Delayed hyperenhancement obtained by non-contrast computed tomography following coronary angiography in patients of extracorporeal cardiopulmonary resuscitation

Background/Introduction

Extracorporeal cardiopulmonary resuscitation (ECPR) has been reported to improve survival and neurologic outcome as compared to conventional CPR in refractory cardiac arrest. Although prognostic factors of these patients have been reported, predicting of outcome is difficult in real world. Recently, early evaluation of myocardial viability in acute myocardial infarction by non-contrast computed tomography (CT) post coronary angiography (CAG) has been reported. And myocardial contrast delayed enhancement obtained by this method related to higher risk of cardiac events. However, few studies have reported delayed enhancement on left ventricular wall findings in non-contrast CT after CAG in terms of patients performed ECPR.

Purpose

To investigate the impact of delayed hyperenhancement obtained by non-contrast CT following CAG in patients performed ECPR.

Methods

We investigated 79 patients treated by ECPR for refractory cardiac arrest regardless of whether in-hospital or out-hospital in our institute from Apr 2009 to Feb 2018. Thirty-two in these patients received non-contrast CT following CAG with ECPR were enrolled. All ECPR cases underwent VA-ECMO in the catheter laboratory using percutaneous procedure while maintaining conventional CPR. Non-ECG-gated and non-contrast CT was performed using a 64-row multidetector CT scanner.

Results

Survival rate was 18.8% in this cohort. There was no significant difference between survive and in-hospital death group in terms of patient characteristics, clinical time courses, initial blood samples and procedure characteristics. Only delayed hyperenhancement showed significant difference between 2 groups (p=0.04). All delayed hyperenhancements were detected in only in-hospital death group. Delayed hyperenhancement was detected in 12 cases (37.5%). Initial shockable rhythm was less common in cases with delayed hyperenhancement. Cardiac death tended to be more frequent in patients with delayed hyperenhancement. The major causes of death were bleeding (41.7%) and heart failure (33%).

Conclusion(s)

Delayed hyperenhancement in patients treated ECPR was strong predictor of in-hospital death.

Image of delayed hyperenhancement

Funding Acknowledgement

Type of funding source: None

Long-term serial changes of cardiac sympathetic nerve dysfunction in acute decompensated heart failure patients with reduced, mid-range and preserved left ventricular ejection fraction

Background

Cardiac sympathetic nerve dysfunction, which is assessed by I-123 metaiodobenzylguanidine (MIBG) imaging, is associated with the poor outcomes in patients with chronic heart failure (CHF). Serial evaluation of cardiac MIBG imaging was shown to be useful for predicting adverse outcome in CHF. However, there was no information available on long-term serial changes of cardiac sympathetic nerve dysfunction after discharge of acute decompensated heart failure (ADHF) hospitalization.

Purpose

We aimed to clarify the serial change of cardiac MIBG imaging parameter in long-term after discharge of heart failure hospitalization, especially relating to HFrEF (LVEF<40%), HFmrEF (40%≤LVEF<50%) and HFpEF (LVEF≥50%).

Methods

We studied 112 patients (HFrEF; n=44, HFmrEF; n=23 and HFpEF; n=45) who were admitted for ADHF, discharged with survival and without heart failure hospitalization during follow-up period. All patients underwent cardiac MIBG imaging at the timing of discharge, in 6–12 months and in 18–24 months after discharge. The cardiac MIBG heart to mediastinum ratio (H/M) was calculated on the early image and the delayed image (late H/M). The cardiac MIBG washout rate (WR) was calculated from the early and delayed planar images after taking radioactive decay of I-123 into consideration.

Results

In HFrEF patients, late H/M was significantly improved from discharge to 6–12 months data (1.60±0.24 vs 1.75±0.31, p<0.0001). Late H/M of HFmrEF patients was also significantly improved from discharge to 18–24 months data (1.71±0.27 vs 1.84±0.29 p=0.043). On the other hand, late H/M of HFpEF patients was not significantly changed. As for WR, WR in HFrEF and HFmrEF patients was significantly improved from discharge to 18–24 months data, although WR of HFpEF was not significantly changed.

Conclusion

The improvement in cardiac sympathetic nerve dysfunction was observed in patients with HFrEF and HFmrEF, not in HFpEF, after the discharge of acute heart failure hospitalization.

Funding Acknowledgement

Type of funding source: None

Long-term prognostic value of the combination of malnutrition and pulmonary-systemic pressure ratio in patients admitted with acute decompensated heart failure

Background

Malnutrition is associated with increased mortality risk in patients (pts) with acute decompensated heart failure (ADHF). On the other hand, concomitant presence of pulmonary hypertension in heart failure is associated with increased adverse events and may be related to interventricular uncoupling and impaired cardiac efficiency. It has recently been shown that an increased mean pulmonary artery pressure to mean systemic arterial pressure ratio (MPS ratio), a marker of interventricular coupling and efficiency, is associated with worse clinical outcomes in patients with advanced heart failure. However, there is no information available on the long-term prognostic value of the combination of malnutrition and MPS ratio in pts admitted for ADHF.

Methods and results

We studied 248 pts admitted for ADHF, who underwent right heart catheterization at the admission and were discharged with survival. Malnutrition was assessed by geriatric nutritional risk index (GNRI), prognostic nutritional index (PNI) and controlling nutritional status score (CONUT). During a mean follow-up period of 5.2±4.4 yrs, 62 pts had cardiovascular death (CVD). MPS ratio was significantly greater in pts with than without CVD (0.408±0.114 vs 0.347±0.102, p=0.0001). GNRI and PNI were significantly lower, CONUT was significantly greater in pts with than without CVD. At multivariate Cox regression analysis, GNRI and MPS ratio were significantly associated with CVD, independently of prior heart failure hospitalization, eGFR, and serum sodium level and anemia, although PNI and CONUT showed the association with CVD at unvariate analysis. Pts with malnutrition (GNRI≤median value=96.5) and greater MPS ratio (≥median value=0.346) had a significantly higher CVD risk than those with either and none of them (51% vs 20% vs 12%, p<0.0001, respectively).

Conclusions

The combination of malnutrition and MPS ratio might be useful for stratifying pts at risk for CVD in patients with ADHF.

