Percutaneous Mitral Valve Repair in Cancer Patients with Heart Failure and Severe Mitral Regurgitation.

BACKGROUND: Cancer patients with heart failure (HF) and severe mitral regurgitation (MR) are often considered to be at risk for surgical mitral valve repair/replacement. Severe MR inducing symptomatic HF may prevent delivery of potentially cardiotoxic chemotherapy and complicate fluid management with other cancer treatments. OBJECTIVES: To evaluate the outcome of percutaneous mitral valve repair (PMVR) in oncology patients with HF and significant MR. METHODS: Our study comprised 145 patients who underwent PMVR, MitraClip, at Hadassah Medical Center between August 2015 and September 2019, including 28 patients who had active or history of cancer. Data from 28 cancer patients were compared to 117 no-cancer patients from the cohort. RESULTS: There was no significant difference in the mean age of cancer patients and no-cancer patients (76 vs. 80 years, P = 0.16); 67% of the patients had secondary (functional) MR. Among cancer patients, 21 had solid tumor and 7 had hematologic malignancies. Nine patients (32%) had active malignancy at the time of PMVR. The mean short-term risk score of the patients was similar in the two groups, as were both 30-day and 1-year mortality rates (7% vs. 4%, P = 0.52) and (29% vs. 16%, P = 0.13), respectively. CONCLUSIONS: PMVR in cancer patients is associated with similar 30-day and 1-year survival rate compared with patients without cancer. PMVR should be considered for cancer patients presenting with HF and severe MR and despite their malignancy. This approach may allow cancer patients to safely receive planned oncological treatment.

The need for palliative and support care services for heart failure patients in the community.

BACKGROUND: Palliative care is a care option considered appropriate for those with heart failure, but is uncommon partially due to a lack of timely identification of those needing palliative care. A standard mechanism that triggers which heart failure patients should receive palliative care is not available. The Gold Standards Framework (GSF) identifies those needing palliative care but has not been investigated with heart failure patients. OBJECTIVES: To describe palliative care provided in the community and determine whether the GSF can identify heart failure patients in need of palliative care. METHODS: Descriptive study. A total of 252 heart failure patients in the community completed a demographic characteristics questionnaire, the Edmonton symptom assessment scale-revised and the Minnesota living with heart failure questionnaire. Clinical data were collected from the medical chart and the primary physician completed the GSF prognostic indicator guidance. RESULTS: Participants had a mean age of 76.9 years (standard deviation 10.9), most at New York Heart Association level III (n=152, 60%). Fewer than half received pain medications (n=76, 30%), anxiolytics (n=35, 14%), antidepressants (n=64, 25%) or sleep medications (n=65, 26%). Eight patients spoke with a psychologist or psychologist (3%). One had an advanced directive and 16 (6%) had a record of discussions with their family caregivers. Three (1%) had end-of-life discussions with their healthcare providers. Most healthcare providers responded 'no' to the 'surprise question' (n=160, 63%). Sensitivity and specificity of the gold standards framework was poor. CONCLUSIONS: Few community dwelling heart failure patients received most aspects of palliative care. The gold standards framework was not a good indicator of those who should receive palliative care.

Prevalence and impact of concomitant malignancy on outcomes among ambulatory heart failure population.

INTRODUCTION: Heart failure (HF) and cancer are medical conditions with a rising prevalence resulting in increased co-occurrence. We assessed the impact of cancer on clinical outcome in patients with HF and the prognostic impact of specific types of cancers on different HF subpopulations. METHODS: All patients with HF were evaluated for the occurrence of malignant neoplasm at a health maintenance organization and were followed for cardiac-related hospitalizations and death. RESULTS: The study cohort included 7106 HF patients, 1564 of them (22%) had a diagnosis of malignant neoplasm. HF patients with concomitant cancer were older, had more comorbidities and were more likely to have NYHA class III/IV (42% vs. 37%, P < .01), compared with patients with no malignancy. The overall 2-year mortality rate of the entire HF cohort was 23.2%. Survival rate by Kaplan-Meier analysis demonstrated that the presence of a malignancy was directly associated with reduced survival: 67.2 ± 1.2% vs 79.5 ± 0.5%, P < .001. Malignancy was associated with an increase in mortality with a hazard ratio (HR) of 1.36, 95% confidence interval (CI) 1.21-1.54, P < .001. The strongest impact of malignancy on outcomes was related to age; among patients <70 years old, the increase in the risk of mortality was the highest with a HR of 2.07, 95% CI 1.54-2.80, P < .001. CONCLUSIONS: Malignancy is common among patients with HF. Patients with concomitant HF and malignancies have poor outcomes, and the impact of cancer on outcome is stronger among young patients.

