Distinguishing Clinical From Statistical Significances in Contemporary Comparative Effectiveness Research.

OBJECTIVE: To determine the prevalence of clinical significance reporting in contemporary comparative effectiveness research (CER). BACKGROUND: In CER, a statistically significant difference between study groups may or may not be clinically significant. Misinterpreting statistically significant results could lead to inappropriate recommendations that increase health care costs and treatment toxicity. METHODS: CER studies from 2022 issues of the Annals of Surgery , Journal of the American Medical Association , Journal of Clinical Oncology , Journal of Surgical Research , and Journal of the American College of Surgeons were systematically reviewed by 2 different investigators. The primary outcome of interest was whether the authors specified what they considered to be a clinically significant difference in the "Methods." RESULTS: Of 307 reviewed studies, 162 were clinical trials and 145 were observational studies. Authors specified what they considered to be a clinically significant difference in 26 studies (8.5%). Clinical significance was defined using clinically validated standards in 25 studies and subjectively in 1 study. Seven studies (2.3%) recommended a change in clinical decision-making, all with primary outcomes achieving statistical significance. Five (71.4%) of these studies did not have clinical significance defined in their methods. In randomized controlled trials with statistically significant results, sample size was inversely correlated with effect size ( r = -0.30, P = 0.038). CONCLUSIONS: In contemporary CER, most authors do not specify what they consider to be a clinically significant difference in study outcome. Most studies recommending a change in clinical decision-making did so based on statistical significance alone, and clinical significance was usually defined with clinically validated standards.

Superior Outcomes of Dual-Arterial Coronary Artery Bypass Grafting Are Maintained in the Veterans Health Administration.

INTRODUCTION: Controversy surrounds the long-term clinical benefit of coronary artery bypass grafting (CABG) using dual arterial grafts (DAGs) compared to single arterial grafts (SAGs). We investigated outcomes of DAG, using single internal thoracic artery and radial artery (DAG-RA) or bilateral internal thoracic artery grafts (DAG-BITA), compared to SAG, using the left internal thoracic artery and saphenous vein grafts, in the U.S. Veterans Health Administration (VA). METHODS: We conducted a cross-sectional study of U.S. Veterans undergoing isolated on-pump CABG between 2005 and 2015 at 44 VA medical centers. The primary composite outcome was first occurrence of a major adverse cardiac and cerebrovascular event (MACCE), comprised of death from any cause, myocardial infarction, stroke, or repeat revascularization. RESULTS: Among 25,969 Veterans undergoing isolated CABG, 1261 (4.9%) underwent DAG (66.8% DAG-RA and 33.2% DAG-BITA). Over a 5-y follow-up, DAG was associated with lower rates of all-cause death (adjusted hazard ratio [AHR] 0.70, 95% confidence interval [CI] 0.58-0.85), MACCE (AHR 0.80, 95% CI 0.71-0.91), and stroke (AHR 0.74, 95% CI 0.57-0.96) versus SAG. DAG-BITA was associated with lower rates of all-cause death (AHR 0.52, 95% CI 0.35-0.77) and MACCE (AHR 0.66, 95% CI 0.51-0.84) than SAG, while DAG-RA was associated with lower rates of all-cause death (AHR 0.79, 95% CI 0.64-0.99). CONCLUSIONS: In the VA, DAG was associated with improved long-term MACCE outcomes compared to SAG. These results suggest that the practice of DAG in the VA benefits Veterans and should be promoted further.

Impact of Oral Anticoagulation on Clinical Outcomes in Postoperative Atrial Fibrillation.

