Circulating T cell specific extracellular vesicle profiles in cardiac allograft acute cellular rejection.

There is a critical need for biomarkers of acute cellular rejection (ACR) in organ transplantation. We hypothesized that ACR leads to changes in donor-reactive T cell small extracellular vesicle (sEV) profiles in transplant recipient circulation that match the kinetics of alloreactive T cell activation. In rodent heart transplantation, circulating T cell sEV quantities (P < .0001) and their protein and mRNA cargoes showed time-specific expression of alloreactive and regulatory markers heralding early ACR in allogeneic transplant recipients but not in syngeneic transplant recipients. Next generation sequencing of their microRNA cargoes identified novel candidate biomarkers of ACR, which were validated by stem loop quantitative reverse transcription polymerase chain reaction (n = 10). Circulating T cell sEVs enriched from allogeneic transplant recipients mediated targeted cytotoxicity of donor cardiomyocytes by apoptosis assay (P < .0001). Translation of the concept and EV methodologies to clinical heart transplantation demonstrated similar upregulation of circulating T cell sEV profiles at time points of grade 2 ACR (n = 3 patients). Furthermore, T cell receptor sequencing of T cell sEV mRNA cargo demonstrated expression of T cell clones with intact complementarity determining region 3 signals. These data support the diagnostic potential of T cell sEVs as noninvasive biomarker of ACR and suggest their potential functional roles.

Network Meta-Analysis Comparing Angiotensin Receptor-Neprilysin Inhibitors, Angiotensin Receptor Blockers, and Angiotensin-Converting Enzyme Inhibitors in Heart Failure With Reduced Ejection Fraction.

The superiority of angiotensin receptor-neprilysin inhibitor (ARNI) over angiotensin-converting enzyme inhibitor (ACE-I) and angiotensin receptor blocker (ARB) has not been reassessed after the publication of recent trials that did not find clinical benefits. Therefore, we performed an updated network meta-analysis comparing the efficacy and safety of ARNI, ACE-I, ARB, and placebo in heart failure with reduced ejection fraction. We included randomized clinical trials that compared ARNI, ARB, ACE-I, and placebo in heart failure with reduced ejection fraction. We extracted prespecified efficacy end points and produced network estimates, p scores, and surface under the cumulative ranking curve scores using frequentist and Bayesian network meta-analysis approaches. A total of 28 randomized controlled trials including 47,407 patients were included. ARNI was associated with lower risk of all-cause mortality (relative risk [RR] 0.81, 95% confidence interval [CI] 0.68 to 0.96), cardiac death (RR 0.79, 95% CI 0.64 to 0.99), and major adverse cardiac events (MACEs; RR 0.83, 95% CI 0.72 to 0.97) but higher risk of hypotension (RR 1.46, 95% CI 1.02 to 2.10) than ARB. ARNI was associated with lower risk of MACE (RR 0.85, 95% CI 0.74 to 0.97), but higher risk of hypotension (RR 1.69, 95% CI 1.27 to 2.24) compared with ACE-I. P scores and surface under the cumulative ranking curve scores demonstrated superiority of ARNI over ARB and ACE-I in all-cause mortality, cardiac death, MACE, and hospitalization for heart failure. In conclusion, ARNI was associated with improved clinical outcomes, except for higher risk of hypotension, compared with ARB and ACE-I.

Electrical storm in patients with left ventricular assist devices: Risk factors, incidence, and impact on survival.

BACKGROUND: Ventricular arrhythmias (VAs) and electrical storm (ES) are recognized complications following left ventricular assist device (LVAD) implantation; however, their association with long term-outcomes remains poorly understood. OBJECTIVE: The purpose of this study was to describe the clinical impact of ES in a population of patients undergoing LVAD implantation at a quaternary care center in the United States. METHODS: This was an observational retrospective study of patients undergoing LVAD implantation from 2009 to 2020 at Duke University Hospital. The incidence of ES (≥3 sustained VA episodes over a 24-hour period without an identifiable reversible cause) was determined from patient records. Risk factors for ES were identified using multivariable Cox proportional hazards modeling. RESULTS: Among 730 patients undergoing LVAD implant, 78 (10.7%) developed ES at a median of 269 (interquartile range [IQR] 7-766) days following surgery. Twenty-seven patients (34.6%) developed ES within 30 days, while 51 (65.4%) presented with ES at a median 639 (IQR 281-1017) days after implant. Following ES, 41% of patients died within 1 year. Patients who developed ES were more likely to have a history of VAs, ventricular tachycardia ablation, antiarrhythmic drug use, and perioperative mechanical circulatory support around the time of LVAD implant than patients without ES. CONCLUSION: ES occurs in 1 in 10 patients after LVAD and is associated with higher mortality. Risk factors for ES include a history of VAs, VT ablation, antiarrhythmic drug use, and perioperative mechanical circulatory support. Optimal management of ES surrounding LVAD implant, including escalation of medical therapy, catheter ablation, or adjunctive sympatholytic therapies, remains uncertain.

Regional-Level Correlations in Inappropriate Imaging Rates for Prostate and Breast Cancers: Potential Implications for the Choosing Wisely Campaign.

