Incorporation of Drone Technology Into the Chain of Survival for OHCA: Estimation of Time Needed for Bystander Treatment of OHCA and CPR Performance

BACKGROUND

Drone-delivered automated external defibrillators (AEDs) hold promises in the treatment of out-of-hospital cardiac arrest. Our objective was to estimate the time needed to perform resuscitation with a drone-delivered AED and to measure cardiopulmonary resuscitation (CPR) quality.

METHODS

Mock out-of-hospital cardiac arrest simulations that included a 9-1-1 call, CPR, and drone-delivered AED were conducted. Each simulation was timed and video-recorded. CPR performance metrics were recorded by a Laerdal Resusci Anne Quality Feedback System. Multivariable regression modeling examined factors associated with time from 9-1-1 call to AED shock and CPR quality metrics (compression rate, depth, recoil, and chest compression fraction). Comparisons were made among those with recent CPR training (≤2 years) versus no recent (>2 years) or prior CPR training.

RESULTS

We recruited 51 research participants between September 2019 and March 2020. The median age was 34 (Q1-Q3, 23-54) years, 56.9% were female, and 41.2% had recent CPR training. The median time from 9-1-1 call to initiation of CPR was 1:19 (Q1-Q3, 1:06-1:26) minutes. A median time of 1:59 (Q1-Q3, 01:50-02:20) minutes was needed to retrieve a drone-delivered AED and deliver a shock. The median CPR compression rate was 115 (Q1-Q3, 109-124) beats per minute, the correct compression depth percentage was 92% (Q1-Q3, 25-98), and the chest compression fraction was 46.7% (Q1-Q3, 39.9%-50.6%). Recent CPR training was not associated with CPR quality or time from 9-1-1 call to AED shock. Younger age (per 10-year increase; β, 9.97 [95% CI, 4.63-15.31] s; P<0.001) and prior experience with AED (β, -30.0 [95% CI, -50.1 to -10.0] s; P=0.004) were associated with more rapid time from 9-1-1 call to AED shock. Prior AED use (β, 6.71 [95% CI, 1.62-11.79]; P=0.011) was associated with improved chest compression fraction percentage.

CONCLUSION

Research participants were able to rapidly retrieve an AED from a drone while largely maintaining CPR quality according to American Heart Association guidelines. Chest compression fraction was lower than expected.

Sex Differences in Receipt of Bystander Cardiopulmonary Resuscitation Considering Neighborhood Racial and Ethnic Composition

BACKGROUND

Bystander cardiopulmonary resuscitation (B-CPR) and defibrillation for out-of-hospital cardiac arrest (OHCA) vary by sex, with women being less likely to receive these interventions in public. It is unknown whether sex differences persist when considering neighborhood racial and ethnic composition. We examined the odds of receiving B-CPR stratified by location and neighborhood. We hypothesized that women in predominantly Black neighborhoods will have a lower odds of receiving B-CPR.

METHODS AND RESULTS

We conducted a retrospective study using the Cardiac Arrest Registry to Enhance Survival (CARES). Neighborhoods were classified by census tract. We modeled the odds of receipt of B-CPR (primary outcome), automatic external defibrillation application, and survival to hospital discharge (secondary outcomes) by sex. CARES collected 457 621 arrests (2013-2019); after appropriate exclusion, 309 662 were included. Women who had public OHCA had a 14% lower odds of receiving B-CPR (odds ratio [OR], 0.86 [95% CI, 0.82-0.89]), but effect modification was not seen by neighborhood (P=not significant). In predominantly Black neighborhoods, women who had public OHCA had a 13% lower odds of receiving B-CPR (adjusted OR, 0.87 [95% CI, 0.76-0.98]) and 12% lower odds of receiving automatic external defibrillation application (adjusted OR, 0.88 [95% CI, 0.78-0.99]). In predominantly Hispanic neighborhoods, women who had public OHCA were less likely to receive B-CPR (adjusted OR, 0.83 [95% CI, 0.73-0.96]) and less likely to receive automatic external defibrillation application (adjusted OR, 0.74 [95% CI, 0.64-0.87]).