INTRODUCTION: The impact of postoperative oral anticoagulation (OAC) with warfarin on postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) was the focus of this examination of patients from the randomized endo-vein graft prospective (REGROUP) Trial. MATERIAL AND METHODS: REGROUP was a prospective randomized Veterans Affairs cooperative study comparing endoscopic versus open vein harvest in elective CABG patients (March 2014-April 2017) at 16 Veterans Affairs facilities. This study compared new-onset POAF patients who were treated with warfarin versus no-warfarin. Outcomes included stroke during active follow-up and a major adverse cardiac event composite of mortality, acute myocardial infarction, and repeat revascularization during active and passive follow-up. RESULTS: Of the 316/1103 (28.6%) of REGROUP patients who developed new-onset POAF, 45 patients were excluded - mainly for preoperative warfarin use. Of the remaining 269 patients, 85 received OAC with warfarin (OAC group); 184 did not (no-OAC group). Stroke rates during active follow-up (32 [IQR 24-38] mo) were 3.5% OAC group versus 5.4% no-OAC group (P = 0.76); major adverse cardiac eventrates were 20% OAC versus 11.4% no-OAC (P = 0.06). On longer follow-up of (median 4.61 [IQR 3.9-5.1] y), discharge OAC use was associated with all-cause mortality after adjusting for Society of Thoracic Surgeons mortality risk (20.0% versus 11.4% no-OAC use; HR = 2.00, 95% CI: 1.05-3.81, P = 0.035). CONCLUSIONS: REGROUP patients with POAF treated with OAC had similar stroke and higher mortality rates versus no-OAC patients. Further investigation of the risk-benefit ratio of OAC in post-CABG patients and which POAF patient subgroups might derive the most benefit with anticoagulation appears warranted.

An Open-Source, Interoperable Architecture for Generating Real-Time Surgical Team Cognitive Alerts from Heart-Rate Variability Monitoring.

Clinical alarm and decision support systems that lack clinical context may create non-actionable nuisance alarms that are not clinically relevant and can cause distractions during the most difficult moments of a surgery. We present a novel, interoperable, real-time system for adding contextual awareness to clinical systems by monitoring the heart-rate variability (HRV) of clinical team members. We designed an architecture for real-time capture, analysis, and presentation of HRV data from multiple clinicians and implemented this architecture as an application and device interfaces on the open-source OpenICE interoperability platform. In this work, we extend OpenICE with new capabilities to support the needs of the context-aware OR including a modularized data pipeline for simultaneously processing real-time electrocardiographic (ECG) waveforms from multiple clinicians to create estimates of their individual cognitive load. The system is built with standardized interfaces that allow for free interchange of software and hardware components including sensor devices, ECG filtering and beat detection algorithms, HRV metric calculations, and individual and team alerts based on changes in metrics. By integrating contextual cues and team member state into a unified process model, we believe future clinical applications will be able to emulate some of these behaviors to provide context-aware information to improve the safety and quality of surgical interventions.

Measuring and Improving Emotional Intelligence in Surgery: A Systematic Review.

OBJECTIVE: Evaluate how emotional intelligence (EI) has been measured among surgeons and to investigate interventions implemented for improving EI. SUMMARY BACKGROUND: EI has relevant applications in surgery given its alignment with nontechnical skills. In recent years, EI has been measured in a surgical context to evaluate its relationship with measures such as surgeon burnout and the surgeon-patient relationship. METHODS: A systematic review was conducted by searching MEDLINE, EMBASE, CINAHL, and PSYCINFO databases using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MeSH terms and keywords included "emotional intelligence," "surgery," and "surgeon." Eligible studies included an EI assessment of surgeons, surgical residents, and/or medical students within a surgical context. RESULTS: The initial search yielded 4627 articles. After duplicate removal, 4435 articles were screened by title and abstract and 49 articles proceeded to a full-text read. Three additional articles were found via hand search. A total of 37 articles were included. Studies varied in surgical specialties, settings, and outcome measurements. Most occurred in general surgery, residency programs, and utilized self-report surveys to estimate EI. Notably, EI improved in all studies utilizing an intervention. CONCLUSIONS: The literature entailing the intersection between EI and surgery is diverse but still limited. Generally, EI has been demonstrated to be beneficial in terms of overall well-being and job satisfaction while also protecting against burnout. EI skills may provide a promising modifiable target to achieve desirable outcomes for both the surgeon and the patient. Future studies may emphasize the relevance of EI in the context of surgical teamwork.

Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass.

