Anxiety relaxation during MRI with a patient-friendly audiovisual system

INTRODUCTION

Many patients experience anxiety, not limited to claustrophobia, before magnetic resonance imaging (MRI) examination. We performed a non-randomized controlled trial to evaluate whether a patient-friendly audiovisual (AV) system in the MR scanner room reduces patient anxiety.

METHODS

We randomly selected 61 participants from outpatients who required brain MRI examination. Patients were informed that they could choose to undergo an MRI examination with a patient-friendly AV system (Ambient Experience, Philips Healthcare, Best, The Netherlands) or the standard system. To complete the MRI examination without affecting clinical practice, all patients who preferred the patient-friendly AV system were assigned to the preferring AV group. Patients who indicated that either system was acceptable were randomly assigned to the no preference but allocated AV group or control (using the standard system) groups. In both groups, state anxiety using the State-Trait Anxiety Inventory (STAI) was assessed before and after the MRI examination (A-State-before and A-State-after MRI, respectively). The changes in A-State-before and A-State-after MRI were categorized as follows: relieved high-state anxiety, no change in high-state anxiety, stable easiness, and intensified anxiety.

RESULTS

Among the 61 included patients, 19 were assigned to the preferring AV group, 20 to the no preference but allocated AV group, and 22 to the control group. There were no significant differences between the group. However, in patients with high-state anxiety before MRI, the preferring AV group and the no preference but allocated AV group, which used the patient-friendly AV system, relieved high-state anxiety by 63.6% (7 of 11 patients) and 81.8% (9 of 11 patients), respectively. In contrast, the control group using the standard system relieved high-level anxiety by only 42.9% (three out of seven patients).

CONCLUSION

The patient-friendly AV system may reduce anxiety in patients undergoing MRI examinations.

IMPLICATIONS FOR PRACTICE

The patient-friendly AV system may reduce anxiety in patients undergoing MRI examination by providing a more patient-centered MRI examination environment. These findings may help ameliorate negative perceptions associated with MRI examination.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Explanation of machine learning models using shapley additive explanation and application for real data in hospital

BACKGROUND AND OBJECTIVE

When using machine learning techniques in decision-making processes, the interpretability of the models is important. In the present paper, we adopted the Shapley additive explanation (SHAP), which is based on fair profit allocation among many stakeholders depending on their contribution, for interpreting a gradient-boosting decision tree model using hospital data.

METHODS

For better interpretability, we propose two novel techniques as follows: (1) a new metric of feature importance using SHAP and (2) a technique termed feature packing, which packs multiple similar features into one grouped feature to allow an easier understanding of the model without reconstruction of the model. We then compared the explanation results between the SHAP framework and existing methods using cerebral infarction data from our hospital.

RESULTS

The interpretation by SHAP was mostly consistent with that by the existing methods. We showed how the A/G ratio works as an important prognostic factor for cerebral infarction using proposed techniques.

CONCLUSION

Our techniques are useful for interpreting machine learning models and can uncover the underlying relationships between features and outcome.

Colchicine protects against cartilage degeneration by inhibiting MMP13 expression via PLC-γ1 phosphorylation

OBJECTIVE

Low molecular weight compounds that reduce the expression of MMP13 at the mRNA level might serve as disease-modifying osteoarthritis (OA) drugs (DMOADs). The objective of this study was to identify a candidate DMOAD that targets MMP13 expression.

DESIGN

High-throughput screening was performed to identify compounds that suppress inflammatory cytokine-induced MMP13 expression. Ingenuity pathway analysis (IPA) using isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic analysis was conducted to identify signaling pathways related to cytokines. MMP13 expression in chondrocytes was evaluated through RT-qPCR and western blotting analyses. Additionally, 10-week-old mice were subjected to destabilization of the medial meniscus (DMM) surgery to induce OA and were sacrificed 12 weeks post-surgery for pathological examination. OA was evaluated using the OARSI scoring system.

