Frequency and Clinical Implications of Referrals to Heart Failure Among Patients with Peripartum Cardiomyopathy.

Peripartum cardiomyopathy (PPCM) is a rare but significant cause of new-onset heart failure (HF) during the peri- and post-partum periods. Advances in GDMT for HF with reduced ventricular function have led to substantial improvements in survival and quality of life, yet few studies examine the longitudinal care received by patients with PPCM. The aim of this research is to address this gap by retrospectively characterizing patients with PPCM across a multihospital health system and investigating the frequency of cardiology and HF specialty referrals. Understanding whether surveillance and medical management differ among patients referred to HF will help to underscore the importance of referring patients with PPCM to HF specialists for optimal care.

Frailty Measures of Patient-reported Activity and Fatigue May Predict 1-year Outcomes in Ambulatory Advanced Heart Failure: A Report From the REVIVAL Registry.

BACKGROUND: The Fried Frailty Phenotype predicts adverse outcomes in geriatric populations, but has not been well-studied in advanced heart failure (HF). The Registry Evaluation of Vital Information for Ventricular Assist Devices (VADs) in Ambulatory Life (REVIVAL) study prospectively collected frailty measures in patients with advanced HF to determine relevant assessments and their impact on clinical outcomes. METHODS AND RESULTS: HF-Fried Frailty was defined by 5 baseline components (1 point each): (1) weakness: hand grip strength less than 25% of body weight; (2) slowness based on time to walk 15 feet; (3) weight loss of more than 10 lbs in the past year; (4) inactivity; and (5) exhaustion, both assessed by the Kansas City Cardiomyopathy Questionnaire. A score of 0 or 1 was deemed nonfrail, 2 prefrail, and 3 or greater was considered frail. The primary composite outcome was durable mechanical circulatory support implantation, cardiac transplant or death at 1 year. Event-free survival for each group was determined by the Kaplan-Meier method and the hazard of prefrailty and frailty were compared with nonfrailty with proportional hazards modeling. Among 345 patients with all 5 frailty domains assessed, frailty was present in 17%, prefrailty in 40%, and 43% were nonfrail, with 67% (n = 232) meeting the criteria based on inactivity and 54% (n = 186) for exhaustion. Frail patients had an increased risk of the primary composite outcome (unadjusted hazard ratio [HR] 2.82, 95% confidence interval [CI] 1.52-5.24; adjusted HR 3.41, 95% CI 1.79-6.52), as did prefrail patients (unadjusted HR 1.97, 95% CI 1.14-3.41; adjusted HR 2.11, 95% CI 1.21-3.66) compared with nonfrail patients, however, the predictive value of HF-Fried Frailty criteria was modest (Harrel's C-statistic of 0.603, P = .004). CONCLUSIONS: The HF-Fried Frailty criteria had only modest predictive power in identifying ambulatory patients with advanced HF at high risk for durable mechanical circulatory support, transplant, or death within 1 year, driven primarily by assessments of inactivity and exhaustion. Focus on these patient-reported measures may better inform clinical trajectories in this population.

Continuous-flow mechanical circulatory support is not associated with early graft failure: An analysis of the International Society for Heart and Lung Transplantation registry.

BACKGROUND: Continuous-flow mechanical circulatory support (CF-MCS) is associated with impaired vascular function and increased risk of vasoplegia. One contributing factor to early graft failure (EGF) is severe vasoplegia. We tested the hypothesis that CF-MCS is associated with increased risk of EGF. METHODS: Adult primary heart transplant recipients in the ISHLT Registry from 2005 to 2013 were stratified into three groups based on pre-transplant MCS: No MCS (n = 11 748), pulsatile (P)-MCS (n = 718), and CF-MCS (n = 3818). EGF was defined as death/retransplantation due to graft failure within 30 days after HT. Comparisons were made using descriptive statistics and associations. EGF was assessed with multivariable Cox proportional hazard regression. RESULTS: The incidence of EGF within 30 days was similar between groups (No MCS 2.2%, P-MCS 3.3%, CF-MCS 2.1%, P = .10). Following multivariable adjustment, the risk of EGF was not statistically different for those with CF-MCS compared with P-MCS (HR 0.75, 95% CI 0.46-1.21, P = .24). The risk of EGF was numerically, but not statistically significantly higher for CF-MCS compared with No MCS (HR 1.24, 95% CI 0.92-1.67, P = .16). CONCLUSION: CF-MCS use was not associated with a statistically significant increased risk of EGF resulting in death or retransplantation in the first 30 days after transplant.

