Neutral Effects of Combined Treatment With GLP-1R Agonist Exenatide and MR Antagonist Potassium Canrenoate on Cardiac Function in Porcine and Murine Chronic Heart Failure Models

Background: Ischemia-reperfusion and cardiac remodeling is associated with cardiomyocyte death, excessive fibrosis formation, and functional decline, eventually resulting in heart failure (HF). Glucagon-like peptide (GLP)-1 agonists are reported to reduce apoptosis and myocardial infarct size after ischemia-reperfusion. Moreover, mineralocorticoid receptor antagonists (MRAs) have been described to reduce reactive fibrosis and improve cardiac function. Here, we investigated whether combined treatment with GLP-1R agonist exenatide and MRA potassium canrenoate could minimize cardiac injury and limit HF progression in animal models of chronic HF.

Methods and Results: Forty female Topigs Norsvin pigs were subjected to 150 min balloon occlusion of the left anterior descending artery (LAD). Prior to reperfusion, pigs were randomly assigned to placebo or combination therapy (either low dose or high dose). Treatment was applied for two consecutive days or for 8 weeks with a continued high dose via a tunneled intravenous catheter. Using 2,3,5-Triphenyltetrazolium chloride (TTC) staining we observed that combination therapy did not affect the scar size after 8 weeks. In line, left ventricular volume and function assessed by three-dimensional (3D) echocardiography (baseline, 7 days and 8 weeks), and cardiac magnetic resonance imaging (CMR, 8 weeks) did not differ between experimental groups. In addition, 36 C57Bl/6JRj mice underwent permanent LAD-occlusion and were treated with either placebo or combination therapy prior to reperfusion, for two consecutive days via intravenous injection, followed by continued treatment via placement of osmotic mini-pumps for 28 days. Global cardiac function, assessed by 3D echocardiography performed at baseline, 7, 14, and 28 days, did not differ between treatment groups. Also, no differences were observed in cardiac hypertrophy, assessed by heart weight/bodyweight and heart weight/tibia length ratio.

Conclusion: In the current study, combined treatment with GLP-1R agonist exenatide and MR antagonist potassium canrenoate did not show beneficial effects on cardiac remodeling nor resulted in functional improvement in a small and large animal chronic HF model.

Aging-induced isoDGR-modified fibronectin activates monocytic and endothelial cells to promote atherosclerosis

BACKGROUND AND AIMS

Aging is the primary risk factor for cardiovascular disease (CVD), but the mechanisms underlying age-linked atherosclerosis remain unclear. We previously observed that long-lived vascular matrix proteins can acquire 'gain-of-function' isoDGR motifs that might play a role in atherosclerotic pathology.

METHODS

IsoDGR-specific mAb were generated and used for ELISA-based measurement of motif levels in plasma samples from patients with coronary artery diseases (CAD) and non-CAD controls. Functional consequences of isoDGR accumulation in age-damaged fibronectin were determined by bioassay for capacity to activate monocytes, macrophages, and endothelial cells (signalling activity, pro-inflammatory cytokine expression, and recruitment/adhesion potential). Mice deficient in the isoDGR repair enzyme PCMT1 were used to assess motif distribution and macrophage localisation in vivo.

RESULTS

IsoDGR-modified fibronectin and fibrinogen levels in patient plasma were significantly enhanced in CAD and further associated with smoking status. Functional assays demonstrated that isoDGR-modified fibronectin activated both monocytes and macrophages via integrin receptor 'outside in' signalling, triggering an ERK:AP-1 cascade and expression of pro-inflammatory cytokines MCP-1 and TNFα to drive additional recruitment of circulating leukocytes. IsoDGR-modified fibronectin also induced endothelial cell expression of integrin β1 to further enhance cellular adhesion and matrix deposition. Analysis of murine aortic tissues confirmed accumulation of isoDGR-modified proteins co-localised with CD68+ macrophages in vivo.

CONCLUSIONS

Age-damaged fibronectin features isoDGR motifs that increase binding to integrins on the surface of monocytes, macrophages, and endothelial cells. Subsequent activation of 'outside-in' signalling elicits a range of potent cytokines and chemokines that drive additional leukocyte recruitment to the developing atherosclerotic matrix.