RESULTS

Colchicine was identified as a DMOAD candidate as it inhibited inflammatory cytokine-induced MMP13 expression in vitro, and the colchicine-administered mice with DMM presented significantly lower OARSI scores (adjusted P: 0.0242, mean difference: 1.6, 95% confidence interval (CI) of difference: 0.1651-3.035) and significantly lower synovial membrane inflammation scores (adjusted P: 0.0243, mean difference: 0.6, 95% CI of difference: 0.06158-1.138) than mice with DMM. IPA further revealed that components of the Rho signaling pathways are regulated by cytokines and colchicine. IL-1β and TNF-α activate RAC1 and SRC signals, respectively, leading to the phosphorylation of PLC-γ1 and synergistic induction of MMP13 expression. Most notably, colchicine abrogates inflammatory cytokine-induced phosphorylation of PLC-γ1, leading to the induction of MMP13 expression.

CONCLUSIONS

Colchicine is a potential DMOAD candidate that inhibits MMP13 expression and consequent cartilage degradation by disrupting the SRC/RAC1-phospho-PLCγ1-Ca2+ signaling pathway.

Early and chronic phased local coagulative responses following bioresorbable-polymer drug-eluting stent implantation

Background

Neointimal maturation after bioresorbable-polymer (BP) drug-eluting stent (DES) implantation will not be complete in the absorption phase of the polymer. We have previously reported local persistent hypercoagulation after sirolimus-eluting stent (SES) implantation by measuring local plasma prothrombin fragment 1+2 (F1+2) levels. The aim of this study is to examine time-dependent local coagulative response after BP-DES implantation.

Methods

Sixty-four patients who were treated about ten months earlier with coronary angioplasty, with no evidence of restenosis, were studied [durable-polymer (DP)-DES {SES; Cypher®: 26pts and everolimus-eluting stent (EES); Xience®: 16pts} and BP-DES (BP-EES; Synergy®: 10pts and BP-SES; Ultimaster®: 12pts)]. We measured plasma levels of F1+2 sampled in coronary sinus (CS) and sinus of Valsalva (V) at the early (2±1 months) and chronic (10±2 months) phases. The transcardiac gradient (Δ) was defined as CS level minus V level.

Results

No significant differences were observed in the percent diameter stenosis between the DP- and BP- DES groups (11.5±15.5 vs 14.1±11.9%). The ΔF1+2 was significantly lower in the BP-DES group than in the DP-DES group at the chronic phase (7.5±16.1 vs 16.4±17.1pmol/l, p<0.05). In the BP-DES group, the ΔF1+2 did not differ significantly between the early and chronic phases (7.0±14.1 vs 7.5±16.1pmol/l, NS).

Conclusion

Lower local coagulative response was observed at the chronic phase after BP-DES implantation compared to DP-DES implantation, and local hypercoagulation after BP-DES implantation was not observed at the early phase compared to the chronic phase. These findings might lead to the possibility of shorter dual antiplatelet therapy after BP-DES implantation.

Funding Acknowledgement

Type of funding sources: None.

Basic Study of Extensional Flow Mixing for the Dispersion of Carbon Nanotubes in Polypropylene by Using Capillary Extrusion

