionated radiotherapy (RT) in O6-methylguanine methyltransferase (MGMT) unmethylated tumors exceeding a prespecified PK threshold in non-enhancing tumor.

MATERIALS/METHODS

Patients with presumed newly-diagnosed GBM were enrolled in a phase 0 study receiving 4 days of niraparib (300 or 200 mg QD) prior to planned resection 3-5 or 8-12 hours following the last dose. Tumor tissue (enhancing and non-enhancing regions), cerebrospinal fluid (CSF), and plasma were collected. Total and unbound niraparib concentrations were measured using validated LC-MS/MS methods. PARP inhibition was assessed by quantification of PAR induction after 10 Gy ex vivo irradiation in surgical tissue compared to non-irradiated control tissue. A PK 'trigger' determined eligibility for the therapeutic phase 2 expansion portion of the study. This was defined as unbound [niraparib] > 5-fold biochemical IC50 (i.e., 19 nM) in non-enhancing tumor. Patients with MGMT unmethylated tumors exceeding this PK threshold were eligible for expansion phase dosing of niraparib with concurrent RT followed by a maintenance phase of niraparib. Patients with MGMT methylated tumors were not eligible for the expansion phase and proceeded with temozolomide (TMZ) plus RT followed by maintenance TMZ. RT dose was 60 Gy in 30 fractions using volumetric-modulated arc therapy (VMAT).

RESULTS

All 29 patients enrolled in the phase 0 portion of the study met the PK threshold. In non-enhancing regions, the mean unbound concentration of niraparib was 258.2 nM. The suppression of PAR levels after ex vivo RT was observed in 79% of the patients (17/22). Sixteen patients had unmethylated tumors, and of those, 11 patients enrolled in phase 2. Five of the 6 initial patients enrolled in phase 2 experienced thrombocytopenia related to niraparib, and 3/5 cases were deemed serious and life-threatening. Consequently, starting dose in both phases was lowered to 200 mg, and no serious AEs were observed thereafter. At a median follow-up of 8.1 months [range: 6.0-12.9 months], 6-month PFS was 64% with 4 patients remaining on treatment and 5 patients ongoing survival follow-up.

CONCLUSION

Niraparib achieves pharmacologically-relevant concentrations in non-enhancing, newly-diagnosed GBM tissue in excess of any other studied PARP inhibitor. When delivered with concurrent RT, niraparib was well-tolerated, with low rates of grade 3+ toxicity. Initial clinical efficacy data are encouraging.

Immune-mediated hematological disease in dogs is associated with alterations of the fecal microbiota: a pilot study

BACKGROUND

The dog is the most popular companion animal and is a valuable large animal model for several human diseases. Canine immune-mediated hematological diseases, including immune-mediated hemolytic anemia (IMHA) and immune thrombocytopenia (ITP), share many features in common with autoimmune hematological diseases of humans. The gut microbiome has been linked to systemic illness, but few studies have evaluated its association with immune-mediated hematological disease. To address this knowledge gap, 16S rRNA gene sequencing was used to profile the fecal microbiota of dogs with spontaneous IMHA and ITP at presentation and following successful treatment. In total, 21 affected and 13 healthy control dogs were included in the study.

RESULTS

IMHA/ITP is associated with remodeling of fecal microbiota, marked by decreased relative abundance of the spirochete Treponema spp., increased relative abundance of the pathobionts Clostridium septicum and Escherichia coli, and increased overall microbial diversity. Logistic regression analysis demonstrated that Treponema spp. were associated with decreased risk of IMHA/ITP (odds ratio [OR] 0.24-0.34), while Ruminococcaceae UCG-009 and Christensenellaceae R-7 group were associated with increased risk of disease (OR = 6.84 [95% CI 2-32.74] and 8.36 [95% CI 1.85-71.88] respectively).

CONCLUSIONS

This study demonstrates an association of immune-mediated hematological diseases in dogs with fecal dysbiosis, and points to specific bacterial genera as biomarkers of disease. Microbes identified as positive or negative risk factors for IMHA/ITP represent an area for future research as potential targets for new diagnostic assays and/or therapeutic applications.

Characteristics and outcomes of patients with acute myeloid leukemia admitted to intensive care unit with acute respiratory failure: a post-hoc analysis of a prospective multicenter study

BACKGROUND

Acute respiratory failure (ARF) is the leading cause of intensive care unit (ICU) admission in patients with Acute Myeloid Leukemia (AML) and data on prognostic factors affecting short-term outcome are needed.

METHODS

This is a post-hoc analysis of a multicenter, international prospective cohort study on immunocompromised patients with ARF admitted to ICU. We evaluated hospital mortality and associated risk factors in patients with AML and ARF; secondly, we aimed to define specific subgroups within our study population through a cluster analysis.

RESULTS

Overall, 201 of 1611 immunocompromised patients with ARF had AML and were included in the analysis. Hospital mortality was 46.8%. Variables independently associated with mortality were ECOG performance status ≥ 2 (OR = 2.79, p = 0.04), cough (OR = 2.94, p = 0.034), use of vasopressors (OR = 2.79, p = 0.044), leukemia-specific pulmonary involvement [namely leukostasis, pulmonary infiltration by blasts or acute lysis pneumopathy (OR = 4.76, p = 0.011)] and liver SOFA score (OR = 1.85, p = 0.014). Focal alveolar chest X-ray pattern was associated with survival (OR = 0.13, p = 0.001). We identified 3 clusters, that we named on the basis of the most frequently clinical, biological and radiological features found in each cluster: a "leukemic cluster", with high-risk AML patients with isolated, milder ARF; a "pulmonary cluster", consisting of symptomatic, highly oxygen-requiring, severe ARF with diffuse radiological findings in heavily immunocompromised patients; a clinical "inflammatory cluster", including patients with multi-organ failures in addition to ARF. When included in the multivariate analysis, cluster 2 and 3 were independently associated with hospital mortality.

CONCLUSIONS

Among AML patients with ARF, factors associated with a worse outcome are related to patient's background (performance status, leukemic pulmonary involvement), symptoms, radiological findings, the need for vasopressors and the liver SOFA score. We identified three specific ARF syndromes in AML patients, which showed a prognostic significance and could guide clinicians to optimize management strategies.