BACKGROUND: The saphenous-vein graft is the most common conduit for coronary-artery bypass grafting (CABG). The influence of the vein-graft harvesting technique on long-term clinical outcomes has not been well characterized. METHODS: We randomly assigned patients undergoing CABG at 16 Veterans Affairs cardiac surgery centers to either open or endoscopic vein-graft harvesting. The primary outcome was a composite of major adverse cardiac events, including death from any cause, nonfatal myocardial infarction, and repeat revascularization. Leg-wound complications were also evaluated. RESULTS: A total of 1150 patients underwent randomization. Over a median follow-up of 2.78 years, the primary outcome occurred in 89 patients (15.5%) in the open-harvest group and 80 patients (13.9%) in the endoscopic-harvest group (hazard ratio, 1.12; 95% confidence interval [CI], 0.83 to 1.51; P=0.47). A total of 46 patients (8.0%) in the open-harvest group and 37 patients (6.4%) in the endoscopic-harvest group died (hazard ratio, 1.25; 95% CI, 0.81 to 1.92); myocardial infarctions occurred in 34 patients (5.9%) in the open-harvest group and 27 patients (4.7%) in the endoscopic-harvest group (hazard ratio, 1.27; 95% CI, 0.77 to 2.11), and revascularization occurred in 35 patients (6.1%) in the open-harvest group and 31 patients (5.4%) in the endoscopic-harvest group (hazard ratio, 1.14; 95% CI, 0.70 to 1.85). Leg-wound infections occurred in 18 patients (3.1%) in the open-harvest group and in 8 patients (1.4%) in the endoscopic-harvest group (relative risk, 2.26; 95% CI, 0.99 to 5.15). CONCLUSIONS: Among patients undergoing CABG, we did not find a significant difference between open vein-graft harvesting and endoscopic vein-graft harvesting in the risk of major adverse cardiac events. (Funded by the Cooperative Studies Program, Office of Research and Development, Department of Veterans Affairs; REGROUP ClinicalTrials.gov number, NCT01850082 .).

Fraction of expired oxygen: an additional safety approach to monitor oxygen delivery to the heart lung machine oxygenator.

BACKGROUND: Monitoring oxygen delivery to the oxygenator of a heart lung machine (HLM) is typically accomplished with an O2 analyzer connected to the gas inflow line. It is assumed when the FiO2 is greater than 21% that oxygen is being delivered to the oxygenator. However, this assumption is imperfect because the connection of the inflow line to the oxygenator is downstream from the O2 analyzer. FiO2 monitoring will not alert the perfusionist if the inflow line is not actually connected to the oxygenator. Measuring the fraction of expired oxygen (FEO2) is a more reliable way of monitoring O2 delivery. METHODS: An O2 analyzer was placed on the scavenging line that is attached to the exhaust port of oxygenator (FEO2). RESULTS: Whenever the FiO2 is greater than 21%, and the inflow line is properly connected, the FEO2 exiting the oxygenator is greater than 21%. The FEO2 falls to 21% when the inflow line is not functioning. CONCLUSION: Monitoring the FEO2 is a more reliable way to verify O2 delivery to an oxygenator. An alarm can be set on the FEO2 monitor to alert the perfusionist if the FEO2 falls below a predetermined threshold so any issue with O2 delivery will always be recognized.

Dissecting Cardiac Surgery: A Video-based Recall Protocol to Elucidate Team Cognitive Processes in the Operating Room.

OBJECTIVE: The aim of this study was to elucidate the cognitive processes involved in surgical procedures from the perspective of different team roles (surgeon, anesthesiologist, and perfusionist) and provide a comprehensive compilation of intraoperative cognitive processes. SUMMARY BACKGROUND DATA: Nontechnical skills play a crucial role in surgical team performance and understanding the cognitive processes underlying the intraoperative phase of surgery is essential to improve patient safety in the operating room (OR). METHODS: A mixed-methods approach encompassing semistructured interviews with 9 subject-matter experts. A cognitive task analysis was built upon a hierarchical segmentation of coronary artery bypass grafting procedures and a cued-recall protocol using video vignettes was used. RESULTS: A total of 137 unique surgical cognitive processes were identified, including 33 decision points, 23 critical communications, 43 pitfalls, and 38 strategies. Self-report cognitive workload varied substantially, depending on team role and surgical step. A web-based dashboard was developed, providing an integrated visualization of team cognitive processes in the OR that allows readers to intuitively interact with the study findings. CONCLUSIONS: This study advances the current body of knowledge by making explicit relevant cognitive processes involved during the intraoperative phase of cardiac surgery from the perspective of multiple OR team members. By displaying the research findings in an interactive dashboard, we provide trainees with new knowledge in an innovative fashion that could be used to enhance learning outcomes. In addition, the approach used in the present study can be used to deeply understand the cognitive factors underlying surgical adverse events and errors in the OR.