CONCLUSIONS

Women with public OHCA have a decreased likelihood of receiving B-CPR and automatic external defibrillation application. Findings did not differ significantly according to neighborhood composition. Despite this, our work has implications for considering strategies to reduce disparities around bystander response.

Factors influencing support for the implementation of community-based out-of-hospital cardiac arrest interventions in high- and low-performing counties

Aim of the study

Survival to hospital discharge from out-of-hospital cardiac arrest (OHCA) after receiving treatment from emergency medical services (EMS) is less than 10% in the United States. Community-focused interventions improve survival rates, but there is limited information on how to gain support for new interventions or program activities within these populations. Using data from the RAndomized Cluster Evaluation of Cardiac ARrest Systems (RACE-CARS) trial, we aimed to identify the factors influencing emergency response agencies' support in implementing an OHCA intervention.

Methods

North Carolina counties were stratified into high-performing or low-performing counties based on the county's cardiac arrest volume, percent of bystander-cardiopulmonary resuscitation (CPR) performed, patient survival to hospital discharge, cerebral performance in patients after cardiac arrest, and perceived engagement in the RACE-CARS project. We randomly selected 4 high-performing and 3 low-performing counties and conducted semi-structured qualitative interviews with emergency response stakeholders in each county.

Results

From 10/2021 to 02/2022, we completed 29 interviews across the 7 counties (EMS (n = 9), telecommunications (n = 7), fire/first responders (n = 7), and hospital representatives (n = 6)). We identified three themes salient to community support for OHCA intervention: (1) initiating support at emergency response agencies; (2) obtaining support from emergency response agency staff (senior leadership and emergency response teams); and (3) and maintaining support. For each theme, we described similarities and differences by high- and low-performing county.

Conclusions

We identified techniques for supporting effective engagement of emergency response agencies in community-based interventions for OHCA improving survival rates. This work may inform future programs and initiatives around implementation of community-based interventions for OHCA.

Association of Acute Kidney Injury and Cardiovascular Disease Following Percutaneous Coronary Intervention: Assessment of Interactions by Race, Diabetes, and Kidney Function

RATIONALE & OBJECTIVE

Black patients and those with diabetes or reduced kidney function experience a disproportionate burden of acute kidney injury (AKI) and cardiovascular events. However, whether these factors modify the association between AKI and cardiovascular events following percutaneous coronary intervention (PCI) is unknown and was the focus of this study.

STUDY DESIGN

Observational cohort.

SETTING & PARTICIPANTS

Patients who underwent PCI at Duke between January 1, 2003, and December 31, 2013, with data available in the Duke Databank for Cardiovascular Disease.

EXPOSURES

AKI, defined as ≥1.5-fold relative elevation in serum creatinine within seven days from a reference value ascertained 30 days before PCI, or a 0.3 mg/dl increase from the reference value within 48 hours.

OUTCOMES

A composite of all-cause death, myocardial infarction, stroke, or revascularization during the first year following PCI.

ANALYTIC APPROACH

Cox regression models adjusted for potential confounders, and with interaction terms between AKI and race, diabetes, or baseline eGFR.

RESULTS

Among 9422 patients, 9% (n=865) developed AKI and the primary composite outcome occurred in 21% (n=2017). AKI was associated with a nearly 2-fold higher risk of the primary outcome (adjusted hazards ratio [HR], 1.94; 95% confidence interval (CI), 1.71 to 2.20). The association between AKI and cardiovascular risk did not significantly differ by race (P-interaction, 0.4), diabetes, (P-interaction, 0.06) or eGFR (P-interaction, 0.2). However, Black race and severely reduced eGFR, but not diabetes, each had a cumulative impact with AKI on risk for the primary outcome. Compared with White patients with no AKI as the reference, the risk for the outcome was highest in Black patients with AKI (HR, 2.27; 95% CI, 1.83 to 2.82), followed by White patients with AKI (HR, 1.87; 95% CI, 1.58 to 2.21), and least in patients of other races with AKI (HR, 1.48; 95% CI, 0.88 to 2.48).

