Clinical Impact of Routine Assessment of Patient-Reported Health Status in Heart Failure Clinic.

BACKGROUND: The impact of routine clinic use of patient-reported outcome (PRO) measures on clinical outcomes in patients with heart failure (HF) has not been well-characterized. We tested if clinic-based use of a disease-specific PRO improves patient-reported quality of life at 1 year. METHODS: PRO-HF was an open-label, parallel, patient-level randomized clinical trial of routine PRO assessment or usual care at an academic HF clinic between August 30, 2021, and June 30, 2022, with 1 year of follow-up. In the PRO assessment arm, participants completed the Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12) at each HF clinic visit and results were shared with their treating clinician. The usual care arm completed the KCCQ-12 at randomization and 1 year later, which was not shared with the treating clinician. The primary outcome was the KCCQ-12 Overall Summary Score (OSS) between 12-15 months post-randomization. Secondary outcomes included domains of the KCCQ-12, hospitalization and emergency department visit rates, HF medication therapy, clinic visit frequency, and testing rates. RESULTS: Across 17 clinicians, 1,248 participants were enrolled and randomized to PRO assessment (n=624) or usual care (n=624). The median age was 63.9 (interquartile range [IQR] 51.8-72.8), 38.9% were women, and the median baseline KCCQ-12 OSS was 82.3 (IQR 58.3-94.8). Final KCCQ-12 (available in 87.9% of the PRO arm and 85.1% in usual care [p=0.16]) median OSS scores were 87.5 (IQR 68.8-96.9) in the PRO arm and 87.6 (IQR 69.7-96.9) in the usual care arm with a baseline-adjusted mean difference of 0.2 (95% CI: -1.7 to 2.0; p=0.85). The results were consistent across pre-specified subgroups. A post hoc analysis demonstrated a significant interaction with greater benefit among participants with baseline KCCQ-12 OSS scores of 60-80 but not in less or more symptomatic participants. No significant differences were found in 1-year mortality, hospitalizations, ED visits, medication therapy, clinic follow-up, or testing rates between arms. CONCLUSIONS: Routine PRO assessment in HF clinic visits did not impact patient-reported quality of life or other clinical outcomes. Alternate strategies and settings for embedding PROs into routine clinical care should be tested.

Biomechanical Forces of the Lateral Knee Joint Following Meniscectomy and Meniscus Transplantation in Pediatric Cadavers.

INTRODUCTION: Lateral meniscus transplantation successfully treats symptomatic meniscus deficiency in children. Although clinical outcomes are well-characterized, joint forces in meniscus-deficient and transplant states are unknown. The purpose of this study was to characterize contact area (CA) and contact pressures (CP) of transplanted lateral meniscus in pediatric cadavers. We hypothesize that (1) compared with the intact state, meniscectomy will decrease femorotibial CA and increase CP, and increase contact pressure (CP) and (2) compared with the meniscectomy state, meniscus transplantation will improve contact biomechanics toward the intact meniscus state. METHODS: Pressure-mapping sensors were inserted underneath the lateral meniscus of eight cadaver knees aged 8 to 12 years. CA and CP on the lateral tibial plateau were measured in the intact, meniscectomy, and transplant states each at 0°, 30°, and 60° of knee flexion. Meniscus transplant was anchored with transosseous pull-out sutures and sutured to the joint capsule with vertical mattresses. The effects of meniscus states and flexion angle on CA and CP were measured by a two-way analysis of variance repeated measures model. One-way analysis of variance measured pairwise comparisons between meniscus states. RESULTS: Regarding CA, at 0°, no differences between the groups reached significance. Meniscectomy reduced CA at 30° ( P = 0.043) and 60° ( P = 0.001). Transplant and intact states were comparable at 30°. At 60°, transplant significantly increased CA ( P = 0.04). Regarding contact pressure, the average pressure increased with meniscectomy at all angles of flexion (0° P = 0.025; 30° P = 0.021; 60° P = 0.016) and decreased with transplant relative to respective intact values. Peak pressure increased with meniscectomy at 30° ( P = 0.009) and 60° ( P = 0.041), but only reached intact comparable values at 60°. Pairwise comparisons support restoration of average CP with transplant, but not peak CP. DISCUSSION: Pediatric meniscus transplantation improves average CP and CA more than peak CP, but does not completely restore baseline biomechanics. Net improvements in contact biomechanics after transplant, relative to the meniscectomy state, support meniscus transplant. STUDY DESIGN: Descriptive laboratory study, Level III.