Prognostic significance of the frontal QRS-T angle in patients with AL cardiac amyloidosis.

INTRODUCTION: Cardiac involvement is a leading cause of morbidity and mortality in primary light chain (AL) amyloidosis. The electrocardiographic spatial QRS-T angle reflects changes in the direction of the repolarization sequence and is a powerful predictor of outcome in patients with heart failure. We examined the significance of the frontal QRS-T angle in predicting the clinical outcome in patients with AL cardiac amyloidosis. METHODS: Forty-three consecutive patients with cardiac involvement of AL amyloidosis were studied. Patients were followed for survival. RESULTS: Patient median age was 62 years, 56% were males. After a median follow up of 56 months, 16 out of 43 patients had died (37%). The median QRS-T angle was 102° (interquartile range 35-148). QRS-T angle>102° was associated with increased prevalence of lambda free light chain disease and the presence of a pleural effusion. It was also associated with increased interventricular septum thickness, smaller left ventricle end-diastolic diameter, echocardiographic myocardial sparkling texture, pericardial effusion, elevated NT-Pro-BNP and increased restrictive physiology evident by increased E/A and E/e`. A QRS-T angle>102° was a significant predictor of increased mortality by Kaplan-Meier survival analysis (71.6 ± 11.1% vs. 45.7 ± 11.1%, P = .02). A QRS-T angle>102° was an independent predictor of mortality by Cox regression analysis (HR 3.00, 95% CI 1.01-8.89, P < .05). CONCLUSIONS: The QRS-T angle is associated with indices of advanced amyloid disease and is an independent predictor of survival.

A Theranostic Cathepsin Activity-Based Probe for Noninvasive Intervention in Cardiovascular Diseases.

Despite the common use of lipid-lowering medications, cardiovascular diseases continue to be a significant health concern. Atherosclerosis, one of the most frequent causes of cardiovascular morbidity, involves extensive inflammatory activity and remodeling of the vascular endothelium. This relentless inflammatory condition can ultimately give rise to clinical manifestations, such as ischemic heart disease or stroke. Accumulating evidence over the past decades implicates cysteine protease cathepsins in cardiovascular disorders. In particular, Cathepsins B, L, and S are over-expressed during vascular inflammation, and their activity is associated with impaired clinical outcomes. Here we took advantage of these molecular events to introduce a non-invasive detection and treatment approach to modulate vascular inflammation using a Photosensitizing quenched Activity-Based Probed (PS-qABP) that targets these proteases. Methods: We tested the application of this approach in LDL receptor-deficient mice and used non-invasive imaging and heart cross-section staining to assess the theranostic efficacy of this probe. Moreover, we used fresh human endarterectomy tissues to analyze cathepsin signals on gel, and verified cathepsin identity by mass spectrometry. Results: We showed that our PS-qABP can rapidly accumulate in areas of inflammatory atheromas in vivo, and application of light therapy profoundly reduced lesional immune cell content without affecting smooth muscle cell and collagen contents. Lastly, using human tissue samples we provided proof-of-concept for future clinical applications of this technology. Conclusions: Photodynamic therapy guided by cysteine cathepsin activity is an effective approach to reduce vascular inflammation and attenuate atherosclerosis progression. This approach could potentially be applied in clinical settings.

Cathepsins Drive Anti-Inflammatory Activity by Regulating Autophagy and Mitochondrial Dynamics in Macrophage Foam Cells.

