IL-6 trans-signaling in a humanized mouse model of scleroderma.

Fibrosis is regulated by interactions between immune and mesenchymal cells. However, the capacity of cell types to modulate human fibrosis pathology is poorly understood due to lack of a fully humanized model system. MISTRG6 mice were engineered by homologous mouse/human gene replacement to develop an immune system like humans when engrafted with human hematopoietic stem cells (HSCs). We utilized MISTRG6 mice to model scleroderma by transplantation of healthy or scleroderma skin from a patient with pansclerotic morphea to humanized mice engrafted with unmatched allogeneic HSC. We identified that scleroderma skin grafts contained both skin and bone marrow-derived human CD4 and CD8 T cells along with human endothelial cells and pericytes. Unlike healthy skin, fibroblasts in scleroderma skin were depleted and replaced by mouse fibroblasts. Furthermore, HSC engraftment alleviated multiple signatures of fibrosis, including expression of collagen and interferon genes, and proliferation and activation of human T cells. Fibrosis improvement correlated with reduced markers of T cell activation and expression of human IL-6 by mesenchymal cells. Mechanistic studies supported a model whereby IL-6 trans-signaling driven by CD4 T cell-derived soluble IL-6 receptor complexed with fibroblast-derived IL-6 promoted excess extracellular matrix gene expression. Thus, MISTRG6 mice transplanted with scleroderma skin demonstrated multiple fibrotic responses centered around human IL-6 signaling, which was improved by the presence of healthy bone marrow-derived immune cells. Our results highlight the importance of IL-6 trans-signaling in pathogenesis of scleroderma and the ability of healthy bone marrow-derived immune cells to mitigate disease.

Eutectic Mixture of Lidocaine and Prilocaine Decreases Movement and Propofol Requirements for Pediatric Lumbar Puncture During Deep Sedation: A Randomized, Placebo-Controlled, Double Blind Trial.

Deep sedation/general anesthesia is commonly used in pediatric oncology patients undergoing lumbar puncture (LP). Propofol is often used for sedation, with or without a narcotic. We hypothesized that eutectic mixture of lidocaine and prilocaine (EMLA) would allow for lower cumulative doses of propofol and less movement. We performed a prospective, randomized, double blind, placebo-controlled trial in children undergoing sedation for LP. Standard initial weight-based doses of propofol and fentanyl were administered, with either EMLA cream or a placebo cream applied topically. The primary outcome was the total dose of propofol administered to each patient. We also tracked patient movement and complications. Twenty-seven patients underwent 152 LPs. Patients randomized to EMLA cream (n=75) were significantly more likely to receive a lower dose of propofol (2.94 mg/kg, SE=0.25, vs. 3.22 mg/kg, SE=0.19; P=0.036) and to not require additional propofol doses (probability 0.49, SE=0.08 vs. 0.69, SE=0.06; P=0.001) compared with patients randomized to placebo cream (n=77). In addition, patients with EMLA cream were significantly less likely to demonstrate minor or major movement. EMLA cream results in less movement and less propofol administration in pediatric oncology patients undergoing sedation for LP.

An Innovative Approach to Integrating Nephrology Nursing into Acute and Critical Care.

There is a growing number of individuals living with chronic kidney disease in the United States and worldwide. There is also a nursing shortage and increased need for nurses, particularly in specialties like nephrology. Meeting these growing demands and improving conditions for nurses will take multiple approaches and broadening of current systems. An area of focus is the training and expansion of the nephrology nursing workforce. This article discusses a dialysis training program for acute and critical care nurses who are able to provide both bedside care and kidney replacement therapy in the hospital setting.

Nephrology Nurses' Perspectives for the Designs of Mobile Hemodialysis Devices: A Human Factors Engineering Approach.