IMPORTANCE: The association between regional norms of clinical practice and appropriateness of care is incompletely understood. Understanding regional patterns of care across diseases might optimize implementation of programs like Choosing Wisely, an ongoing campaign to decrease wasteful medical expenditures. OBJECTIVE: To determine whether regional rates of inappropriate prostate and breast cancer imaging were associated. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using the the Surveillance, Epidemiology, and End Results-Medicare linked database. We identified patients diagnosed from 2004 to 2007 with low-risk prostate (clinical stage T1c/T2a; Gleason score, ≤6; and prostate-specific antigen level, <10 ng/mL) or breast cancer (in situ, stage I, or stage II disease), based on Choosing Wisely definitions. MAIN OUTCOMES AND MEASURES: In a hospital referral region (HRR)-level analysis, our dependent variable was HRR-level imaging rate among patients with low-risk prostate cancer. Our independent variable was HRR-level imaging rate among patients with low-risk breast cancer. In a subsequent patient-level analysis we used multivariable logistic regression to model prostate cancer imaging as a function of regional breast cancer imaging and vice versa. RESULTS: We identified 9219 men with prostate cancer and 30,398 women with breast cancer residing in 84 HRRs. We found high rates of inappropriate imaging for both prostate cancer (44.4%) and breast cancer (41.8%). In the first, second, third, and fourth quartiles of breast cancer imaging, inappropriate prostate cancer imaging was 34.2%, 44.6%, 41.1%, and 56.4%, respectively. In the first, second, third, and fourth quartiles of prostate cancer imaging, inappropriate breast cancer imaging was 38.1%, 38.4%, 43.8%, and 45.7%, respectively. At the HRR level, inappropriate prostate cancer imaging rates were associated with inappropriate breast cancer imaging rates (ρ = 0.35; P < .01). At the patient level, a man with low-risk prostate cancer had odds ratios (95% CIs) of 1.72 (1.12-2.65), 1.19 (0.78-1.81), or 1.76 (1.15-2.70) for undergoing inappropriate prostate imaging if he lived in an HRR in the fourth, third, or second quartiles, respectively, of inappropriate breast cancer imaging, compared with the lowest quartile. CONCLUSIONS AND RELEVANCE: At a regional level, there is an association between inappropriate prostate and breast cancer imaging rates. This finding suggests the existence of a regional-level propensity for inappropriate imaging utilization, which may be considered by policymakers seeking to improve quality of care and reduce health care spending in high-utilization areas.

For-profit hospital ownership status and use of brachytherapy after breast-conserving surgery.

BACKGROUND: Little is known about the relationship between operative care for breast cancer at for-profit hospitals and subsequent use of adjuvant radiation therapy (RT). Among Medicare beneficiaries, we examined whether hospital ownership status is associated with the use of breast brachytherapy--a newer and more expensive modality--as well as overall RT. METHODS: We conducted a retrospective study of female Medicare beneficiaries who received breast-conserving surgery for invasive breast cancer in 2008 and 2009. We assessed the relationship between hospital ownership and receipt of brachytherapy or overall RT by using hierarchical generalized linear models. RESULTS: The sample consisted of 35,118 women, 8.0% of whom had breast-conserving operations at for-profit hospitals. Among patients who received RT, those who underwent operation at for-profit hospitals were more likely to receive brachytherapy (20.2%) than patients treated at not-for-profit hospitals (15.2%; odds ratio [OR] for for-profit versus not-for-profit: 1.50; 95% confidence interval [95% CI] 1.23-1.84; P < .001). Among women aged 66-79 years, there was no relationship between hospital ownership status and overall use of RT. Among women ages 80-94 years of age--the group least likely to benefit from RT due to shorter life expectancy--undergoing breast-conserving operations at a for-profit hospital was associated with greater overall use of RT (OR 1.22; 95% CI 1.03-1.45, P = .03) and brachytherapy use (OR 1.66; 95% CI 1.18-2.34, P = .003). CONCLUSION: Operative care at for-profit hospitals was associated with increased use of the newer and more expensive RT modality, brachytherapy. Among the oldest women who are least likely to benefit from RT, operative care at a for-profit hospital was associated with greater overall use of RT, with this difference largely driven by the use of brachytherapy.

Examining the cost-effectiveness of radiation therapy among older women with favorable-risk breast cancer.

BACKGROUND: Little is known about the cost-effectiveness of external beam radiation therapy (EBRT) or newer radiation therapy (RT) modalities such as intensity modulated radiation (IMRT) or brachytherapy among older women with favorable-risk breast cancer. METHODS: Using a Markov model, we estimated the cost-effectiveness of no RT, EBRT, and IMRT over 10 years. We estimated the incremental cost-effectiveness ratio (ICER) of IMRT compared with EBRT under different scenarios to determine the necessary improvement in effectiveness for newer modalities to be cost-effective. We estimated model inputs using women in the Surveillance, Epidemiology, and End Results-Medicare database fulfilling the Cancer and Leukemia Group B C9343 trial criteria. RESULTS: The incremental cost of EBRT compared with no RT was $9500 with an ICER of $44600 per quality-adjusted life year (QALY) gained. The ICERs increased with age, ranging from $38300 (age 70-74 years) to $55800 (age 80 to 94 years) per QALY. The ICERs increased to more than $63800 per QALY for women aged 70 to 74 years with an expected 10-year survival of 25%. Reduction in local recurrence by IMRT compared with EBRT did not have a substantial impact on the ICER of IMRT. IMRT would have to increase the utility of baseline state by 20% to be cost-effective (<$100000 per QALY). CONCLUSIONS: EBRT is cost-effective for older women with favorable risk breast cancer, but substantially less cost-effective for women with shorter expected survival. Newer RT modalities would have to be substantially more effective than existing therapies in improving quality of life to be cost-effective.

