Defective angiogenesis delays thrombus resolution: a potential pathogenetic mechanism underlying chronic thromboembolic pulmonary hypertension.

OBJECTIVE: Restoration of patency is a natural target of vascular remodeling after venous thrombosis that involves vascular endothelial cells and smooth muscle cells, as well as leukocytes. Acute pulmonary emboli usually resolve <6 months. However, in some instances, thrombi transform into fibrous vascular obstructions, resulting in occlusion of the deep veins, or in chronic thromboembolic pulmonary hypertension (CTEPH). We proposed that dysregulated thrombus angiogenesis may contribute to thrombus persistence. APPROACH AND RESULTS: Mice with an endothelial cell-specific conditional deletion of vascular endothelial growth factor receptor 2/kinase insert domain protein receptor were used in a model of stagnant flow venous thrombosis closely resembling human deep vein thrombosis. Biochemical and functional analyses were performed on pulmonary endarterectomy specimens from patients with CTEPH, a human model of nonresolving venous thromboembolism. Endothelial cell-specific deletion of kinase insert domain protein receptor and subsequent ablation of thrombus vascularization delayed thrombus resolution. In accordance with these findings, organized human CTEPH thrombi were largely devoid of vascular structures. Several vessel-specific genes, such as kinase insert domain protein receptor, vascular endothelial cadherin, and podoplanin, were expressed at lower levels in white CTEPH thrombi than in organizing deep vein thrombi and organizing thrombi from aortic aneurysms. In addition, red CTEPH thrombi attenuated the angiogenic response induced by vascular endothelial growth factor. CONCLUSIONS: In the present work, we propose a mechanism of thrombus nonresolution demonstrating that endothelial cell-specific deletion of kinase insert domain protein receptor abates thrombus vessel formation, misguiding thrombus resolution. Medical conditions associated with the development of CTEPH may be compromising early thrombus angiogenesis.

Cardio-oncology in Austria: cardiotoxicity and surveillance of anti-cancer therapies : Position paper of the Heart Failure Working Group of the Austrian Society of Cardiology.

Survival in cancer is continuously improving due to evolving oncological treatment. Therefore, cardiovascular short-term and long-term side effects gain crucial importance for overall outcome. Cardiotoxicity not only presents as heart failure, but also as treatment-resistant hypertension, acute coronary ischemia with plaque rupture or vasospasm, thromboembolism, arrhythmia, pulmonary hypertension, diastolic dysfunction, acute myocarditis and others. Recent recommendations have proposed baseline cardiac risk assessment and surveillance strategies. Major challenges are the availability of monitoring and imaging resources, including echocardiography with speckle tracking longitudinal strain (GLS), serum biomarkers such as natriuretic peptides (NT-proBNP) and highly sensitive cardiac troponins. This Austrian consensus encompasses cardiotoxicity occurrence in frequent antiproliferative cancer drugs, radiotherapy, immune checkpoint inhibitors and cardiac follow-up considerations in cancer survivors in the context of the Austrian healthcare setting. It is important to optimize cardiovascular risk factors and pre-existing cardiac diseases without delaying oncological treatment. If left ventricular ejection fraction (LVEF) deteriorates during cancer treatment (from >10% to <50%), or myocardial strain decreases (>15% change in GLS), early initiation of cardioprotective therapies (angiotensin-converting enzyme inhibitors, angiotensin or beta receptor blockers) is recommended, and LVEF should be reassessed before discontinuation. Lower LVEF cut-offs were recently shown to be feasible in breast cancer patients to enable optimal anticancer treatment. Interdisciplinary cardio-oncology cooperation is pivotal for optimal management of cancer patients.

Echocardiographic evaluation of patients undergoing cancer therapy.

As advances in oncology therapies lead to significant improvement in life expectancy of many cancer entities, short-, and long-term cardiac side effects of oncology treatments gain increasing importance. In search of new screening modalities, echocardiography currently presents the best established and clinically easily feasible tool to detect cardiotoxicity in patients undergoing cancer therapy. This review focusses on the most commonly used oncology therapies and aims to give a practical approach to guide clinicians caring for this growing number of patients.

Sacubitril/valsartan is well tolerated in patients with longstanding heart failure and history of cancer and improves ventricular function: real-world data.