Intramyocardial Injection of Mesenchymal Precursor Cells and Successful Temporary Weaning From Left Ventricular Assist Device Support in Patients With Advanced Heart Failure: A Randomized Clinical Trial.

Importance: Left ventricular assist device (LVAD) therapy improves myocardial function, but few patients recover sufficiently for explant, which has focused attention on stem cells to augment cardiac recovery. Objective: To assess efficacy and adverse effects of intramyocardial injections of mesenchymal precursor cells (MPCs) during LVAD implant. Design, Setting, and Participants: A randomized phase 2 clinical trial involving patients with advanced heart failure, undergoing LVAD implant, at 19 North American centers (July 2015-August 2017). The 1-year follow-up ended August 2018. Interventions: Intramyocardial injections of 150 million allogeneic MPCs or cryoprotective medium as a sham treatment in a 2:1 ratio (n = 106 vs n = 53). Main Outcomes and Measures: The primary efficacy end point was the proportion of successful temporary weans (of 3 planned assessments) from LVAD support within 6 months of randomization. This end point was assessed using a Bayesian analysis with a predefined threshold of a posterior probability of 80% to indicate success. The 1-year primary safety end point was the incidence of intervention-related adverse events (myocarditis, myocardial rupture, neoplasm, hypersensitivity reactions, and immune sensitization). Secondary end points included readmissions and adverse events at 6 months and 1-year survival. Results: Of 159 patients (mean age, 56 years; 11.3% women), 155 (97.5%) completed 1-year of follow-up. The posterior probability that MPCs increased the likelihood of successful weaning was 69%; below the predefined threshold for success. The mean proportion of successful temporary weaning from LVAD support over 6 months was 61% in the MPC group and 58% in the control group (rate ratio [RR], 1.08; 95% CI, 0.83-1.41; P = .55). No patient experienced a primary safety end point. Of 10 prespecified secondary end points reported, 9 did not reach statistical significance. One-year mortality was not significantly different between the MPC group and the control group (14.2% vs 15.1%; hazard ratio [HR], 0.89; 95%, CI, 0.38-2.11; P = .80). The rate of serious adverse events was not significantly different between groups (70.9 vs 78.7 per 100 patient-months; difference, -7.89; 95% CI, -39.95 to 24.17; P = .63) nor was the rate of readmissions (0.68 vs 0.75 per 100 patient-months; difference, -0.07; 95% CI, -0.41 to 0.27; P = .68). Conclusions and Relevance: Among patients with advanced heart failure, intramyocardial injections of mesenchymal precursor cells, compared with injections of a cryoprotective medium as sham treatment, did not improve successful temporary weaning from left ventricular assist device support at 6 months. The findings do not support the use of intramyocardial mesenchymal stem cells to promote cardiac recovery as measured by temporary weaning from device support. Trial Registration: clinicaltrials.gov Identifier: NCT02362646.

New developments for the detection and treatment of cardiac vasculopathy.

PURPOSE OF REVIEW: Cardiac allograft vasculopathy (CAV) is a major limitation to long-term survival after heart transplantation. Innovative new techniques to diagnose CAV have been applied to detect disease. This review will examine the current diagnostic and treatment options available to clinicians for CAV. RECENT FINDINGS: Diagnostic modalities addressing the pathophysiology underlying CAV (arterial wall thickening and decreased coronary blood flow) improve diagnostic sensitivity when compared to traditional (angiography and dobutamine stress echocardiography) techniques. SUMMARY: Limited options are available to prevent and treat CAV; however, progress has been made in making an earlier and more accurate diagnosis. Future research is needed to identify the optimal time to modify immunosuppression and investigate novel treatments for CAV.

Analysis of Skeletal Muscle Torque Capacity and Circulating Ceramides in Patients with Advanced Heart Failure.