Outcomes of critically ill older adults with COVID-19: a multicentre retrospective cohort study

PURPOSE

Older adults with COVID-19 have a high prevalence of complications and mortality during hospitalization. Given the large proportion of older adults requiring admission to an intensive care unit (ICU), we aimed to describe the management and outcomes of older adults with COVID-19 requiring ICU care and identify predictors of hospital mortality.

METHODS

We included consecutive patients ≥ 65 yr of age who were admitted between 11 March 2020 and 30 June 2021 to one of five Toronto (ON, Canada) ICUs with a primary diagnosis of SARS-CoV-2 infection in a retrospective cohort study. Patient characteristics, ICU treatment, and outcomes were recorded. We used multivariable logistic regression to identify predictors of in-hospital mortality.

RESULTS

Of the 273 patients, the median [interquartile range] age was 74 [69-80] yr, 104 (38.1%) were female, and 164 (60.1%) required invasive mechanical ventilation. One hundred and forty-two patients (52.0%) survived their hospital stay. Compared with survivors, nonsurvivors were older (74 [70-82] yr vs 73 [68-78] yr; P = 0.03), and a smaller proportion was female (39/131, 29.8% vs 65/142, 45.8%; P = 0.01). Patients had long hospital (19 [11-35] days) and ICU (9 [5-22] days) stays, with no significant differences in ICU length of stay or duration of invasive mechanical ventilation between the two groups. Higher APACHE II score, increasing age, and the need for organ support were independently associated with higher in-hospital mortality while female sex was associated with lower mortality.

CONCLUSIONS

Older critically ill COVID-19 patients had long ICU and hospital stays, and approximately half died in hospital. Further research is needed to identify individuals who will benefit most from an ICU admission and to evaluate posthospitalization outcomes.

Resuscitation outcomes in patients with cancer: experience in a large urban cancer centre

PURPOSE

Hospitalized patients with cancer who experience cardiopulmonary arrest have historically low survival rates. This retrospective cohort study describes outcomes of patients at a large Canadian cancer centre who had a "code medical emergency" activated, and the use of pragmatic criteria to identify patients with poor survival following resuscitation.

METHODS

We included hospitalized patients with cancer who had a "code blue" activated between January 2007 and December 2018. Our primary outcome was intensive care unit (ICU) mortality. We developed pragmatic criteria to identify patients with "poor prognosis" for survival from cardiopulmonary resuscitation (CPR) based on disease status and candidacy for further cancer treatment. We used descriptive statistics to analyze the outcomes of poor prognosis patients.

RESULTS

Two hundred and twenty-five patients had a code blue activated. The median age was 61 yr, 52% were male, and 48% had a solid tumour. Overall, 173/225 (77%) patients survived the code blue; 164 were admitted to the ICU, where 49% (81/164) died; 31% survived to hospital discharge; and 16% (n = 27) were alive at one year. One hundred and twenty out of 225 (53%) required chest compressions; spontaneous circulation returned in 61% (73/120), and 12% (14/120) survived to hospital discharge. Patients meeting "poor prognosis" criteria (114, 51%) were more likely to die in the ICU (64% vs 35%; P < 0.001) or in hospital (86% vs 59%; P < 0.001), and more often had goals-of-care discussions prior to the code blue (46% vs 7%; P < 0.001). At one year, only 2% of poor prognosis patients were alive, compared with 24% of patients who did not meet any poor prognosis criteria.

CONCLUSION

Hospitalized patients with cancer requiring CPR have poor hospital and long-term outcomes. The proposed set of pragmatic criteria may be useful to identify patients unlikely to benefit from CPR and life support, to trigger early goals of care discussions, and to avoid potentially goal-discordant interventions.

Critical Care Cycling to Improve Lower Extremity Strength (CYCLE): protocol for an international, multicentre randomised clinical trial of early in-bed cycling for mechanically ventilated patients

INTRODUCTION

In-bed leg cycling with critically ill patients is a promising intervention aimed at minimising immobility, thus improving physical function following intensive care unit (ICU) discharge. We previously completed a pilot randomised controlled trial (RCT) which supported the feasibility of a large RCT. In this report, we describe the protocol for an international, multicentre RCT to determine the effectiveness of early in-bed cycling versus routine physiotherapy (PT) in critically ill, mechanically ventilated adults.

METHODS AND ANALYSIS

We report a parallel group RCT of 360 patients in 17 medical-surgical ICUs and three countries. We include adults (≥18 years old), who could ambulate independently before their critical illness (with or without a gait aid), ≤4 days of invasive mechanical ventilation and ≤7 days ICU length of stay, and an expected additional 2-day ICU stay, and who do not fulfil any of the exclusion criteria. After obtaining informed consent, patients are randomised using a web-based, centralised system to either 30 min of in-bed cycling in addition to routine PT, 5 days per week, up to 28 days maximum, or routine PT alone. The primary outcome is the Physical Function ICU Test-scored (PFIT-s) at 3 days post-ICU discharge measured by assessors blinded to treatment allocation. Participants, ICU clinicians and research coordinators are not blinded to group assignment. Our sample size estimate was based on the identification of a 1-point mean difference in PFIT-s between groups.

ETHICS AND DISSEMINATION

Critical Care Cycling to improve Lower Extremity (CYCLE) is approved by the Research Ethics Boards of all participating centres and Clinical Trials Ontario (Project 1345). We will disseminate trial results through publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03471247 (Full RCT); NCT02377830 (CYCLE Vanguard 46 patient internal pilot).

Machine Learning Classification of Alzheimer's Disease Pathology Reveals Diffuse Amyloid as a Major Predictor of Cognitive Impairment in Human Hippocampal Subregions