BACKGROUND/AIMS: Atherosclerosis underlies the majority of cardiovascular events, consequent to non-resolving inflammation. Considerable evidence implicates autophagy dysfunction at the core of this inflammatory condition, but the basis of this dysfunction is not fully understood. METHODS: Using an in vitro model of lipid-laden macrophages, activity-based probes and high-throughput techniques, we studied the role of the cysteine proteases cathepsins in autophagy. RESULTS: We showed that cathepsin activity is suppressed by oxidized lipids and that cathepsin has an indispensable role in the autophagy-lysosomal degradation pathway. Accordingly, loss of cathepsin function resulted in autophagy derangement. Shotgun proteomics confirmed autophagy dysfunction and unveiled a pivotal role of cathepsin L in a putative cathepsin degradation network. At the physiological level, cathepsin inhibition resulted in mitochondrial stress, which translated into impaired oxidative metabolism, excessive production of reactive oxygen species and activation of the cellular stress response, driven by ATF4-CHOP transcription factors. In addition, transcriptomic analysis of these cells uncovered some genetic similarities with the inflammatory macrophage phenotype (a.k.a M1 macrophages) and increased expression of inflammatory cytokines. CONCLUSION: Our data highlight the importance of cathepsins for mitochondrial quality control mechanisms and amelioration of vascular inflammation.

Cysteine proteases in atherosclerosis.

Atherosclerosis predisposes patients to cardiovascular diseases, such as myocardial infarction and stroke. Instigation of vascular injury is triggered by retention of lipids and inflammatory cells in the vascular endothelium. Whereas these vascular lesions develop in young adults and are mostly considered harmless, over time persistent inflammatory and remodeling processes will ultimately damage the arterial wall and cause a thrombotic event due to exposure of tissue factors into the lumen. Evidence from human tissues and preclinical animal models has clearly established the role of cathepsin cysteine proteases in the development and progression of vascular lesions. Hence, understanding the function of cathepsins in atherosclerosis is important for developing novel therapeutic strategies and advanced point of care diagnostics. In this review we will describe the roles of cysteine cathepsins in different cellular process that become dysfunctional in atherosclerosis, such as lipid metabolism, inflammation and apoptosis, and how they contribute to arterial remodeling and atherogenesis. Finally, we will explore new horizons in protease molecular imaging, which may potentially become a surrogate marker to identify future cardiovascular events.

Acute viral myocarditis: current concepts in diagnosis and treatment.

Acute myocarditis is one of the most challenging diseases to diagnose and treat in cardiology. The true incidence of the disease is unknown. Viral infection is the most common etiology. Modern techniques have improved the ability to diagnose specific viral pathogens in the myocardium. Currently, parvovirus B19 and adenoviruses are most frequently identified in endomyocardial biopsies. Most patients will recover without sequelae, but a subset of patients will progress to chronic inflammatory and dilated cardiomyopathy. The pathogenesis includes direct viral myocardial damage as well as autoimmune reaction against cardiac epitopes. The clinical manifestations of acute myocarditis vary widely--from asymptomatic changes on electrocardiogram to fulminant heart failure, arrhythmias and sudden cardiac death. Magnetic resonance imaging is emerging as an important tool for the diagnosis and follow-up of patients, and for guidance of endomyocardial biopsy. In the setting of acute myocarditis endomyocardial biopsy is required for the evaluation of patients with a clinical scenario suggestive of giant cell myocarditis and of those who deteriorate despite supportive treatment. Treatment of acute myocarditis is still mainly supportive, except for giant cell myocarditis where immunotherapy has been shown to improve survival. Immunotherapy and specific antiviral treatment have yet to demonstrate definitive clinical efficacy in ongoing clinical trials. This review will focus on the clinical manifestations, the diagnostic approach to the patient with clinically suspected acute myocarditis, and an evidence-based treatment strategy for the acute and chronic form of the disease.

Changes in uric acid levels and allopurinol use in chronic heart failure: association with improved survival.

OBJECTIVE: Uric acid (UA) levels are frequently increased in patients with heart failure (HF), and may be an indicator of a poor prognosis and an innovative target for treatment. We evaluated the effect of UA and allopurinol use on clinical outcome in patients with HF. METHODS AND RESULTS: We evaluated patients with a diagnosis of HF at a Health Maintenance Organization (n = 6204). Patients were followed for cardiac-related hospitalizations and death. Mean UA levels were 6.5 ± 1.9 mg/dL. Median follow-up was 498 days. We divided patients into quartiles of serum UA; 22.6% (n = 1,568) were in the highest UA level quartile (>7.7 mg/dL). Cox regression analysis after adjustment for significant predictors including age, sex, ischemic heart disease, hypertension, atrial fibrillation, body mass index, hemoglobin, sodium, estimated glomerular filtration rate, urea levels, standard HF drug therapies, and allopurinol demonstrated that high UA levels (>7.7 mg/dL) were a predictor of increased mortality (hazard ratio [HR] 1.37, 95% confidence interval [CI] 1.17-1.60; P < .0001) and increased cardiac hospitalizations (HR 1.10, 95% CI 1.01-1.22; P < .05). An increase in UA levels during follow-up was also an independent predictor of mortality (HR 1.46, 95% CI 1.25-1.71; P < .00001) and cardiac hospitalizations (HR 1.15, 95% CI 1.06-1.23; P < .00001). Treatment with allopurinol was independently associated with improved survival (HR 0.79, 95% CI 0.64-0.98; P < .05). Echocardiographic data demonstrated a significant correlation between UA levels and E/A ratio, a marker of diastolic dysfunction. CONCLUSIONS: Increased UA levels and an increase in UA during follow-up were independent predictors of increased morbidity and mortality. Treatment with allopurinol was associated with improved survival.