The goal of this study was to guide the early conceptual designs of two devices intended to improve the quality of life for patients on hemodialysis: a portable hemodialysis device and a wearable hemodialysis device. Thirty-two nephrology nurses were interviewed using a mixed approach of open-ended, rating, and rank-order questions. Results show most nurses try to persuade patients to try a modality of treatment that offers them the best clinical outcome and highest quality of life. Many nurses, however, indicate that patients are often not given the opportunity to choose their preferred modality of treatment, and that current hemodialysis treatments are one-size-fits-all and should be more individualized. Nurses also believe high-frequency home-based, portable, or wearable hemodialysis treatments are better for patients than in-center treatments, and patients can learn to safely connect and disconnect a hemodialysis device to their catheter. Using content analysis, we identified six categories of potential benefits a patient may experience using either a portable or a wearable hemodialysis device. We also identified six categories of potential barriers that may hinder nephrology nurses in recommending either a portable or a wearable hemodialysis device to their patients and seven categories of ideal features for the designs of the devices. Statistical analysis of rank-order questions shows nephrology nurses prefer a wearable hemodialysis device in the form of a belt compared to other designs (p < 0.05). Findings from this study provide valuable information guiding the design process of mobile hemodialysis devices that nephrology nurses will feel comfortable recommending to their patients.

Complement Membrane Attack Complexes Assemble NLRP3 Inflammasomes Triggering IL-1 Activation of IFN-γ-Primed Human Endothelium.

RATIONALE: Complement activation contributes to multiple immune-mediated pathologies. In late allograft failure, donor-specific antibody deposits complement membrane attack complexes (MAC) on graft endothelial cells (ECs), substantially increasing their immunogenicity without causing lysis. Internalized MAC stabilize NIK (NF-κB [nuclear factor kappa-light-chain-enhancer of activated B cells]-inducing kinase) protein on Rab5+MAC+ endosomes, activating noncanonical NF-κB signaling. However, the link to increased immunogenicity is unclear. OBJECTIVE: To identify mechanisms by which alloantibody and internalized MAC activate ECs to enhance their ability to increase T-cell responses. METHODS AND RESULTS: In human EC cultures, internalized MAC also causes NLRP3 (NOD-like receptor family pyrin domain containing 3) translocation from endoplasmic reticulum to Rab5+MAC+NIK+ endosomes followed by endosomal NIK-dependent inflammasome assembly. Cytosolic NIK, stabilized by LIGHT (lymphotoxin-like inducible protein that competes with glycoprotein D for herpesvirus entry on T cells), does not trigger inflammasome assembly, and ATP-triggered inflammasome assembly does not require NIK. IFN-γ (interferon-γ) primes EC responsiveness to MAC by increasing NLRP3, pro-caspase 1, and gasdermin D expression. NIK-activated noncanonical NF-κB signaling induces pro-IL (interleukin)-1ß expression. Inflammasome processed pro-IL-1ß, and gasdermin D results in IL-1ß secretion that increases EC immunogenicity through IL-1 receptor signaling. Activation of human ECs lining human coronary artery grafts in immunodeficient mouse hosts by alloantibody and complement similarly depends on assembly of an NLRP3 inflammasome. Finally, in renal allograft biopsies showing chronic rejection, caspase-1 is activated in C4d+ ECs of interstitial microvessels, supporting the relevance of the cell culture findings. CONCLUSIONS: In response to antibody-mediated complement activation, IFN-γ-primed human ECs internalize MAC, triggering both endosomal-associated NIK-dependent NLRP3 inflammasome assembly and IL-1 synthesis, resulting in autocrine/paracrine IL-1ß-mediated increases in EC immunogenicity. Similar responses may underlie other complement-mediated pathologies.

Patterns of granulocyte colony-stimulating factor prophylaxis in patients with cancer receiving myelosuppressive chemotherapy.