A Stepwise Replicable Approach to Negotiating Value-driven Supply Chain Contracts for Orthobiologics.

INTRODUCTION: Orthobiologics are increasingly used to augment healing of tissues. Despite growing demand for orthobiologic products, many health systems do not enjoy substantial savings expected with high-volume purchases. The primary goal of this study was to evaluate an institutional program designed to (1) prioritize high-value orthobiologics and (2) incentivize vendor participation in value-driven contractual programs. METHODS: A three-step approach was used to reduce costs through optimization of orthobiologics supply chain. First, surgeons with orthobiologics expertise were engaged in key supply chain purchasing decisions. Second, eight orthobiologics formulary categories were defined. Capitated pricing expectations were established for each product category. Capitated pricing expectations were established for each product using institutional invoice data and market pricing data. In comparison with similar institutions, products offered by multiple vendors were priced at a lower benchmark (10th percentile of market price) than more rare products priced at the 25th percentile of the market price. Pricing expectations were transparent to vendors. Third, a competitive bidding process required vendors to submit pricing proposals for products. Clinicians and supply chain leaders jointly awarded contracts to vendors that met pricing expectations. RESULTS: Compared with our projected estimate of $423,946 savings using capitated product prices, our actual annual savings was $542,216. Seventy-nine percent of savings came from allograft products. Although the number of total vendors decreased from 14 to 11, each of the nine returning vendors received a larger, three-year institutional contract. Average pricing decreased across seven of the eight formulary categories. DISCUSSION: This study demonstrates a three-step replicable approach to increase institutional savings for orthobiologic products, engaging clinician experts, and strengthening relationships with select vendors. Vendor consolidation permits a symbiotic win-win relationship: Health systems achieve increased value by reducing unnecessary complexity of multiple contracts, and vendors obtain larger contracts with increased market share. LEVEL OF EVIDENCE: Level IV study.

Impact of Patient-Reported Outcome Measurement in Heart Failure Clinic on Clinician Health Status Assessment and Patient Experience: A Substudy of the PRO-HF Trial.

BACKGROUND: Clinicians typically estimate heart failure health status using the New York Heart Association Class, which is often discordant with patient-reported health status. It is unknown whether collecting patient-reported health status improves the accuracy of clinician assessments. METHODS: The PRO-HF trial (Patient-Reported Outcomes in Heart Failure Clinic) is a randomized, nonblinded trial evaluating routine Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12) collection in heart failure clinic. Patients with a scheduled visit to Stanford heart failure clinic between August 30, 2021 and June 30, 2022 were enrolled and randomized to KCCQ-12 assessment or usual care. In this prespecified substudy, we evaluated whether access to the KCCQ-12 improved the accuracy of clinicians' New York Heart Association assessment or patients' perspectives on their clinician interaction. We surveyed clinicians regarding their patients' New York Heart Association Class, quality of life, and symptom frequency. Clinician responses were compared with patients' KCCQ-12 responses. We surveyed patients regarding their clinician interactions. RESULTS: Of the 1248 enrolled patients, 1051 (84.2%) attended a visit during the substudy. KCCQ-12 results were given to the clinicians treating the 528 patients in the KCCQ-12 arm; the 523 patients in the usual care arm completed the KCCQ-12 without the results being shared. The correlation between New York Heart Association Class and KCCQ-12 Overall Summary Score was stronger when clinicians had access to the KCCQ-12 (r=-0.73 versus r=-0.61, P<0.001). More patients in the KCCQ-12 arm strongly agreed that their clinician understood their symptoms (95.2% versus 89.7% of respondents [odds ratio' 2.27; 95% CI' 1.32-3.87]). However, patients in both arms reported similar quality of clinician communication and therapeutic alliance. CONCLUSIONS: Collecting the KCCQ-12 in heart failure clinic improved clinicians' accuracy of health status assessment; correspondingly, patients believed their clinicians better understood their symptoms. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04164004.