Analyzing Alzheimer's disease (AD) pathology within anatomical subregions is a significant challenge, often carried out by pathologists using a standardized, semi-quantitative approach. To augment traditional methods, a high-throughput, high-resolution pipeline was created to classify the distribution of AD pathology within hippocampal subregions. USC ADRC post-mortem tissue sections from 51 patients were stained with 4G8 for amyloid, Gallyas for neurofibrillary tangles (NFTs) and Iba1 for microglia. Machine learning (ML) techniques were utilized to identify and classify amyloid pathology (dense, diffuse and APP (amyloid precursor protein)), NFTs, neuritic plaques and microglia. These classifications were overlaid within manually segmented regions (aligned with the Allen Human Brain Atlas) to create detailed pathology maps. Cases were separated into low, intermediate, or high AD stages. Further data extraction enabled quantification of plaque size and pathology density alongside ApoE genotype, sex, and cognitive status. Our findings revealed that the increase in pathology burden across AD stages was driven mainly by diffuse amyloid. The pre and para-subiculum had the highest levels of diffuse amyloid while NFTs were highest in the A36 region in high AD cases. Moreover, different pathology types had distinct trajectories across disease stages. In a subset of AD cases, microglia were elevated in intermediate and high compared to low AD. Microglia also correlated with amyloid pathology in the Dentate Gyrus. The size of dense plaques, which may represent microglial function, was lower in ApoE4 carriers. In addition, individuals with memory impairment had higher levels of both dense and diffuse amyloid. Taken together, our findings integrating ML classification approaches with anatomical segmentation maps provide new insights on the complexity of disease pathology in AD progression. Specifically, we identified diffuse amyloid pathology as being a major driver of AD in our cohort, regions of interest and microglial responses that might advance AD diagnosis and treatment.

Sex differences in thromboprophylaxis of the critically ill: a secondary analysis of a randomized trial

PURPOSE

Venous thromboembolism (VTE) is a common complication of critical illness. Sex- or gender-based analyses are rarely conducted and their effect on outcomes is unknown. We assessed for an effect modification of thromboprophylaxis (dalteparin or unfractionated heparin [UFH]) by sex on thrombotic (deep venous thrombosis [DVT], pulmonary embolism [PE], VTE) and mortality outcomes in a secondary analysis of the Prophylaxis for Thromboembolism in Critical Care Trial (PROTECT).

METHODS

We conducted unadjusted analyses using Cox proportional hazards analysis, stratified by centre and admission diagnostic category, including sex, treatment, and an interaction term. Additionally, we performed adjusted analyses and assessed the credibility of our findings.

RESULTS

Critically ill female (n = 1,614) and male (n = 2,113) participants experienced similar rates of DVT, proximal DVT, PE, any VTE, ICU death, and hospital death. In unadjusted analyses, we did not find significant differences in treatment effect favouring males (vs females) treated with dalteparin (vs UFH) for proximal leg DVT, any DVT, or any PE, but found a statistically significant effect (moderate certainty) favouring dalteparin in males for any VTE (males: hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.52 to 0.96 vs females: HR, 1.16; 95% CI, 0.81 to 1.68; P = 0.04). This effect remained after adjustment for baseline characteristics (males: HR, 0.70; 95% CI, 0.52 to 0.96 vs females: HR, 1.17; 95% CI, 0.81 to 1.68; P = 0.04) and weight (males: HR, 0.70; 95% CI, 0.52 to 0.96 vs females: HR, 1.20; 95% CI, 0.83 to 1.73; P = 0.03). We did not identify a significant effect modification by sex on mortality.

CONCLUSIONS

We found an effect modification by sex of thromboprophylaxis on VTE in critically ill patients that requires confirmation. Our findings highlight the need for sex- and gender-based analyses in acute care research.

Outcomes of COVID-19 manuscripts submitted to the Canadian Journal of Anesthesia: a retrospective audit of author gender and person of colour status

PURPOSE

We aimed to evaluate the representation of women and persons of colour (POC) authors of COVID-19 manuscripts submitted to, accepted in, and rejected from the Journal and to evaluate trends in their representation during the pandemic.

METHODS

All COVID-19 manuscripts submitted to the Journal between 1 February 2020 and 30 April 2021 were included. Manuscript data were retrieved from Editorial Manager, and gender and POC status were obtained through: 1) e-mail communication with corresponding authors; 2) e-mail queries to other coauthors; 3) NamSor software, and 4) Internet searches. The data were described using percentages and summary statistics. A two-sample test of proportions was used for comparisons and trends were analyzed with linear regression.

RESULTS

We identified 314 manuscripts (1,555 authors), 95 (461 authors) of which were accepted for publication. Of all authors, 515 (33%) were women, and women were the lead and senior authors of 101 (32%) and 69 (23%) manuscripts, respectively. There were no differences in women's representation as authors between accepted and rejected manuscripts. Overall, 923/1,555 (59%) authors were identified as POC, with a significantly lower proportion of POC authors among accepted vs rejected manuscripts (41%, 188/461 vs 67%, 735/1,094; difference, -26%; 95% CI, -32 to -21; P < 0.001). We did not observe significant trends in the proportion of women and POC authors over the study period.

CONCLUSION

The proportion of women authors of COVID-19 manuscripts was lower than men's representation. Further research is required to determine the factors that account for the higher proportion of POC authors across rejected manuscripts.

Microaggressions in anesthesiology and critical care: individual and institutional approaches to change

Microaggressions are subtle verbal or nonverbal insults that convey derogatory and negative messages to and about people who belong to oppressed groups. Microaggressions reflect structurally and historically perpetuated societal values, which advantage some groups of people by considering them to be inherently more worthy than others, while simultaneously disadvantaging others. While microaggressions may seem innocuous and are often unintentional, they cause tangible harm. Microaggressions are commonly experienced by physicians and learners working in perioperative and critical care contexts and are often not adequately addressed, for a multitude of reasons, including witnesses not knowing how to respond. In this narrative review, we provide examples of microaggressions towards physicians and learners working in anesthesia and critical care, and offer individual and institutional approaches to managing such incidents. Concepts of privilege and power are introduced to ground interpersonal interventions within the larger context of systemic discrimination, and to encourage anesthesia and critical care physicians to contribute to systemic solutions.

Addressing health care inequities in Canadian critical care through inclusive science: a pilot tool for standardized data collection

PURPOSE

Sociodemographic risks contributing to health inequities are often inadequately captured and reported in critical care studies. To address the lack of standardized terms and definitions, we sought to develop a practical and convenient resource of questions and response options for collecting sociodemographic variables for critical care research.

SOURCE

To identify domains and variables that impact health equity, we searched: 1) PubMed for critical care randomized trials (2010 to 2021); 2) high-impact critical care and general medicine journals for special issues relating to equity; and 3) governmental and nongovernmental resources.

PRINCIPAL FINDINGS

We identified 23 domains associated with health equity, including pronouns, age, sex, gender identity, sexual orientation, race and ethnicity, visible minorities, language, household income, marital/relationship status, education, disabilities, immigrant and refugee status, employment, primary care access, expanded health insurance, internet access, housing security, food security, dependents, religion, and postal code. For each domain we provided standardized questions and response options; for 13/23 domains, we included more than one version of the question and response categories.