Funding Acknowledgement

Type of funding source: None

Gut microbiome alterations in type 1 autoimmune pancreatitis after induction of remission by prednisolone

Although increasing evidence demonstrates the association between intestinal dysbiosis and pancreatic diseases such as chronic pancreatitis and pancreatic cancer, it remains largely unknown whether intestinal dysbiosis is involved in the immunopathogenesis of autoimmune pancreatitis (AIP). Recently, we found that intestinal dysbiosis mediates experimental AIP via the activation of plasmacytoid dendritic cells (pDCs), which can produce interferon (IFN)-α and interleukin (IL)-33. However, candidate intestinal bacteria, which promote the development of AIP, have not been identified. Fecal samples were obtained from type 1 AIP patients before and after prednisolone (PSL) treatment and subjected to 16S ribosomal RNA sequencing to evaluate the composition of intestinal bacteria. Induction of remission by PSL was associated with the complete disappearance of Klebsiella species from feces in two of the three analyzed patients with type 1 AIP. To assess the pathogenicity of Klebsiella species, mild experimental AIP was induced in MRL/MpJ mice by repeated injections of 10 μg of polyinosinic-polycytidylic acid [poly(I:C)], in combination with oral administration of heat-killed Klebsiella pneumoniae. The AIP pathology score was significantly higher in MRL/MpJ mice that received both oral administration of heat-killed K. pneumoniae and intraperitoneal injections of poly(I:C) than in those administered either agent alone. Pancreatic accumulation of pDCs capable of producing large amounts of IFN-α and IL-33 was also significantly higher in mice that received both treatments. These data suggest that intestinal colonization by K. pneumoniae may play an intensifying role in the development of type 1 AIP.

Case studies of SARS-CoV-2 treated with favipiravir among patients in critical or severe condition

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak is rising globally. However, clinically effective antiviral treatments are not established. Favipiravir may prevent pneumonia and acute respiratory distress syndrome aggravation. We describe SARS-CoV-2-positive patients, two of whom were in a critical condition and one of whom was in a severe condition, who were administered favipiravir for their deteriorating conditions and cured.

Weaker prepulse exerts stronger suppression of a change-detecting neural circuit

Change-N1 peaking 90-180 ms after changes in a sound feature of a continuous sound is clearly attenuated by a preceding change stimulus (called a "prepulse"). Here, we investigated the effects of a preceding decrease in sound pressure on the degree of inhibition of the subsequent Change-N1 amplitude. Using 100-Hz click train sounds, we obtained Change-N1s from 11 healthy volunteers. The two types of test stimuli were an abrupt 10-dB increase from the baseline (70 dB) and the insertion of a 0.45-ms inter-aural time difference in the middle of the sound. Three consecutive clicks at 30, 40, and 50 ms before the change onset that was used as a prepulse were weaker than the background by 5 or 10 dB. The Change-N1 elicited by the two test stimuli was attenuated more strongly by the weaker prepulse, which was not congruent with the theory that the inhibition of the subsequent sensory/sensory-motor processing depends on the sound pressure level of a prepulse. These results suggest that a change in any type of sound feature elicits a change-related response that is inhibited by any type of preceding change stimulus, which reflects auto-inhibition of the change-responding circuit.

Phylogenetic diversity in fim and mfa gene clusters between Porphyromonas gingivalis and Porphyromonas gulae, as a potential cause of host specificity

Background

Periodontopathic bacteria Porphyromonas gingivalis in humans and Porphyromonas gulae in animals are phylogenetically close and commonly have FimA and Mfa1 fimbriae. However, little is known about how fimA and mfa1 are phylogenetically different between P. gingivalis and P. gulae. Here, we examined phylogenetic diversity in their fim and mfa gene clusters.

Methods

Twenty P. gulae strains were isolated from the periodontal pocket of 20 dogs. For their genomic information, along with 64 P. gingivalis and 11 P. gulae genomes, phylogenetic relationship between the genotypes of fimA and mfa1 was examined. Variability of amino acid sequences was examined in the three-dimensional structure of FimA. The distance between strains was calculated for fim and mfa genes.

Results

Some fimA genotypes in P. gulae were close to particular types in P. gingivalis. Two types of mfa1 were classified as 70-kDa and 53-kDa protein-coding mfa1. The variable amino acid positions were primarily at the outer part of FimA. The genes encoding the structural proteins and the main component were similarly distant from the reference strain in P. gingivalis, but not in P. gulae.

Conclusions

The differences in the gene clusters between P. gingivalis and P. gulae may result in their host specificity.

Vertical and horizontal distributions of 137Cs on paved surfaces affected by the Fukushima Dai-ichi Nuclear Power Plant accident

Vertical and horizontal distributions are fundamental for sampling and in-situ gamma spectrum measurement strategies. The distributions of ¹³⁷Cs were investigated for paved surfaces affected by the Fukusima Dai-ichi Nuclear Power Plant accident. Additionally, the effects of the distributions on the measurement uncertainties of in-situ spectrometry were evaluated. Relaxation mass depth, representing the depth profile of ¹³⁷Cs, was estimated to be less than 0.23 g cm^-2. Variation in the relaxation mass depth, of 0.1-0.23 g cm^-2, led to a minor error (less than 5%) in the spectral analysis of the¹³⁷Cs inventory (activity per unit area, kBq m^-2). The ¹³⁷Cs inventory, within a 20 × 20 m square of 400 cells each measuring 1 m², showed an uneven distribution with large variation; coefficient of variation ranged from 54 to 136% of geometric average inventory of 424 kBq m^-2. Increasing the grid size decreased ¹³⁷Cs inventory variation among cells, revealing the relationship between instrument field of view and the spatial uncertainty of the results of in-situ gamma spectrometry.

Combined Atomic Force Microscope and Volumetric Light Sheet System for Correlative Force and Fluorescence Mechanobiology Studies

The central goals of mechanobiology are to understand how cells generate force and how they respond to environmental mechanical stimuli. A full picture of these processes requires high-resolution, volumetric imaging with time-correlated force measurements. Here we present an instrument that combines an open-top, single-objective light sheet fluorescence microscope with an atomic force microscope (AFM), providing simultaneous volumetric imaging with high spatiotemporal resolution and high dynamic range force capability (10 pN - 100 nN). With this system we have captured lysosome trafficking, vimentin nuclear caging, and actin dynamics on the order of one second per single-cell volume. To showcase the unique advantages of combining Line Bessel light sheet imaging with AFM, we measured the forces exerted by a macrophage during FcɣR-mediated phagocytosis while performing both sequential two-color, fixed plane and volumetric imaging of F-actin. This unique instrument allows for a myriad of novel studies investigating the coupling of cellular dynamics and mechanical forces.