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

BACKGROUND: Among patients with heart failure (HF), patient-reported health status provides information beyond standard clinician assessment. Although HF management guidelines recommend collecting patient-reported health status as part of routine care, there is minimal data on the impact of this intervention. STUDY DESIGN: The Patient-Reported Outcomes in Heart Failure Clinic (PRO-HF) trial is a pragmatic, randomized, implementation-effectiveness trial testing the hypothesis that routine health status assessment via the Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12) leads to an improvement in patient-reported health status among patients treated in a tertiary health system HF clinic. PRO-HF has completed randomization of 1,248 participants to routine KCCQ-12 assessment or usual care. Patients randomized to the KCCQ-12 arm complete KCCQ-12 assessments before each HF clinic visit with the results shared with their treating clinician. Clinicians received education regarding the interpretation and potential utility of the KCCQ-12. The primary endpoint is the change in KCCQ-12 over 1 year. Secondary outcomes are HF therapy patterns and health care utilization, including clinic visits, testing, hospitalizations, and emergency department visits. As a sub-study, PRO-HF will also evaluate the impact of routine KCCQ-12 assessment on patient experience and the accuracy of clinician-assessed health status. In addition, clinicians completed semi-structured interviews to capture their perceptions on the trial's implementation of routine KCCQ-12 assessment in clinical practice. CONCLUSIONS: PRO-HF is a pragmatic, randomized trial based in a real-world HF clinic to determine the feasibility of routinely assessing patient-reported health status and the impact of this intervention on health status, care delivery, patient experience, and the accuracy of clinician health status assessment.

Transtibial Repair of Lateral Meniscus Posterior Root Tears Improves Contact Biomechanics in Pediatric Cadavers.

Purpose: A paucity of data exists on the treatment of pediatric lateral meniscus root tears (LMPRTs). This study aims to characterize the biomechanics of the lateral knee joint in pediatric cadavers following LMPRT and root repair. Our hypotheses were: (1) compared with the intact state, LMPRT would be associated with decreased contact area; (2) compared with the intact state, LMPRT would be associated with increased contact pressures; and (3) compared with LMPRT, root repair would restore contact area and pressures toward intact meniscus values. Methods: Eight cadaver knees (ages 8-12 years) underwent contact area and pressure testing of the lateral compartment. Tekscan pressure mapping sensors covering the tibial plateau were inserted underneath the lateral meniscus. Appropriate pressure load equivalents were applied by a robot at degrees of flexion: 0, 30, 60. Three meniscus conditions were tested: (1) intact, (2) complete root tear, and (3) repaired root tear. Root repairs were performed with transtibial pullout sutures. Statistical analysis was performed. Results: Root tear significantly decreased mean contact area at 30° (P = .0279) and 60° (P = .0397). Root repair increased mean contact area and did not significantly differ from intact states. Differences in contact pressures between meniscus states were not statistically significant. Relative to the intact state. the greatest increase in contact pressures occurred between 0° and 30°. Root repair decreased mean contact pressures at 0° and 30°. At 60°, mean contact pressures of the repair state were closer in magnitude to the tear state than the intact state. Conclusions: LMPRT decreases contact area and increases contact pressures in the lateral knee compartment. Repair of LMPRT improves tibiofemoral contact area at high (>30°) degrees of flexion and contact pressures at low (<30°) degrees of flexion. Clinical Relevance: Transosseous pullout repair is a clinically validated treatment for LMPRT. This study provides baseline biomechanics data of transtibial pullout repair of pediatric LMPRTs.