Experimental parameters and infarct size in closed chest pig LAD ischemia reperfusion models; lessons learned

BACKGROUND

Preclinical models that resemble the clinical setting as closely as possible are essential in translating promising therapies for the treatment of acute myocardial infarction. Closed chest pig left anterior descending coronary artery (LAD) ischemia reperfusion (I/R) models are valuable and clinically relevant. Knowledge on the influence of experimental design on infarct size (IS) in these models is a prerequisite for suitable models. To this end, we investigated the impact of several experimental features (occlusion and follow-up time and influence of area at risk (AAR)) on IS.

METHODS

A total of fifty-one female Landrace pigs were subjected to closed chest LAD balloon occlusion and evaluated in three substudies with varying protocols. To assess the relationship between time of occlusion and the IS, 18 pigs were subjected to 60-, 75- and 90 min of occlusion and terminated after 24 h of follow-up. Influence of prolonged follow-up on IS was studied in 18 pigs after 75 min of occlusion that were terminated at 1, 3 and 7 days. The relation between AAR and IS was studied in 28 pigs after 60 min of occlusion and 24 h of follow-up. The relation between VF, number of shocks and IS was studied in the same 28 pigs after 60 min of occlusion.

RESULTS

Increasing occlusion time resulted in an increased IS as a ratio of the AAR (IS/AAR). This ranged from 53 ± 23% after 60 min of occlusion to 88 ± 2.2% after 90 min (P = 0.01). Increasing follow-up, from 1 to 3 or 7 days after 75 min of occlusion did not effect IS/AAR. Increasing AAR led to a larger IS/AAR (r2 = 0.34, P = 0.002), earlier VF (r2 = 0.32, P = 0.027) and a higher number of shocks (r2 = 0.29, P = 0.004) in pigs subjected to 60 min of occlusion.

CONCLUSIONS

These experiments describe the association of occlusion time, follow-up duration, AAR and VF with IS in closed chest pig LAD I/R models. These results have important implications for future I/R studies in pigs and can serve as a guideline for the selection of appropriate parameters and the optimal experimental design.

Monocyte-Chemoattractant Protein-1 Levels in Human Atherosclerotic Lesions Associate With Plaque Vulnerability

[Figure: see text].

Immunomodulation of the NLRP3 Inflammasome in Atherosclerosis, Coronary Artery Disease, and Acute Myocardial Infarction

Cardiovascular disease (CVD) remains the leading cause of mortality and morbidity worldwide. Atherosclerosis is responsible for the majority of cardiovascular disorders with inflammation as one of its driving processes. The nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, responsible for the release of the pro-inflammatory cytokines, interleukin-1β (IL-1β), and interleukin-18 (IL-18), has been studied extensively and showed to play a pivotal role in the progression of atherosclerosis, coronary artery disease (CAD), and myocardial ischemia reperfusion (I/R) injury. Both the NLRP3 inflammasome and its downstream cytokines, IL-1ß and IL-18, could therefore be promising targets in cardiovascular disease. This review summarizes the role of the NLRP3 inflammasome in atherosclerosis, CAD, and myocardial I/R injury. Furthermore, the current therapeutic approaches targeting the NLRP3 inflammasome and its downstream signaling cascade in atherosclerosis, CAD, and myocardial I/R injury are discussed.

The prognostic value of automated coronary calcium derived by a deep learning approach on non-ECG gated CT images from 82Rb-PET/CT myocardial perfusion imaging

BACKGROUND

Assessment of both coronary artery calcium(CAC) scores and myocardial perfusion imaging(MPI) in patients suspected of coronary artery disease(CAD) provides incremental prognostic information. We used an automated method to determine CAC scores on low-dose attenuation correction CT(LDACT) images gathered during MPI in one single assessment. The prognostic value of this automated CAC score is unknown, we therefore investigated the association of this automated CAC scores and major adverse cardiovascular events(MACE) in a large chest-pain cohort.

METHOD

We analyzed 747 symptomatic patients referred for ⁸²RubidiumPET/CT, without a history of coronary revascularization. Ischemia was defined as a summed difference score≥2. We used a validated deep learning(DL) method to determine CAC scores. For survival analysis CAC scores were dichotomized as low(<400) and high(≥400). MACE was defined as all cause death, late revascularization (>90 days after scanning) or nonfatal myocardial infarction. Cox proportional hazard analysis were performed to identify predictors of MACE.

RESULTS

During 4 years follow-up, 115 MACEs were observed. High CAC scores showed higher cumulative event rates, irrespective of ischemia (nonischemic: 25.8% vs 11.9% and ischemic: 57.6% vs 23.4%, P-values <0.001). Multivariable cox regression revealed both high CAC scores (HR 2.19 95%CI 1.43-3.35) and ischemia (HR 2.56 95%CI 1.71-3.35) as independent predictors of MACE. Addition of automated CAC scores showed a net reclassification improvement of 0.13(0.022-0.245).