LIMITATIONS

Residual confounding, including the impact of clinical care following PCI on cardiovascular outcomes of AKI.

CONCLUSIONS

Neither race, diabetes, nor reduced eGFR potentiated the association of AKI with cardiovascular risk, but Black patients with AKI had a qualitatively greater risk than White patients with AKI or patients of other races with AKI.

In-Hospital Cardiac Arrest Survival in the United States During and After the Initial Novel Coronavirus Disease 2019 Pandemic Surge

BACKGROUND

Recent reports on challenges in resuscitation care at hospitals severely affected by the novel coronavirus disease 2019 (COVID-19) pandemic raise questions about how the pandemic affected outcomes for in-hospital cardiac arrest throughout the United States.

METHODS

Within Get With The Guidelines-Resuscitation, we conducted a retrospective cohort study to compare in-hospital cardiac arrest survival during the presurge (January 1-February 29), surge (March 1-May 15) and immediate postsurge (May 16-June 30) periods in 2020 compared to 2015 to 2019. Monthly COVID-19 mortality rates for each hospital's county were categorized, per 1 000 000 residents, as low (0-10), moderate (11-50), high (51-100), or very high (>100). Using hierarchical regression models, we compared rates of survival to discharge in 2020 versus 2015 to 2019 for each period.

RESULTS

Of 61 586 in-hospital cardiac arrests, 21 208 (4309 in 2020), 26 459 (5949 in 2020), and 13 919 (2686 in 2020) occurred in the presurge, surge, and postsurge periods, respectively. During the presurge period, 24.2% survived to discharge in 2020 versus 24.7% in 2015 to 2019 (adjusted odds ratio, 1.12 [95% CI, 1.02-1.22]). In contrast, during the surge period, 19.6% survived to discharge in 2020 versus 26.0% in 2015 to 2019 (adjusted odds ratio, 0.81 [0.75-0.88]). Lower survival was most pronounced in communities with high (28% lower survival) and very high (42% lower survival) monthly COVID-19 mortality rates (interaction P<0.001). Resuscitation times were shorter (median: 22 versus 25 minutes; P<0.001), and delayed epinephrine treatment was more prevalent (11.3% versus 9.9%; P=0.004) during the surge period. Survival was lower even when patients with confirmed/suspected COVID-19 infection were excluded from analyses. During the postsurge period, survival rates were similar in 2020 versus 2015 to 2019 (22.3% versus 25.8%; adjusted odds ratio, 0.93 [0.83-1.04]), including communities with high COVID-19 mortality (interaction P=0.16).

CONCLUSIONS

Early during the pandemic, rates of survival to discharge for IHCA decreased, even among patients without COVID-19 infection, highlighting the early impact of the COVID-19 pandemic on in-hospital resuscitation.

Race Differences in Interventions and Survival After Out-of-Hospital Cardiac Arrest in North Carolina, 2010 to 2014

Background

Following the implementation of the HeartRescue project, with interventions in the community, emergency medical services, and hospitals to improve care and outcomes for out‐of‐hospital cardiac arrests (OHCA) in North Carolina, improved bystander and first responder treatments as well as survival were observed. This study aimed to determine whether these improvements were consistent across Black versus White individuals.