This study evaluated the mixing effect of simple uniaxial extensional flow for the dispersion of multiwalled carbon nanotubes (MWCNTs) into polypropylene (PP) as a nonpolar matrix. An only converging flow allowed for a high strain rate and was suitable for the compounding process. The extensional flow was characterized from the entrance pressure drop (ΔP0) at the converging section. Thus, in this study, capillary extrusion was employed to generate uniaxial extensional flow. Based on the hypothesis that the dispersion of nanofillers depends on the magnitude of flow-induced stress, ΔP0, which related to extensional stress, was measured directly during capillary extrusion by using an orifice die. The influences of the mass flow rate and the hole diameter in the orifice die, which affected ΔP0, on the extrusion of PP nanocomposites with an MWCNT loading of 1.0 wt.% were studied. The extruded samples were collected, and the dispersion state was evaluated based on the melt viscoelastic properties, volume resistivity, and morphological observations by optical microscopy (OM) and transmission electron microscopy (TEM). The agglomeration area of the MWCNTs decreased with higher ΔP0 (higher mass flow rate and smaller hole diameter), which increased the uniformity of the dispersion. Moreover, the influence of the length-to-diameter (L/D) ratio of the hole in the capillary die on the dispersion state of the MWCNTs was investigated. A higher L/D ratio of the capillary die did not improve the dispersion state, although shear and extensional stresses were provided.

Impact of a learning health system on acute care and medical complications after intracerebral hemorrhage

INTRODUCTION

Patients with stroke often experience pneumonia during the acute stage after stroke onset. Oral care may be effective in reducing the risk of stroke-associated pneumonia (SAP). We aimed to determine the changes in oral care, as well as the incidence of SAP, in patients with intracerebral hemorrhage, following implementation of a learning health system in our hospital.

METHODS

We retrospectively analyzed the data of 1716 patients with intracerebral hemorrhage who were hospitalized at a single stroke center in Japan between January 2012 and December 2018. Data were stratified on the basis of three periods of evolving oral care: period A, during which conventional, empirically driven oral care was provided (n = 725); period B, during which standardized oral care was introduced, with SAP prophylaxis based on known risk factors (n = 469); and period C, during which oral care was risk-appropriate based on learning health system data (n = 522). Logistic regression analysis was performed to evaluate associations between each of the three treatment approaches and the risk of SAP.

RESULTS

Among the included patients, the mean age was 71.3 ± 13.6 years; 52.6% of patients were men. During the course of each period, the frequency of oral care within 24 hours of admission increased (P < .001), as did the adherence rate to oral care ≥3 times per day (P < .001). After adjustment for confounding factors, a change in the risk of SAP was not observed in period B; however, the risk significantly decreased in period C (odds ratio 0.61; 95% confidence interval 0.43-0.87) compared with period A. These associations were maintained for SAP diagnosed using strict clinical criteria or after exclusion of 174 patients who underwent neurosurgical treatment.

CONCLUSIONS

Risk-appropriate care informed by the use of learning health system data could improve care and potentially reduce the risk of SAP in patients with intracerebral hemorrhage in the acute stage.

Transient Hyperintensity of the Infant Thyroid Gland on T1-Weighted MR Imaging: Correlation with Postnatal Age, Gestational Age, and Signal Intensity of the Pituitary Gland

BACKGROUND AND PURPOSE

The signal intensity of the thyroid in neonates is high on T1WI. It is affected by gestational and postnatal ages. However, the extent of the influence of these ages is unknown. This study investigated the relationship of signal intensities of the infant thyroid with postnatal and gestational ages and anterior pituitary using 3D gradient-echo T1WI.

MATERIALS AND METHODS

This retrospective study included 183 T1-weighted images from 181 infants. Using a multiple linear regression analysis, we evaluated the effects of postnatal and gestational ages on the thyroid-muscle signal intensity ratio. The relationship between the thyroid and anterior pituitary signal intensities on T1WI and the age of the infants was evaluated.

RESULTS

Multiple linear regression analysis showed that the thyroid signal intensity was affected negatively by postnatal age at examination and positively by gestational age at birth (P < .01 and P = .04, respectively). According to the standardized partial regression coefficients, the influence of postnatal age at examination was stronger than that of gestational age at birth (-0.72 and 0.13, respectively). The thyroid and anterior pituitary signal intensities reached constant values at 12 weeks' postnatal age, and the mean thyroid-anterior pituitary signal intensity ratios were almost 1 throughout the entire period.