Vitamin D deficiency is a predictor of reduced survival in patients with heart failure; vitamin D supplementation improves outcome.

AIMS: Vitamin D deficiency is a highly prevalent, global phenomenon. The prevalence in heart failure (HF) patients and its effect on outcome are less clear. We evaluated vitamin D levels and vitamin D supplementation in patients with HF and its effect on mortality. METHODS AND RESULTS: 25-Hydroxyvitamin D [25(OH)D] levels were evaluated in HF patients from a health maintenance organization (HMO), and compared them with those of the rest of the members of the HMO. Patients with HF (n = 3009) had a lower median 25(OH)D level compared with the control group (n = 46 825): 36.9 nmol/L (interquartile range 23.2-55.9) vs. 40.7 nmol/L (26.7-56.9), respectively, P < 0.00001. The percentage of patients with vitamin D deficiency [25(OH)D <25 nmol/L] was higher in patients with HF compared with the control group (28% vs. 22%, P < 0.00001). Only 8.8% of the HF patients had optimal 25(OH)D levels (≥75 nmol/L). Median clinical follow-up was 518 days. Cox regression analysis demonstrated that vitamin D deficiency was an independent predictor of increased mortality in patients with HF [hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.21-1.92, P < 0.001] and in the control group (HR 1.91, 95% CI 1.48-2.46, P < 0.00001). Vitamin D supplementation was independently associated with reduced mortality in HF patients (HR 0.68, 95% CI 0.54-0.85, P < 0.0001). Parameters associated with vitamin D deficiency in HF patients were decreased previous solar radiation exposure, body mass index, diabetes, female gender, pulse, and decreased calcium and haemoglobin levels. CONCLUSIONS: Vitamin D deficiency is highly prevalent in HF patients and is a significant predictor of reduced survival. Vitamin D supplementation was associated with improved outcome.

Cutting balloon angioplasty and stent implantation for aorto-ostial lesions: clinical outcome and 1-year follow-up.

BACKGROUND: Percutaneous interventions for aorto-ostial narrowing of native coronary arteries are challenging because of early elastic recoil after the procedure and the high restenosis rate. Cutting balloon angioplasty may reduce this complication. HYPOTHESIS: The purpose of the study was to evaluate the clinical outcomes of cutting balloon angioplasty and stent implantation for aorto-ostial lesions with a 1-year clinical follow-up. METHODS: All patients with aorto-ostial lesions in our laboratory underwent cutting balloon angioplasty and were followed for approximately 1 year. RESULTS: Forty-eight patients underwent balloon angioplasty; 36 of whom had lesions in the ostial right coronary artery, and 12 of whom had lesions in the left main coronary artery (LMCA). Thirty-five patients (73%) had a stent implanted. Procedural success was achieved in all patients. The in-hospital rate of major adverse cardiac events (MACEs) was 2.1% because of the death of 1 patient following urgent bypass surgery. Mean clinical follow-up was 11.6 +/- 7 month. Twelve patients (27%) required repeat coronary angiography, and restenosis was found in 7 patients (16%). Six patients (13.6%) had MACEs. CONCLUSIONS: Cutting balloon angioplasty in combination with bare metal stent (BMS) implantation has a good clinical outcome. This technique should be compared with implantation of drug-eluting stents (DESs) in a controlled study.

T-cell costimulation and coinhibition in atherosclerosis.