Methods and Results

Using the Cardiac Arrest Registry to Enhance Survival (CARES), we identified OHCA from 16 counties in North Carolina (population 3 million) from 2010 to 2014. Temporal changes in interventions and outcomes were assessed using multilevel multivariable logistic regression, adjusted for patient and socioeconomic neighborhood‐level factors. Of 7091 patients with OHCA, 36.5% were Black and 63.5% were White. Black patients were younger, more females, had more unwitnessed arrests and non‐shockable rhythm (Black: 81.0%; White: 75.4%). From 2010 to 2014, the adjusted probabilities of bystander cardiopulmonary resuscitation (CPR) went from 38.5% to 51.2% in White, P<0.001; and 36.9% to 45.6% in Black, P=0.002, and first‐responder defibrillation went from 13.2% to 17.2% in White, P=0.002; and 14.7% to 17.3% in Black, P=0.16. From 2010 to 2014, survival to discharge only increased in White (8.0% to 11.4%, P=0.004; Black 8.9% to 9.5%, P=0.60), though, in shockable patients the probability of survival to discharge went from 24.8% to 34.6% in White, P=0.02; and 21.7% to 29.0% in Black, P=0. 10.

Conclusions

After the HeartRescue program, bystander CPR and first‐responder defibrillation increased in both patient groups; however, survival only increased significantly for White patients.

Racial Differences in AKI Incidence Following Percutaneous Coronary Intervention

BACKGROUND

Undergoing percutaneous coronary intervention (PCI) is a risk factor for AKI development, but few studies have quantified racial differences in AKI incidence after this procedure.

METHODS

We examined the association of self-reported race (Black, White, or other) and baseline eGFR with AKI incidence among patients who underwent PCI at Duke University Medical Center between January 1, 2003, and December 31, 2013. We defined AKI as a 0.3 mg/dl absolute increase in serum creatinine within 48 hours, or ≥1.5-fold relative elevation within 7 days post-PCI from the reference value ascertained within 30 days before PCI.

RESULTS

Of 9422 patients in the analytic cohort (median age 63 years; 33% female; 75% White, 20% Black, 5% other race), 9% developed AKI overall (14% of Black, 8% of White, 10% of others). After adjustment for demographics, socioeconomic status, comorbidities, predisposing medications, PCI indication, periprocedural AKI prophylaxis, and PCI procedural characteristics, Black race was associated with increased odds for incident AKI compared with White race (odds ratio [OR], 1.79; 95% confidence interval [95% CI], 1.48 to 2.15). Compared with Whites, odds for incident AKI were not significantly higher in other patients (OR, 1.30; 95% CI, 0.93 to 1.83). Low baseline eGFR was associated with graded, higher odds of AKI incidence (P value for trend <0.001); however, there was no interaction between race and baseline eGFR on odds for incident AKI (P value for interaction = 0.75).

CONCLUSIONS

Black patients had greater odds of developing AKI after PCI compared with White patients. Future investigations should identify factors, including multiple domains of social determinants, that predispose Black individuals to disparate AKI risk after PCI.

Sample size requirements for detecting treatment effect heterogeneity in cluster randomized trials

Cluster randomized trials (CRTs) refer to experiments with randomization carried out at the cluster or the group level. While numerous statistical methods have been developed for the design and analysis of CRTs, most of the existing methods focused on testing the overall treatment effect across the population characteristics, with few discussions on the differential treatment effect among subpopulations. In addition, the sample size and power requirements for detecting differential treatment effect in CRTs remain unclear, but are helpful for studies planned with such an objective. In this article, we develop a new sample size formula for detecting treatment effect heterogeneity in two-level CRTs for continuous outcomes, continuous or binary covariates measured at cluster or individual level. We also investigate the roles of two intraclass correlation coefficients (ICCs): the adjusted ICC for the outcome of interest and the marginal ICC for the covariate of interest. We further derive a closed-form design effect formula to facilitate the application of the proposed method, and provide extensions to accommodate multiple covariates. Extensive simulations are carried out to validate the proposed formula in finite samples. We find that the empirical power agrees well with the prediction across a range of parameter constellations, when data are analyzed by a linear mixed effects model with a treatment-by-covariate interaction. Finally, we use data from the HF-ACTION study to illustrate the proposed sample size procedure for detecting heterogeneous treatment effects.