Analysis of Dynamic Changes in Cognitive Workload During Cardiac Surgery Perfusionists' Interactions With the Cardiopulmonary Bypass Pump.

OBJECTIVE: This novel preliminary study sought to capture dynamic changes in heart rate variability (HRV) as a proxy for cognitive workload among perfusionists while operating the cardiopulmonary bypass (CPB) pump during real-life cardiac surgery. BACKGROUND: Estimations of operators' cognitive workload states in naturalistic settings have been derived using noninvasive psychophysiological measures. Effective CPB pump operation by perfusionists is critical in maintaining the patient's homeostasis during open-heart surgery. Investigation into dynamic cognitive workload fluctuations, and their relationship with performance, is lacking in the literature. METHOD: HRV and self-reported cognitive workload were collected from three Board-certified cardiac perfusionists (N = 23 cases). Five HRV components were analyzed in consecutive nonoverlapping 1-min windows from skin incision through sternal closure. Cases were annotated according to predetermined phases: prebypass, three phases during bypass, and postbypass. Values from all 1min time windows within each phase were averaged. RESULTS: Cognitive workload was at its highest during the time between initiating bypass and clamping the aorta (preclamp phase during bypass), and decreased over the course of the bypass period. CONCLUSION: We identified dynamic, temporal fluctuations in HRV among perfusionists during cardiac surgery corresponding to subjective reports of cognitive workload. Not only does cognitive workload differ for perfusionists during bypass compared with pre- and postbypass phases, but differences in HRV were also detected within the three bypass phases. APPLICATION: These preliminary findings suggest the preclamp phase of CPB pump interaction corresponds to higher cognitive workload, which may point to an area warranting further exploration using passive measurement.

Epiaortic Ultrasound for Assessment of Intraluminal Atheroma; Insights from the REGROUP Trial.

OBJECTIVES: To assess the use of epiaortic ultrasound in contemporary cardiac surgery, as well as its impact on surgical cannulation strategy and cerebrovascular events. DESIGN: Epiaortic ultrasound data was prospectively collected in the Randomized Endovein Graft Prospective (REGROUP) trial (VA Cooperative Studies Program #588, ClinicalTrials.gov, NCT01850082), which randomized 1,150 coronary artery bypass graft patients between 2014 and 2017 to endoscopic or open-vein graft harvest. SETTING: Sixteen cardiac surgery programs within the Veterans Affairs Healthcare System with expertise at performing endoscopic vein-graft harvesting. PARTICIPANTS: Veterans Affairs patients, greater than 18 years of age, undergoing elective or urgent coronary artery bypass grafting with cardiopulmonary bypass and cardioplegic arrest with at least one planned saphenous vein graft were eligible for enrollment. INTERVENTIONS: Epiaortic ultrasound was performed by the surgeon using a high frequency (>7 MHz) ultrasound transducer. Two-dimensional images of the ascending aorta in multiple planes were acquired before aortic cannulation and cross-clamping. MEASUREMENTS AND MAIN RESULTS: Epiaortic ultrasound was performed in 34.1% (269 of 790) of patients in REGROUP. Among these patients, simple intraluminal atheroma was observed in 21.9% (59 269), and complex intraluminal atheroma comprised 2.2% (6 of 269). The aortic cannulation or cross-clamp strategy was modified based on these findings in 7.1% of cases (19 of 269). There was no difference in stroke between patients who underwent epiaortic ultrasound and those who did not (1.9% v 1.2% p = 0.523). CONCLUSIONS: Despite current guidelines recommending routine use of epiaortic ultrasound (IIa/B) to reduce the risk of stroke in cardiac surgery, in this contemporary trial, use remains infrequent, with significant site-to-site variability.

Sensors for Continuous Monitoring of Surgeon's Cognitive Workload in the Cardiac Operating Room.