Evidence from many human and rodent studies has established that T lymphocytes enhance inflammation in atherosclerotic plaques and contribute to lesion progression and remodeling. Recent work also indicates that regulatory T cells are important in limiting proatherogenic T-cell responses. Given the important role of T cells in atherosclerosis, there is a need to fully understand how proatherogenic T cells are activated and regulated. Antigen-dependent activation of naïve T cells, leading to clonal expansion and effector T-cell differentiation, and effector and memory T cells, is enhanced by signals provided by costimulatory molecules expressed by antigen presenting cells, which bind to receptors on the T cells. In addition, T-cell responses to antigen are negatively regulated by coinhibitory molecules expressed by antigen-presenting cells, which bind to receptors on T cells. Two major families of costimulatory molecules include the B7 and the tumor necrosis factor (TNF) families. These molecules bind to receptors on T cells belonging to the CD28 or TNF receptor families, respectively. The best-defined coinhibitors and their receptors belong to the B7 and CD28 families. Recent work has begun to define how these T-cell costimulatory and coinhibitory pathways influence atherosclerosis, largely in mouse models of the disease. Profound effects are attributable to molecules in both the B7/CD28 (B7-1/2, ICOS, and PDL-1/2) and the TNF/TNF receptor (CD40, OX40, and CD137) families. One emerging theme is that both pathogenic effector T-cell responses and regulatory T cells are influenced by overlapping sets of costimulators and coinhibitors. These complexities must be considered as immunotherapeutic approaches for atherosclerotic disease are developed.

CD11c(+) dendritic cells maintain antigen processing, presentation capabilities, and CD4(+) T-cell priming efficacy under hypercholesterolemic conditions associated with atherosclerosis.

Recent reports suggest dyslipidemia impairs dendritic cell (DC) function and adaptive immunity. This study aimed to characterize the effect of hypercholesterolemia on antigen-presenting cell function of DCs and DC-dependent CD4(+) T-cell responses. DCs incubated in vitro with acetylated low-density lipoprotein cholesterol with or without an acyl-coenzyme A:cholesterol acyl-transferase inhibitor maintained their ability to prime CD4(+) T cells. Analysis of T-cell proliferation and interferon-gamma and tumor necrosis factor-alpha production after ex vivo coculture of naïve CD4(+) T cells with splenic, inguinal, or iliac DCs from low-density lipoprotein receptor-deficient (LDLR(-/-)) or apolipoprotein E-deficient (ApoE(-/-)) mice fed an atherogenic diet highlighted DC efficacy in effector T-cell generation under hypercholesterolemic conditions. Adoptive transfer of carboxyfluorescein diacetate, succinimidyl ester (CFSE)-labeled naïve CD4(+) T cells in LDLR(-/-) recipients and subsequent immunization demonstrated effective priming of naïve T cells in hypercholesterolemic mice. CFSE dilution analyses revealed that hypercholesterolemic DCs were equipotent in naïve CD4(+) T-cell priming efficacy with normocholesterolemic DCs. Quantitative real-time PCR and flow cytometric analyses demonstrated that DC expression of multiple molecules involved in antigen processing, presentation, and T-cell stimulation remained unaltered by dyslipidemia. Finally, endogenous antigen-primed CD4(+) T cells responded equivalently to a secondary ex vivo antigenic challenge, regardless of whether they were primed in vivo under hypercholesterolemic or control conditions, demonstrating that all essential steps in CD4(+) T-cell responses remain intact under atherogenic conditions. This study affirms that the adaptive immune response prevails under the hypercholesterolemic conditions present in atherosclerosis. In particular, DCs remain functional antigen-presenting cells and maintain their ability to prime CD4(+) T cells even when cholesterol-loaded.

Serum cytokine tumor necrosis factor-alpha and interleukin-6 associated with the severity of coronary artery disease: indicators of an active inflammatory burden?