Variation in Bystander Cardiopulmonary Resuscitation Delivery and Subsequent Survival From Out-of-Hospital Cardiac Arrest Based on Neighborhood-Level Ethnic Characteristics

BACKGROUND

Bystander cardiopulmonary resuscitation (B-CPR) delivery and survival after out-of-hospital cardiac arrest vary at the neighborhood level, with lower survival seen in predominantly black neighborhoods. Although the Hispanic population is the fastest-growing minority population in the United States, few studies have assessed whether the proportion of Hispanic residents in a neighborhood is associated with B-CPR delivery and survival from out-of-hospital cardiac arrest. We assessed whether B-CPR rates and survival vary by neighborhood-level ethnicity. We hypothesized that neighborhoods with a higher proportion of Hispanic residents have lower B-CPR rates and lower survival.

METHODS

We conducted a retrospective cohort study using data from the Resuscitation Outcomes Consortium Epistry at US sites. Neighborhoods were classified by census tract based on percentage of Hispanic residents: <25%, 25% to 50%, 51% to 75%, or >75%. We independently modeled the likelihood of receipt of B-CPR and survival by neighborhood-level ethnicity controlling for site and patient-level confounding characteristics.

RESULTS

From 2011 to 2015, the Resuscitation Outcomes Consortium collected 27 481 US arrest events; after excluding pediatric arrests, emergency medical services-witnessed arrests, or arrests occurring in a healthcare or institutional facility, 18 927 were included. B-CPR was administered in 37% of events. In neighborhoods with <25% Hispanic residents, B-CPR was administered in 39% of events, whereas it was administered in 27% of events in neighborhoods with >75% Hispanic residents. Compared with <25% Hispanic neighborhoods in a multivariable analysis, out-of-hospital cardiac arrest in predominantly Hispanic neighborhoods had lower B-CPR rates (51% to 75% Hispanic: odds ratio, 0.79 [CI, 0.65-0.95], P=0.014; >75% Hispanic: odds ratio, 0.72 [CI, 0.55-0.96], P=0.025) and lower survival rates (global P value 0.029; >75% Hispanic: odds ratio, 0.56 [CI, 0.34-0.93], P=0.023).

CONCLUSIONS

Individuals with out-of-hospital cardiac arrest in predominantly Hispanic neighborhoods were less likely to receive B-CPR and had lower likelihood of survival. These findings suggest a need to understand the underlying disparities in cardiopulmonary resuscitationdelivery and an unmet cardiopulmonary resuscitationtraining need in Hispanic communities.

Association of Bystander and First-Responder Efforts and Outcomes According to Sex: Results From the North Carolina HeartRescue Statewide Quality Improvement Initiative

Background

The Institute of Medicine has called for actions to understand and target sex‐related differences in care and outcomes for out‐of‐hospital cardiac arrest patients. We assessed changes in bystander and first‐responder interventions and outcomes for males versus females after statewide efforts to improve cardiac arrest care.

Methods and Results

We identified out‐of‐hospital cardiac arrests from North Carolina (2010–2014) through the CARES (Cardiac Arrest Registry to Enhance Survival) registry. Outcomes for men versus women were examined through multivariable logistic regression analyses adjusted for (1) nonmodifiable factors (age, witnessed status, and initial heart rhythm) and (2) nonmodifiable plus modifiable factors (bystander cardiopulmonary resuscitation and defibrillation before emergency medical services), including interactions between sex and time (ie, year and year²). Of 8100 patients, 38.1% were women. From 2010 to 2014, there was an increase in bystander cardiopulmonary resuscitation (men, 40.5%–50.6%; women, 35.3%–51.8%; P for each <0.0001) and in the combination of bystander cardiopulmonary resuscitation and first‐responder defibrillation (men, 15.8%–23.0%, P=0.007; women, 8.5%–23.7%, P=0.004). From 2010 to 2014, the unadjusted predicted probability of favorable neurologic outcome was higher and increased more for men (men, from 6.5% [95% confidence interval (CI), 5.1–8.0] to 9.7% [95% CI, 8.1–11.3]; women, from 6.3% [95% CI, 4.4–8.3] to 7.4% [95% CI, 5.5–9.3%]); while adjusted for nonmodifiable factors, it was slightly higher but with a nonsignificant increase for women (from 9.2% [95% CI, 6.8–11.8] to 10.2% [95% CI, 8.0–12.5]; men, from 5.8% [95% CI, 4.6–7.0] to 8.4% [95% CI, 7.1–9.7]). Adding bystander cardiopulmonary resuscitation and defibrillation before EMS (modifiable factors) did not substantially change the results.