Distance to the Neurovascular Bundle for Iliotibial Band Graft Passage During Anterior Cruciate Ligament Reconstruction: A Pediatric Cadaveric Study.

Background: The Micheli technique for anterior cruciate ligament (ACL) reconstruction (ACLR) has proven to be a reliable method with a minimal risk for growth disturbance among skeletally immature patients. Purposes: To evaluate the Micheli technique of iliotibial band (ITB) graft passage for ACLR using cadaveric knee models and to measure the distance between the surgical instrument tip and the neurovascular bundle in the posterior knee joint: specifically, the peroneal nerve, tibial nerve, and popliteal artery. Study Design: Descriptive laboratory study. Methods: Gross dissection was performed on 17 pediatric cadaveric knees (12 male and 5 female) aged between 4 and 12 years. To simulate ITB graft passage, we passed a curved-tip hemostat clamp through the posterior capsule, with the knee flexed from 90° to 100°. Next, clinical photographs were taken, and digital imaging software was used to measure the distance in centimeters from the clamp tip to each respective neurovascular structure. Results: The mean distances from the clamp tip to the tibial nerve, popliteal artery, and peroneal nerve were 0.875 cm (range, 0.468-1.737 cm), 0.968 cm (range, 0.312-1.819 cm), and 1.149 cm (range, 0.202-2.409 cm), respectively. Mean values were further calculated for age groups of ≤8, 9-10, and 11-12 years. The mean distance from the clamp tip to the peroneal nerve was 1.400 cm larger for 11- to 12-year-old specimens than for ≤8-year-old specimens (95% CI, 0.6-2.2 cm; P = .005). Conclusion: The neurovascular structures in the posterior knee were in close proximity to the path of graft passage, with distances <1 cm in many specimens in this study. When passing the graft through the knee for an over-the-top position, surgeons should consider these small distances between the path of graft passage and critical neurovascular structures. Clinical Relevance: As the incidence of ACL tears is continuously increasing within the pediatric population, there are a larger number of ACLR procedures being performed. Although neurovascular injuries during ACLR are rare, this study clarifies the close proximity of neurovascular structures during ITB graft passage using the Micheli technique of ACLR.

Quantifying the Relationship Between the Medial Quadriceps Tendon-Femoral Ligament and Patellar Borders: A Pediatric Cadaveric Study.

BACKGROUND: The medial patellofemoral complex (MPFC) is a structure composed of the medial quadriceps tendon-femoral ligament (MQTFL) superiorly and the medial patellofemoral ligament (MPFL) inferiorly. The pediatric MPFL anatomy has been well described, but the precise anatomy of the MQTFL has only recently been described and studied in skeletally immature patients. PURPOSE: To describe the anatomic relationship between the MQTFL and its insertion on the quadriceps tendon and patella in pediatric specimens. STUDY DESIGN: Descriptive laboratory study. METHODS: A total of 22 pediatric cadaveric knee specimens were dissected to analyze attachment of the MQTFL to the quadriceps tendon and patella. Dissection was facilitated using lateral parapatellar arthrotomy followed by eversion of the extensor mechanism to evaluate MQTFL fibers from its undersurface. RESULTS: The mean specimen age was 7.4 years. Specimens were divided based on age into a younger cohort (1-2 years), middle cohort (4-8 years), and older cohort (9-12 years). The quadriceps tendon attachment (QTA) of the MQTFL proximal to the patella extended a median of 5.0 mm in the younger cohort, 11.4 mm in the middle cohort, and 12.0 mm in the older cohort, with significant differences found between the younger and middle cohorts (P < .047) and the younger and older cohorts (P < .001). The QTA as a percentage of patellar articular height averaged 44.4% across all specimens. The vertical height of the patella measured a median of 14.0 mm, 22.3 mm, and 27.3 mm in the younger, middle, and older cohorts, respectively. CONCLUSION: This study expands on the recently described anatomy of the pediatric MPFC to quantify the anatomic relationship between the MQTFL attachment to the quadriceps tendon and patella in a more clinically relevant cohort of donor specimens. CLINICAL RELEVANCE: As access to pediatric cadaveric tissue is extremely limited, a better understanding of MPFC and MQTFL anatomy will support surgeons in preoperative planning and intraoperative considerations for their approach to MQTFL and MPFL reconstruction. This may facilitate improved anatomic surgical stabilization of the patellofemoral joint in pediatric patients.