Usefulness of Contrast-Enhanced 3D-FLAIR MR Imaging for Differentiating Rathke Cleft Cyst from Cystic Craniopharyngioma

BACKGROUND AND PURPOSE

Because it can be difficult to discriminate between a Rathke cleft cyst and cystic craniopharyngioma by conventional MR imaging alone, we investigated whether contrast-enhanced 3D T2-FLAIR MR imaging at 3T helps to distinguish a Rathke cleft cyst from a cystic craniopharyngioma.

MATERIALS AND METHODS

We evaluated pre- and postcontrast T1-weighted and 3D T2-FLAIR images of 17 patients with pathologically confirmed Rathke cleft cyst (n = 10) or cystic craniopharyngioma (n = 7). All underwent 3T MR imaging studies before surgery. Two neuroradiologists independently recorded the enhancement grade of the lesion wall as grade 2 (most of the wall enhanced), grade 1 (some of the wall enhanced), and grade 0 (none of the wall enhanced). One neuroradiologist performed a blinded reading study of conventional MR images with/without 3D T2-FLAIR images. Interobserver agreement was determined by calculating the κ coefficient. Statistical analyses, including receiver operating characteristic curve analysis were performed.

RESULTS

Interobserver agreement for postcontrast T1WI and 3D T2-FLAIR images was excellent (κ = 0.824 and κ = 0.867, respectively). Although the difference in the mean enhancement grade of Rathke cleft cysts and cystic craniopharyngiomas was not significant on postcontrast T1WIs, it was significant on postcontrast 3D T2-FLAIR images (P = .0011). The area under the receiver operating characteristic curve of the conventional MR alone and conventional MR with 3D T2-FLAIR readings was 0.879 and 1.0, respectively, though there was no significant difference in the area under the curve between the 2 readings.

CONCLUSIONS

Contrast-enhanced 3D T2-FLAIR imaging at 3T helps to distinguish a Rathke cleft cyst from cystic craniopharyngioma.

Evolution of the neural sex-determination system in insects: does fruitless homologue regulate neural sexual dimorphism in basal insects?

In the brain of holometabolous insects such as the fruit fly Drosophila melanogaster, the fruitless gene produces sex-specific gene products under the control of the sex-specific splicing cascade and contributes to the formation of the sexually dimorphic circuits. Similar sex-specific gene products of fruitless homologues have been identified in other holometabolous insects such as mosquitoes and a parasitic wasp, suggesting the fruitless-dependent neural sex-determination system is widely conserved amongst holometabolous insects. However, it remains obscure whether the fruitless-dependent neural sex-determination system is present in basal hemimetabolous insects. To address this issue, identification, characterization, and expression analyses of the fruitless homologue were conducted in the two-spotted cricket, Gryllus bimaculatus, as a model hemimetabolous insect. The Gryllus fruitless gene encodes multiple isoforms with a unique zinc finger domain, and does not encode a sex-specific gene product. The Gryllus Fruitless protein is broadly expressed in the neurones and glial cells in the brain, and there was no prominent sex-related difference in the expression levels of Gryllus fruitless isoforms. The results suggest that the Gryllus fruitless gene is not involved in the neural sex-determination in the cricket brain.

Simultaneous measurement of p53:Mdm2 and p53:Mdm4 protein-protein interactions in whole cells using fluorescence labelled foci

In this report we describe the development of a Fluorescent Protein-Protein Interaction-visualization (FLUOPPI) to enable the simultaneous measurement of both Mdm2:p53 and Mdm4:p53 interactions in order to assess the relative efficiencies of mimetic molecules of the p53 peptide helix against both PPIs. Mdm2 and Mdm4 overexpression frequently leads to the inactivation of non-mutated p53 in human cancers, via inhibition of its transcriptional activity, enhancing its degradation by the proteasome or by preventing its nuclear import. Development of inhibitors to disrupt the binding of one or both of these protein interactions have been the subject of intensive pharmaceutical development for anti-cancer therapies. Using the bimodal FLUOPPI system we have characterised compounds that were either monospecific for Mdm2 or bispecific for both Mdm2 and Mdm4. We have also demonstrated that the FLUOPPI assay can reliably differentiate between specific and non-specific disruption of these protein complexes via accurate assessment and normalization to the cell population under measurement. We envision that this methodology will increase the efficiency of identifying compounds that are either specific against a single PPI from a closely related family of interactions or compounds that interact across multiple related PPI pairs, depending on which is more desirable.

Social relationships and functional status among Japanese elderly adults living in a suburban area

OBJECTIVES

Social relationships may help in maintaining functional status among older adults. This study examined the types of social relationships that were related to functional status among Japanese community-dwelling older adults.

STUDY DESIGN

This is a prospective cohort study.

METHODS

We used baseline data from 2008 and conducted follow-up surveys six years later. Participants included individuals older than 65 years who lived in a suburban community in Japan. The Index of Social Interaction measure was used to assess multiple elements of social relationships. Two functional status outcomes were set: (1) functional decline and (2) functional decline and mortality. A multiple logistic regression model was used to examine the association between social relationships and functional decline six years later.

RESULTS

After controlling for age, sex, family structure and disease status in 2008, poor social curiosity (odds ratio [OR] = 1.31, 95% confidence interval [CI]: 1.02-1.69) and interaction (OR = 2.57, 95% CI: 1.20-5.51) were found to be associated with functional decline. Furthermore, social curiosity (OR = 1.39, 95% CI: 1.14-1.69) and interaction (OR = 2.84, 95% CI: 1.44-5.59) were also associated with the composite outcome.

CONCLUSIONS

Social curiosity and interacting with others were significantly associated with functional status. Promotion of social interaction may be essential for preventing future need for care.

P3615The number of coronary risk factors and mortality in patients with acute myocardial infarction from Japanese nation-wide real-world database

Background

Hypertension, diabetes, dyslipidemia and smoking are so-called coronary risk factors for coronary heart disease, which were established by extensive epidemiological research. However, in Japanese patients with acute myocardial infarction (AMI), the impact of number of coronary risk factors on in-hospital morality has not been elucidated.

Methods

The Japan Acute Myocardial Infarction Registry (JAMIR) is a nationwide real-world database integrated form 10 regional registries. We examined the association between number of coronary risk factors and in-hospital mortality from this JAMIR registry.