Dynamic culture enhances stem cell infiltration and modulates extracellular matrix production on aligned electrospun nanofibrous scaffolds.

Electrospun nanofibrous scaffolds have become widely investigated for tissue engineering applications, owing to their ability to replicate the scale and organization of many fiber-reinforced soft tissues such as the knee meniscus, the annulus fibrosus of the intervertebral disc, tendon, and cartilage. However, due to their small pore size and dense packing of fibers, cellular ingress into electrospun scaffolds is limited. Progress in the application of electrospun scaffolds has therefore been hampered, as limited cell infiltration results in heterogeneous deposition of extracellular matrix and mechanical properties that remain below native benchmarks. In the present study, dynamic culture conditions dramatically improved the infiltration of mesenchymal stem cells into aligned nanofibrous scaffolds. While dynamic culture resulted in a reduction of glycosaminoglycan content, removal from dynamic culture to free-swelling conditions after 6 weeks resulted recovery of glycosaminoglycan content. Dynamic culture significantly increased collagen content, and collagen was more uniformly distributed throughout the scaffold thickness. While mechanical function was assessed and tensile modulus increased with culture duration, dynamic culture did not result in any additional improvement beyond free-swelling culture. Transient dynamic (6 weeks dynamic followed by 6 weeks free-swelling) culture significantly enhanced cell infiltration while permitting GAG accumulation. In this study, we demonstrated that a simple modification to standard in vitro culture conditions effectively improves cellular ingress into electrospun scaffolds, resolving a challenge which has until now limited the utility of these materials for various tissue engineering applications.

Engineered disc-like angle-ply structures for intervertebral disc replacement.

STUDY DESIGN: To develop a construction algorithm in which electrospun nanofibrous scaffolds are coupled with a biocompatible hydrogel to engineer a mesenchymal stem cell (MSC)-based disc replacement. OBJECTIVE: To engineer a disc-like angle-ply structure (DAPS) that replicates the multiscale architecture of the intervertebral disc. SUMMARY OF BACKGROUND DATA: Successful engineering of a replacement for the intervertebral disc requires replication of its mechanical function and anatomic form. Despite many attempts to engineer a replacement for ailing and degenerated discs, no prior study has replicated the multiscale hierarchical architecture of the native disc, and very few have assessed the mechanical function of formed neo-tissues. METHODS: A new algorithm for the construction of a disc analogue was developed, using agarose to form a central nucleus pulposus (NP) and oriented electrospun nanofibrous scaffolds to form the anulus fibrosus region (AF). Bovine MSCs were seeded into both regions and biochemical, histologic, and mechanical maturation were evaluated with in vitro culture. RESULTS: We show that mechanical testing in compression and torsion, loading methods commonly used to assess disc mechanics, reveal equilibrium and time-dependent behaviors that are qualitatively similar to native tissue, although lesser in magnitude. Further, we demonstrate that cells seeded into both AF and NP regions adopt distinct morphologies that mirror those seen in native tissue, and that, in the AF region, this ordered community of cells deposit matrix that is organized in an angle-ply configuration. Finally, constructs demonstrate functional development with long-term in vitro culture. CONCLUSION: These findings provide a new approach for disc tissue engineering that replicates multi-scale form and function of the intervertebral disc, providing a foundation from which to build a multi-scale, biologic, anatomically and hierarchically relevant composite disc analogue for eventual disc replacement.

Nanofibrous biologic laminates replicate the form and function of the annulus fibrosus.

Successful engineering of load-bearing tissues requires recapitulation of their complex mechanical functions. Given the intimate relationship between function and form, biomimetic materials that replicate anatomic form are of great interest for tissue engineering applications. However, for complex tissues such as the annulus fibrosus, scaffolds have failed to capture their multi-scale structural hierarchy. Consequently, engineered tissues have yet to reach functional equivalence with their native counterparts. Here, we present a novel strategy for annulus fibrosus tissue engineering that replicates this hierarchy with anisotropic nanofibrous laminates seeded with mesenchymal stem cells. These scaffolds directed the deposition of an organized, collagen-rich extracellular matrix that mimicked the angle-ply, multi-lamellar architecture and achieved mechanical parity with native tissue after 10 weeks of in vitro culture. Furthermore, we identified a novel role for inter-lamellar shearing in reinforcing the tensile response of biologic laminates, a mechanism that has not previously been considered for these tissues.