BACKGROUND: Heart failure (HF)-related exercise intolerance is thought to be perpetuated by peripheral skeletal muscle functional, structural, and metabolic abnormalities. We analyzed specific dynamics of muscle contraction in patients with HF compared with healthy, sedentary controls. METHODS: Isometric and isokinetic muscle parameters were measured in the dominant upper and lower limbs of 45 HF patients and 15 healthy age-matched controls. Measurements included peak torque normalized to body weight, work normalized to body weight, power, time to peak torque, and acceleration and deceleration to maximum strength times. Body morphometry (dual energy X-ray absorptiometry scan) and circulating fatty acids and ceramides (lipodomics) were analyzed in a subset of subjects (18 HF and 9 controls). RESULTS: Extension and flexion time-to-peak torque was longer in the lower limbs of HF patients. Furthermore, acceleration and deceleration times in the lower limbs were also prolonged in HF subjects. HF subjects had increased adiposity and decreased lean muscle mass compared with controls. Decreased circulating unsaturated fatty acids and increased ceramides were found in subjects with HF. CONCLUSIONS: Delayed torque development suggests skeletal muscle impairments that may reflect abnormal neuromuscular functional coupling. These impairments may be further compounded by increased adiposity and inflammation associated with increased ceramides.

Utility of the Seattle Heart Failure Model in patients with cardiac resynchronization therapy and implantable cardioverter defibrillator referred for heart transplantation.

BACKGROUND: The Seattle Heart Failure Model (SHFM) predicts survival in heart failure but may underestimate risk in severe heart failure, and the performance has not been evaluated explicitly in patients with cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillator (ICD) referred for heart transplantation. We aimed to assess the utility of the SHFM by validation in patients with CRT and/or ICD referred for heart transplantation. METHODS: We assessed the SHFM performance in 382 patients with CRT and/or ICD referred for heart transplantation. Outcome was survival free from urgent transplantation or left ventricular assist device. Model discrimination and calibration were assessed graphically and by formal tests. RESULTS: During a mean follow-up of 2.3 years, 195 events occurred. One-, 2-, and 3-year observed event-free survival was 77%, 62%, and 52%, and the observed to predicted event-free survival ratio was 0.89, 0.80, and 0.76. Calibration plots demonstrated results deviating from the ideal calibration line at 1, 2, and 3 years. The SHFM score adequately assigned patients in discrete risk strata, according to Kaplan-Meier estimated survival. Time-dependent receiver operating characteristic curve analyses demonstrated good discrimination overall, which was slightly better for 1-year (area under the curve [AUC] 0.774) compared with 2-year (AUC 0.742) and 3-year (AUC 0.728) event-free survival. CONCLUSIONS: The SHFM has good discrimination but underestimates risk of adverse outcomes in patients with CRT and/or ICD referred for heart transplantation. The SHFM may be used to assess relative risk and changes over time, but when assessing absolute percentage of event-free survival, the overestimation of event-free survival should be accounted for.

Reduced handgrip strength as a marker of frailty predicts clinical outcomes in patients with heart failure undergoing ventricular assist device placement.

BACKGROUND: Heart failure (HF) is associated with the derangement of muscle structure and metabolism, contributing to exercise intolerance, frailty, and mortality. Reduced handgrip strength is associated with increased patient frailty and higher morbidity and mortality. We evaluated handgrip strength as a marker of muscle function and frailty for prediction of clinical outcomes after ventricular assist device (VAD) implantation in patients with advanced HF. METHODS AND RESULTS: Handgrip strength was measured in 72 patients with advanced HF before VAD implantation (2.3 ± 4.9 days pre-VAD). We analyzed dynamics in handgrip strength, laboratory values, postoperative complications, and mortality. Handgrip strength correlated with serum albumin levels (r = 0.334, P = .004). Compared with baseline, handgrip strength increased post-VAD implantation by 18.2 ± 5.6% at 3 months (n = 29) and 45.5 ± 23.9% at 6 months (n = 27). Patients with a handgrip strength <25% of body weight had an increased risk of mortality, increased postoperative complications, and lower survival after VAD implantation. CONCLUSION: Patients with advanced HF show impaired handgrip strength indicating a global myopathy. Handgrip strength <25% of body weight is associated with higher postoperative complication rates and increased mortality after VAD implantation. Thus, the addition of measures of skeletal muscle function underlying the frailty phenotype to traditional risk markers might have incremental prognostic value in patients undergoing evaluation for VAD placement.

SGLT2 Inhibitors, Functional Capacity, and Quality of Life in Patients With Heart Failure: A Systematic Review and Meta-Analysis.