BACKGROUND: Sacubitril/valsartan has been shown to significantly reduce cardiovascular mortality and hospitalizations due to heart failure in patients with reduced ejection fraction (HFrEF) when compared to enalapril. Data about sacubitril/valsartan in patients with a history of cancer are scarce, as these patients were excluded from the pivotal trial, PARADIGM-HF. The aim of the current study was to assess tolerability of sacubitril/valsartan in patients with a history of cancer. METHODS: We identified 225 patients at our heart failure out-patient unit who fulfilled the indication criteria to receive sacubitril/valsartan. Out of these, 9.3% (n = 21) had a history of histologically confirmed cancer. Oncologic surgery was performed in 16 (76.2%) patients, 11 (52.4%) patients received previous antineoplastic therapy and 9 patients (42.9%) radiation. RESULTS: Sacubitril/valsartan was withdrawn in 3 of 21 patients (14.3%) because of dizziness (n = 2) or pruritus (n = 1). After a median follow-up of 12 months (range 1-34 months), NYHA functional class improved significantly from NYHA 3 to NYHA 2 (mean -0.6, p = 0.006) and left ventricular ejection fraction as assessed by echocardiography increased significantly from 26.8 ± 5.4% to 39.2 ± 10% (mean + 12%, CI 95% [8.4-16.4], p = 0.0004). NT-proBNP was significantly reduced (baseline median 2774 pg/ml, range 1441 - 12,982 vs follow-up 1266 pg/ml, range 199-6324, p = 0.009). There was no significant change in creatinine levels (1.18 ± 0.4 vs 1.22 ± 0.4 mg/dl; mean + 0.005 mg/dl, CI 95% [-0.21- 0.12], p = 0.566). CONCLUSIONS: In our pilot study we show that sacubitril/valsartan is generally well tolerated in patients with HFrEF and history of cancer. Importantly, even patients with long-standing cardiotoxicity induced heart failure can be treated and up-titrated with sacubitril/valsartan to usual target dosages, leading to improvement in LV function and biomarkers. Larger studies are needed to confirm these findings in cancer patients with cardiotoxicity.

Natural Course of Nonsevere Secondary Tricuspid Regurgitation.

BACKGROUND: Secondary tricuspid regurgitation (sTR) is frequent in patients with heart failure with reduced ejection fraction and is associated with adverse outcomes despite guideline-directed therapy. However, little is known about the natural course of nonsevere sTR and its relation to cardiac remodeling and outcomes. The aims of this study were therefore to investigate the natural course of sTR progression using quantitative measurements, to assess the prognostic impact on long-term mortality, and to identify risk factors associated with progressive sTR. METHODS: A total of 216 patients with heart failure with reduced ejection fraction receiving guideline-directed therapy were included in this long-term observational study. Progression of sTR was quantitatively defined as an increase of 0.2 cm2 in effective regurgitant orifice area or 15 mL in regurgitant volume, with transition to at least moderate sTR. Kaplan-Meier and Cox regression analyses were applied to assess survival during a 5-year follow-up period. RESULTS: Among patients with nonsevere sTR at baseline, 62 (29%) experienced sTR progression. Progressive sTR was accompanied by larger left and right atrial volumes (P = .02 and P < .02, respectively) and a higher prevalence of atrial fibrillation (P < .04). During a median follow-up period of 60 months (interquartile range, 37-60 months), 82 patients died. Progression of sTR conveyed a higher risk for long-term mortality (hazard ratio, 1.77; 95% CI, 1.1-2.83; P < .02), even after multivariate adjustment for bootstrap-selected (adjusted hazard ratio, 1.70; 95% CI, 1.06-2.74; P < .03) and clinical confounder (adjusted hazard ratio, 1.80; 95% CI, 1.07-3.05; P < .03) models. CONCLUSIONS: The incidence of progressive sTR despite guideline-directed therapy is associated with adverse cardiac and valvular remodeling as well as a significantly higher long-term mortality. Biatrial enlargement as well as atrial fibrillation are associated with the development of subsequent progressive sTR and may help identify patients at risk for sTR progression, potentially creating a window of opportunity for closer follow-up and newly arising minimally invasive transcatheter repair therapies.

Increased resting heart rate and prognosis in treatment-naïve unselected cancer patients: results from a prospective observational study.