BACKGROUND: Atherosclerosis is a chronic inflammatory process resulting in coronary artery disease. OBJECTIVES: To determine the relationship between inflammatory markers and the angiographic severity of CAD. METHODS: We measured inflammatory markers in consecutive patients undergoing coronary angiography. This included C-reactive protein, fibrinogen, serum cytokines (interleukin-1 beta, IL-1 receptor antagonist, IL-6, IL-8, IL-10) and tumor necrosis factor-alpha), all measured by high sensitivity enzyme-linked immunoabsorbent assay. RESULTS: There was a significant correlation between TNFalpha and the severity of CAD as assessed by the number of obstructed coronary vessels and the Gensini severity score, which is based on the proximity and severity of the lesions. Patients had more coronary vessel disease (> 70% stenosis) with increasing tertiles of serum TNFalpha; the mean number of vessels affected was 1.15, 1.33, and 2.00 respectively (P< 0.001). IL-6 correlated with the Gensini severity score and coronary vessel disease (> 70% stenosis). A weaker correlation was present with IL-1 receptor antagonist. A significant correlation was not found with the other inflammatory markers. After adjustment for major risk factors, multivariate analyses showed that significant independent predictors of CAD vessel disease were TNFalpha (P< 0.05) and combined levels of TNFalpha and IL-6 (P< 0.05). IL-6 levels were independently predictive of Gensini coronary score (P< 0.05). CONCLUSION: TNFalpha and IL-6 are significant predictors of the severity of coronary artery disease. This association is likely an indicator of the chronic inflammatory burden and an important marker of increased atherosclerosis risk.

Interferon-gamma, a Th1 cytokine, regulates fat inflammation: a role for adaptive immunity in obesity.

Adipose tissue (AT) can accumulate macrophages and secrete several inflammatory mediators. Despite its pivotal role in the progression of chronic inflammatory processes such as atherosclerosis, the adaptive role of immunity in obesity remains poorly explored. Visceral AT of diet-induced obese C57BL/6 mice had higher numbers of both CD4(+) and CD8(+) T cells than lean controls, monitored by flow cytometry. When stimulated in vitro, T cells from obese AT produced more interferon (IFN)gamma than those from controls. AT from obese animals also had more cells expressing I-A(b), a mouse class II histocompatibility marker implicated in antigen presentation, as determined by immunostaining. Differentiated 3T3-L1 cells stimulated with recombinant IFNgamma or T-helper 1-derived supernatant produced several chemokines and their mRNAs. Obese IFNgamma-deficient animals had significantly reduced AT expression of mRNA-encoding inflammatory genes such as tumor necrosis factor-alpha and monocyte chemoattractant protein-1, decreased AT inflammatory cell accumulation, and better glucose tolerance than control animals consuming the same diet. Obese mice doubly deficient for IFNgamma receptor and apolipoprotein (Apo)E on a mixed 129SvEv/C57BL/6 (129/B6) genetic background, despite exhibiting similar AT mRNA levels of tumor necrosis factor-alpha and monocyte chemoattractant protein-1 as 129/B6-ApoE(-/-) controls, had decreased expression of important T cell-related genes, such as IFNgamma-inducible protein-10 and I-A(b), and lower plasma triglycerides and glucose. These results indicate a role for T cells and IFNgamma, a prototypical T-helper 1 cytokine, in regulation of the inflammatory response that accompanies obesity.

Endothelial programmed death-1 ligand 1 (PD-L1) regulates CD8+ T-cell mediated injury in the heart.

BACKGROUND: PD-L1 and PD-L2 are ligands for the inhibitory receptor programmed death-1 (PD-1), which is an important regulator of immune responses. PD-L1 is induced on cardiac endothelial cells under inflammatory conditions, but little is known about its role in regulating immune injury in the heart. METHODS AND RESULTS: Cytotoxic T-lymphocyte-mediated myocarditis was induced in mice, and the influence of PD-L1 signaling was studied with PD-L1/L2-deficient mice and blocking antibodies. During cytotoxic T-lymphocyte-induced myocarditis, the upregulation of PD-L1 on cardiac endothelia was dependent on T-cell-derived interferon-gamma, and blocking of interferon-gamma signaling worsened disease. Genetic deletion of both PD-1 ligands [PD-L1/2(-/-)], as well as treatment with PD-L1 blocking antibody, transformed transient myocarditis to lethal disease, in association with widespread polymorphonuclear leukocyte-rich microabscesses but without change in cytotoxic T-lymphocyte recruitment. PD-L1/2(-/-) mice reconstituted with bone marrow from wild-type mice remained susceptible to severe disease, which demonstrates that PD-L1 on non-bone marrow-derived cells confers the protective effect. Finally, depletion of polymorphonuclear leukocytes reversed the enhanced susceptibility to lethal myocarditis attributable to PD-L1 deficiency. CONCLUSIONS: Myocardial PD-L1, mainly localized on endothelium, is critical for control of immune-mediated cardiac injury and polymorphonuclear leukocyte inflammation.