Importance: The associations of sodium glucose cotransporter-2 inhibitors (SGLT2is) with reduction in mortality and hospitalization rates in patients with heart failure (HF) are well established. However, their association with improving functional capacity and quality of life (QOL) has been variably studied and less reported. Objective: To provide evidence on the extent to which SGLT2is are associated with improvement on objective measures of functional capacity and QOL in patients living with HF. Data Sources: The MEDLINE, EMBASE, and Cochrane databases were systematically searched for relevant articles on July 31, 2023. Study Selection: Randomized, placebo-controlled clinical trials reporting the effect of SGLT2i on functional outcomes of exercise capacity (peak oxygen consumption [peak VO2] or 6-minute walk distance [6MWD]) and/or QOL using validated questionnaires for patients with HF were included. Data Extraction and Synthesis: Data were extracted by 2 authors following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, and a meta-analysis using the restricted maximum likelihood random-effects model was conducted. Main Outcomes and Measures: Outcomes of interest included changes in peak VO2, 6MWD, and Kansas City Cardiomyopathy Questionnaire-12 total symptom score (KCCQ-TSS), clinical summary score (KCCQ-CSS), and overall summary score (KCCQ-OSS). Results: In this meta-analysis of 17 studies, 23 523 patients (mean [range] age, 69 [60-75] years) were followed over a period ranging from 12 to 52 weeks. Four studies included peak VO2 as an outcome, 7 studies included 6MWD, and 10 studies reported KCCQ scores. Mean (SD) left ventricular ejection fraction was 43.5% (12.4%). Compared with controls, patients receiving SGLT2i treatment experienced significant increases in peak VO2 (mean difference [MD], 1.61 mL/kg/min; 95% CI, 0.59-2.63 mL/kg/min; P = .002) and 6MWD (MD, 13.09 m; 95% CI, 1.20-24.97 m; P = .03). SGLT2i use was associated with increased KCCQ-TSS (MD, 2.28 points; 95% CI, 1.74-2.81 points; P < .001), KCCQ-CSS (MD, 2.14 points; 95% CI, 1.53-2.74 points; P < .001), and KCCQ-OSS (MD, 1.90 points; 95% CI, 1.41-2.39 points; P < .001) scores. Subgroup analysis and meta-regression demonstrated almost all improvements were consistent across ejection fraction, sex, and the presence of diabetes. Conclusions and Relevance: These findings suggest that in addition to known clinical associations with mortality and hospitalization outcomes, SGLT2i use is associated with improvement in outcomes of interest to patients' everyday lives as measured by objective assessments of maximal exercise capacity and validated QOL questionnaires, regardless of sex or ejection fraction.

Ventricular assist device implantation corrects myocardial lipotoxicity, reverses insulin resistance, and normalizes cardiac metabolism in patients with advanced heart failure.

BACKGROUND: Heart failure is associated with impaired myocardial metabolism with a shift from fatty acids to glucose use for ATP generation. We hypothesized that cardiac accumulation of toxic lipid intermediates inhibits insulin signaling in advanced heart failure and that mechanical unloading of the failing myocardium corrects impaired cardiac metabolism. METHODS AND RESULTS: We analyzed the myocardium and serum of 61 patients with heart failure (body mass index, 26.5±5.1 kg/m(2); age, 51±12 years) obtained during left ventricular assist device implantation and at explantation (mean duration, 185±156 days) and from 9 control subjects. Systemic insulin resistance in heart failure was accompanied by decreased myocardial triglyceride and overall fatty acid content but increased toxic lipid intermediates, diacylglycerol, and ceramide. Increased membrane localization of protein kinase C isoforms, inhibitors of insulin signaling, and decreased activity of insulin signaling molecules Akt and Foxo were detectable in heart failure compared with control subjects. Left ventricular assist device implantation improved whole-body insulin resistance (homeostatic model of analysis-insulin resistance, 4.5±0.6-3.2±0.5; P<0.05) and decreased myocardial levels of diacylglycerol and ceramide, whereas triglyceride and fatty acid content remained unchanged. Improved activation of the insulin/phosphatidylinositol-3 kinase/Akt signaling cascade after left ventricular assist device implantation was confirmed by increased phosphorylation of Akt and Foxo, which was accompanied by decreased membrane localization of protein kinase C isoforms after left ventricular assist device implantation. CONCLUSIONS: Mechanical unloading after left ventricular assist device implantation corrects systemic and local metabolic derangements in advanced heart failure, leading to reduced myocardial levels of toxic lipid intermediates and improved cardiac insulin signaling.