AIMS: Cancer patients suffer from impaired cardiovascular function. Elevated resting heart rate (RHR) has been identified as a marker for increased long-term mortality in cancer patients prior to the receipt of anticancer treatment. We aimed to establish whether RHR is associated with survival in treatment-naïve cancer patients. METHODS AND RESULTS: This prospective study enrolled 548 unselected treatment-naïve cancer patients between 2011 and 2013. The median age of the cohort was 62 years; 40.9% were male and 32.7% had metastatic disease. Median RHR was 72 b.p.m. Most patients were in sinus rhythm (n = 507, 92.5%). Clinical heart failure was noted in 37 (6.8%) patients. RHR was not related to cancer stage (P = 0.504). Patients in the highest RHR tertile had higher levels of high-sensitivity troponin (P = 0.003) and N-terminal pro-B-type natriuretic peptide (P = 0.039). During a median follow-up of 25 months (interquartile range: 16-32 months; range: 0-40 months), 185 (33.8%) patients died from any cause [1-year-mortality: 17%, 95% confidence interval (CI) 13-20%]. In univariate survival analysis, RHR predicted all-cause mortality [crude hazard ratio (HR) for a 5 b.p.m. increase in RHR: 1.09, 95% CI 1.04-1.15; P < 0.001], and remained significantly associated with outcome after adjustment for age, gender, tumour entity, tumour stage, cardiac status and haemoglobin (adjusted HR for a 5 b.p.m. increase in RHR: 1.10, 95% CI 1.04-1.16; P < 0.001). There was no significant impact of metastatic/non-metastatic disease state on the predictive value of RHR (P = 0.433 for interaction). In subgroup analyses, the strongest associations for RHR with mortality were observed in lung (crude HR 1.14; P = 0.007) and gastrointestinal (crude HR 1.31; P < 0.001) cancer. CONCLUSIONS: Treatment-naïve cancer patients with higher RHRs display higher levels of cardiovascular biomarkers. RHR was independently associated with all-cause mortality, especially in lung and gastrointestinal cancers. Elevated RHR and cardiovascular biomarkers may represent early signs of incipient cardiac dysfunction.

Natural History of Functional Tricuspid Regurgitation: Implications of Quantitative Doppler Assessment.

OBJECTIVES: This study sought to define the relationship between functional tricuspid regurgitation (TR) and mortality in patients with heart failure with reduced ejection fraction (HFrEF); and to establish the prognostic value of quantitative measures of TR severity (i.e., effective regurgitant orifice area [EROA] and regurgitant volume). BACKGROUND: The significance of TR in chronic heart failure is controversial. Earlier studies have shown an independent impact of TR on mortality, whereas more recent evidence suggests myocardial impairment to be the driving force of mortality rather than TR itself. Earlier studies have used qualitative measures of TR severity, hence the prognostic value of more quantitative measures of TR severity (i.e., EROA and regurgitant volumes) remains unclear. METHODS: We enrolled 382 patients with HFrEF on guideline-directed medical therapy and assessed TR EROA and regurgitant volume by Doppler/2-dimensional echocardiography. All-cause mortality was defined as the primary study endpoint. RESULTS: TR severity was associated with the HFrEF phenotype with more symptoms (p = 0.004), higher neurohumoral activation (p < 0.001), progressive right-ventricular dilatation (p < 0.001), and impaired function (p < 0.001). Cox regression showed a strong association between quantitative measures of TR with mortality (all p < 0.001). Quantitative metrics of TR severity were consistently associated with mortality with a hazard ratio of 1.009 (95% confidence interval: 1.004 to 1.013; p < 0.001) per 0.01 cm2 increase of the EROA and of 1.013 (95% confidence interval: 1.007 to 1.020; p < 0.001) per 1-ml increase in regurgitant volume. Results remained unchanged after bootstrap- or clinical confounder-based adjustment. A spline curve pattern illustrates the association with mortality with thresholds for the EROA ≥0.2 cm2, and the regurgitant volume ≥20 ml with sustained excess mortality thereafter. CONCLUSIONS: This large-scale outcome study demonstrates the prognostic value of quantitative Doppler-echocardiographic measures of TR severity in HFrEF. The thresholds for EROA and TR regurgitant volume associated with mortality in our study fall within current ranges defining nonsevere TR. This may potentially impact therapeutic decision making, particularly timing of intervention.

Transgenic expression of plant-specific insert of potato aspartic proteases (StAP-PSI) confers enhanced resistance to Botrytis cinerea in Arabidopsis thaliana.

The plant-specific insert of Solanum tuberosum aspartic proteases (StAP-PSI) has high structural similarity with NK-lysin and granulysin, two saposin-like proteins (SAPLIPs) with antimicrobial activity. Recombinant StAP-PSI and some SAPLIPs show antimicrobial activity against pathogens that affect human and plants. In this work, we transformed Arabidopsis thaliana plants with StAP-PSI encoding sequence with its corresponding signal peptide under the control of the cauliflower mosaic virus (CaMV) 35S promoter. Results obtained show that StAP-PSI significantly enhances Arabidopsis resistance against Botrytis cinerea infection. StAP-PSI is secreted into the leaf apoplast and acts directly against pathogens; thereby complementing plant innate immune responses. Data obtained from real-time PCR assays show that the constitutive expression of StAP-PSI induces the expression of genes that regulate jasmonic acid signalling pathway, such as PDF1.2, in response to infection due to necrotrophic pathogens. On the other hand, according to the data described for other antimicrobial peptides, the presence of the StAP-PSI protein in the apoplast of A. thaliana leaves is responsible for the expression of salicylic acid-associated genes, such as PR-1, irrespective of infection with B. cinerea. These results indicate that the increased resistance demonstrated by A. thaliana plants that constitutively express StAP-PSI owing to B. cinerea infection compared to the wild-type plants is a consequence of two factors, i.e., the antifungal activity of StAP-PSI and the overexpression of A. thaliana defense genes induced by the constitutive expression of StAP-PSI. We suggest that the use of this protein would help in minimizing the ecological and health risks that arise from the use of pesticides. We suggest that the use of this protein would help in minimizing the ecological and health risks that arise from the spreading of resistance of agriculturally important pathogens.