Proatherogenic immune responses are regulated by the PD-1/PD-L pathway in mice.

T lymphocyte responses promote proatherogenic inflammatory events, which are influenced by costimulatory molecules of the B7 family. Effects of negative regulatory members of the B7 family on atherosclerosis have not been described. Programmed death-ligand 1 (PD-L1) and PD-L2 are B7 family members expressed on several cell types, which inhibit T cell activation via binding to programmed death-1 (PD-1) on T cells. In order to test whether the PD-1/PD-L pathway regulates proatherogenic T cell responses, we compared atherosclerotic lesion burden and phenotype in hypercholesterolemic PD-L1/2(-/-)LDLR(-/-) mice and LDLR(-/-) controls. PD-L1/2 deficiency led to significantly increased atherosclerotic burden throughout the aorta and increased numbers of lesional CD4(+) and CD8(+) T cells. Compared with controls, PD-L1/2(-/-)LDLR(-/-) mice had iliac lymphadenopathy and increased numbers of activated CD4(+) T cells. Serum levels of TNF-alpha were higher in PD-L1/2(-/-)LDLR(-/-) mice than in controls. PD-L1/2-deficient APCs were more effective than control APCs in activating CD4(+) T cells in vitro, with or without cholesterol loading. Freshly isolated APCs from hypercholesterolemic PD-L1/2(-/-)LDLR(-/-) mice stimulated greater T cell responses than did APCs from hypercholesterolemic controls. Our findings indicate that the PD-1/PD-L pathway has an important role in downregulating proatherogenic T cell response and atherosclerosis by limiting APC-dependent T cell activation.

Clinical and echocardiographic predictors of morbidity and mortality in infective endocarditis: the significance of vegetation size.

BACKGROUND: Infective endocarditis is a common disease with significant morbidity and mortality. OBJECTIVES: To define clinical and echocardiographic parameters predicting morbidity and in-hospital mortality in patients with infective endocarditis hospitalized in a tertiary hospital from 1991 to 2000. METHODS: All patients with definite infective endocarditis diagnosed according to the Duke criteria were included. We examined relevant clinical features that might influence outcome. RESULTS: The study group comprised 100 consecutive patients, 77 with native valve and 23 with prosthetic valve endocarditis. The overall in-hospital mortality rate was 8%. There was a higher mortality in the PVE group compared to the NVE group (13% vs. 7%, P = 0.07). The mortality rate in each group, with or without surgery, was not significantly different. Clinical predictors of mortality were older age and hospital-acquired endocarditis. The presence of vegetations and their size were significant predictors of major embolic events and mortality. Staphylococcus aureus was a predictor of mortality (25% vs. 5%, P < 0.005) and abscess formation. Multivariate logistic analysis identified vegetation size and S. aureus as independent predictors of mortality. CONCLUSIONS: Mortality is higher in older hospitalized patients. S. aureus is associated with a poor outcome. Vegetation size is an independent predictor of embolic events and of a higher mortality.

Impaired regulatory T-cell response and enhanced atherosclerosis in the absence of inducible costimulatory molecule.

BACKGROUND: T-cell-mediated immunity contributes to the pathogenesis of atherosclerosis, but little is known about how these responses are regulated. We explored the influence of the inducible costimulatory molecule (ICOS) on atherosclerosis and associated immune responses. METHODS AND RESULTS: Bone marrow chimeras were generated by transplanting ICOS-deficient or wild-type bone marrow into irradiated atherosclerosis-prone, LDR receptor-deficient mice, and the chimeric mice were fed a high-cholesterol diet for 8 weeks. Compared with controls, mice transplanted with ICOS-deficient marrow had a 43% increase in the atherosclerotic burden, and importantly, their lesions had a 3-fold increase in CD4+ T cells, as well as increased macrophage, smooth muscle cell, and collagen content. CD4+ T cells from ICOS-deficient chimeras proliferated more and secreted more interferon-gamma and tumor necrosis factor-alpha than T cells from control mice, which suggests a lack of regulation. FoxP3+ regulatory T cells (Treg) were found to constitutively express high ICOS levels, which suggests a role for ICOS in Treg function. ICOS-deficient mice had decreased numbers of FoxP3+ Treg and impaired in vitro Treg suppressive function compared with control mice. CONCLUSIONS: ICOS has a key role in regulation of atherosclerosis, through its effect on regulatory T-cell responses.