PURPOSE: To evaluate patterns of primary prophylactic (PP) granulocyte colony-stimulating factor (G-CSF) use following chemotherapy by cancer type and febrile neutropenia (FN) risk. METHODS: Using a commercial administrative database, we identified adult patients diagnosed with breast, colorectal, lung, ovarian cancer, or non-Hodgkin lymphoma (NHL) who initiated chemotherapy with high risk (HR) or intermediate risk (IR) for FN between January 1, 2013, and August 31, 2017. We describe use of PP-G-CSF, proportion completing all their cycles with pegfilgrastim, timing of pegfilgrastim, and duration of short-acting G-CSF. RESULTS: Among 22,868 patients (breast 11,513; colorectal 3765; lung 4273; ovarian 1287; and NHL 2030), 36.8% received HR and 63.2% received IR (64.4% of whom had ≥ 1 risk factor [RF] for FN). Proportions of patients receiving PP-G-CSF in the first cycle were 76.1%, 28.2%, and 26.4% among patients receiving HR, IR, and IR plus ≥ 1 RF, respectively. Among breast cancer patients receiving HR regimens and initiating PP-pegfilgrastim, 60.4% (95% confidence interval [CI] 57.2-63.6%) initiating via on-body injector (OBI) and 51.9% (95% CI 48.0-55.8%) initiating via prefilled syringe (PFS) completed all their cycles with OBI and PFS, respectively. Among all cycles with PP-PFS, 8.5% received PFS on the same day as chemotherapy completion. Mean administrations/cycle were 3.2 (standard deviation [SD] 2.3) for filgrastim, 3.0 (SD 1.6) for filgrastim-sndz, and 4.3 (SD 2.5) for tbo-filgrastim. CONCLUSIONS: There is under- and mistimed use of PP-G-CSF among patients at HR for FN. Novel pegfilgrastim delivery devices could help breast cancer patients at HR for FN complete all their cycles with timely prophylaxis.

Dietary supplementation of Ascophylum nodosum improved kidney function of mink challenged with Aleutian mink disease virus.

BACKGROUND: Feed additives which can ease the negative effects of infection by the Aleutian mink disease virus (AMDV) are of interest to mink farmers. The effects of kelp meal (Ascophylum nodosum) supplementation on immune response, virus replication and blood parameters of mink inoculated with AMDV were assessed. AMDV-free black mink (n = 75) were intranasally inoculated with a local strain of AMDV and fed a commercial pellet supplemented with kelp meal at the rates of 1.5% or 0.75% of the feed or were kept as controls (no kelp) for 451 days. Blood was collected on days 0 (pre-inoculation), 31, 56, 99, 155, 366 and 451 post-inoculation (dpi). RESULTS: No significant difference was observed among the treatments for the proportion of animals positive for antibodies against the virus measured by the counter-immunoelectrophoresis (CIEP), viremia measured by PCR, antibody titer measured by quantitative ELISA, total serum protein measured by a refractometer or elevated levels of gamma globulin measured by iodine agglutination test at the sampling occasions. At the termination of the experiment on 451 dpi, there were no differences among treatments for antibody titer measured by CIEP, total serum protein, albumin, globulins, albumin:globulin ratio, alkaline phosphatase, gamma-glutamyl transferase, and proportions of PCR positive spleen, lymph node or bone marrow samples, but blood urea nitrogen and creatine levels were significantly lower in the 1.5% kelp supplemented group than in the controls. CONCLUSION: Kelp supplementation improved kidney function of mink infected with AMDV with no effect on liver function, immune response to infection by AMDV or virus replication.

Standing on the Shoulders of Giants: Innovations in Dialysis.

Prior to the 1960s, chronic hemodialysis was limited by vascular access. Pioneers in dialysis technology created the first artificial kidney, chronic vascular access for hemodialysis, and peritoneal dialysis access. Now it is estimated that 600,000 people in the United States and over 2 million people worldwide receive renal replacement therapy. Unfortunately, there has been limited growth in dialysis technology and fairly stagnant outcomes. As a growing body of literature supports improved outcomes and symptoms management with longer dialysis treatments, innovations in wearable and implantable devices are being developed, as well as new options for creating and maintaining vascular access. As the nephrology community stands on the shoulders of the inventors who came before us, we continue to reach for a future with infinite possibilities to improve kidney care. This article discusses some of the new technology for dialysis care and systems that are supporting innovation in this field.