Results

The data were obtained from total of 20462 AMI patients (mean age, 68.8±13.3 years old; 15281 men, 5181 women). Figure 1 shows the prevalence of each coronary risk factors stratified by sex and decade. The prevalence of hypertension became higher with the advanced age while the prevalence of smoking became lower with the advanced age. Prevalence of diabetes and dyslipidemia were highest in middle age. Majority (76.9%) of the patients with AMI had at least 1 of these coronary risk factors and, 23.1% had none of them. Overall, except women under 50, number of coronary risk factor was relatively less in older age (Figure 2). In-hospital mortality by sex and decades was shown in figure 3. In-hospital mortality rates were 10.7%, 10.5%, 7.2%, 5.0% and 4.5% with 0, 1, 2, 3 and 4 risk factors, respectively (Figure 4A). After adjusting age and sex, there was an inverse association between the number of coronary risk factors and in-hospital mortality (adjusted odds ratio [1.68; 95% CI, 1.20–2.35] among individuals with 0 vs. 4 risk factors, Figure 4B).

Conclusion

In the present study of Japanese patients with AMI, who received modern medical treatment, in-hospital mortality was inversely related to the number of coronary risk factors.

Acknowledgement/Funding

Grant-in-Aid for Scientific Research

P321A single factor related to left atrial pressure overload is useful for prognosis in elderly patients with heart failure with preserved ejection fraction: PURSUIT HFpEF study

Background

E/e' and the ratio of diastolic elastance (Ed)/arterial elastance (Ea) = (E/e')/(0.9 × systolic blood pressure), indices of left atrial (LA) pressure overload, are elevated in elderly women with heart failure with preserved ejection fraction (HFpEF). The severity of diastolic dysfunction is assessed by a combination of several indices of LA volume and pressure overload. However, which overload is more important as a single factor for the prognosis of these patients remains undefined.

Methods

We enrolled patients with HFpEF showing sinus rhythm (n=145; left ventricular ejection fraction >50%; men/women, 56/89; mean age, 80.5 years). Blood examination and transthoracic echocardiography were performed before discharge. All-cause mortality and admission for cardiac events were evaluated after more than 1 year (mean, 370 days).

Results

The all-cause mortality rate was 11% (16/145). There were significant differences in age (p=0.005), serum N-terminal pro-brain natriuretic peptide (NT-proBNP) level (p<0.001), LA volume index (p=0.018), E/e' (p=0.022), and Ed/Ea (p=0.016) between patients with and without all-cause mortality. When cutoff points for mortality by receiver operating characteristic curve analysis were examined, the area under the curve in LA volume index (0.564) was slightly smaller than that in age (0.734), NT-proBNP level (0.732), E/e' (0.695), and Ed/Ea (0.709). Kaplan-Meier survival analysis clearly showed that age >85 years (p<0.001), NT-proBNP level >888 pg/mL (p=0.003), E/e' >14.4 (p=0.020), and Ed/Ea >0.153 (p<0.001) were determinant factors for mortality. Cox hazard ratios were also significant in these indices (p=0.002, p=0.012, p=0.028, and p=0.001, respectively). In the case of all-cause mortality or admission for cardiac events, the results were nearly similar as those in the case of all-cause mortality. Ed/Ea exhibited a larger Cox hazard ratio for prognosis than E/e' in the multivariate analysis.

Conclusions

LA pressure overload compared to volume overload was a useful marker for prognosis in elderly patients with HFpEF. As a single index for LA pressure overload in noninvasive echocardiographic findings, Ed/Ea may be more suitable than E/e'.

5950Lymphocyte-to-monocyte ratio could predict adverse clinical outcomes in patients with heart failure with preserved ejection fraction

Background

Heart failure with preserved ejection fraction (HFpEF) is increasing with aging of the population, whereas the mechanisms of HFpEF remain poorly understood. It was reported that systemic inflammation is associated with pathophysiology of HFpEF. Lymphocyte-to-monocyte ratio (LMR) is a marker of systemic inflammation, which predicts clinical outcomes in various cancers. However, the prognostic value of LMR has not yet been elucidated in patients with HFpEF.

Purpose

The aim of this study was to investigate the impact of LMR on clinical outcomes in patients with HFpEF.

Methods and results

We prospectively analyzed 414 consecutive patients with HFpEF. Preserved EF was defined as an EF ≥50%. During a median follow-up period of 740 days, there were 111 major adverse cardiovascular events (MACE). When patients were divided into tertiles according to LMR, Kaplan-Meier analysis demonstrated that the low LMR was associated with the greatest risk for MACE. Multivariate Cox proportional hazard regression analysis showed that the low LMR was significantly associated with MACE after adjustment for confounding factors.

Conclusions

Low LMR could predict poor clinical outcomes in patients with HFpEF. LMR is a feasible marker for predicting MACE in patients with HFpEF.

129Elevated plasma xanthine oxidoreductase activity predicts cardiovascular events in patients with heart failure with preserved ejection fraction

Background

The pathophysiology of heart failure with preserved ejection fraction (HFpEF) remains poorly understood, although reactive oxygen species (ROS) is reportedly involved in underlying mechanisms. Xanthine oxidoreductase (XOR) is the rate-limiting enzyme of purine metabolism that plays an important role in producing uric acid, and also generates the ROS. However, the impact of plasma XOR activity on the clinical outcomes in patients with HFpEF remains unclear.

Purpose

The aim of this study was to assess whether plasma XOR activity predicts cardiovascular events in patients with HFpEF.

Methods and results

We measured plasma XOR activity in 257 patients with HFpEF. The patients were divided into 3 groups based on XOR activity: low XOR group (<33 pmol/h/mL, n=45), normal XOR group (33 - 120 pmol/h/mL, n=160), and high XOR group (≥120 pmol/h/mL, n=52). During a median follow-up period of 809 days, there were 74 major adverse cardiovascular events (MACEs). Kaplan-Meier analysis demonstrated that the patients with high XOR activity were at greatest risk for MACEs. A multivariate Cox proportional hazard regression analysis showed that high XOR activity was significantly associated with MACEs after adjustment for confounding factors. Furthermore, we divided the patients into 4 groups according to the presence of high XOR activity and/or hyperuricemia. Cox multivariate hazard regression analysis revealed that the patients with high XOR activity were associated with cardiovascular events in patients with HFpEF, regardless of whether hyperuricemia was present or not.

Conclusions

Elevated plasma XOR activity is significantly associated with adverse clinical outcomes in patients with HFpEF. Inhibition of XOR could be a potential therapy for HFpEF.

P1626MicroRNA-21 deteriorates left ventricular reverse remodeling by promoting cardiac fibrosis in non-ischemic cardiomyopathy

Background

Left ventricular reverse remodeling (LVRR) contributes to better outcomes in patients with non-ischemic cardiomyopathy (NICM). It is reported that LVRR is associated with progression of cardiac fibrosis. MicroRNAs (miRs) have emerged as powerful regulators of post-transcriptional gene expression. We focused on miR-21, which plays a key role in pathogenesis of fibrosis in multiple organs. The aim of this study was to clarify the effect of miR-21 on cardiac fibrosis and LVRR in patients with NICM.