Conclusions

Bystander and first‐responder interventions increased for men and women, but outcomes improved significantly only for men. Additional strategies may be necessary to improve survival among female cardiac arrest patients.

Cardiac Arrest and Cardiopulmonary Resuscitation Outcome Reports: Update of the Utstein Resuscitation Registry Template for In-Hospital Cardiac Arrest: A Consensus Report From a Task Force of the International Liaison Committee on Resuscitation (American Heart Association, European Resuscitation Council, Australian and New Zealand Council on Resuscitation, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Southern Africa, Resuscitation Council of Asia)

Utstein-style reporting templates provide a structured framework with which to compare systems of care for cardiac arrest. The 2004 Utstein reporting template encompassed both out-of-hospital and in-hospital cardiac arrest. A 2015 update of the Utstein template focused on out-of-hospital cardiac arrest, which makes this update of the in-hospital template timely. Representatives of the International Liaison Committee on Resuscitation developed an updated in-hospital Utstein reporting template iteratively by meeting face-to-face, by teleconference, and by online surveys between 2013 and 2018. Data elements were grouped by hospital factors, patient variables, pre-event factors, cardiac arrest and postresuscitation processes, and outcomes. Elements were classified as core or supplemental by use of a modified Delphi process. Variables were described as core if they were considered essential. Core variables should enable reasonable comparisons between systems and are considered essential for quality improvement programs. Together with core variables, supplementary variables are considered useful for research.

Cardiac Arrest and Cardiopulmonary Resuscitation Outcome Reports: Update of the Utstein Resuscitation Registry Template for In-Hospital Cardiac Arrest: A Consensus Report From a Task Force of the International Liaison Committee on Resuscitation (American Heart Association, European Resuscitation Council, Australian and New Zealand Council on Resuscitation, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Southern Africa, Resuscitation Council of Asia)

Utstein-style reporting templates provide a structured framework with which to compare systems of care for cardiac arrest. The 2004 Utstein reporting template encompassed both out-of-hospital and in-hospital cardiac arrest. A 2015 update of the Utstein template focused on out-of-hospital cardiac arrest, which makes this update of the in-hospital template timely. Representatives of the International Liaison Committee on Resuscitation developed an updated in-hospital Utstein reporting template iteratively by meeting face-to-face, by teleconference, and by online surveys between 2013 and 2018. Data elements were grouped by hospital factors, patient variables, pre-event factors, cardiac arrest and postresuscitation processes, and outcomes. Elements were classified as core or supplemental by use of a modified Delphi process. Variables were described as core if they were considered essential. Core variables should enable reasonable comparisons between systems and are considered essential for quality improvement programs. Together with core variables, supplementary variables are considered useful for research.

Outcomes for Hemodialysis Patients Given Cardiopulmonary Resuscitation for Cardiac Arrest at Outpatient Dialysis Clinics

BACKGROUND

Out-of-hospital cardiac arrest, the leading cause of death among patients on hemodialysis, occurs frequently within outpatient dialysis centers. Practice guidelines recommend resuscitation training for all dialysis clinic staff and on-site defibrillator availability, but the extent of staff involvement in cardiopulmonary resuscitation (CPR) efforts and its association with outcomes is unknown.