Monitoring healthcare providers' cognitive workload during surgical procedures can provide insight into the dynamic changes of mental states that may affect patient clinical outcomes. The role of cognitive factors influencing both technical and non-technical skill are increasingly being recognized, especially as the opportunities to unobtrusively collect accurate and sensitive data are improving. Applying sensors to capture these data in a complex real-world setting such as the cardiac surgery operating room, however, is accompanied by myriad social, physical, and procedural constraints. The goal of this study was to investigate the feasibility of overcoming logistical barriers in order to effectively collect multi-modal psychophysiological inputs via heart rate (HR) and near-infrared spectroscopy (NIRS) acquisition in the real-world setting of the operating room. The surgeon was outfitted with HR and NIRS sensors during aortic valve surgery, and validation analysis was performed to detect the influence of intra-operative events on cardiovascular and prefrontal cortex changes. Signals collected were significantly correlated and noted intra-operative events and subjective self-reports coincided with observable correlations among cardiovascular and cerebral activity across surgical phases. The primary novelty and contribution of this work is in demonstrating the feasibility of collecting continuous sensor data from a surgical team member in a real-world setting.

Surgery Task Load Index in Cardiac Surgery: Measuring Cognitive Load Among Teams.

Background. The most commonly used subjective assessment of perceived cognitive load, the NASA Task Load Index (TLX), has proven valuable in measuring individual load among general populations. The surgery task load index (SURG-TLX) was developed and validated to measure cognitive load specifically among individuals within a surgical team. Notably, the TLX lacks temporal sensitivity in its typical retrospective administration. Objective. This study sought to expand the utility of SURG-TLX by investigating individual measures of cognitive load over time during cardiac surgery, and the relationship between individual and team measures of cognitive load and proxies for surgical complexity. Materials & Methods. SURG-TLX was administered retrospectively in the operating room immediately following each case to approximate cognitive load before, during, and after cardiopulmonary bypass for cardiac surgery team members (surgeon, anesthesiologist, and perfusionist). Correlations were calculated to determine the relationship of individual and team measures of cognitive load over the entire procedure with bypass length and surgery length. Results. Results suggest that perceived cognitive load varies throughout the procedure such that cognitive load during bypass significantly differs compared to before or after bypass, across all 3 roles. While on bypass, results show that anesthesiologists experience significantly lower levels of perceived cognitive load than both surgeons and perfusionists. Correlational analyses reveal that perceived cognitive load of both the surgeon and the team had significant positive associations with bypass length and surgery length. Conclusion. Our findings support the utility of SURG-TLX in real cardiac cases as a measure of cognitive load over time, and on an individual and team-wide basis.

Physiological synchronization and entropy as measures of team cognitive load.

The operating room (OR) is a high-risk and complex environment, where multiple specialized professionals work as a team to effectively care for patients in need of surgical interventions. Surgical tasks impose high cognitive demands on OR staff and cognitive overload may have deleterious effects on team performance and patient safety. The aim of the present study was to investigate the feasibility and describe a novel methodological approach to characterize dynamic changes in team cognitive load by measuring synchronization and entropy of heart rate variability parameters during real-life cardiac surgery. Cognitive load was measured by capturing interbeat intervals (IBI) from three team members (surgeon, anesthesiologist and perfusionist) using an unobtrusive wearable heart rate sensor and transmitted in real-time to a smartphone application. Clinical data and operating room audio/video recordings were also collected to provide behavioral and contextual information. We developed symbolic representations of the transient cognitive state of individual team members (Individual Cognitive State - ICS), and overall team (Team Cognitive State - TCS) by comparing IBI data from each team member with themselves and with others. The distribution of TCS symbols during surgery enabled us to display and analyze temporal states and dynamic changes of team cognitive load. Shannon's entropy was calculated to estimate the changing levels of team organization and to detect fluctuations resulting from a variety of cognitive demands and/or specific situations (e.g. medical error, emergency, flow disruptions). An illustrative example from a real cardiac surgery team shows how cognitive load patterns shifted rapidly after an actual near-miss medication event, leading the team to a more organized and synchronized state. The methodological approach described in this study provides a measurement technique for the assessment of team physiological synchronization, which can be applied to many other team-based environments. Future research should gather additional validity evidence to support the proposed methods for team cognitive load measurement.