CONCLUSION

We developed a standardized, practical, and convenient demographic data collection tool for critical care research studies. Questions and response options can be adapted by researchers for inclusion in individual study questionnaires or case report forms.

Etiologies and Outcome of Patients with Solid Tumors Admitted to ICU with Acute Respiratory Failure: A Secondary Analysis of the EFRAIM Study

BACKGROUND

Acute respiratory failure (ARF) remains the most frequent reason for ICU admission in patients who are immunocompromised. This study reports etiologies and outcomes of ARF in subjects with solid tumors.

METHODS

This study was a post hoc analysis of the EFRAIM study, a prospective multinational cohort study that included 1611 subjects who were immunocompromised and with ARF admitted to the ICU. Subjects with solid tumors admitted to the ICU with ARF were included in the analysis.

RESULTS

Among the subjects from the EFRAIM cohort, 529 subjects with solid tumors (32.8%) were included in the analysis. At ICU admission, the median (interquartile range) Sequential Organ Failure Assessment score was 5 (3-9). The types of solid tumor were mostly lung cancer (n = 111, 21%), breast cancer (n = 52, 9.8%), and digestive cancer (n = 47, 8.9%). A majority, 379 subjects (71.6%) were full code at ICU admission. The ARF was caused by bacterial or viral infection (n = 220, 41.6%), extrapulmonary sepsis (n = 62, 11.7%), or related to cancer or treatment toxicity (n = 83, 15.7%), or fungal infection (n = 23, 4.3%). For 63 subjects (11.9%), the ARF etiology remained unknown after an extensive diagnostic workup. The hospital mortality rate was 45.7% (n = 232/508). Hospital mortality was independently associated with chronic cardiac failure (odds ratio 1.78, 95% CI 1.09-2.92; P = .02), lung cancer (odds ratio 2.50, 95% CI 1.51-4.19; P < .001), day 1 Sequential Organ Failure Assessment score (odds ratio 1.97, 95% CI 1.32-2.96; P < .001). ARF etiologies other than infectious, related to cancer, or treatment toxicity were associated with better outcomes (odds ratio 0.32, 95% CI 0.16-0.61; P < .001).

CONCLUSIONS

Infectious diseases remained the most frequent cause of ARF in subjects with solid tumors admitted to the ICU. Hospital mortality was related to severity at ICU admission, previous comorbidities, and ARF etiologies related to non-malignant causes or pulmonary embolism. Lung tumor was also independently associated with higher mortality.

Symptom Assessment for Mechanically Ventilated Patients: Principles and Priorities: An Official American Thoracic Society Workshop Report

Mechanically ventilated patients experience many adverse symptoms, such as anxiety, thirst, and dyspnea. However, these common symptoms are not included in practice guideline recommendations for routine assessment of mechanically ventilated patients. An American Thoracic Society-sponsored workshop with researchers and clinicians with expertise in critical care and symptom management was convened for a discussion of symptom assessment in mechanically ventilated patients. Members included nurses, physicians, a respiratory therapist, a speech-language pathologist, a critical care pharmacist, and a former intensive care unit patient. This report summarizes existing evidence and consensus among workshop participants regarding 1) symptoms that should be considered for routine assessment of adult patients receiving mechanical ventilation; 2) key symptom assessment principles; 3) strategies that support symptom assessment in nonvocal patients; and 4) areas for future clinical practice development and research. Systematic patient-centered assessment of multiple symptoms has great potential to minimize patient distress and improve the patient experience. A culture shift is necessary to promote ongoing holistic symptom assessment with valid and reliable instruments. This report represents our workgroup consensus on symptom assessment for mechanically ventilated patients. Future work should address how holistic, patient-centered symptom assessment can be embedded into clinical practice.

Physical restraint practices in an adult intensive care unit: A prospective observational study

AIM AND OBJECTIVES

To conduct a diagnostic evaluation of physical restraint practice using the integrated-Promoting Action on Research Implementation in Health Services (i-PARIHS) framework.

BACKGROUND

Evidence indicates that physical restraints are associated with adverse physical, emotional and psychological sequelae and do not consistently prevent intensive care unit (ICU) patient-initiated device removal. Nevertheless, physical restraints continue to be used extensively in ICUs both in Canada and internationally. Implementation science frameworks have not been previously used to diagnose, develop and guide the implementation of restraint minimisation interventions.

DESIGN

A prospective observational study of restrained patients in a 20-bed, academic ICU in Toronto, Canada.

METHODS

Data collection methods included patient observation, electronic medical record review, and verbal check with the point-of-care nurses. Data were collected pertaining to framework domains of unit culture (restraint application/removal), evaluation capacity (documentation) and leadership (rounds discussion). The reporting of this study followed the STROBE guidelines.

RESULTS

A total of 102 restrained patients, 67 (66%) male and mean age 58 years (SD 1.92), were observed. All observed devices were wrist restraints. Restraint application and removal time was verified in 83 and 57 of 102 patients respectively. At application, 96.4% were mechanically ventilated and 71% sedated/unarousable. Nurses confirmed 71% were prophylactically restrained; 7.2% received restraint alternatives. Restraint removal occurred after interprofessional team rounds (87%), during daytime (79%) and following extubation (52.6%). Of the 923 discrete patient observation of physical restraint use, 691 (75%) were not documented. Of the 30 daytime interprofessional team rounds reviewed, physical restraint was discussed at 3 (10%).

CONCLUSION

In this single-centre study, a culture of prophylactic physical restraint was observed. Future facilitation of restraint minimisation warrants theoretically informed implementation strategies including leadership involvement to advance interprofessional collaboration.

RELEVANCE TO CLINICAL PRACTICE

The findings draw attention to the importance of a preliminary diagnostic study of the context prior to designing, and implementing, a physical restraint minimisation intervention.

Association of early mobility with the incidence of deep-vein thrombosis and mortality among critically ill patients: a post hoc analysis of PREVENT trial

BACKGROUND

This study assessed the mobility levels among critically ill patients and the association of early mobility with incident proximal lower-limb deep-vein thrombosis and 90-day mortality.