CONCLUSIONS

The signal intensity of the infant thyroid on T1WI was more strongly influenced by the postnatal age at examination than the gestational age at birth, and it was almost equal to that of the anterior pituitary.

Impaired preload reserve is an important haemodynamic characteristics that discriminates between physiological ageing and overt heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: None.

Background

 Ageing process per se is a major risk factor for heart failure (HF). In fact, the incidence of HF with preserved ejection fraction (HFpEF) dramatically increases with age. Although ageing plays a central role in the development of HFpEF, not all the elderly patients develop clinical HFpEF. Multiple abnormalities in the cardiovascular system have been proposed to contribute to the development of HFpEF. However, the pathophysiology that discriminates between physiological ageing and overt HFpEF is incompletely understood.

Purpose

 The purpose of this study was to assess the effects of ageing on the cardiac structures and haemodynamics. Moreover, we evaluated the determinant factor that discriminates between physiological ageing and overt HFpEF by non-invasive preload increasing manoeuvre using leg-positive pressure (LPP) stress echocardiography.

Methods

 A total of 91 subjects were prospectively recruited in this study: 22 patients with HFpEF and 69 healthy controls. Normal controls were further stratified into 3 age groups: young (n = 19, 20-40 years of age), middle-aged (N = 25, 40-65 years) and elderly (n = 25, &gt;65 years). All subjects underwent LPP stress with a continuous external pressure of 90 mmHg around both lower limbs using dedicated airbags (Fig.). 

Results

 The left ventricular mass index (LVMI; young, 68 ± 19 g/m²; middle-age, 70 ± 18 g/m²; elderly, 84 ± 21 g/m²) and also the relative wall thickness (RWT; young, 0.34 ± 0.09; middle-age, 0.41 ± 0.06; elderly 0.55 ± 0.10) increased with ageing, which was accelerated in HFpEF (LVMI: 111 ± 32 g/m², RWT; 0.63 ± 0.19, ANOVA P &lt; 0.001, respectively). Although baseline LV ejection fraction and cardiac output were quite comparable between groups, E/e’ ratio significantly increased with with ageing (ANOVA P &lt; 0.001, Fig.). During LPP stress, E/e’ ratio significantly increased in the middle-aged and elderly groups (from 8.8 ± 2.7 to 9.7 ± 3.3, and from 11.4 ± 2.4 to 13.0 ± 2.2, P &lt; 0.05, respectively), which was further deteriorated in HFpEF (from 16.8 ± 5.8 to 18.0 ± 7.6, P &lt; 0.05). On the other hand, stroke volume index (SVi) significantly increased in each healthy group during LPP stress (young; from 45 ± 10 to 50 ± 11 mL/m², middle-age; from 39 ± 7 to 44 ± 6 mL/m² and elderly; from 37 ± 7 to 43 ± 8 mL/m², all P &lt; 0.001), while SVi failed to increase in the HFpEF group (from 45 ± 13 to 45 ± 14 mL/m², P = 0.60). In a multivariate logistic regression analysis, LVMI (hazard ratio; HR 1.055, P &lt; 0.05), baseline E/e’ (HR 1.444; P &lt; 0.05), and ΔSVi (HR 0.755; P &lt; 0.05) during LPP stress were the independent parameters that characterised overt HFpEF.

Conclusions

 Striking parallels between structure-function alterations were observed in the physiological cardiovascular ageing process, which was further accelerated in patients with HFpEF. Not only structural remodeling and impaired diastolic function, but also impaired systolic reserve during preload stress is important haemodynamic feature that characterise the pathophysiology of HFpEF.

Abstract Figure.

Association between clinical risk factors and left ventricular function in patients with breast cancer following chemotherapy

Funding Acknowledgements

Type of funding sources: None.