Racial Disparities in Pediatric Kidney Transplantation under the New Kidney Allocation System in the United States.

BACKGROUND AND OBJECTIVES: In December 2014, the Kidney Allocation System (KAS) was implemented to improve equity in access to transplantation, but preliminary studies in children show mixed results. Thus, we aimed to assess how the 2014 KAS policy change affected racial and ethnic disparities in pediatric kidney transplantation access and related outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a retrospective cohort study of children <18 years of age active on the kidney transplant list from 2008 to 2019 using the Scientific Registry of Transplant Recipients. Log-logistic accelerated failure time models were used to determine the time from first activation on the transplant list and the time on dialysis to deceased donor transplant, each with KAS era or race and ethnicity as the exposure of interest. We used logistic regression to assess odds of delayed graft function. Log-rank tests assessed time to graft loss within racial and ethnic groups across KAS eras. RESULTS: All children experienced longer wait times from activation to transplantation post-KAS. In univariable analysis, Black and Hispanic children and other children of color experienced longer times from activation to transplant compared with White children in both eras; this finding was largely attenuated after multivariable analysis (time ratio, 1.16; 95% confidence interval, 1.01 to 1.32; time ratio, 1.13; 95% confidence interval, 1.00 to 1.28; and time ratio, 1.17; 95% confidence interval, 0.96 to 1.41 post-KAS, respectively). Multivariable analysis also showed that racial and ethnic disparities in time from dialysis initiation to transplantation in the pre-KAS era were mitigated in the post-KAS era. There were no disparities in odds of delayed graft function. Black and Hispanic children experienced longer times with a functioning graft in the post-KAS era. CONCLUSIONS: No racial and ethnic disparities from activation to deceased donor transplantation were seen before or after implementation of the KAS in multivariable analysis, whereas time on dialysis to transplantation and odds of short-term graft loss improved in equity after the implementation of the KAS, without compromising disparities in delayed graft function. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_12_07_CJN06740521.mp3.

Outcomes after Surgery among Patients Diagnosed with One or More Multi-Drug-Resistant Organisms.

Background: Infections with multi-drug-resistant organisms (MDROs) may be difficult to treat and prolong patient hospitalization and recovery. Multiple MDRO coinfections may increase the complexity of clinical management. However, association between multiple MDROs and outcomes of patients who undergo surgery is unknown. Patients and Methods: We performed a retrospective, cross-sectional analysis of the 2016 National Inpatient Sample for identified by International Classification of Disease, 10th Revision Clinical Modification (ICD-10-CM) diagnosis codes associated with multi-drug-resistant organisms: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), multi-drug-resistant gram-negative bacilli, and Clostridioides difficile infection (CDI). Admitted patients with diagnosis codes for MDROs were cross-matched with codes for common general surgery procedures. Outcomes of interest included length of stay and mortality. Weighted univariable and multivariable analyses accounting for the survey methodology were performed. Results: Of 1,550,224 patients undergoing surgery in 2016, 39,065 (3%) admissions were diagnosed with an MDRO and 1,176 (0.1%) were associated with dual MDROs diagnoses. Patients diagnosed with one MDRO were hospitalized three times longer (17.3 days; 95% confidence interval [CI], 16.8-17.7) and patients diagnosed with two MDROs five times longer (31.6 days; 95% CI, 27.0-36.2; p < 0.0001) than undiagnosed patients (6.1 days; 95% CI, 6.1-6.1; all p < 0.0001). On multivariable analysis, the strongest predictor of mortality was a diagnosis of two MDRO infections (odds ratio [OR], 4.8; 95% CI, 3.16-7.21; p < 0.0001). The second strongest predictor was diagnosis of single MDRO infection (OR, 2.9; 95% CI, 2.64-3.20; p < 0.0001). Conclusion: Presence of an MDRO was associated with increased odds of mortality and length of stay in admitted surgical patients. Interventions to reduce MDRO infection among surgical patients may reduce hospital length of stay and mortality.