METHODS

This was a post hoc analysis of the multicenter PREVENT trial, which evaluated adjunctive intermittent pneumatic compression in critically ill patients receiving pharmacologic thromboprophylaxis with an expected ICU stay ≥ 72 h and found no effect on the primary outcome of incident proximal lower-limb deep-vein thrombosis. Mobility levels were documented daily up to day 28 in the ICU using a tool with an 8-point ordinal scale. We categorized patients according to mobility levels within the first 3 ICU days into three groups: early mobility level 4-7 (at least active standing), 1-3 (passive transfer from bed to chair or active sitting), and 0 (passive range of motion). We evaluated the association of early mobility and incident lower-limb deep-vein thrombosis and 90-day mortality by Cox proportional models adjusting for randomization and other co-variables.

RESULTS

Of 1708 patients, only 85 (5.0%) had early mobility level 4-7 and 356 (20.8%) level 1-3, while 1267 (74.2%) had early mobility level 0. Patients with early mobility levels 4-7 and 1-3 had less illness severity, femoral central venous catheters, and organ support compared to patients with mobility level 0. Incident proximal lower-limb deep-vein thrombosis occurred in 1/85 (1.3%) patients in the early mobility 4-7 group, 7/348 (2.0%) patients in mobility 1-3 group, and 50/1230 (4.1%) patients in mobility 0 group. Compared with early mobility group 0, mobility groups 4-7 and 1-3 were not associated with differences in incident proximal lower-limb deep-vein thrombosis (adjusted hazard ratio [aHR] 1.19, 95% confidence interval [CI] 0.16, 8.90; p = 0.87 and 0.91, 95% CI 0.39, 2.12; p = 0.83, respectively). However, early mobility groups 4-7 and 1-3 had lower 90-day mortality (aHR 0.47, 95% CI 0.22, 1.01; p = 0.052, and 0.43, 95% CI 0.30, 0.62; p < 0.0001, respectively).

CONCLUSIONS

Only a small proportion of critically ill patients with an expected ICU stay ≥ 72 h were mobilized early. Early mobility was associated with reduced mortality, but not with different incidence of deep-vein thrombosis. This association does not establish causality, and randomized controlled trials are required to assess whether and to what extent this association is modifiable.

TRIAL REGISTRATION

The PREVENT trial is registered at ClinicalTrials.gov, ID: NCT02040103 (registered on 3 November 2013) and Current controlled trials, ID: ISRCTN44653506 (registered on 30 October 2013).

A qualitative descriptive study of the impact of the COVID-19 pandemic on staff in a Canadian intensive care unit

PURPOSE

We sought to explore the lived experiences of a professionally diverse sample of healthcare workers (HCWs) in a single intensive care unit (ICU) serving a large and generalizable Canadian population. We aimed to understand how working during the COVID-19 pandemic affected their professional and personal lives, including their perceptions of institutional support, to inform interventions to ameliorate impacts of the COVID-19 and future pandemics.

METHODS

In this qualitative descriptive study, 23 ICU HCWs, identified using convenience purposive sampling, took part in individual semistructured interviews between July and November 2020, shortly after the first wave of the pandemic in Ontario. We used inductive thematic analysis to identify major themes.

RESULTS

We identified five major themes related to the COVID-19 pandemic: 1) communication and informational needs (e.g., challenges communicating policy changes); 2) adjusting to restricted visitation (e.g., spending less time interacting with patients); 3) staffing and workplace supports (e.g., importance of positive team dynamics); 4) permeability of professional and personal lives (e.g., balancing shift work and childcare); and 5) a dynamic COVID-19 landscape (e.g., coping with constant change). The COVID-19 pandemic contributed to HCWs in the ICU experiencing varied negative repercussions on their work environment, including staffing and institutional support, which carried into their personal lives.

CONCLUSION

Healthcare workers in the ICU perceived that the COVID-19 pandemic had negative repercussions on their work environment, including staffing and institutional support, as well as their professional and personal lives. Understanding both the negative and positive experiences of all ICU HCWs working during the COVID-19 pandemic is critical to future pandemic preparedness. Their perspectives will help to inform the development of mental health and wellbeing interventions to support staff during the COVID-19 pandemic and beyond.

Oxygenation thresholds for invasive ventilation in hypoxemic respiratory failure: a target trial emulation in two cohorts

BACKGROUND

The optimal thresholds for the initiation of invasive ventilation in patients with hypoxemic respiratory failure are unknown. Using the saturation-to-inspired oxygen ratio (SF), we compared lower versus higher hypoxemia severity thresholds for initiating invasive ventilation.

METHODS

This target trial emulation included patients from the Medical Information Mart for Intensive Care (MIMIC-IV, 2008-2019) and the Amsterdam University Medical Centers (AmsterdamUMCdb, 2003-2016) databases admitted to intensive care and receiving inspired oxygen fraction ≥ 0.4 via non-rebreather mask, noninvasive ventilation, or high-flow nasal cannula. We compared the effect of using invasive ventilation initiation thresholds of SF < 110, < 98, and < 88 on 28-day mortality. MIMIC-IV was used for the primary analysis and AmsterdamUMCdb for the secondary analysis. We obtained posterior means and 95% credible intervals (CrI) with nonparametric Bayesian G-computation.

RESULTS

We studied 3,357 patients in the primary analysis. For invasive ventilation initiation thresholds SF < 110, SF < 98, and SF < 88, the predicted 28-day probabilities of invasive ventilation were 72%, 47%, and 19%. Predicted 28-day mortality was lowest with threshold SF < 110 (22.2%, CrI 19.2 to 25.0), compared to SF < 98 (absolute risk increase 1.6%, CrI 0.6 to 2.6) or SF < 88 (absolute risk increase 3.5%, CrI 1.4 to 5.4). In the secondary analysis (1,279 patients), the predicted 28-day probability of invasive ventilation was 50% for initiation threshold SF < 110, 28% for SF < 98, and 19% for SF < 88. In contrast with the primary analysis, predicted mortality was highest with threshold SF < 110 (14.6%, CrI 7.7 to 22.3), compared to SF < 98 (absolute risk decrease 0.5%, CrI 0.0 to 0.9) or SF < 88 (absolute risk decrease 1.9%, CrI 0.9 to 2.8).

CONCLUSION

Initiating invasive ventilation at lower hypoxemia severity will increase the rate of invasive ventilation, but this can either increase or decrease the expected mortality, with the direction of effect likely depending on baseline mortality risk and clinical context.