Methods

We measured plasma miR-21 levels in 16 patients with NICM. LVRR was defined as increased LVEF by ≥10% and decreased LV end-diastolic diameter index by ≥10% from baseline data after optimal medication treatment at 1-year of follow-up. Further, we examined miR-21 expression and its potential role in cardiac fibrosis induced by transverse aortic constriction (TAC) in mice and angiotensin II (Ang II) stimulation in neonatal rat cardiomyocytes (NRCMs).

Results

There were 12 patients without LVRR and 4 patients with LVRR. Plasma miR-21 levels were significantly higher in patients without LVRR compared with those with LVRR. In TAC mice heart, miR-21 levels were significantly increased and programmed cell death 4 (PDCD4), a main target of miR-21, was decreased. In vitro, miR-21 levels were significantly increased and its upstream transcriptional factor, activator protein 1 (AP-1), was activated by Ang II stimulation in NRCMs. After transfection of miR-21 specific inhibitor, PDCD4 levels were upregulated. Furthermore, AP-1 activity, expression of collagen type I, and α-smooth muscle actin levels were significantly decreased after miR-21 inhibition.

Conclusions

These findings suggested that miR-21/PDCD4/AP-1 feedback loop pathway was involved in LVRR in patients with NICM by promoting cardiac fibrosis. MiR-21 can be the therapeutic target in NICM.

P3395Arrival time at hyperemia of below the ankle as a determinant factor for limb salvage: evaluation by 2 dimension perfusion angiography

Background

In patients with critical limb ischemia, it is desirable to obtain enough skin perfusion pressure (SPP) levels through revascularization. 2D-perfusion angiography is an emerging technology for the quantification of tissue perfusion consisted of 6 parameters calculated by time-density curve of digital subtraction angiography (DSA).

Purpose

We evaluated the feasibility of 2D-perfusion angiography for below the knee (BTK) endovascular therapy (EVT). We aimed to clarify which angiographical parameters of lower limb are related to SPP after EVT.

Methods

Consecutive 33 limbs (mean age 74.5 years, men 55%), which successfully underwent EVT for isolated BTK lesions, were enrolled in this study. We excluded Rutherford 6 limbs with severe gangrene or tissue loss, consequently 26 limbs were Rutherford 4 or 5 critical limb ischemia. We treated total 47 lesions, including 26 chronic total occlusive lesions. 5Fr guiding sheath was advanced to popliteal artery. DSA images were obtained by mechanical contrast infusion. We quantified indexed blood flow on below the ankle area by using 2D-perfusion angiography, and examined 6 parameters [arrival time (AT), time to peak (TTP), wash-in rate, width, area under the curve and mean transit time (MTT)] from acquired DSA. Hyperemia was induced by 20mg papaverine intra-arterial infusion through the guiding sheath.

Results

The parameters except wash-in rate were significantly shortened after hyperemia induced by intra-arterial papaverine infusion below the ankle region. Dorsal and plantar SPP were significantly correlated with hyperemic AT, hyperemic wash-in rate and AT ratio (hyperemic/rest) of lower ankle regions after EVT. However, only AT ratio was independently associated with dorsal SPP in multivariate analysis (P=0.032). A receiver operating characteristic curve showed hyperemic AT <4.5 seconds and AT ratio <0.49 predicted to obtain SPP levels >50 mmHg after EVT with the area under the curve of 0.71 (95% confidence interval, 0.52–0.90) and 0.73 (95% confidence interval, 0.55–0.90), respectively.

Representative Case of 2D-perfusion

Conclusion

Hyperemic AT <4.5 seconds and AT ratio <0.49 of lower ankle regions may be essential to obtain the sufficient levels of SPP for limb salvage after BTK intervention. 2D perfusion angiography technique at hyperemic condition is feasible and has the potential to monitor lower limb tissue perfusion through EVT and to optimize the interventional treatment.

P5639Risk stratification for mortality using electrocardiographic markers based on 24-hour holter recordings: the JANIES-SHD study

Background

Recent guidelines have stated that reduced left ventricular ejection fraction (LVEF) is the gold standard marker for identifying patients at risk for cardiac mortality. Although reduced LVEF identifies patients at an increased risk of cardiac arrest, sudden cardiac deaths (SCDs) occur considerably more often in patients with relatively preserved LVEF. Current guidelines on SCD risk stratification do not adequately cover this general population pool. Several noninvasive electrocardiographic (ECG) risk stratifiers that reflect depolarization abnormality, repolarization abnormality, and autonomic imbalance have been evaluated so far. With current therapeutic advances using new medicines or devices, an LVEF is often preserved in patients with structural heart disease (SHD). However, the usefulness of noninvasive ECG markers for risk stratification in such a patient population has not yet been elucidated.

Purpose

This study aimed to assess clinical indices and ECG markers based on 24-hour Holter ECG recordings for predicting cardiac mortality in patients with SHD who have left ventricular dysfunction (LVD) but relatively preserved LVEF.

Methods

In total, 1,829 patients were enrolled into the Japanese Multicenter Observational Prospective Study (JANIES study). In this study, we analyzed data of 719 patients (569 men, age 64±13 years) with SHD including mainly ischemic heart disease (65.8%). As ECG markers based on 24-hour Holter recordings, nonsustained ventricular tachycardia (NSVT), ventricular late potentials, and heart rate turbulence (HRT) were assessed. The primary endpoint was all-cause mortality, and the secondary endpoint was fatal arrhythmic events.

Results

During a mean follow-up of 21±11 months, all-cause mortality was eventually observed in 39 patients (5.4%). Among those patients, 32 patients (82%) suffered from cardiac causes such as heart failure and arrhythmia. Multivariate Cox regression analysis showed that after adjustment for age and LVEF, documented NSVT (hazard ratio=2.82, 95% confidence interval [CI]: 1.38–5.76, P=0.005) and abnormal HRT (hazard ratio=2.31, 95% CI: 1.15–4.65, P=0.02) were significantly associated with the primary endpoint. These two ECG markers also had significant predictive values with the secondary endpoint. The combined assessment documented NSVT and abnormal HRT improved predictive accuracy.

Conclusion

This study demonstrated that combined assessment of documented NSVT and abnormal HRT based on 24-hour Holter ECG recordings are recommended for predicting future serious events in SHD patients who have relatively preserved LVEF.