Fibrin(ogen)olytic and antiplatelet activities of a subtilisin-like protease from Solanum tuberosum (StSBTc-3).

Plant serine proteases have been widely used in food science and technology as well as in medicine. In this sense, several plant serine proteases have been proposed as potential anti-coagulants and anti-platelet agents. Previously, we have reported the purification and identification of a plant serine protease from Solanum tuberosum leaves. This potato enzyme, named as StSBTc-3, has a molecular weight of 72 kDa and it was characterized as a subtilisin like protease. In this work we determine and characterize the biochemical and medicinal properties of StSBTc-3. Results obtained show that, like the reported to other plant serine proteases, StSBTc-3 is able to degrade all chains of human fibrinogen and to produces fibrin clot lysis in a dose dependent manner. The enzyme efficiently hydrolyzes ß subunit followed by partially hydrolyzed α and γ subunits of human fibrinogen. Assays performed to determine StSBTc-3 substrate specificity using oxidized insulin ß-chain as substrate, show seven cleavage sites: Asn3-Gln4; Cys7-Gly8; Glu13-Ala14; Leu15-Tyr16; Tyr16-Leu17; Arg22-Gly23 and Phe25-Tyr26, all of them were previously reported for other serine proteases with fibrinogenolytic activity. The maximum StSBTc-3 fibrinogenolytic activity was determined at pH 8.0 and at 37 C. Additionally, we demonstrate that StSBTc-3 is able to inhibit platelet aggregation and is unable to exert cytotoxic activity on human erythrocytes in vitro at all concentrations assayed. These results suggest that StSBTc-3 could be evaluated as a new agent to be used in the treatment of thromboembolic disorders such as strokes, pulmonary embolism and deep vein thrombosis.

Splenectomy is modifying the vascular remodeling of thrombosis.

BACKGROUND: Splenectomy is a clinical risk factor for complicated thrombosis. We hypothesized that the loss of the mechanical filtering function of the spleen may enrich for thrombogenic phospholipids in the circulation, thereby affecting the vascular remodeling of thrombosis. METHODS AND RESULTS: We investigated the effects of splenectomy both in chronic thromboembolic pulmonary hypertension (CTEPH), a human model disease for thrombus nonresolution, and in a mouse model of stagnant flow venous thrombosis mimicking deep vein thrombosis. Surgically excised thrombi from rare cases of CTEPH patients who had undergone previous splenectomy were enriched for anionic phospholipids like phosphatidylserine. Similar to human thrombi, phosphatidylserine accumulated in thrombi after splenectomy in the mouse model. A postsplenectomy state was associated with larger and more persistent thrombi. Higher counts of procoagulant platelet microparticles and increased leukocyte-platelet aggregates were observed in mice after splenectomy. Histological inspection revealed a decreased number of thrombus vessels. Phosphatidylserine-enriched phospholipids specifically inhibited endothelial proliferation and sprouting. CONCLUSIONS: After splenectomy, an increase in circulating microparticles and negatively charged phospholipids is enhanced by experimental thrombus induction. The initial increase in thrombus volume after splenectomy is due to platelet activation, and the subsequent delay of thrombus resolution is due to inhibition of thrombus angiogenesis. The data illustrate a potential mechanism of disease in CTEPH.

Tadalafil for the treatment of pulmonary arterial hypertension.

INTRODUCTION: Pulmonary arterial hypertension (PAH) is a progressive occlusive disease affecting the pulmonary vasculature; it carries a poor prognosis. Because right ventricular failure is the key feature of deterioration in PAH patients, vasodilator treatments relieving right ventricular afterload have gained ground in the treatment of this disorder. Phosphodiesterase-5 inhibitors are effective and well tolerated vasodilators that were originally developed for erectile dysfunction. Tadalafil , the first once-daily drug of this class, was approved by the USFDA in May 2009 for the treatment of patients suffering from PAH. AREAS COVERED: This review outlines the currently available data about tadalafil and its effects in patients with PAH. It also presents evidence from recent clinical trials of tadalafil and discusses potential improvements over existing therapy options and their impact on current treatment strategies. EXPERT OPINION: Tadalafil is an efficacious drug with a favorable side-effect profile and convenient mode of administration. More studies are needed to analyze its impact on survival and to substantiate its role in an upfront combination treatment strategy.