Sustained intra-cartilage delivery of interleukin-1 receptor antagonist using cationic peptide and protein-based carriers

OBJECTIVE

Blocking the interleukin-1 (IL-1) catabolic cascade following joint trauma can be achieved using its receptor antagonist, IL-1Ra. However, its clinical translation for osteoarthritis therapy has been unsuccessful due to its rapid joint clearance and lack of targeting and penetration into deep cartilage layers at therapeutic concentrations. Here, we target the high negative charge of cartilage aggrecan-glycosaminoglycans (GAGs) by attaching cationic carriers to IL-1Ra. IL-1Ra was conjugated to the cartilage targeting glycoprotein, Avidin, and a short length optimally charged cationic peptide carrier (CPC+14). It is hypothesized that electro-diffusive transport and binding properties of IL-1Ra-Avidin and IL-1Ra-CPC+14 will create intra-cartilage depots of IL-1Ra, resulting in long-term suppression of IL-1 catabolism with only a single administration.

DESIGN

IL-1Ra was conjugated to Avidin or CPC+14 using site specific maleimide linkers, and confirmed using gel electrophoresis, high-performance liquid chromatography (HPLC), and mass spectrometry. Intra-cartilage transport and retention of conjugates was compared with native IL-1Ra. Attenuation of IL-1 catabolic signaling with one-time dose of IL-1Ra-CPC+14 and IL-1Ra-Avidin was assessed over 16 days using IL-1α challenged bovine cartilage and compared with unmodified IL-1Ra.

RESULTS

Positively charged IL-1Ra penetrated through the full-thickness of cartilage, creating a drug depot. A single dose of unmodified IL-1Ra was not sufficient to attenuate IL-1-induced cartilage deterioration over 16 days. However, when delivered using Avidin, and to a greater extent CPC+14, IL-1Ra significantly suppressed cytokine induced GAG loss and nitrite release while improving cell metabolism and viability.

CONCLUSION

Charge-based cartilage targeting drug delivery systems hold promise as they can enable long-term therapeutic benefit with only a single dose.

The association between nutritional risk index and ICU outcomes across hematologic malignancy patients with acute respiratory failure

Patients with hematological malignancies (HM) are at risk of acute respiratory failure (ARF). Malnutrition, a common association with HM, has the potential to influence ICU outcomes. Geriatric nutritional risk index (G-NRI) is a score derived from albumin and weight, which reflects risk of protein-energy malnutrition. We evaluated the association between G-NRI at ICU admission and ICU mortality in HM patients with ARF. We conducted a single center retrospective study of ventilated HM patients between 2014 and 2018. We calculated G-NRI for all patients using their ICU admission albumin and weight. Our primary outcome was ICU mortality. Secondary outcomes included duration of mechanical ventilation and ICU length of stay. Two hundred eighty patients were admitted to the ICU requiring ventilation. Median age was 62 years (IQR 51-68), 42% (n = 118) were females, and median SOFA score was 11 (IQR 9-14). The most common type of HM was acute leukemia (54%) and 40% underwent hematopoietic cell transplant. Median G-NRI was 87 (IQR 79-99). ICU mortality was 51% (n = 143) with a median duration of ventilation of 4 days (IQR 2-7). Mortality across those at severe malnutrition (NRI < 83.5) was 59% (65/111) compared to 46% (76/164) across those with moderate-no risk (p = 0.047). On multivariable analysis, severe NRI (OR 2.34, 95% CI 1.04-5.27, p = 0.04) was significantly associated with ICU mortality. In this single center, exploratory study, severe G-NRI was prognostic of ICU mortality in HM patients admitted with respiratory failure.

Do Thresholds for Invasive Ventilation in Hypoxemic Respiratory Failure Exist? A Cohort Study

Rationale: Invasive ventilation is a significant event for patients with respiratory failure. Physiologic thresholds standardize the use of invasive ventilation in clinical trials, but it is unknown whether thresholds prompt invasive ventilation in clinical practice. Objectives: To measure, in patients with hypoxemic respiratory failure, the probability of invasive ventilation within 3 hours after meeting physiologic thresholds. Methods: We studied patients admitted to intensive care receiving Fi_O2 of 0.4 or more via nonrebreather mask, noninvasive positive pressure ventilation, or high-flow nasal cannula, using data from the Medical Information Mart for Intensive Care (MIMIC)-IV database (2008-2019) and the Amsterdam University Medical Centers Database (AmsterdamUMCdb) (2003-2016). We evaluated 17 thresholds, including the ratio of arterial to inspired oxygen, the ratio of saturation to inspired oxygen ratio, composite scores, and criteria from randomized trials. We report the probability of invasive ventilation within 3 hours of meeting each threshold and its association with covariates using odds ratios (ORs) and 95% credible intervals (CrIs). Measurements and Main Results: We studied 4,726 patients (3,365 from MIMIC, 1,361 from AmsterdamUMCdb). Invasive ventilation occurred in 28% (1,320). In MIMIC, the highest probability of invasive ventilation within 3 hours of meeting a threshold was 20%, after meeting prespecified neurologic or respiratory criteria while on vasopressors, and 19%, after a ratio of arterial to inspired oxygen of <80 mm Hg. In AmsterdamUMCdb, the highest probability was 34%, after vasopressor initiation, and 25%, after a ratio of saturation to inspired oxygen of <90. The probability after meeting the threshold from randomized trials was 9% (MIMIC) and 13% (AmsterdamUMCdb). In MIMIC, a race/ethnicity of Black (OR, 0.75; 95% CrI, 0.57-0.96) or Asian (OR, 0.6; 95% CrI, 0.35-0.95) compared with White was associated with decreased probability of invasive ventilation after meeting a threshold. Conclusions: The probability of invasive ventilation within 3 hours of meeting physiologic thresholds was low and associated with patient race/ethnicity.

Wellness and Coping of Physicians Who Worked in ICUs During the Pandemic: A Multicenter Cross-Sectional North American Survey

OBJECTIVES

Few surveys have focused on physician moral distress, burnout, and professional fulfilment. We assessed physician wellness and coping during the COVID-19 pandemic.

DESIGN

Cross-sectional survey using four validated instruments.

SETTING

Sixty-two sites in Canada and the United States.