Volumetric intravascular ultrasound assessment of mechanisms and results of stent expansion in heart transplant patients.

BACKGROUND: Percutaneous coronary intervention with stent placement for the treatment of patients with cardiac allograft vasculopathy is common, but data regarding stent behavior in this setting is lacking. OBJECTIVES: We investigated mechanisms and potential differences in stent expansion among transplant patients vs. patients with native coronary artery atherosclerotic disease ("controls"). METHODS: We compared pre- and poststent intravascular ultrasound in 12 transplant patients (17 lesions) and 33 control patients (34 lesions) matched according to age (60.1 ± 9.2 years), diabetes mellitus, and lesion location. Planar and volumetric analysis was conducted for every 1 mm at the lesion site as well as the first 5 mm proximal and distal to the stent edge. Focal stent expansion was defined as minimum stent area (MSA) divided by mean reference lumen area. Diffuse stent expansion was defined as mean stent area divided by mean reference lumen area. RESULTS: Transplant patients had more plaque than "controls" prestenting, but similar MSA and focal and diffuse stent expansion afterwards. The increase in mean lumen area correlated with the increase in mean vessel area in both groups, transplant (R = 0.64, P = 0.008) and controls (R = 0.70, P < 0.0001), but correlated inversely with changes in mean plaque area only in the transplant group (R = 0.55, P = 0.027). There were no differences in calcification between the two groups and no axial plaque distribution from the lesion into the reference segments in either group. CONCLUSIONS: The mechanism of stent expansion in transplant vasculopathy appears to be similar to de novo atherosclerosis-i.e., mainly vessel expansion to achieve similar acute results.

Asymmetric pattern of cerebrovascular lesions in patients after left ventricular assist device implantation.

BACKGROUND AND PURPOSE: Stroke is a major adverse event after left ventricular assist device (LVAD) surgery. The purpose of this study was to describe differences in hemispheric distribution of stroke in LVAD patients. METHODS: We reviewed 317 consecutive patients who underwent LVAD surgery between November 2000 and July 2011. Stroke during LVAD support was analyzed. RESULTS: In total, 46 strokes occurred at 76.0±96.8 days postoperatively. Among the 46 strokes, 27 events (58.7%) occurred in right hemisphere, 13 events (28.2%) in the left hemisphere, 3 events (8.7%) occurred bilaterally, and 2 events (4.3%) were vertebrobasilar lesions. The right hemispheric stroke was significantly more common in patients with postoperative infection compared with left hemispheric events. CONCLUSIONS: Stroke after LVAD implantation has a right hemispheric predominance. This finding suggests LVAD-related thrombus in the setting of infection and/or the anatomic configuration of LVAD outflow cannula-ascending aorta anastomosis to be highly associated with stroke after LVAD surgery.

Cardiac transplantation in adult patients with mental retardation: do outcomes support consensus guidelines?

BACKGROUND: Selection criteria guidelines list mental retardation as a relative contraindication to heart transplantation, but not to kidney transplantation. OBJECTIVE: The authors present a case series of adults with mental retardation or comparable acquired intellectual disability who underwent heart transplantation. They discuss the literature on heart and kidney transplantation in people with mental retardation and the ethical reasoning that guides how recipients of solid organ grafts are chosen. METHOD: Literature review and retrospective review of long-term outcomes for five adult patients with mental retardation or comparable disability who received heart transplants. RESULTS: Among these cases, survival times to date ranged from 4 to 16 years, with a median survival of greater than 12 years. Medical non-adherence was a significant factor in only 1 of the 5 cases. In that case, the patient's medical non-adherence was due to a functional decline in the primary caretaker. CONCLUSION: People with mental retardation can receive long-term benefit from heart transplantation when they have the cognitive and social support necessary to ensure adherence to post-transplant regimens. There is no ethical or medical reason for guidelines to consider mental retardation, in and of itself, a contraindication to heart transplantation. The totality of the individual patient's circumstances should be considered in assessing transplant candidacy.

De novo human leukocyte antigen allosensitization patterns in patients bridged to heart transplantation using left ventricular assist devices.