Prospectively Assigned AAST Grade versus Modified Hinchey Class and Acute Diverticulitis Outcomes.

BACKGROUND: The American Association for the Surgery of Trauma (AAST) recently developed a classification system to standardize outcomes analyses for several emergency general surgery conditions. To highlight this system's full potential, we conducted a study integrating prospective AAST grade assignment within the electronic medical record. METHODS: Our institution integrated AAST grade assignment into our clinical workflow in July 2018. Patients with acute diverticulitis were prospectively assigned AAST grades and modified Hinchey classes at the time of surgical consultation. Support vector machine-a machine learning algorithm attuned for small sample sizes-was used to compare the associations between the two classification systems and decision to operate and incidence of complications. RESULTS: 67 patients were included (median age of 62 y, 40% male) for analysis. The decision for operative management, hospital length of stay, intensive care unit admission, and intensive care unit length of stay were associated with both increasing AAST grade and increasing modified Hinchey class (all P < 0.001). AAST grade additionally showed a correlation with complication severity (P = 0.02). Compared with modified Hinchey class, AAST grade better predicted decision to operate (88.2% versus 82.4%). CONCLUSIONS: This study showed the feasibility of electronic medical record integration to support the full potential of AAST classification system's utility as a clinical decision-making tool. Prospectively assigned AAST grade may be an accurate and pragmatic method to find associations with outcomes, yet validation requires further study.

COVID-19 Solutions Are Climate Solutions: Lessons From Reusable Gowns.

The COVID-19 pandemic has laid bare the inadequacy of the U.S. healthcare system to deliver timely and resilient care. According to the American Hospital Association, the pandemic has created a $202 billion loss across the healthcare industry, forcing health care systems to lay off workers and making hospitals scramble to minimize supply chain costs. However, as the demand for personal protective equipment (PPE) grows, hospitals have sacrificed sustainable solutions for disposable options that, although convenient, will exacerbate supply strains, financial burden, and waste. We advocate for reusable gowns as a means to lower health care costs, address climate change, and improve resilience while preserving the safety of health care workers. Reusable gowns' polyester material provides comparable capacity to reduce microbial cross-transmission and liquid penetration. In addition, previous hospitals have reported a 50% cost reduction in gown expenditures after adopting reusable gowns; given the current 2000% price increase in isolation gowns during COVID-19, reusable gown use will build both healthcare resilience and security from price fluctuations. Finally, with the United States' medical waste stream worsening, reusable isolation gowns show promising reductions in energy and water use, solid waste, and carbon footprint. The gowns are shown to withstand laundering 75-100 times in contrast to the single-use disposable gown. The circumstances of the pandemic forewarn the need to shift our single-use PPE practices to standardized reusable applications. Ultimately, sustainable forms of protective equipment can help us prepare for future crises that challenge the resilience of the healthcare system.

Therapy-Induced Evolution of Human Lung Cancer Revealed by Single-Cell RNA Sequencing.