SUBJECTS

Attending physicians (adult, pediatric; intensivist, nonintensivist) who worked in North American ICUs.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

We analysed 431 questionnaires (43.3% response rate) from 25 states and eight provinces. Respondents were predominantly male (229 [55.6%]) and in practice for 11.8 ± 9.8 years. Compared with prepandemic, respondents reported significant intrapandemic increases in days worked/mo, ICU bed occupancy, and self-reported moral distress (240 [56.9%]) and burnout (259 [63.8%]). Of the 10 top-ranked items that incited moral distress, most pertained to regulatory/organizational ( n = 6) or local/institutional ( n = 2) issues or both ( n = 2). Average moral distress (95.6 ± 66.9), professional fulfilment (6.5 ± 2.1), and burnout scores (3.6 ± 2.0) were moderate with 227 physicians (54.6%) meeting burnout criteria. A significant dose-response existed between COVID-19 patient volume and moral distress scores. Physicians who worked more days/mo and more scheduled in-house nightshifts, especially combined with more unscheduled in-house nightshifts, experienced significantly more moral distress. One in five physicians used at least one maladaptive coping strategy. We identified four coping profiles (active/social, avoidant, mixed/ambivalent, infrequent) that were associated with significant differences across all wellness measures.

CONCLUSIONS

Despite moderate intrapandemic moral distress and burnout, physicians experienced moderate professional fulfilment. However, one in five physicians used at least one maladaptive coping strategy. We highlight potentially modifiable factors at individual, institutional, and regulatory levels to enhance physician wellness.

Artificial intelligence-guided, single-lead EKG may be a game-changer for symptom-to-balloon time reduction in ST-elevated myocardial infarction

Background

Over decades, efforts to shave off life-saving minutes from ST-Elevated Myocardial Infarction (STEMI) care centred on reducing door-to-needle and door-to-balloon times. We firmly believe that symptom-to-balloon time should prove a better focus to this end. Challenges come with this goal as it heavily relies on a patient's perception and initiative to seek care, which we deem intelligent and wearable Artificial Intelligence (AI)-driven Single Lead EKG technologies as an attractive solution in modern-day cardiology.

Purpose

To provide an accurate, accessible, and cost-effective AI-driven Single Lead STEMI detection algorithm that can be embedded into wearable devices and employed in a self-administered fashion.

Methods

Database: EKG records from Mexico, Colombia, Argentina, and Brazil from April 2014 to December 2019. Dataset: A total of 11,567 12-lead EKG records of 10[s] length with a sampling frequency of 500 Hz, including the following balanced classes: angiographically confirmed and unconfirmed STEMI, branch blocks, non-specific ST-T abnormalities, normal and abnormal (200+ CPT codes, excluding those mentioned above). Cardiologists manually checked the label of each record to ensure precision. Pre-processing: We discard the first and last 250 samples as they may contain a standardisation pulse. The study applied a digital low pass filter of order 5 with a frequency cut-off of 35 Hz. The mean was subtracted from each Lead. Classification: The determined classes were “STEMI” (Including STEMI in different locations of the myocardium – anterior, inferior, and lateral); and “Not-STEMI” (Combination of randomly sample, branch blocks, non-specific ST-T changes, and abnormal records – 25% of each). Training and Testing: A 1-D Convolutional Neural Network was trained and tested with a dataset proportion of 90/10, respectively. A different model was trained and tested for each Lead, using the central 4,500 samples of the records. The last dense layer outputs a probability for each report of being STEMI or Not-STEMI. Lead V2 showed the best overall results. The model was further tested through the same methodology using the best Lead with a subset of the previous data, excluding the unconfirmed STEMI EKG records (Total 7,230 12-lead EKG records for Confirmed Only STEMI dataset). Performance metrics were reported for each experiment and compared.

Results

Combined STEMI data: Accuracy: 91.2%; Sensitivity: 89.6%; Specificity: 92.9%. Confirmed STEMI Only dataset: Accuracy: 92.4%; Sensitivity: 93.4%; Specificity: 91.4% (Figure 1).

Conclusion

By assiduously improving the quality of the model's input, we continue to assess our algorithm's performance and reliability for future clinical validation as a potential remote monitoring and early STEMI detection device.

Funding Acknowledgement

Type of funding sources: None.

Digoxin improves systolic cardiac function in patients with AF and HFpEF: the RATE-AF randomised trial

Background

The RAte control Therapy Evaluation in permanent AF trial (RATE-AF; NCT02391337) was the first head-to-head controlled trial of beta-blockers versus digoxin in patients with permanent atrial fibrillation (AF) and symptoms of heart failure. Patients randomised to digoxin had similar physical-related quality of life and heart rate, with significantly improved functional class, reduced N-terminal pro-brain natriuretic peptide (NT-proBNP) and substantially less adverse events. The impact of rate control therapy on measures of cardiac function is not currently understood.

Purpose

To compare the effect of digoxin versus beta-blockers on systolic and diastolic cardiac function according to heart failure sub-type.

Methods

Blinded echocardiograms assessing systolic and diastolic function were performed at baseline and 12 month follow-up, using a robust method to account for rhythm irregularity (average of three index-beats acquired in appropriate cardiac cycles). Outcomes were the change in left-ventricular ejection fraction (LVEF), systolic tissue Doppler velocity (s'), stroke volume, global longitudinal strain (GLS), diastolic tissue Doppler (e'), mitral E wave deceleration time, E/e', pulmonary vein diastolic deceleration time, isovolumic relaxation time and left atrial ejection fraction. Analyses were stratified by baseline LVEF (≥50%, 40–50% and &lt;40%).

Results

160 patients were randomised, of which 145 patients survived to 12-month follow-up with median age 75 years (IQR 69–82) and 44% women. Median baseline heart rate was 96 beats/min (IQR 86–112), blood pressure 135/85 mmHg (IQR 124/77–146/91), NTproBNP 1049 pg/mL (744–1463) and mean NYHA class 2.4 (SD 0.6). In 119 patients with LVEF ≥50% at baseline, diastolic and systolic parameters improved over time with digoxin therapy. There was a significantly greater improvement in systolic function in 63 patients on digoxin compared to 67 with beta-blockers; Figure 1. Patients randomised to digoxin had a higher LVEF at follow-up (adjusted mean difference [AMD] 2.3%, 95% CI 0.3–4.2; p=0.021), higher s' (1.1cm/s, 1.0–1.2; p=0.003) and higher stroke volume (6.5mL, 0.4–12.6; p=0.037) compared to beta-blockers, without any difference in diastolic parameters (Figure 2). In 16 patients with LVEF 40–50% at baseline, s' significantly increased with digoxin compared to beta-blockers (AMD 1.5 cm/s, 1.2–1.7; p=0.001), with no difference for other systolic or diastolic parameters. 10 patients with LVEF &lt;40% at baseline showed no difference between digoxin and beta-blockers for any echocardiographic measures.