CONCLUSION

Automatically derived CAC scores determined during a single imaging session are independently associated with MACE. This validated DL method could improve risk stratification and subsequently lead to more personalized treatment in patients suspected of CAD.

Damage-Associated Molecular Patterns in Myocardial Infarction and Heart Transplantation: The Road to Translational Success

In the setting of myocardial infarction (MI), ischemia reperfusion injury (IRI) occurs due to occlusion (ischemia) and subsequent re-establishment of blood flow (reperfusion) of a coronary artery. A similar phenomenon is observed in heart transplantation (HTx) when, after cold storage, the donor heart is connected to the recipient's circulation. Although reperfusion is essential for the survival of cardiomyocytes, it paradoxically leads to additional myocardial damage in experimental MI and HTx models. Damage (or danger)-associated molecular patterns (DAMPs) are endogenous molecules released after cellular damage or stress such as myocardial IRI. DAMPs activate pattern recognition receptors (PRRs), and set in motion a complex signaling cascade resulting in the release of cytokines and a profound inflammatory reaction. This inflammatory response is thought to function as a double-edged sword. Although it enables removal of cell debris and promotes wound healing, DAMP mediated signalling can also exacerbate the inflammatory state in a disproportional matter, thereby leading to additional tissue damage. Upon MI, this leads to expansion of the infarcted area and deterioration of cardiac function in preclinical models. Eventually this culminates in adverse myocardial remodeling; a process that leads to increased myocardial fibrosis, gradual further loss of cardiomyocytes, left ventricular dilation and heart failure. Upon HTx, DAMPs aggravate ischemic damage, which results in more pronounced reperfusion injury that impacts cardiac function and increases the occurrence of primary graft dysfunction and graft rejection via cytokine release, cardiac edema, enhanced myocardial/endothelial damage and allograft fibrosis. Therapies targeting DAMPs or PRRs have predominantly been investigated in experimental models and are potentially cardioprotective. To date, however, none of these interventions have reached the clinical arena. In this review we summarize the current evidence of involvement of DAMPs and PRRs in the inflammatory response after MI and HTx. Furthermore, we will discuss various current therapeutic approaches targeting this complex interplay and provide possible reasons why clinical translation still fails.

The TAXINOMISIS Project: A multidisciplinary approach for the development of a new risk stratification model for patients with asymptomatic carotid artery stenosis

INTRODUCTION

Asymptomatic carotid artery stenosis (ACAS) may cause future stroke and therefore patients with ACAS require best medical treatment. Patients at high risk for stroke may opt for additional revascularization (either surgery or stenting) but the future stroke risk should outweigh the risk for peri/post-operative stroke/death. Current risk stratification for patients with ACAS is largely based on outdated randomized-controlled trials that lack the integration of improved medical therapies and risk factor control. Furthermore, recent circulating and imaging biomarkers for stroke have never been included in a risk stratification model. The TAXINOMISIS Project aims to develop a new risk stratification model for cerebrovascular complications in patients with ACAS and this will be tested through a prospective observational multicentre clinical trial performed in six major European vascular surgery centres.

METHODS AND ANALYSIS

The risk stratification model will compromise clinical, circulating, plaque and imaging biomarkers. The prospective multicentre observational study will include 300 patients with 50%-99% ACAS. The primary endpoint is the three-year incidence of cerebrovascular complications. Biomarkers will be retrieved from plasma samples, brain MRI, carotid MRA and duplex ultrasound. The TAXINOMISIS Project will serve as a platform for the development of new computer tools that assess plaque progression based on radiology images and a lab-on-chip with genetic variants that could predict medication response in individual patients.

CONCLUSION

Results from the TAXINOMISIS study could potentially improve future risk stratification in patients with ACAS to assist personalized evidence-based treatment decision-making.