Acknowledgement/Funding

Grants-in-Aid (21590909, 24591074, and 15K09103 to T.I.) for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technol

P3355Stress-induced left ventricular dyssynchrony predicts future cardiac events in patients with known or suspected coronary artery disease

Background

Prognostic value of stress induced left ventricular (LV) dyssynchrony has not been fully understood.

The aim of this study was to evaluate the possible impact between cardiovascular events and stress induced worsening LV dyssynchrony.

Methods and results

One hundred and eighty consecutive subjects with known or suspected coronary artery disease (CAD) (142 men, mean age 68±12 years) underwent both gated myocardial single photon emission computed tomography (SPECT) with 99mTc-sestamibi or tetrofosmin according to a standard same day stress-rest protocol and coronary angiography or coronary computed tomography. The summed difference score (SDS) was calculated in every subjects. LV ejection fraction (EF) and phase Entropy at after stress and rest were determined by cardioREPO software. We determined %ΔEntropy = (stress Entropy - rest Entropy)/rest Entropy x100, as an indicator of stress-induced LV dyssynchrony. In the study population, the mean SDS was 2.7±3.9 and LVEF was 58±16%, stress and rest Entropy were 0.62±0.15 and 0.57±0.13, respectively.

%ΔEntropy was higher in patients with CAD than in those without CAD (3.3±11.5 vs. 10.2±15.0, respectively). Moreover, there was a strict correlation between the presence of CAD and %ΔEntropy, indicator of stress induced LV dyssynchrony (non-CAD vs. CAD and/or 1 vessel disease vs. multivessel disease: 4.3±12.5 vs. 8.8±15.6 vs. 12.7±14.3, respectively. p<0.05)

We examined all study subjects and they were divided into 2 groups by cut off value of the %ΔEntropy constructed with receiver operating characteristic curve (=15.4). Kaplan-Meier analysis revealed that future cardiovascular event rate was significantly higher in %ΔEntropy >15.4 group (20/57) than in %ΔEntropy <15.4 group (24/123) (Log-rank p<0.01). On the other hand, summed stress score and SDS were no significant differences between 2 groups.

However, SDS was higher in patients with future cardiovascular event than in those without cardiovascular event (4.4±5.4 vs. 2.2±3.2, respectively. p=0.001).

Conclusion

In patients with known or suspected CAD, stress-induced worsening LV dyssynchrony may predict the presence of CAD and future cardiac events.

Acknowledgement/Funding

None

P4341Sex differences in the U-shaped relationship between physical activity and cardiovascular mortality in the general population

Background

The beneficial effect of moderate physical activity on morbidity and mortality has been observed in the general population. However, sex differences in the impact of physical activity on cardiovascular mortality remain unclear. The aim of this study was to investigate the relationship between physical activity and cardiovascular mortality in the general population.

Methods

This longitudinal cohort study included 1,826 apparently healthy subjects who participated in a community-based health checkup.

Results

There were 97 deaths, including 31 cardiovascular deaths during 10-year follow-up. Subjects were divided into 4 groups based on the quartiles of physical activity (low, mild, moderate and high). There was a U-shaped relationship between physical activity and cardiovascular mortality in male subjects, but not in female subjects. Kaplan-Meier analysis demonstrated that high and low physical activity groups showed higher cardiovascular mortality compared with mild and moderate physical activity groups in male subjects. Cox proportional hazard analysis revealed that low and high physical activities were associated with cardiovascular mortality (hazard ratio 3.59 and 5.11, respectively) in male subjects. In contrast, physical activity was not associated with cardiovascular mortality in female subjects.

Conclusion

We identified a U-shaped relationship between the amount of physical activity and cardiovascular mortality in male subjects, but not in female subjects.

5945Single nucleotide polymorphisms of PAR2 gene is associated with subclinical myocardial damage in the general population

Introduction

The protease activated receptor (PAR) 2 is a G protein-coupled receptor and expressed in cardiomyocytes, vascular cells, and leukocytes. Experimental studies demonstrated that PAR2 signaling is associated with adverse cardiac remodeling, heart failure, vascular inflammation and atherosclerosis. Recently, we and others demonstrated that subclinical myocardial damage is associated with cardiovascular mortality in general population. However, the impact of single nucleotide polymorphisms (SNPs) of PAR2 gene on subclinical myocardial damage in general population is unclear.

Purpose

The aim of this study was to investigate whether SNPs of PAR2 gene is associated with subclinical myocardial damage in general population.

Methods

The present study included 2,926 apparently healthy subjects (aged ≥40) who participated in a community-based health checkup. We investigated 639 SNPs and measured serum heart-type fatty acid binding protein (H-FABP) as markers of subclinical myocardial damage.

Results

We found the association of SNPs rs616235 within a PAR2 gene with subclinical myocardial damage. The homozygous A-allele (AA), heterozygous (AG), and homozygous G-allele (GG) carriers of rs616235 were identified in 2084 (71%), 791 (27%), and 51 (2%) subjects, respectively. The prevalence rates of subclinical myocardial damage were 29% in AA carriers, 23% in AG carriers, and 18% in GG carriers. Multivariate logistic analysis showed that the homozygous (AA) of rs616235 was independently associated with subclinical myocardial damage (odds ratio: 1.330, 95% confidence interval: 1.077–1.641, P=0.0080) after adjustment for conventional cardiovascular risk factors.

Conclusions

Genetic variant of PAR2 gene was independently associated with subclinical myocardial damage in the general population.

P52714D-flow cardiac magnetic resonance analysis of left ventricular blood flow dynamics in mid-ventricular obstructive hypertrophic cardiomyopathy

Background

Mid-ventricular obstructive hypertrophic cardiomyopathy (MVO-HCM) has different blood flow dynamics from other phenotypes, but there are few detailed data on blood flow dynamics in the left ventricle.

Methods

4D-Flow MRI were performed at 1.5 T or 3 T with 9 MVO-HCM patients and 22 control patients (LVEF>50%, no wall motion abnormality). Myocardial infarction, severe valvular disease, HCM cases other than MVO were excluded. We calculated the cardiac function parameters and observed blood flow dynamics in the left ventricle using 4D-Flow MRI.

Results

LV mass was significantly higher in MVO-HCM group than in Control group (Control group; 73.3g vs MVO-HCM group; 109.5g, P=0.019). LVEF was higher in MVO-HCM group (Control group; 61.6% vs MVO-HCM group; 70.6%, P=0.026), but Stroke volume did not differ between the two groups (Control group; 68.8ml vs MVO-HCM group; 64.4ml, P=0.43).One or two vortices were observed in the left ventricle after opening the mitral valve. Two vortices were observed in 16 cases (72.7%) in the control group and 9 cases (100%) in the MVO-HCM group. Two vortices were formed on the anterior side and the posterior side. Blood flow pattern in which the vortex on the posterior side was formed to be the same size or larger than the vortex on the anterior side was observed only in the MVO-HCM group (Control group; 0% vs MVO-HCM group; 66.7%, P<0.001).