A Quick Reference Tool for Goal-Directed Perfusion in Cardiac Surgery.

Traditionally, blood flow rates on cardiopulmonary bypass are based primarily on a formula that matches cardiac index to the patient's body surface area (BSA). However, Ranucci and associates in the Goal-Directed Perfusion Trial (GIFT) trial have shown that coupling the BSA with delivery of oxygen (DO2), known as goal-directed perfusion (GDP), may be a safer approach to determine appropriate blood flows. The objective of this study was to create a GDP reference tool that would allow perfusionists to quickly determine the lowest acceptable blood flow needed to provide a patient of any BSA with a satisfactory DO2 without the need for additional dedicated technology. We approached this problem by deriving a formula for flow (L/min), based on BSA, oxygen content of the blood, and a minimum DO2 of 280 mL·min-1m-2. A quick reference GDP chart was created based on the derived formula, requiring only the patient's BSA and hemoglobin level to determine a safe minimum flow rate. The proposed tool allows any cardiac surgery center to adopt the GDP technique, even in the absence of instantaneous DO2 monitoring equipment.

Establishing a Ventilator-Heart Lung Machine Communication Bridge to Mitigate Errors when Weaning from Bypass.

If a perfusionist weans a patient off the heart lung machine (HLM) and the anesthesiologist has not re-started the ventilator, the patient will become hypoxic. The objective of this project was to create a redundant safety system of verbal and electronic communication to prevent failure to ventilate errors after cardiopulmonary bypass. This objective could be realized by building an electronic communication bridge directly between the HLM and ventilator. A software application was created to retrieve and interpret data from the pump and ventilator and trigger a programmed smart alarm. The software is able to interpret data from the pump and ventilator. When both are off simultaneously (defined as a pump flow of 0 L/min with a respiratory rate of 0 breaths/min), the application will raies an alarm. Communication between a pump and ventilator is possible, enabling the deployment of a safety system that could exist in the operating room (OR) as a standalone alarm. A device dataset can be used to optimize clinical performance of the alarm. The application could also be integrated into smart checklists and computer-assisted OR process models that are currently in development.

Performance of left internal thoracic artery-left anterior descending artery anastomosis by residents versus attendings and coronary artery bypass grafting outcomes.

OBJECTIVES: Performance of a technically sound left internal thoracic artery to left anterior descending artery (LITA-LAD) anastomosis during coronary artery bypass grafting (CABG) is critically important. We used prospectively collected data from the multicentre, randomized REGROUP (Randomized Endograft Vein Perspective) trial to investigate CABG outcomes based on whether a resident or an attending surgeon performed the LITA-LAD anastomosis. METHODS: This was a post hoc subanalysis of the REGROUP trial, which randomized veterans undergoing isolated on-pump CABG to endoscopic versus open vein harvest from 2014 through 2017. The primary end point was major cardiac adverse events, defined as the composite of all-cause deaths, nonfatal myocardial infarctions or repeat revascularizations. RESULTS: Among 1,084 patients, 344 (31.8%) LITA-LAD anastomoses were performed by residents and 740 (68.2%), by attending surgeons. Residents (compared to attendings) operated on fewer patients with high tercile SYNTAX scores (22.1% vs 37.4%, P < 0.001), performed fewer multiarterial CABGs (5.2% vs 14.6%, P < 0.001) and performed more anastomoses to distal targets with diameters > 2.0 mm (19.0% vs 10.9%, P < 0.001) and non-calcified landing zones (25.1% vs 21.6%, P < 0.001). During a median observation time of 4.7 years (interquartile range 3.84-5.45), major cardiac adverse events occurred in 77 patients (22.4%) in the group treated by residents and 169 patients (22.8%) in the group treated by attendings (unadjusted HR 1.00; 95% confidence interval, 0.76-1.33; P = 0.99). Outcomes persisted on adjusted analyses. CONCLUSIONS: Based on this REGROUP trial subanalysis, under careful supervision and with appropriate patient selection, LITA-LAD anastomoses performed by the residents yielded clinical outcomes similar to those of the attendings.