METHODS

We used data from the Cardiac Arrest Registry to Enhance Survival and the Centers for Medicare & Medicaid Services dialysis facility database to identify patients who had cardiac arrest within outpatient dialysis clinics between 2010 and 2016 in the southeastern United States. We compared outcomes of patients who received dialysis staff-initiated CPR with those who did not until the arrival of emergency medical services (EMS).

RESULTS

Among 398 OHCA events in dialysis clinics, 66% of all patients presented with a nonshockable initial rhythm. Dialysis staff initiated CPR in 81.4% of events and applied defibrillators before EMS arrival in 52.3%. Staff were more likely to initiate CPR among men and witness cardiac arrests, and were more likely to provide CPR within larger dialysis clinics. Staff-initiated CPR was associated with a three-fold increase in the odds of hospital discharge and favorable neurologic status on discharge. There was no overall association between staff-initiated defibrillator use and outcomes, but there was a nonsignificant trend toward improved survival to hospital discharge in the subgroup with shockable initial cardiac arrest rhythms.

CONCLUSIONS

Dialysis staff-initiated CPR was associated with a large increase in survival but was only performed in 81% of cardiac arrest events. Further investigations should focus on understanding the potential facilitators and barriers to CPR in the dialysis setting.

The Association of Duration of participation in get with the guidelines-resuscitation with quality of Care for in-Hospital Cardiac Arrest

BACKGROUND

Large variations exist in the care processes and outcomes for patients who experience in-hospital cardiac arrest (IHCA). We examined if Get With The Guidelines-Resuscitation (GWTG-R) participation duration was associated with improved care processes.

METHODS AND RESULTS

We calculated an overall process composite performance score for IHCA patients using five guideline-recommended process measures, calculating composite adherence among patients, and grouped at hospitals based on GWTG-R participation duration. Trend tests using logistic regression with generalized estimating equations examined the impact of participation duration on quality. Using multivariable regression models adjusting for patient factors, hospital factors, secular trends, and GWTG-R participation duration, we assessed the association between participation duration and process composite performance. We examined 149,551 patients from 447 hospitals (2000-2012). Over the study period we saw decreases in: median age of cardiac arrest (71 to 67 years), the proportion of whites (69.2% to 66.6%), and pulseless ventricular tachycardia/ventricular fibrillation frequency (32.3% to 17.3%). Hospitals were increasingly more likely to be in urban locations and have higher nurse-to-bed ratios. Guideline performance adherence improved with participation duration for several individual process measures and overall process composite performance: process composite score (P-value trend P < .001), confirmation of endotracheal tube (P < .001 trend), monitored/witnessed event (P < .001 trend), time to first chest compressions ≤1 minute (P < .001 trend), and time to vasopressor use ≤5 minutes (P-value trend = 0.0004). There was a decrease in adherence as duration of participation increased for time to defibrillation ≤2 minutes (P-value trend = 0.005). After adjusting for several factors including calendar time, GWTG-R participation duration was independently associated with improved process composite performance (OR 1.05 per year, 95% CI 1.03-1.07).

CONCLUSIONS

GWTG-R participation duration was associated with a significant improvement in IHCA quality of care, yet significant opportunities remain to find ways to maximize quality of care in this high-risk patient group.

Representation of black patients in randomized clinical trials of heart failure with reduced ejection fraction

BACKGROUND

Black individuals have a disproportionately higher burden of heart failure with reduced ejection fraction (HFrEF) relative to other racial and ethnic populations. We conducted a systematic review to determine the representation, enrollment trends, and outcomes of black patients in historic and contemporary randomized clinical trials (RCTs) for HFrEF.

METHODS

We searched PubMed and Embase for RCTs of patients with chronic HFrEF that evaluated therapies that significantly improved clinical outcomes. We extracted trial characteristics and compared them by trial type. Linear regression was used to assess trends in enrollment among HFrEF RCTs over time.