INTRODUCTION: We examined the impact and time course of de novo human leukocyte antigen (HLA) allosensitization following left ventricular assist device (LVAD) implantation. METHODS AND RESULTS: Forty patients had a calculated panel reactive antibody (cPRA) prior to LVAD surgery between January 2014 and December 2018. Of these patients, we retrospectively studied 33 patients who had pre-LVAD cPRA <10%. De novo allosensitization was defined as cPRA ≥10% within 3 months following LVAD surgery, and "persistent allosensitization" was defined as cPRA ≥10% at time of heart transplant or death. One-third (11/33) of our cohort developed de novo allosensitization within 3-months post-LVAD. Median duration of follow-up during LVAD support was 588 days (IQR 337-1071 days), or approximately 19 months. In an adjusted, multivariable analysis, female sex remained associated with de novo allosensitization (adjusted odds ratio [95%CI]: 11 (1.4-85), P = 0.026). De novo allosensitization was subsequently associated with persistent allosensitization (P = 0.024). Both axial-flow and centrifugal-flow LVADs had similar rates of allosensitization. Compared to those with no allosensitization, patients with de novo allosensitization did not appear to have inferior post-transplant outcomes of death or treated rejection. CONCLUSION: In our single-center experience, one-third of patients developed de novo allosensitization which did not appear to associate with inferior post-transplant outcomes. Female sex was associated with de novo allosensitization.

Safety and effects of SGLT-2 inhibitor use among LVAD patients with type 2 diabetes mellitus.

SGLT-2 inhibitors have been shown to confer reduced risk of adverse cardiovascular events in patients with heart failure, and have also been studied preliminarily among heart transplant patients, with overall positive findings. Use of SGLT-2 inhibitors among patients with durable mechanical circulatory support has not been studied. Here we present our results from a combined retrospective cohort of LVAD patients on SGLT-2 inhibitors at two major academic centers, which showed a good safety profile but prompted questions for further investigation. We advocate for further research into the safety and impact of SGLT-2 inhibitors among LVAD patients.

The STARBRITE trial: a randomized, pilot study of B-type natriuretic peptide-guided therapy in patients with advanced heart failure.

BACKGROUND: STARBRITE, a multicenter randomized pilot trial, tested whether outpatient diuretic management guided by B-type natriuretic peptide (BNP) and clinical assessment resulted in more days alive and not hospitalized over 90 days compared with clinical assessment alone. METHODS AND RESULTS: A total of 130 patients from 3 sites with left ventricular ejection fraction ≤35% were enrolled during hospitalization for heart failure (HF) and randomly assigned to therapy guided by BNP and clinical assessment (BNP strategy) or clinical assessment alone. The clinical goal was resolution of congestion without hypotension or renal dysfunction. In the BNP arm, therapy was adjusted to achieve optimal fluid status, defined as the BNP level and congestion score obtained at the time of discharge. In the clinical assessment arm, therapy was titrated to achieve optimal fluid status, represented by the patient's signs and symptoms at the time of discharge. Exclusion criteria were serum creatinine >3.5 mg/dL and acute coronary syndrome. Follow-up was done in HF clinics. BNP was measured with the use of a rapid assay test. There was no significant difference in number of days alive and not hospitalized (hazard ratio 0.72, 95% confidence interval 0.41-1.27; P = .25), change in serum creatinine, or change in systolic blood pressure (SBP). BNP strategy was associated with a trend toward a lower blood urea nitrogen (24 mg/dL vs 29 mg/dL; P = .07); BNP strategy patients received significantly more angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, and the combination of ACE inhibitor or angiotensin receptor blocker plus beta-blockers. CONCLUSIONS: BNP strategy was not associated with more days alive and not hospitalized, but the strategy appeared to be safe and was associated with increased use of evidence-based medications.

Ig-like transcript 3 regulates expression of proinflammatory cytokines and migration of activated T cells.

Ig-like transcript 3 (ILT3), an inhibitory receptor expressed by APC is involved in functional shaping of T cell responses toward a tolerant state. We have previously demonstrated that membrane (m) and soluble (s) ILT3 induce allogeneic tolerance to human islet cells in humanized NOD/SCID mice. Recombinant sILT3 induces the differentiation of CD8(+) T suppressor cells both in vivo and in vitro. To better understand the molecular mechanisms by which ILT3 suppresses immune responses, we have generated ILT3 knockdown (ILT3KD) dendritic cells (DC) and analyzed the phenotypic and functional characteristics of these cells. In this study, we report that silencing of ILT3 expression in DC (ILT3KD DC) increases TLR responsiveness to their specific ligands as reflected in increased synthesis and secretion of proinflammatory cytokines such as IL-1alpha, IL-1beta, and IL-6 and type I IFN. ILT3KD-DC also secretes more CXCL10 and CXCL11 chemokines in response to TLR ligation, thus accelerating T cell migration in diffusion chamber experiments. ILT3KD-DC elicit increased T cell proliferation and synthesis of proinflammatory cytokines IFN-gamma and IL-17A both in MLC and in culture with autologous DC pulsed with CMV protein. ILT3 signaling results in inhibition of NF-kappaB and, to a lesser extent, MAPK p38 pathways in DC. Our results suggest that ILT3 plays a critical role in the control of inflammation.