Extracellular Vesicles in Diagnosing Chronic Coronary Syndromes the Bumpy Road to Clinical Implementation

Coronary artery disease (CAD), comprising both acute coronary syndromes (ACS) and chronic coronary syndromes (CCS), remains one of the most important killers throughout the entire world. ACS is often quickly diagnosed by either deviation on an electrocardiogram or elevated levels of troponin, but CCS appears to be more complicated. The most used noninvasive strategies to diagnose CCS are coronary computed tomography and perfusion imaging. Although both show reasonable accuracy (80–90%), these modalities are becoming more and more subject of debate due to costs, radiation and increasing inappropriate use in low-risk patients. A reliable, blood-based biomarker is not available for CCS but would be of great clinical importance. Extracellular vesicles (EVs) are lipid-bilayer membrane vesicles containing bioactive contents e.g., proteins, lipids and nucleic acids. EVs are often referred to as the “liquid biopsy” since their contents reflect changes in the condition of the cell they originate from. Although EVs are studied extensively for their role as biomarkers in the cardiovascular field during the last decade, they are still not incorporated into clinical practice in this field. This review provides an overview on EV biomarkers in CCS and discusses the clinical and technological aspects important for successful clinical application of EVs.

Systemic Mesenchymal Stem Cell-Derived Exosomes Reduce Myocardial Infarct Size: Characterization With MRI in a Porcine Model

The observations that mesenchymal stem cells (MSCs) exert cardiac protection and repair via their secretome with the active component(s) identified as exosomes underpinned our test of the efficacy of MSC exosomes in a porcine model of myocardial infarction (MI) when administered systemically by the convenient method of intravenous (IV) bolus injection. Results show that 7 days of IV exosomes results in clear reduction (30-40%) of infarct size measured at both 7 and 28 days post-MI, despite near identical release of hs Troponin T. Together with reduced infarct size, exosome treatment reduced transmurality and lessened wall thinning in the infarct zone. Exosome treated pigs showed relative preservation of LV function with significant amelioration of falls in fractional wall thickening compared with control. However, global measures of LV function were less protected by exosome treatment. It is possible that greater preservation of global LV function may have been attenuated by increased cardiac fibrosis, as T1 values showed significant increase in the exosome pigs compared to control particularly in the infarct related segments. Taken together, these results show clear effects of IV exosomes administered over 7 days to reduce infarct size with relatively preserved cardiac function compared to control treated infarct pigs.

Extracellular Vesicle cystatin c is associated with unstable angina in troponin negative patients with acute chest pain

Background

Despite the use of high-sensitive cardiac troponin there remains a group of high-sensitive cardiac troponin negative patients with unstable angina with a non-neglectable risk for future adverse cardiovascular events, emphasising the need for additional risk stratification. Plasma extracellular vesicles are small bilayer membrane vesicles known for their potential role as biomarker source. Their role in unstable angina remains unexplored. We investigate if extracellular vesicle proteins are associated with unstable angina in patients with chest pain and low high-sensitive cardiac troponin.

Methods

The MINERVA study included patients presenting with acute chest pain but no acute coronary syndrome. We performed an exploratory retrospective case-control analysis among 269 patients. Cases were defined as patients with low high-sensitive cardiac troponin and proven ischemia. Patients without ischemia were selected as controls. Blood samples were fractionated to analyse the EV proteins in three plasma-subfractions: TEX, HDL and LDL. Protein levels were quantified using electrochemiluminescence immunoassay.

Results

Lower levels of (adjusted) EV cystatin c in the TEX subfraction were associated with having unstable angina (OR 0.93 95% CI 0.88–0.99).

Conclusion

In patients with acute chest pain but low high-sensitive cardiac troponin, lower levels of plasma extracellular vesicle cystatin c are associated with having unstable angina. This finding is hypothesis generating only considering the small sample size and needs to be confirmed in larger cohort studies, but still identifies extracellular vesicle proteins as source for additional risk stratification.

The age- and sex-specific composition of atherosclerotic plaques in vascular surgery patients

BACKGROUND AND AIMS

The sex- and age-related differences in the composition of iliofemoral atherosclerotic plaques are largely unknown. Therefore, the aim of the current study is to gain insight into plaque composition across strata of age and sex in a large cohort of vascular surgery patients.

METHODS

Peripheral atherosclerotic plaques of patients who underwent iliofemoral endarterectomy (n = 790) were harvested between 2002 and 2014. The plaques were semi-quantitatively analyzed for the presence of lipid cores, calcifications, plaque hemorrhages (PH), collagen, macrophage and smooth muscle cell (SMC) content, and quantitatively for microvessel density. Patients were stratified by age tertiles and sex.