IL-17 Promotes Neutrophil-Mediated Immunity by Activating Microvascular Pericytes and Not Endothelium.

A classical hallmark of acute inflammation is neutrophil infiltration of tissues, a multistep process that involves sequential cell-cell interactions of circulating leukocytes with IL-1- or TNF-activated microvascular endothelial cells (ECs) and pericytes (PCs) that form the wall of the postcapillary venules. The initial infiltrating cells accumulate perivascularly in close proximity to PCs. IL-17, a proinflammatory cytokine that acts on target cells via a heterodimeric receptor formed by IL-17RA and IL-17RC subunits, also promotes neutrophilic inflammation but its effects on vascular cells are less clear. We report that both cultured human ECs and PCs strongly express IL-17RC and, although neither cell type expresses much IL-17RA, PCs express significantly more than ECs. IL-17, alone or synergistically with TNF, significantly alters inflammatory gene expression in cultured human PCs but not ECs. RNA sequencing analysis identifies many IL-17-induced transcripts in PCs encoding proteins known to stimulate neutrophil-mediated immunity. Conditioned media from IL-17-activated PCs, but not ECs, induce pertussis toxin-sensitive neutrophil polarization, likely mediated by PC-secreted chemokines, and they also stimulate neutrophil production of proinflammatory molecules, including TNF, IL-1α, IL-1ß, and IL-8. Furthermore, IL-17-activated PCs, but not ECs, can prolong neutrophil survival by producing G-CSF and GM-CSF, delaying the mitochondrial outer membrane permeabilization and caspase-9 activation. Importantly, neutrophils exhibit enhanced phagocytic capacity after activation by conditioned media from IL-17-treated PCs. We conclude that PCs, not ECs, are the major target of IL-17 within the microvessel wall and that IL-17-activated PCs can modulate neutrophil functions within the perivascular tissue space.

Complement membrane attack complexes activate noncanonical NF-κB by forming an Akt+ NIK+ signalosome on Rab5+ endosomes.

Complement membrane attack complexes (MACs) promote inflammatory functions in endothelial cells (ECs) by stabilizing NF-κB-inducing kinase (NIK) and activating noncanonical NF-κB signaling. Here we report a novel endosome-based signaling complex induced by MACs to stabilize NIK. We found that, in contrast to cytokine-mediated activation, NIK stabilization by MACs did not involve cIAP2 or TRAF3. Informed by a genome-wide siRNA screen, instead this response required internalization of MACs in a clathrin-, AP2-, and dynamin-dependent manner into Rab5(+)endosomes, which recruited activated Akt, stabilized NIK, and led to phosphorylation of IκB kinase (IKK)-α. Active Rab5 was required for recruitment of activated Akt to MAC(+) endosomes, but not for MAC internalization or for Akt activation. Consistent with these in vitro observations, MAC internalization occurred in human coronary ECs in vivo and was similarly required for NIK stabilization and EC activation. We conclude that MACs activate noncanonical NF-κB by forming a novel Akt(+)NIK(+) signalosome on Rab5(+) endosomes.

Trends in Cervical Cancer Screening in Title X-Funded Health Centers - United States, 2005-2015.