Background

The sequential or concurrent use of two different types of agents such as anthracyclines and trastuzumab may increase myocardial injury and cancer therapeutics-related cardiac dysfunction (CTRCD), which is often the result of the combined detrimental effect of the two therapies for breast cancer patients. For risk stratification to detect the development of CTRCD, the current position paper from the European Society of Cardiology (ESC) lists several factors associated with risk of cardiotoxicity.

Purpose

Our purpose was to investigate the impact of baseline risk factors on left ventricular (LV) function in patients with preserved LV ejection fraction (LVEF) who have undergone chemotherapy for breast cancer.

Methods

We studied 86 breast cancer patients treated with anthracyclines, trastuzumab, or both. Mean age was 59 ± 13 years and LVEF was 67 ± 5%. In accordance with the current definition, CTRCD was defined as a decline in LVEF of &gt;10% to an absolute value of &lt;53% after chemotherapy. Based on the 2016 ESC position paper, clinical risk factors for CTRCD were defined as: (1) a cumulative total doxorubicin dose of ≥ 240mg/m², (2) age ≥ 65-year-old, (3) body mass index ≥ 30kg/m², (4) a previous history of radiation therapy to chest or mediastinum, (5) B-type natriuretic peptide ≥ 100pg/mL, (6) a previous history of cardiovascular disease, (7) atrial fibrillation, (8) hypertension, (9) diabetes mellitus, (10) current or ex-smoker.

Results

The relative decrease in LVEF after chemotherapy for patients with more than four risk factors was significantly greater than that for patients without (-9.3 ± 10.8% vs. -2.2 ± 10.2%; p = 0.02). However, this finding did not apply to patients with more than one, two or three risk factors. Patients with more than four risk factors also tended to show a higher prevalence of CTRCD than those without (14.3% vs. 2.8%, p = 0.12). Moreover, patients with more than four risk factors were more likely to have higher LV mass index (109.3 ± 29.0g/m² vs. 83.2 ± 21.0g/m², p &lt; 0.001), lower global longitudinal strain (18.4 ± 2.8% vs. 20.0 ± 2.6%, p = 0.06) and higher E/e’ (10.4 (8.9-13.0) vs. 9.0 (7.4-10.9), p = 0.06) compared to those without. 

Furthermore, receiver-operator characteristics curve analysis showed that an optimal cut off value of a cumulative total doxorubicin dose for developing LV dysfunction in patients with more than any of four risk factors was lower than that in those without (180 mg/m² vs. 280 mg/m²).

Conclusions

Association between clinical risk factors and LV dysfunction following chemotherapy became stronger with an increase in the number of risk factors in breast cancer patients, and was especially strong for patients treated with chemotherapy who had more than four risk factors. Our findings can thus be expected to have clinical implications for better management of patients with breast cancer referred for chemotherapy.

Abstract Figure.

impact of dapagliflozin on left ventricular diastolic function in diabetic patients with heart failure complicating cardiovascular risk factors

Funding Acknowledgements

Type of funding sources: None.

Background

Type 2 diabetes mellitus (T2DM) is a well-known risk factor for heart failure (HF), even in patients without a structural heart disease or a symptom of HF. Diabetes-related cardiomyopathy is presented as an left ventricular (LV) diastolic dysfunction, which, like cardiovascular disease, is a contributor of the development of HF in both patients with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF). Furthermore, comorbid factors other than T2DM also have been identified as high risk factors for of progression to HF. Dapagliflozin is a sodium glucose cotransporter type 2 (SGLT2) inhibitor, and represents a new class of anti-hyperglycemic agents for T2DM. A result from a recent large clinical trial showed that dapagliflozin reduced risk of worsening HF or death from cardiovascular causes for patients with HFrEF compared to those who received a placebo, regardless of the presence or absence of T2DM. However, the effect of SGLT2 inhibitors on LV diastolic function in T2DM patients with HF who had cardiovascular risk factors other than T2DM remains uncertain.

Purpose

Our purpose was to investigate the impact of dapagliflozin on LV diastolic function in T2DM patients with stable HF complicating cardiovascular risk factors.