Streamline of MVO-HCM & Control

Conclusion

Characteristic blood flow patterns in the left ventricle of the MVO-HCM were revealed by using 4D-MRI. We thought that blood flow collides with the left ventricle wall due to the marked hypertrophy in the mid-ventricle, and normal vortex ring can not be formed in the MVO-HCM cases.

P2462Left atrial appendage wall velocity evaluated by transthoracic echocardiography is a feasible parameter for predicting cardiac prognosis in patients with heart failure

Background

It was reported that left atrial (LA) remodeling is occurred in patients with heart failure (HF), and increased LA volume index (LAVI) is a feasible predictor for poor prognosis of HF. It was reported that LA remodeling is associated with LA appendage (LAA) dysfunction. We previously reported that LAA wall motion velocity (LAWV) obtained by transthoracic echocardiography (TTE) can noninvasively evaluate LAA dysfunction. However, it remains to be determined whether LAWV is useful for predicting poor prognosis in patients with HF.

Purpose

We investigated whether LAA dysfunction assessed by LAWV is associated with poor prognosis in patients with HF.

Methods

We performed TTE at discharge in 217 consecutive patients who hospitalized for HF (126 males, 71±13 years) and prospectively followed them up. LAWV was measured using Doppler tissue imaging at the LAA tip from the parasternal short-axis view on TTE imaging.

Results

There were 86 patients with cardiac events including 14 cardiac deaths and 72 rehospitalizations for HF during a median follow-up period of 404 days (interquartile range 168–748 days). LAWV was significantly lower in patients with cardiac events than in those without. LAWV was significantly decreased with advancing left ventricular diastolic dysfunction grade. Kaplan-Meier analysis demonstrated that significantly higher cardiac event rate was observed in patients with low LAWV (log-rank test, P=0.004). Cox multivariate hazard analysis revealed that LAWV was an independent predictor for cardiac events after adjusting for confounding factors (hazard ratio 0.57, 95% confidence interval 0.40–0.82, P<0.05). Further, we categorized the patients into 3 groups based on the median of LAWV and left atrial volume index (LAVI), and Kaplan-Meier analysis showed that patients with both low LAWV and high LAVI had the highest rate of cardiac events among 3 groups (log-rank test, P<0.001; Figure).

Figure 1

Conclusion

LAWV may be a feasible parameter for predicting cardiac prognosis in patients with HF.

P4691Chronic blockade of toll-like receptor 9 ameliorated pulmonary arterial hypertension by reducing perivascular inflammation in rats

Background/Introduction

Perivascular inflammation plays an important role in the pathogenesis of pulmonary arterial hypertension (PAH). Recent studies have demonstrated that damaged mitochondrial DNA induces sterile inflammation by activating toll-like receptor (TLR)9 in spontaneous hypertensive rats. However, it remains unclear whether TLR9 is involved in perivascular inflammation and subsequent development of PAH.

Purpose

The purpose of the present study is to investigate whether chronic inhibition of TLR9 can ameliorate monocrotaline (MCT)-induced PAH in rats.

Methods

Male Sprague-Dawley rats were injected with MCT (60 mg/kg). First, we conducted immunohistochemistory to examine which cell types express TLR9 in lungs of normal rats and MCT-exposed rats. Second, we extracted cell-free DNA from plasma of rats and amplified genes of COX2 by real-time PCR to detect circulating cell-free mitochondrial DNA, a ligand of TLR9. Third, the administration of a selective TLR9 inhibitor (E6446, 10mg/kg/day, drinking water) or non-selective TLR9 inhibitor (chloroquine: 50mg/kg/day, ip) started three days before MCT injection and sacrificed on day 21. We assessed hemodynamic data and histopathological analysis (EVG stain for medial wall thickness (MWT) in pulmonary arteries (outer diameter: 50 ∼ 100 μm) and CD68 for macrophage accumulation around pulmonary arteries (outer diameter: <50 μm)), and measured the levels of interleukin-6 (IL-6) in lungs by real time PCR. Finally, we investigated survival rate in the reversal protocol, where we started the administration of E6446 on day 14.

Results

TLR9 was expressed dominantly in pulmonary endothelial cells and macrophages in the lungs of both normal rats and MCT-exposed rats. Compared with normal rats, MCT-exposed rats showed increased gene expression of COX2 (0.048±0.001 vs. 0.052±0.001 expressed by 1/Ct) in plasma on day 14. MCT-exposed rats also had increased right ventricular systolic pressure (RVSP: 21±1 vs. 60±2 mmHg), total pulmonary vascular resistance index (TPRI: 0.07±0.01 vs. 0.43±0.02 mmHg/min/mL/kg), MWT (0.07±0.01 vs. 0.26±0,02) and accumulation of macrophages (1.6±0.3 vs. 20.0±1.7 cells/HPF) on day 21. In the prevention protocol, either E6446 or chloroquine significantly prevented the elevations of RVSP (49±4 or 48±3 mmHg) and TPRI (0.29±0.04 or 0.27±0.03 mmHg/min/mL/kg) with reducing MWT (0.18±0.01 or 0.18±0.01) and macrophage accumulation (9.7±1.3 or 9.8±2.5 cell/HPF) on day 21. In addition, these drugs significantly reduced the levels of IL-6 mRNA compared with MCT group (4.4±1.0 or 4.8±1.4 vs. 11.9±1.0). In the reversal protocol, the treatment of E6446 had significantly increased the survival rate (50 vs. 10%).

Conclusions

TLR9 largely contributes to the development of PAH by reducing perivascular inflammation. Inhibition of TLR9 could be a novel therapeutic target for PAH.

2381Low-intensity pulsed ultrasound ameliorates DES-induced coronary adventitial inflammation and hyperconstricting responses in pigs in vivo - A novel non-invasive therapy for coronary inflammation

Background

We previously demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of coronary artery spasm, including drug-eluting stent (DES)-induced coronary hyperconstricting responses, in pigs and humans. Indeed, the coronary adventitia has recently attracted much attention as the important site for vascular inflammation. However, a direct therapeutic approach to the coronary adventitia remains to be developed. We have developed a non-invasive low-intensity pulsed ultrasound (LIPUS) therapy for angina, which exerts anti-inflammatory effects through improved coronary microcirculation.