Cervical cancer screening is critical to early detection and treatment of precancerous cells and cervical cancer. In 2015, 83% of U.S. women reported being screened per current recommendations, which is below the Healthy People 2020 target of 93% (1,2). Disparities in screening persist for women who are younger (aged 21-30 years), have lower income, are less educated, are uninsured, lack a source of health care, or who self-identify as Asian or American Indian/Alaska Native (2). Women who are never screened or rarely screened are more likely to develop cancer and receive a cancer diagnosis at later stages than women who are screened regularly (3). In 2013, cervical cancer was diagnosed in 11,955 women in the United States, and 4,217 died from the disease (4). Aggregated administrative data from the Title X Family Planning Program were used to calculate the percentage of female clients served in Title X-funded health centers who received a Papanicolaou (Pap) test during 2005-2015. Trends in the percentage of Title X clients screened for cervical cancer were examined in relation to changes in cervical cancer screening guidelines, particularly the 2009 American College of Obstetricians and Gynecologists (ACOG) update that raised the age for starting cervical cancer screening to 21 years (5) and the 2012 alignment of screening guidelines from ACOG, the U.S. Preventive Services Task Force (USPSTF) and the American Cancer Society (ACS) on the starting age (21 years), screening interval (3 or 5 years), and type of screening test (6-8). During 2005-2015, the percentage of female clients screened for cervical cancer dropped continually, with the largest declines occurring in 2010 and 2013, notably a year after major updates to the recommendations. Although aggregated data contribute to understanding of cervical cancer screening trends in Title X centers, studies using client-level and encounter-level data are needed to assess the appropriateness of cervical cancer screening in individual cases.

Chronic insulin infusion induces reversible glucose intolerance in lean rats yet ameliorates glucose intolerance in obese rats.

BACKGROUND: Although insulin resistance (IR) is a key factor in the pathogenesis of type 2 diabetes (T2D), the precise role of insulin in the development of IR remains unclear. Therefore, we investigated whether chronic basal insulin infusion is causative in the development of glucose intolerance. METHODS: Normoglycemic lean rats surgically instrumented with i.v. catheters were infused with insulin (3mU/kg/min) or physiological saline for 6weeks. At infusion-end, plasma insulin levels along with glucose tolerance were assessed. RESULTS: Six weeks of insulin infusion induced glucose intolerance and impaired insulin response in healthy rats. Interestingly, the effects of chronic insulin infusion were completely normalized following 24h withdrawal of exogenous insulin and plasma insulin response to glucose challenge was enhanced, suggesting improved insulin secretory capacity. As a result of this finding, we assessed whether the effects of insulin therapy followed by a washout could ameliorate established glucose intolerance in obese rats. Obese rats were similarly instrumented and infused with insulin or physiological saline for 7days followed by 24h washout. Seven day-insulin therapy in obese rats significantly improved glucose tolerance, which was attributed to improved insulin secretory capacity and improved insulin signaling in liver and skeletal muscle. CONCLUSION: Moderate infusion of insulin alone is sufficient to cause glucose intolerance and impair endogenous insulin secretory capacity, whereas short-term, intensive insulin therapy followed by insulin removal effectively improves glucose tolerance, insulin response and peripheral insulin sensitivity in obese rats. GENERAL SIGNIFICANCE: New insight into the link between insulin and glucose intolerance may optimize T2D management.

Chronic depression symptoms and salivary NOx are associated with retinal vascular dysregulation: The SABPA study.