Methods

We analyzed data from our previous prospective multicenter study, which investigate the effect of dapagliflozin on LV diastolic function of 53 T2DM patients with stable HF at five institutions in Japan. Patients who had been taking at least one antidiabetic drugs other than SGLT2 inhibitor started the administration of dapagliflozin. Cardiovascular risk factors other than T2DM was determined as age, gender, hypertension, dyslipidemia, history of cardiovascular events and overweight.

Results

E/e′ significantly decreased from 9.3 to 8.5 cm/s 6 months after administration of dapagliflozin (p = 0.020) as previously described. Multivariate logistic regression analysis showed that dyslipidemia was the only independent determinant of an improvement of E/e’ among cardiovascular risk factors. Furthermore, relative changes in E/e’ from baseline to 6 months after administration of dapagliflozin seen in HFpEF patients with dyslipidemia were significantly larger than those in HFpEF patients without dyslipidemia (-15.2% vs. 29.6%, p = 0.014), but such a difference was not observed in non-HFpEF patients. In addition, relative changes in high-density lipoprotein cholesterol (HDL-C) from baseline to 6 months after administration of dapagliflozin had significant correlation with those in E/e’ (r=-0.300, p = 0.038). However, such correlations were not observed in low-density lipoprotein cholesterol (LDL-C) and triglyceride (r = 0.05, p = 0.72 and r = 0.05, p = 0.73). Conclusion: Dapagliflozin was more beneficial effect on LV diastolic function for T2DM patients with stable HF, especially those with complicating dyslipidemia. Our findings may thus offer a new insight into the management of T2DM patients with HF.

Abstract Figure.

Preload stress echocardiography by using dynamic postural alteration can identify high risk patients with heart failure with reduced ejection fraction

Funding Acknowledgements

Type of funding sources: None.

Background

Haemodynamic assessment during stress testing is not commonly performed for patients with heart failure with reduced ejection fraction (HFrEF) due to its invasiveness, less feasibility, and safety concerns. Passive leg-lifting (PLL) manoeuvres have been introduced as a simple alternative for non-invasive preload stress testing; however, the haemodynamic load imposed on the cardiovascular system is unsatisfactory, which precludes the accurate assessment of the preload reserve for patients with HF.

Purpose

The purpose of this study was to assess the haemodynamic characteristics of patients with HFrEF in response to a preload stress during dynamic postural alterations by combining the semi-sitting position (SSP) and PLL. We also evaluated whether combined postural stress could be used for risk stratification for these patients.

Methods

For this study, 101 patients with HFrEF and 35 age- and sex-matched normal controls were prospectively recruited. At each postural position (i.e., baseline, SSP, and PLL), all standard echocardiographic and Doppler variables were obtained. Adverse cardiac events were prespecified as the combined endpoints of death from or hospitalisation for deteriorated HF, or sudden cardiac death. Clinical follow-up was conducted for a median of 7 months.

Results

During PLL stress, the stroke volume index (SVi) significantly increased in both controls (from 40 ± 6 to 43 ± 6 mL/m², P = 0.03) and HFrEF patients (from 31 ± 9 to 34 ± 10 mL/m², P = 0.03). Conversely, during SSP stress, the SVi significantly decreased for both controls (from 40 ± 6 to 37 ± 6 mL/m², P = 0.03) and HFrEF patients (31 ± 9 to 28 ± 8 mL/m², P = 0.03). During the follow-up period, 16 patients developed cardiac events. In patients without events, the Frank-Starling mechanism was well preserved (Fig. A). Namely, the SVi significantly increased from 31 ± 9 to 35 ± 10 mL/m² (P = 0.02) during PLL stress, while the SVi significantly decreased from 31 ± 8 to 28 ± 8 mL/m² (P = 0.02) during SSP stress. In contrast, for patients with cardiac events, the SVi did not change during postural alterations (n.s), which indicated that the failing heart operates on the flat portion of the Frank-Starling curve (Fig. A). When patients were divided into three equal sub-groups based on the total difference in the SVi during dynamic postural stress, patients with impaired preload reserve (third trimester, ΔSVi ≤ 3.0 mL/m²) showed significantly worse event-free survival than the other two sub-groups (Fig. B; P &lt; 0.001). In a Cox proportional-hazard analysis, baseline LVEF (hazard ratio 0.93; P = 0.04), and ΔSVi during postural stress (hazard ratio 0.76; P = 0.004) were predictors of future cardiac events.