RESULTS

Ageing was independently associated with rupture-prone iliofemoral plaque characteristics, such as higher prevalence of plaque calcifications (OR 1.52 (95%CI:1.03-2.24) p = 0.035) and PH (OR 1.46 (95%CI:1.01-2.09) p = 0.042), and lower prevalence of collagen (OR 0.52 (95%CI:0.31-0.86) p = 0.012) and SMCs (OR 0.59 (95%CI:0.39-0.90) p = 0.015). Sex-stratified data showed that men had a higher prevalence of lipid cores (OR 1.62 (95%CI:1.06-2.45) p = 0.025) and PH (OR 1.62 (95%CI:1.16-2.54) p = 0.004) compared to women. These sex-differences attenuated with increasing age, with women showing an age-related increase in calcifications (p = 0.002), PH (p = 0.015) and decrease in macrophages (p = 0.005). In contrast, men only showed a decrease in collagen (p = 0.043).

CONCLUSIONS

Atherosclerotic iliofemoral plaques derived from men display more rupture-prone characteristics compared to women. Yet, this difference is attenuated with an increase in age, with older women having more rupture-prone characteristics compared to younger women.

Plasma extracellular vesicle proteins are associated with stress-induced myocardial ischemia in women presenting with chest pain

Diagnosing stable ischemic heart disease (IHD) is challenging, especially in females. Currently, no blood test is available. Plasma extracellular vesicles (EV) are emerging as potential biomarker source. We therefore aimed to identify stress induced ischemia due to stable IHD with plasma extracellular vesicle protein levels in chest pain patients. We analyzed 450 patients suspected for stable IHD who were referred for ⁸²Rb PET/CT in the outpatient clinic. Blood samples were collected before PET/CT and plasma EVs were isolated in 3 plasma subfractions named: TEX, HDL, LDL. In total 6 proteins were quantified in each of these subfractions using immuno-bead assays. CD14 and CystatinC protein levels were independent significant predictors of stress-induced ischemia in the LDL and the HDL subfraction and SerpinC1 and SerpinG1 protein levels in the HDL fraction. Subgroup-analysis on sex revealed that these associations were completely attributed to the associations in women. None of the significant EV proteins remained significant in men. Plasma EV proteins levels are associated with the presence of stable IHD in females presenting with chest pain. This finding, if confirmed in larger cohort studies could be a crucial step in improving diagnostic assessment of women with suspected IHD.

Extracellular vesicle Cystatin C and CD14 are associated with both renal dysfunction and heart failure

AIMS

Extracellular vesicles (EVs) are small double-membrane plasma vesicles that play key roles in cellular crosstalk and mechanisms such as inflammation. The role of EVs in combined organ failure such as cardiorenal syndrome has not been investigated. The aim of this study is to identify EV proteins that are associated with renal dysfunction, heart failure, and their combination in dyspnoeic patients.

METHODS AND RESULTS

Blood samples were prospectively collected in 404 patients presenting with breathlessness at the emergency department at National University Hospital, Singapore. Renal dysfunction was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m² . The presence of heart failure was independently adjudicated by two clinicians on the basis of the criteria of the European Society of Cardiology guidelines. Protein levels of SerpinG1, SerpinF2, Cystatin C, and CD14 were measured with a quantitative immune assay within three EV sub-fractions and in plasma and were tested for their associations with renal dysfunction, heart failure, and the concurrence of both conditions using multinomial regression analysis, thereby correcting for confounders such as age, gender, ethnicity, and co-morbidities. Renal dysfunction was found in 92 patients (23%), while heart failure was present in 141 (35%). In total, 58 patients (14%) were diagnosed with both renal dysfunction and heart failure. Regression analysis showed that Cystatin C was associated with renal dysfunction, heart failure, and their combination in all three EV sub-fractions and in plasma. CD14 was associated with both renal dysfunction and the combined renal dysfunction and heart failure in all EV sub-fractions, and with presence of heart failure in the high density lipoprotein sub-fraction. SerpinG1 and SerpinF2 were associated with heart failure in, respectively, two and one out of three EV sub-fractions and in plasma, but not with renal dysfunction.

CONCLUSIONS

We provide the first data showing that Cystatin C and CD14 in circulating EVs are associated with both renal dysfunction and heart failure in patients presenting with acute dyspnoea. This suggests that EV proteins may be involved in the combined organ failure of the cardiorenal syndrome and may represent possible targets for prevention or treatment.

Toll-like receptor 7 deficiency promotes survival and reduces adverse left ventricular remodelling after myocardial infarction

AIMS

The Toll-like receptor 7 (TLR7) is an intracellular innate immune receptor activated by nucleic acids shed from dying cells leading to activation of the innate immune system. Since innate immune system activation is involved in the response to myocardial infarction (MI), this study aims to identify if TLR7 is involved in post-MI ischaemic injury and adverse remodelling after MI.