BACKGROUND: Depression has been associated with impaired nitric oxide (NO)-mediated vasodilation and vascular dysregulation (VD). Whether depression and NO levels will disturb retinal haemodynamics is not clear. OBJECTIVES AND METHODS: Associations between the retinal vasculature, diastolic ocular perfusion pressure (DOPP) as measure of hypoperfusion, NO metabolites (NOx) and depression symptoms were assessed. Chronic VD risk markers [depression symptoms (Patient Health Questionnaire/PHQ-9 ≥ 10) and 24 h pulse pressure] were determined in a bi-ethnic cohort (n = 313; 48.6 ± 9 years; 53.9% men). At 3 year follow-up, retinal vessel calibre and retinopathy signs were quantified from digital images. Salivary NOx was obtained pre- and post-flicker light-induced provocation (FLIP). DOPP was defined as diastolic blood pressure minus intraocular pressure. RESULTS: Chronic VD risk was evident in Blacks opposed to acute risk in Whites (P < 0.05). At follow-up, retinopathy (Blacks 60.4%/Whites 39.6%), lower pre-FLIP (µM) and higher post-FLIP NOx (changes from baseline, %), arteriolar narrowing and wider venular calibre values were evident in Blacks compared to Whites, independent of confounders. A wider venular calibre, an index of stroke risk, was associated with chronic depression symptoms [cut point 248 MU: Area under the curve 0.61 (95% CI: 0.51, 0.72); 71% sensitivity; 55% specificity] as well as with hypoperfusion in the Blacks. In this group, arteriolar narrowing was associated with hypoperfusion; and attenuated arteriolar dilation with increased post-FLIP NOx responses. CONCLUSIONS: Chronic depression symptoms may alter NO regulation and facilitate VD. NO-mediated vasoconstriction presumably impeded perfusion, retinal haemodynamics and -remodelling; potentiating stroke risk in Blacks.

Impact of a Collaborative Radiology Utilization Management Program: Does the Specialty of the Referring Provider Matter?

OBJECTIVE: The purpose of this study was to evaluate the impact of a collaborative radiology utilization management program on the disposition of cases according to provider specialty. MATERIALS AND METHODS: A utilization management program directed by a radiology benefit management company provided peer-to-peer decision support for providers ordering advanced outpatient imaging studies. After a radiologist reviewed the cases, based upon provider specialty, the rates of the following dispositions were analyzed: study approved by consensus, study changed by consensus, study not performed by consensus, study approved (no consensus), and study administratively not performed (no callback). Aggregated rates of study changed or not performed by consensus (withdrawals) were used to assess the effect of provider-radiologist collaboration. The rate of no callback was used to assess sentinel effect. The combined rate of withdrawals and no callback represented the overall impact of radiologist participation. The project period was 5 years. RESULTS: A total of 168,915 studies were reviewed: 58.6% were approved, 6.8% were changed, and 13.5% were withdrawn by consensus; 6.0% were approved without consensus; 15.2% were withdrawn because of no callback; 35.5% initially ordered were not performed at the time they were ordered. Family practice (25.3%) and internal medicine (23.8%) had the highest aggregated rates of study changed or withdrawn by consensus. Thoracic surgery (13.3%), neurosurgery (11.2%), and orthopedic surgery (9.3%) had the lowest rates. Internal medicine (18.0%), neurology (17.7%), and family practice (17.4%) had the highest rates of study withdrawn owing to no callback. Pediatrics (7.1%) and ophthalmology (7.3%) had the lowest rates. The overall impact was greatest for family practice (42.7%), internal medicine (41.8%), and neurology (33.4%) and least for orthopedic surgery (22.8%) and neurosurgery (24.0%). CONCLUSION: Radiologist participation had substantial impact regardless of provider specialty. The impact was greatest on primary care providers who are heavier users of radiology.

Frailty Phenotypes, Disability, and Outcomes in Adult Candidates for Lung Transplantation.