Lung cancer, the leading cause of cancer mortality, exhibits heterogeneity that enables adaptability, limits therapeutic success, and remains incompletely understood. Single-cell RNA sequencing (scRNA-seq) of metastatic lung cancer was performed using 49 clinical biopsies obtained from 30 patients before and during targeted therapy. Over 20,000 cancer and tumor microenvironment (TME) single-cell profiles exposed a rich and dynamic tumor ecosystem. scRNA-seq of cancer cells illuminated targetable oncogenes beyond those detected clinically. Cancer cells surviving therapy as residual disease (RD) expressed an alveolar-regenerative cell signature suggesting a therapy-induced primitive cell-state transition, whereas those present at on-therapy progressive disease (PD) upregulated kynurenine, plasminogen, and gap-junction pathways. Active T-lymphocytes and decreased macrophages were present at RD and immunosuppressive cell states characterized PD. Biological features revealed by scRNA-seq were biomarkers of clinical outcomes in independent cohorts. This study highlights how therapy-induced adaptation of the multi-cellular ecosystem of metastatic cancer shapes clinical outcomes.

The Effect of Textiles Impregnated With Particles With High Emissivity in the Far Infrared, on the Temperature of the Cold Hand.

In engineering and medicine, there is a growing interest in using textiles made of composites with enhanced thermal properties. One such type of textile is fabric impregnated with ceramics and mineral particles. This material has high emissivity in the infrared range and may have therapeutic benefits for treatments of diseases, like Raynaud's syndrome. While there is significant clinical and commercial interest, there is an evident lack of fundamental studies on the heat transfer aspects of these fabrics. The goal of this technical brief is to present results from a fundamental study examining the thermal effects of fabric with ceramics and minerals (produced by Nanobionic, Inc., Athens, Greece) on the temperatures of the hands. With a confidence level of 90%, the results show that the textile with ceramics and minerals has an enhanced thermal effect on warming a cold hand in comparison to a placebo fabric without ceramics or minerals. Much more research is needed to increase the level of confidence and develop a fundamental understanding of the mechanism.

Preservation of rat hearts in subfreezing temperature isochoric conditions to - 8 °C and 78 MPa.

Isochoric (constant volume) preservation at subfreezing temperatures is being investigated as a novel method for preserving cells and organs. This study is a first initial effort to evaluate the efficacy of this method for heart preservation, and to provide a preliminary outline of appropriate preservation parameters. To establish a baseline for further studies, rat hearts were preserved in a University of Wisconsin (UW) intracellular solution for one hour under isochoric conditions at: 0 °C (atmospheric pressure - 0.1 MPa), - 4 °C (41 MPa), - 6 °C (60 MPa) and - 8 °C (78 MPa). The viability of the heart was evaluated using Langendorff perfusion and histological examination. The physiological performance of hearts preserved at - 4 °C (41 MPa) was comparable to that of a heart preserved on ice at atmospheric pressure, with no statistically significant difference in histological injury score. However, hearts preserved at -4 °C displayed substantially reduced interstitial edema compared to hearts preserved by conventional hypothermic preservation in UW on ice at atmospheric pressure, suggesting significant protection from increased vascular permeability following preservation. Hearts preserved at - 6 °C (60 MPa) suffered injury from cellular swelling and extensive edema, and at - 8 °C (78 MPa) hearts experienced significant morphological disruption. To the best of our knowledge, this is the first publication showing that a mammalian organ can survive low subfreezing temperatures without the use of a cryoprotective additive. Lowering the preservation temperature reduces metabolism and improves preservation quality, and these results suggest that improvements in preservation are possible at subzero temperatures with low to moderate pressures observed at -4 °C. Notably, tissue damage was observed at lower temperatures (-6 °C or below) accompanying further elevation of pressure associated with isochoric preservation that may prove detrimental. Therefore, subfreezing temperature isochoric preservation protocols should optimize, a combination of temperature and pressure that will minimize the negative effects of elevated pressure while retaining the beneficial effect of lower temperatures and reduced metabolism.