METHODS AND RESULTS

TLR7 involvement in MI was investigated in human tissue from patients with ischaemic heart failure, as well as in a mouse model of permanent left anterior descending artery occlusion in C57BL/6J wild type and TLR7 deficient (TLR7-/-) mice. TLR7 expression was up-regulated in human and mouse ischaemic myocardium after MI. Compared to wild type mice, TLR7-/- mice had less acute cardiac rupture associated with blunted activation of matrix metalloproteinase 2, increased expression of tissue inhibitor of metalloproteinase 1, recruitment of more myofibroblasts, and the formation of a myocardial scar with higher collagen fibre density. Furthermore, inflammatory cell influx and inflammatory cytokine expression post-MI were reduced in the TLR7-/- heart. During a 28-day follow-up after MI, TLR7 deficiency resulted in less chronic adverse left ventricular remodelling and better cardiac function. Bone marrow (BM) transplantation experiments showed that TLR7 deficiency in BM-derived cells preserved cardiac function after MI.

CONCLUSIONS

In acute MI, TLR7 mediates the response to acute cardiac injury and chronic remodelling probably via modulation of post-MI scar formation and BM-derived inflammatory infiltration of the myocardium.

Family history and polygenic risk of cardiovascular disease: Independent factors associated with secondary cardiovascular events in patients undergoing carotid endarterectomy

BACKGROUND AND AIMS

Family history (FHx) of cardiovascular disease (CVD) is a risk factor for CVD and a proxy for cardiovascular heritability. Polygenic risk scores (PRS) summarizing >1 million variants for coronary artery disease (CAD) are associated with incident and recurrent CAD events. However, little is known about the influence of FHx or PRS on secondary cardiovascular events (sCVE) in patients undergoing carotid endarterectomy (CEA).

METHODS

We included 1788 CEA patients from the Athero-Express Biobank. A weighted PRS for CAD including 1.7 million variants was calculated (MetaGRS). The composite endpoint of sCVE during three years of follow-up included coronary, cerebrovascular and peripheral events and cardiovascular death. We assessed the impact of FHx and MetaGRS on sCVE and carotid plaque composition.

RESULTS

Positive FHx was associated with a higher 3-year risk of sCVE independent of cardiovascular risk factors and MetaGRS (adjusted HR 1.40, 95%CI 1.07-1.82, p = 0.013). Patients in the highest MetaGRS quintile had a higher 3-year risk of sCVE compared to the rest of the cohort independent of cardiovascular risk factors including FHx (adjusted HR 1.35, 95%CI 1.01-1.79, p = 0.043), and their atherosclerotic plaques contained more fat (adjusted OR 1.59, 95%CI, 1.11-2.29, p = 0.013) and more macrophages (OR 1.49, 95%CI 1.12-1.99, p = 0.006).

CONCLUSIONS

In CEA patients, both positive FHx and higher MetaGRS were independently associated with increased risk of sCVE. Moreover, higher MetaGRS was associated with vulnerable plaque characteristics. Future studies should unravel underlying mechanisms and focus on the added value of PRS and FHx in individual risk prediction for sCVE.

In Vivo Generation of Post-infarct Human Cardiac Muscle by Laminin-Promoted Cardiovascular Progenitors

Regeneration of injured human heart muscle is limited and an unmet clinical need. There are no methods for the reproducible generation of clinical-quality stem cell-derived cardiovascular progenitors (CVPs). We identified laminin-221 (LN-221) as the most likely expressed cardiac laminin. We produced it as human recombinant protein and showed that LN-221 promotes differentiation of pluripotent human embryonic stem cells (hESCs) toward cardiomyocyte lineage and downregulates pluripotency and teratoma-associated genes. We developed a chemically defined, xeno-free laminin-based differentiation protocol to generate CVPs. We show high reproducibility of the differentiation protocol using time-course bulk RNA sequencing developed from different hESC lines. Single-cell RNA sequencing of CVPs derived from hESC lines supported reproducibility and identified three main progenitor subpopulations. These CVPs were transplanted into myocardial infarction mice, where heart function was measured by echocardiogram and human heart muscle bundle formation was identified histologically. This method may provide clinical-quality cells for use in regenerative cardiology.