Purpose

In this study, we aimed to examine whether our LIPUS therapy ameliorates DES-induced coronary hyperconstricting responses in pigs in vivo, and if so, what mechanisms are involved.

Methods

An everolimus-eluting stent (EES) was implanted into the left anterior descending (LAD) coronary artery in normal male pigs. They were randomly assigned to the LIPUS or the sham therapy groups. After EES implantation, in the LIPUS group, LIPUS (32 cycles, 193 mW/cm2) was applied to the heart at 3 different levels (proximal and distal stent edges and middle portion of the stent) through X-ray for 20 min at each level for every other day for 2 weeks (6 days in total) (Figs. 1A, 1B). The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after the procedure, we performed coronary angiography to examine coronary vasoconstricting responses to intracoronary serotonin in vivo. Finally, stented coronary vessels were harvested for immunohistochemistry of vasa vasorum, lymphatic vessels (LYVE-1), sympathetic nerve fibers (SNF), vascular inflammation (macrophages and IL-1β expression), Rho-kinase expression and activity as evaluated by phosphorylated myosin phosphatase target subunit-1 (pMYPT-1).

Results

Coronary vasoconstricting responses to intracoronary serotonin were significantly enhanced in the sham therapy group but were significantly suppressed in the LIPUS group at the DES edges in the LAD, whereas those responses were comparable at the non-DES implanted segments in the left circumflex (LCx) coronary arteries between the 2 groups. (Figs. 1C, 1D). Furthermore, in vivo lymph transport speed was significantly faster in the LIPUS group than in sham group (Figs. 1E–1G). Histological analysis showed that except vasa vasorum formation, the number of lymphatic vessels, adventitial inflammatory cells infiltration, Rho-kinase expression and activity were all significantly enhanced in the sham therapy group and were significantly suppressed in the LIPUS group (Figs. 1G–1K).

Figure 1

Conclusion

We were able to develop a non-invasive LIPUS therapy for coronary functional abnormalities caused by chronic adventitial inflammation in pigs in vivo, for which multiple beneficial effects appear to be involved (Fig. 1L).

P1671Subclinical persistent hemolysis may affect late renal function deterioration after HeartMateII implantation

Background

Late renal function dysfunction is an increasingly recognized complication in continuous flow left ventricular assist device (CF-LVAD) patients. Although hemolysis is prevalent in CF-LVAD patients and hemolysis may deteriorate renal function, the influence of persistent hemolysis on renal function in CF-LVAD patients remains to be investigated.

Purpose

To investigate the influence of persistent hemolysis on renal function in CF-LVAD patients, using lactate dehydrogenase (LDH) as a sensitive marker of hemolysis.

Methods

Excluding patients who died or underwent pump exchange for pump thrombosis, we retrospectively reviewed 65 consecutive adults who underwent HeartMateII implantation in our center from May 2011 to October 2017. Patient characteristics, chronotropic change of estimated glomerular filtration rate (eGFR) and LDH values weekly for 4 weeks and every 4 weeks between 4 and 48 weeks after implantation were collected. Then, calculating mean LDH during 48 weeks after implantation, study population was divided into low and high mean LDH groups at the median value of mean LDH.

Results

The median value of mean LDH was 304 U/l. Compared with low LDH patients, though high LDH patients were more likely female and had smaller body surface area, there were no significant difference in pre-operative eGFR between the groups (66.0±23.7 vs. 70.2±25.7 ml/min/1.73m2, p=0.495). After 40 weeks after implantation, high LDH patients had significantly lower eGFR than low LDH patients (71.0±23.7 vs. 87.1±31.4 ml/min/1.73m2, p=0.024). In multivariate linear regression analysis, mean LDH [parameter estimate: −0.10 (95% CI: −0.17 to −0.04), p=0.003] and post-operative pulse pressure [parameter estimate: 0.71 (95% CI: 0.05 to 1.37), p=0.036] were significantly associated with eGFR change during 48 weeks after HeartMateII implantation.

Univariate and multivariate linear regression analysis for eGFR change Univariate parameter estimate 95% CI p value Multivariate parameter estimate 95% CI p value Bilirubin, mg/dl 9.97 3.82 to 16.13 0.002 6.55 −0.43 to 13.53 0.065 BNP, pg/ml 0.01 0.00 to 0.02 0.044 0.00 −0.01 to 0.01 0.528 Mean LDH during 4 to 48 weeks, U/l −0.11 −0.18 to −0.05 <0.001 −0.10 −0.17 to −0.04 0.003 Pre-operative right atrial pressure, mmHg 1.43 0.35 to 2.51 0.010 −0.06 −1.52 to 1.40 0.935 Post-operative pulse pressure, mmHg 0.77 0.03 to 1.52 0.042 0.71 0.05 to 1.37 0.036

Conclusions

High mean LDH and low pulse pressure were associated with a significant decrease in eGFR late after HeartMateII implantation. Subclinical persistent hemolysis may be associated with late renal function deterioration in CF-LVAD patients.

P1615HECT-Type Ubiquitin E3 Ligase ITCH attenuates cardiac hypertrophy by suppressing Wnt signaling pathway

Background

The homologous to the E6-AP carboxyl terminus (HECT)–type ubiquitin E3 ligase ITCH is an enzyme that plays an important role in ubiquitin proteasomal protein degradation. Dishevelled proteins (Dvl1, Dvl2 and Dvl3), which are involved in canonical Wnt/β catenin signaling pathway, play a role in cardiac hypertrophy.

Purpose

The aim of this study was to examine whether ITCH interacts with Dvls and prevents cardiac hypertrophy induced by pressure overload.

Methods and results

We confirmed the protein interaction between ITCH and Dvls in cardiomyocytes. Overexpression of ITCH decreased protein expression levels of Dvls, phospho-GSK3β and β-catenin. Conversely, knockdown of ITCH using small interfering RNA augmented canonical Wnt/β catenin signaling pathway. Thoracic transverse aortic constriction (TAC) was performed in transgenic mice with cardiac-specific overexpression of ITCH (ITCH-Tg) and wild-type (WT) mice. The canonical Wnt/β catenin signaling pathway was inhibited and cardiac hypertrophy was attenuated in ITCH-Tg mice compared with WT mice after TAC.

Overexpression of ITCH in cardiomyocytes

Conclusion

We demonstrated that ITCH targets Dvls for ubiquitin-proteasome degradation in cardiomyocytes and ameliorates cardiac hypertrophy by suppressing canonical Wnt/β catenin signaling pathway.