Use of Cardiopulmonary Stress Testing for Patients With Unexplained Dyspnea Post-Coronavirus Disease.

OBJECTIVES: The authors used cardiopulmonary exercise testing (CPET) to define unexplained dyspnea in patients with post-acute sequelae of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection (PASC). We assessed participants for criteria to diagnose myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). BACKGROUND: Approximately 20% of patients who recover from coronavirus disease (COVID) remain symptomatic. This syndrome is named PASC. Its etiology is unclear. Dyspnea is a frequent symptom. METHODS: The authors performed CPET and symptom assessment for ME/CFS in 41 patients with PASC 8.9 ± 3.3 months after COVID. All patients had normal pulmonary function tests, chest X-ray, and chest computed tomography scans. Peak oxygen consumption (peak VO2), slope of minute ventilation to CO2 production (VE/VCO2 slope), and end tidal pressure of CO2 (PetCO2) were measured. Ventilatory patterns were reviewed with dysfunctional breathing defined as rapid erratic breathing. RESULTS: Eighteen men and 23 women (average age: 45 ± 13 years) were studied. Left ventricular ejection fraction was 59% ± 9%. Peak VO2 averaged 20.3 ± 7 mL/kg/min (77% ± 21% predicted VO2). VE/VCO2 slope was 30 ± 7. PetCO2 at rest was 33.5 ± 4.5 mm Hg. Twenty-four patients (58.5%) had a peak VO2 <80% predicted. All patients with peak VO2 <80% had a circulatory limitation to exercise. Fifteen of 17 patients with normal peak VO2 had ventilatory abnormalities including peak respiratory rate >55 (n = 3) or dysfunctional breathing (n = 12). For the whole cohort, 88% of patients (n = 36) had ventilatory abnormalities with dysfunctional breathing (n = 26), increased VE/VCO2 (n = 17), and/or hypocapnia PetCO2 <35 (n = 25). Nineteen patients (46%) met criteria for ME/CFS. CONCLUSIONS: Circulatory impairment, abnormal ventilatory pattern, and ME/CFS are common in patients with PASC. The dysfunctional breathing, resting hypocapnia, and ME/CFS may contribute to symptoms. CPET is a valuable tool to assess these patients.

Estimated Health Care Utilization and Expenditures in Individuals With Heart Failure From the Medical Expenditure Panel Survey.

BACKGROUND: Heart failure (HF) constitutes a growing burden for public health and the US health care system. While the prevalence of HF is increasing, differences in health care utilization and expenditures within various sociodemographic groups remain poorly defined. METHODS: We used the Medical Expenditure Panel Survey to assess annual health care utilization and expenditures from 2012 to 2017. Health care utilization was based on the annual frequency of various health care encounters. Annual total and out-of-pocket expenditures were evaluated for hospital inpatient stays, emergency room visits, outpatient visits, office-based medical provider visits, prescribed medicines, dental visits, home health aid visits, and other medical expenses. We performed univariable and multivariable regression analysis based on patient characteristics including sociodemographic and comorbidity variables. RESULTS: Our results showed that total health care expenditures among patients with HF were $21 177 (95% CI, $18 819-$24 736) per year as compared with $5652 (95% CI, $5469-$5837) in those without HF (P<0.001). Total expenditures within the population with HF were primarily being driven by expenditures associated with inpatient hospitalizations. Increasing number of comorbid conditions was associated with significant increases in total health care expenditures. Older age, female sex, earlier study years, number of comorbidities, higher level of education, and increasing family income brackets independently raised out-of-pocket expenditures. CONCLUSIONS: Our findings of increased health care utilization and expenditures based on sex, age, increasing number of comorbidities, wealthier income status, and increased education attainment level may be used for efforts aimed at better distributing health care resources to improve health outcomes in HF.