Cerebral Small Vessel Disease in Standard Pre-operative Imaging Reports Is Independently Associated with Increased Risk of Cardiovascular Death Following Carotid Endarterectomy

OBJECTIVE

Cerebral white matter lesions (WMLs) and lacunar infarcts are surrogates of cerebral small vessel disease (SVD). WML severity as determined by trained radiologists predicts post-operative stroke or death in patients undergoing carotid endarterectomy (CEA). It is unknown whether routine pre-operative brain imaging reports as part of standard clinical practice also predict short and long term risk of stroke and death after CEA.

METHODS

Consecutive patients from the Athero-Express biobank study that underwent CEA for symptomatic high degree stenosis between March 2002 and November 2014 were included. Pre-operative brain imaging (computed tomography [CT] or magnetic resonance imaging [MRI]) reports were reviewed for reporting of SVD, defined as WMLs or any lacunar infarcts. The primary outcome was defined as any stroke or any cardiovascular death over three year follow up. The secondary outcome was defined as the 30 day peri-operative risk of stroke or cardiovascular death.

RESULTS

A total of 1038 patients were included (34% women), of whom 659 (63.5%) had CT images and 379 (36.5%) MRI images available. Of all patients, 697 (67%) had SVD reported by radiologists. Patients with SVD had a higher three year risk of cardiovascular death than those without (6.5% vs. 2.1%, adjusted HR 2.52 [95% CI 1.12-5.67]; p = .026) but no association was observed for the three year risk of stroke (9.0% vs. 6.7%, for patients with SVD vs. those without, adjusted HR 1.24 [95% CI 0.76-2.02]; p = .395). No differences in 30 day peri-operative risk were observed for stroke (4.4% vs. 2.9%, for patients with vs. those without SVD; adjusted HR 1.49 [95% CI 0.73-3.05]; p = .28), and for the combined stroke/cardiovascular death risk (4.4% vs. 3.5%, adjusted HR 1.20 [95% CI 0.61-2.35]; p = .59).

CONCLUSION

Presence of SVD in pre-operative brain imaging reports can serve as a predictor for the three year risk of cardiovascular death in symptomatic patients undergoing CEA but does not predict peri-operative or long term risk of stroke.

Co-prevalence of extracranial carotid aneurysms differs between European intracranial aneurysm cohorts

Background and purpose

Previously, we showed that co-prevalence of extracranial carotid artery aneurysms (ECAAs) in patients with intracranial aneurysms (IAs) was 2% in a Dutch cohort. In order to obtain more precise estimates and discover potential predictors of ECAA co-prevalence in the European population, we retrospectively compared differences and similarities of our Dutch cohort with a Finnish cohort using protocolled imaging of the cerebrovascular tree.

Methods

IA patients within the prospective database of the Kuopio University Hospital were eligible for this study (n = 1,118). Image analysis and hospital chart review were conducted.

Results

In total, 458 patients with complete carotid imaging conform protocol were analyzed. Twenty-four ECAAs in 21 patients were identified (4.6%, 95% CI 2.9–6.9), a higher co-prevalence than in the Dutch cohort (1.9%; 95% CI 1.0–3.3), prevalence odds ratio (POR) 2.45 (95% CI 1.19–5.03). In the Finnish cohort, 25% of all ECAAs were located around the carotid bifurcation, others in the internal carotid artery distally from the bifurcation. Independent predictors for ECAA co-prevalence were origin of country (POR 2.41, 95% CI 1.15–5.06) and male gender (POR 2.25, 95% CI 1.09–4.64).

Conclusion

The co-prevalence of ECAA in IA patients was twice as high in the Finnish compared to the Dutch IA cohort, with origin of country and male gender as independent predictors. Twenty-five percent of ECAAs would be missed, if the carotid bifurcation was not imaged. Therefore, we propose to always include imaging of the carotid bifurcation as the gold standard technique to identify ECAA in IA patients.

Polygenic Susceptibility of Aortic Aneurysms Associates to the Diameter of the Aneurysm Sac: the Aneurysm-Express Biobank Cohort

Recent genome-wide association studies (GWAS) have discovered ten genetic risk variants for abdominal aortic aneurysms (AAA). To what extent these genetic variants contribute to the pathology of aneurysms is yet unknown. The present study aims to investigate whether genetic risk variants are associated with three clinical features: diameter of aneurysm sac, type of artery and aneurysm related-symptoms in aortic and peripheral aneurysm patients. Aneurysm tissue of 415 patients included in the Aneurysm-Express biobank was used. A best-fit polygenic risk score (PRS) based on previous GWAS effect estimates was modeled for each clinical phenotype. The best-fit PRS (including 272 variants at P_T = 0.01015) showed a significant correlation with aneurysm diameter (R² = 0.019, p = 0.001). No polygenic association was found with clinical symptoms or artery type. In addition, the ten genome-wide significant risk variants for AAA were tested individually, but no associations were observed with any of the clinical phenotypes. All models were corrected for confounders and data was normalized. In conclusion, a weighted PRS of AAA susceptibility explained 1.9% of the phenotypic variation (p = 0.001) in diameter in aneurysm patients. Given our limited sample size, future biobank collaborations need to confirm a potential causal role of susceptibility variants on aneurysmal disease initiation and progression.