Complete Coronary Revascularization and Outcomes in Patients Who Underwent Coronary Artery Bypass Grafting: Insights from The REGROUP Trial.

There is growing evidence in support of coronary complete revascularization (CR). Nonetheless, there is no universally accepted definition of CR in patients who undergo coronary bypass grafting surgery (CABG). We sought to investigate the outcomes of CR, defined as surgical revascularization of any territory supplied by a suitable coronary artery with ≥50% stenosis. We performed a preplanned subanalysis in the Randomized Trial of Endoscopic or Open Saphenous Vein Graft Harvesting (REGROUP) clinical trial cohort. Of 1,147 patients who underwent CABG, 810 (70.6%) received CR. The primary outcome was a composite of major adverse cardiac events (MACEs), including death from any cause, nonfatal myocardial infarction, or repeat revascularization over a median 4.7 years of follow-up. MACE occurred in 175 patients (21.6%) in the CR group and 86 patients (25.5%) in the incomplete revascularization (IR) group (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.67 to 1.13, p = 0.29). A total of 97 patients (12.0%) in the CR group and 48 patients (14.2%) in the IR group died (HR 0.93, 95% CI 0.65 to 1.32, p = 0.67); nonfatal myocardial infarction occurred in 49 patients (6.0%) in the CR group and 30 patients (8.9%) in the IR group (HR 0.76, 95% CI 0.48 to 1.2, p = 0.24), and repeat revascularization occurred in 62 patients (7.7%) in the CR group and 39 patients (11.6%) in the IR group (HR 0.64; 95% CI 0.42 to 0.95, p = 0.027). In conclusion, in patients with a great burden of co-morbidities who underwent CABG in the REGROUP trial over a median follow-up period of a median 4.7 years, CR was associated with similar MACE rates but a reduced risk of repeat revascularization. Longer-term follow-up is warranted.

Using Digital Biomarkers for Objective Assessment of Perfusionists' Workload and Acute Stress During Cardiac Surgery.

The cardiac operating room (OR) is a high-risk, high-stakes environment inserted into a complex socio-technical healthcare system. During cardiopulmonary bypass (CPB), the most critical phase of cardiac surgery, the perfusionist has a crucial role within the interprofessional OR team, being responsible for optimizing patient perfusion while coordinating other tasks with the surgeon, anesthesiologist, and nurses. The aim of this study was to investigate objective digital biomarkers of perfusionists' workload and stress derived from heart rate variability (HRV) metrics captured via a wearable physiological sensor in a real cardiac OR. We explored the relationships between several HRV parameters and validated self-report measures of surgical task workload (SURG-TLX) and acute stress (STAI-SF), as well as surgical processes and outcome measures. We found that the frequency-domain HRV parameter HF relative power - FFT (%) presented the strongest association with task workload (correlation coefficient: -0.491, p-value: 0.003). We also found that the time-domain HRV parameter RMSSD (ms) presented the strongest correlation with perfusionists' acute stress (correlation coefficient: -0.489, p-value: 0.005). A few workload and stress biomarkers were also associated with bypass time and patient length of stay in the hospital. The findings from this study will inform future research regarding which HRV-based biomarkers are best suited for the development of cognitive support systems capable of monitoring surgical workload and stress in real time.

Assessing Team Situational Awareness in the Operating Room via Computer Vision.

Situational awareness (SA) at both individual and team levels, plays a critical role in the operating room (OR). During the pre-incision time-out, the entire OR team comes together to deploy the surgical safety checklist (SSC). Worldwide, the implementation of the SSC has been shown to reduce intraoperative complications and mortality among surgical patients. In this study, we investigated the feasibility of applying computer vision analysis on surgical videos to extract team motion metrics that could differentiate teams with good SA from those with poor SA during the pre-incision time-out. We used a validated observation-based tool to assess SA, and a computer vision software to measure body position and motion patterns in the OR. Our findings showed that it is feasible to extract surgical team motion metrics captured via off-the-shelf OR cameras. Entropy as a measure of the level of team organization was able to distinguish surgical teams with good and poor SA. These findings corroborate existing studies showing that computer vision-based motion metrics have the potential to integrate traditional observation-based performance assessments in the OR.