RATIONALE: Frailty is associated with morbidity and mortality in abdominal organ transplantation but has not been examined in lung transplantation. OBJECTIVES: To examine the construct and predictive validity of frailty phenotypes in lung transplant candidates. METHODS: In a multicenter prospective cohort, we measured frailty with the Fried Frailty Phenotype (FFP) and Short Physical Performance Battery (SPPB). We evaluated construct validity through comparisons with conceptually related factors. In a nested case-control study of frail and nonfrail subjects, we measured serum IL-6, tumor necrosis factor receptor 1, insulin-like growth factor I, and leptin. We estimated the association between frailty and disability using the Lung Transplant Valued Life Activities disability scale. We estimated the association between frailty and risk of delisting or death before transplant using multivariate logistic and Cox models, respectively. MEASUREMENTS AND MAIN RESULTS: Of 395 subjects, 354 completed FFP assessments and 262 completed SPPB assessments; 28% were frail by FFP (95% confidence interval [CI], 24-33%) and 10% based on the SPPB (95% CI, 7-14%). By either measure, frailty correlated more strongly with exercise capacity and grip strength than with lung function. Frail subjects tended to have higher plasma IL-6 and tumor necrosis factor receptor 1 and lower insulin-like growth factor I and leptin. Frailty by either measure was associated with greater disability. After adjusting for age, sex, diagnosis, and transplant center, both FFP and SPPB were associated with increased risk of delisting or death before lung transplant. For every 1-point worsening in score, hazard ratios were 1.30 (95% CI, 1.01-1.67) for FFP and 1.53 (95% CI, 1.19-1.59) for SPPB. CONCLUSIONS: Frailty is prevalent among lung transplant candidates and is independently associated with greater disability and an increased risk of delisting or death.

Pediatric Diabetes Telemedicine Program Improves Access to Care for Rural Families: Role of APRNs.

Type 1 diabetes mellitus has increased in children by 23% from 2001 to 2009. Rural communities additionally have increased disparities related to access barriers and a large minority population with poorer overall health. Research evidence supports telemedicine as an effective alternative to bring preventive diabetes care to remote areas. This article presents an overview of the leadership role of advanced practice registered nurses (APRNs) with the implementation and evaluation of a pediatric diabetes telemedicine program at a rural pediatric outpatient specialty clinic in partnership with a tertiary center telemedicine network. The telemedicine program quality improvement (QI) project explored caregiver satisfaction with a convenience sample of caregivers (N = 14) using a nine-item Telemedicine Diabetes Caregiver Satisfaction Survey (TDCSS), with responses ranging from 1 = strongly disagree to 5 = strongly agree. Findings indicate caregivers were highly satisfied with communication/ privacy (M = 4.8), access to care (M = 4.1), and quality of services (M = 5.0). The multidisciplinary collaborative teamwork, continuous QI, and dependable technology were integral to the quality of the telemedicine clinical initiative. APRNs provided technology expertise, interdisciplinary collaboration leadership, care coordination, and advocacy for policy changes. Results demonstrate that telemedicine and APRN leadership can help implement innovative programs into rural communities to improve access to care, healthcare cost, and outcomes.

Depression as a risk factor for poor prognosis among patients with acute coronary syndrome: systematic review and recommendations: a scientific statement from the American Heart Association.

BACKGROUND: Although prospective studies, systematic reviews, and meta-analyses have documented an association between depression and increased morbidity and mortality in a variety of cardiac populations, depression has not yet achieved formal recognition as a risk factor for poor prognosis in patients with acute coronary syndrome by the American Heart Association and other health organizations. The purpose of this scientific statement is to review available evidence and recommend whether depression should be elevated to the status of a risk factor for patients with acute coronary syndrome. METHODS AND RESULTS: Writing group members were approved by the American Heart Association's Scientific Statement and Manuscript Oversight Committees. A systematic literature review on depression and adverse medical outcomes after acute coronary syndrome was conducted that included all-cause mortality, cardiac mortality, and composite outcomes for mortality and nonfatal events. The review assessed the strength, consistency, independence, and generalizability of the published studies. A total of 53 individual studies (32 reported on associations with all-cause mortality, 12 on cardiac mortality, and 22 on composite outcomes) and 4 meta-analyses met inclusion criteria. There was heterogeneity across studies in terms of the demographic composition of study samples, definition and measurement of depression, length of follow-up, and covariates included in the multivariable models. Despite limitations in some individual studies, our review identified generally consistent associations between depression and adverse outcomes. CONCLUSIONS: Despite the heterogeneity of published studies included in this review, the preponderance of evidence supports the recommendation that the American Heart Association should elevate depression to the status of a risk factor for adverse medical outcomes in patients with acute coronary syndrome.