Conclusion

Patients randomised to digoxin with permanent AF, heart failure symptoms and preserved LVEF have significantly greater improvement in multiple parameters of systolic function compared to conventional treatment with beta-blockers.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Health Research

Performance metrics of AI-enhanced single lead EKG maintained after entry of organised clustered data

Background

Our experience in creating innovative Artificial Intelligence-guided single lead EKG methodologies for ST-Elevation Myocardial Infarction (STEMI) detection within complex EKG records has been previously validated.

Purpose

By expanding the intricate variables of our previously tested algorithm input, we seek to further improve our STEMI detecting tool.

Methods

11,567 12-lead EKG records (10-s length, 500 Hz sample frequency) derived from the Latin America Telemedicine Infarct Network database from April 2014 to December 2019. From these records, we included the following balanced classes: angiographically confirmed and unconfirmed STEMI (divided by wall affected), branch blocks, non-specific ST-T changes, normal, and abnormal (Remaining 200+ CPT codes). Cardiologist annotations ensured precision (Ground truth). Determined classes were “STEMI” and “Not-STEMI”. A 1-D Convolutional Neural Network model was trained and tested for each lead with dataset proportions of 90/10, respectively. The last dense layer outputs a probability for each record being STEMI/Not-STEMI. The analysis also included performance metrics and false-negative reports.

Results

Overall, the most promising Single lead for STEMI detection was V2 (91.2% Accuracy, 89.6% Sensitivity, and 92.9% Specificity). 55% of false negatives were inferior wall STEMI (Table 1).

Conclusion

Appreciable progress of our new methodology compared to our previous experiences in AI-guided Single Lead for STEMI detection, especially for lead V2. By performing a thorough analysis of false-negative reports, we aspire to identify potential areas of STEMI detection weakness which will become the focus of future ventures.

Funding Acknowledgement

Type of funding sources: None.

No need for a cardiologist for AMI diagnosis – progress of transforming a behemoth telemedicine program with artificial intelligence

Background

The Latin American Telemedicine Infarct Network (LATIN) Telemedicine is a mammoth hub and spoke model that provides an umbrella of AMI protection for 100 million patients. In the program, 826,043 patients had a telemedicine encounter; 7,400 with AMI were diagnosed; 4,332 of them managed with guidelines-based strategies. We have gradually begun implementing a system for using Artificial Intelligence (AI) algorithms embedded into EKGs for rapid and accurate STEMI detection and validated the results with a cardiologist's interpretations.

Purpose

To test whether an AI-driven EKG algorithm can effectively substitute a cardiologist for STEMI telemedicine protocols.

Methods

The AI algorithm construction was in the following fashion. Sample: a selection of 8,511 EKG and 90,592 classified heartbeats. Pre-processing: segmentation of each EKG into individual heartbeats. Training & testing: 90% and 10% of the total dataset, respectively. Classification: 1-D Convolutional Neural Network; the study constructed classes for each heartbeat. The algorithm was next deployed on a consecutive series of LATIN EKG records to diagnose STEMI. We afterwards compared the algorithm's results with eight expert cardiologists' interpretations of the same sample.

Results

This study achieved a concordance of 91% between the AI algorithm and cardiologist interpretation (Figure 1).

Conclusions

The initial results with AI algorithms for STEMI diagnosis are encouraging and may provide the base work for new tools for cardiologists to improve their efficiency. Moreover, implementing this innovative tool may overcome current limitations associated with the telemedical management of this disease.

Funding Acknowledgement

Type of funding sources: None.

Effect of aspirin discontinuation according to individualised patient bleeding and ischemic risks after PCI: a TWILIGHT trial sub-analysis

Background

The TWILIGHT trial demonstrated a reduction in BARC 2, 3 or 5 (BARC-235) bleeding without an increase in ischemic events at 1-year in high-risk PCI patients randomized to placebo or aspirin (ASA) on a background of ticagrelor 3-months after PCI. However, the effect of ASA discontinuation according to baseline risk of bleeding and ischemic events remain unclear.

Purpose

To a) develop separate models to predict the risk of bleeding and ischemic events, and b) to assess treatment effect of ASA discontinuation across the risk strata.

Methods

Using the TWILIGHT patient database (N=7,119), two multivariable models, one for BARC-235 bleeding and one for CV death, nonfatal MI or nonfatal ischemic stroke (ischemic endpoint) were developed, and their predictive capacity was assessed. The effect of randomized treatment on bleeding and ischemic events across different patient risk-group categories as determined by the risk scores was investigated.

Results

At 1-year, 350 (5.4%) patients experienced a BARC-235 bleeding event and 258 (3.6%) experienced an ischemic event. Independent predictors of BARC-235 included haemoglobin levels at index PCI, proton-pump inhibitor non-use at discharge, age, liver disease and active smoking (c-statistic 0.64). Independent predictors of the ischemic outcome included a positive troponin ACS, prior CABG, diabetes, age, peripheral artery disease, prior PCI, a history of congestive heart failure, active smoking, the level of index PCI complexity, and prior MI (c-statistic 0.71). The risk of a BARC-235 almost doubled between patients in lower versus higher bleeding risk categories (4.3% versus 7.9%) and ischemic risk more than tripled between patients in lower versus higher ischemic risk categories (2.0% versus 7.0%) (see Figure 1). There was no evidence of a differential treatment effect for dual antiplatelet therapy versus ticagrelor monotherapy across the different risk categories of bleeding (interaction P=0.54) and ischemic risk (interaction P=0.95) (Table 1).

Conclusion

Individual patient bleeding and ischemic risks after PCI can both be readily characterised with good discrimination. The effect of ASA discontinuation in preventing bleeding in ticagrelor-treated patients was consistent regardless of baseline bleeding risk. There was no evidence for increased ischemic events with ASA discontinuation according to baseline ischemic risk.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): AstraZenecaIcahn School of Medicine at Mount Sinai