A porcine model of heart failure with preserved ejection fraction: magnetic resonance imaging and metabolic energetics

AIMS

A significant proportion of heart failure (HF) patients have HF preserved ejection fraction (HFpEF). The lack of effective treatments for HFpEF remains a critical unmet need. A key obstacle to therapeutic innovation in HFpEF is the paucity of pre-clinical models. Although several large animal models have been reported, few demonstrate progression to decompensated HF. We have established a model of HFpEF by enhancing a porcine model of progressive left ventricular (LV) pressure overload and characterized HF in this model including advanced cardiometabolic imaging using cardiac magnetic resonance imaging and hyperpolarized carbon-13 magnetic resonance spectroscopy.

METHODS AND RESULTS

Pigs underwent progressive LV pressure overload by means of an inflatable aortic cuff. Pigs developed LV hypertrophy (50% increase in wall thickness, P < 0.001, and two-fold increase in mass compared to sham control, P < 0.001) with no evidence of LV dilatation but a significant increase in left atrial volume (P = 0.013). Cardiac magnetic resonance imaging demonstrated T1 modified Look-Locker inversion recovery values increased in 16/17 segments compared to sham pigs (P < 0.05-P < 0.001) indicating global ventricular fibrosis. Mean LV end-diastolic (P = 0.047) and pulmonary capillary wedge pressures (P = 0.008) were elevated compared with sham control. One-third of the pigs demonstrated clinical signs of frank decompensated HF, and mean plasma BNP concentrations were raised compared with sham control (P = 0.008). Cardiometabolic imaging with hyperpolarized carbon-13 magnetic resonance spectroscopy agreed with known metabolic changes in the failing heart with a switch from fatty acid towards glucose substrate utilization.

CONCLUSIONS

Progressive aortic constriction in growing pigs induces significant LV hypertrophy with cardiac fibrosis associated with left atrial dilation, raised filling pressures, and an ability to transition to overt HF with raised BNP without reduction in LVEF. This model replicates many aspects of clinical HFpEF with a predominant background of hypertension and can be used to advance understanding of underlying pathology and for necessary pre-clinical testing of novel candidate therapies.

Automated calcium scores collected during myocardial perfusion imaging improve identification of obstructive coronary artery disease

Background

Myocardial perfusion imaging (MPI) is an accurate noninvasive test for patients with suspected obstructive coronary artery disease (CAD) and coronary artery calcium (CAC) score is known to be a powerful predictor of cardiovascular events. Collection of CAC scores simultaneously with MPI is unexplored.

Aim

We aimed to investigate whether automatically derived CAC scores during myocardial perfusion imaging would further improve the diagnostic accuracy of MPI to detect obstructive CAD.

Methods

We analyzed 150 consecutive patients without a history of coronary revascularization with suspected obstructive CAD who were referred for 82Rb PET/CT and available coronary angiographic data. Myocardial perfusion was evaluated both semi quantitatively as well as quantitatively according to the European guidelines. CAC scores were automatically derived from the low-dose attenuation correction CT scans using previously developed software based on deep learning. Obstructive CAD was defined as stenosis >70% (or >50% in the left main coronary artery) and/or fractional flow reserve (FFR) ≤0.80.

Results

In total 58% of patients had obstructive CAD of which seventy-four percent were male. Addition of CAC scores to MPI and clinical predictors significantly improved the diagnostic accuracy of MPI to detect obstructive CAD. The area under the curve (AUC) increased from 0.87 to 0.91 (p: 0.025). Sensitivity and specificity analysis showed an incremental decrease in false negative tests with our MPI + CAC approach (n = 14 to n = 4), as a consequence an increase in false positive tests was seen (n = 11 to n = 28).

Conclusion

CAC scores collected simultaneously with MPI improve the detection of obstructive coronary artery disease in patients without a history of coronary revascularization.