RESULTS

A total of 25 RCTs, 19 for pharmacotherapies and 6 (n=9,501) for implantable cardioverter defibrillators, were included in this analysis. Among these studies, there were 78,816 patients, 4,640 black (5.9%), and the median black participation per trial was 162 patients. Black race was reported in the manuscript of 14 (56.0%) trials, and outcomes by race were available for 12 (48.0%) trials. Implantable cardiac defibrillator trials enrolled a greater percentage of black patients than pharmacotherapy trials (7.1% vs 5.7%). Overall, patient enrollment among the 25 RCTs increased over time (P = .075); however, the percentage of black patients has decreased (P = .001). Outcomes varied significantly between black and white patients in 6 studies.

CONCLUSIONS

Black patients are modestly represented among pivotal RCTs of individuals with HFrEF for both pharmacotherapies and implantable cardioverter defibrillators. The current trend for decreasing black representation in trials of HF therapeutics is concerning and must improve to ensure the generalizability for this vulnerable population.

Cardiorespiratory Responses of Hi Fit and Low Fit Subjects to Mental Challenge during Exercise

The influence of psychological states on physiological responses during exercise is of considerable importance to individuals for which the efficiency of energy production is critical to occupational performance. Numerous studies have shown that aerobic fitness is associated with enhanced cardiovascular efficiency at rest and that responses to mental stress demonstrate evidence of increased sensitivity (relative increase in HR response) and enhanced efficiency (a decrease in absolute HR). However, the effect of aerobic fitness and its impact on cardiorespiratory (CR) responses to psychological stress during exercise has not been investigated. Therefore, the purpose of this study was three-fold; (1) to examine during exercise, anxiety, effort sense, and CR responses to a mental challenge, (2) to examine anxiety and heart rate (HR) responses from rest to exercise with mental challenge between below average fitness (Low Fit) and well-above average fitness (Hi Fit) individuals (exercising at similar relative intensities), and (3) to examine anxiety, effort sense, and CR responses of Low Fit and Hi Fit individuals to a mental challenge during exercise at a similar relative intensity. Twelve Low Fit and eleven Hi Fit subjects participated in two, 32-minute cycle ergometer rides at 65 % of VO2max. In the mental challenge condition (MCC), subjects rode while participating in mentally challenging tasks (Stroop Color-Word task and mental arithmetic) from min 6 to min 14 of the protocol. In the no mental challenge condition (NMCC), subjects exercised at the same intensity and duration without a stressor. Subjects were counter-balanced between fitness levels and condition. HR, VE, VE/VO2, RR, VO2, RER, effort sense (RPE), and state anxiety (SAI) were assessed at 5, 14, 24, and 30 min. SAI was also assessed at - 5 min before exercise and after 15 min of recovery. In addition, the NASA task load index (NTLX) was used to assess perceived overall workload. SAI increased significantly at 14 min in the MCC. NTLX scores indicated that the MCC was perceived as a greater overall workload. Furthermore, HR, VE, VE/VO2, and RR were significantly elevated during the mental challenge condition at 14 min. The Hi Fit subjects tended to respond to the dual stress of exercise and mental challenge with a relative increase in HR, while absolute HR was similar in both groups. An examination of fitness group differences revealed that SAI and NTLX were similar for Low Fit and Hi Fit subjects when exercising in the MCC, although, Hi Fit subjects demonstrated lower HR responses from 6 min to 14 min. VE, VE/VO2, and RR were similar for Low Fit and Hi Fit subjects. These results suggest that psychological stress during physical activity can exacerbate cardiorespiratory responses and suggests that factors that impact CR adjustment to mental challenge from resting baseline may differ from the factors that impact CR adjustment to mental challenge during exercise. Finally, fitness level attenuates HR and may attenuate additional cardiorespiratory responses while participating in a dual stress condition, of exercise and mental challenge.