Conclusions

The combined assessment of dynamic postural stress during PLL and SPP is a simple, time-saving, and easy-to-use clinical tool for the assessment of preload reserve for patients with HFrEF. Moreover, postural stress echocardiography proved to contribute to the risk stratification for these patients.

Abstract Figure.

Cardiac resynchronization therapy improves left atrial reservoir function through resynchronization of the left atrium in patients with heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

The structural remodeling of the left atrium (LA) has been proposed as an important determinant of adverse outcomes in patients with heart failure (HF). However, little is known about the potential impact of LA mechanical dyssynchrony on its reservoir function and the prognosis of patients with HF. In addition, it has not been fully investigated whether cardiac resynchronization therapy (CRT) is also beneficial to LA function.

Purposes

The purposes of this study were to test whether left ventricular (LV) dyssynchrony may negatively affect LA synchronicity and reservoir function, and to assess whether residual LA dyssynchrony after CRT affects the prognosis in patients with HF with reduced ejection fraction (HFrEF).

Methods

This study included total of 90 subjects: 40 HFrEF with a wide-QRS complex (≧130 ms), 28 HFrEF with a narrow-QRS, and 22 age- and sex-matched normal controls. LA global longitudinal strain (LA-GLS) and LA dyssynchrony were quantified using speckle-tracking strain analysis. LA dyssynchrony was defined as the maximal difference of time-to-peak strain (LA time-diff). All wide-QRS HFrEF received CRT, and event-free survival was tracked for 24 months.

Results

At baseline, HFrEF patients showed significant LA remodeling coupled with the reduced LA reservoir function, as evidenced by larger LA volume index (LAVi: 46 ± 16 vs. 30 ± 14 mL/m², P &lt; 0.01) and smaller LA-GLS (13.0 ± 4.8 vs. 30.6 ± 10.7%, P &lt; 0.01). Of note was that, not only LV dyssynchrony (381 ± 178 vs. 177 ± 62 ms, P &lt; 0.01) but also LA dyssynchrony (298 ± 136 vs. 186 ± 78 ms, P &lt; 0.01) were significantly larger in patients with HFrEF compared to normal subjects and this applied even more to patients with a wide-QRS complex. All patients with a wide-QRS complex underwent CRT, and only responders exhibited the significant decrease in LA time-diff (from 338 ± 123 to 245 ± 141 ms, P &lt; 0.05) and increase in LA-GLS (from 11.9 ± 4.7 to 19.6 ± 10.1%, P &lt; 0.05) in parallel with the reduction in LAVi (from 48 ± 17 to 37 ± 18 mL/m², P &lt; 0.05) at 6 months after CRT. Receiver operating characteristic curve analysis identified the optimal cut-off value of LA time-diff at 6 months after CRT as 202 ms (P &lt; 0.05) and that of LA-GLS as 14.6% (P &lt; 0.05) for predicting adverse cardiac events. The patients whose LA time-diff reduced &lt;202 ms after CRT showed significantly favorable event-free survival than the others. Similarly, the patients whose LA-GLS improved &gt;14.6% after CRT exhibited significantly favorable event-free survival than the others (P &lt; 0.05, respectively). Of note was that, when the patients were restricted to CRT responders only, those who showed LA time-diff less than 202 ms at 6 months after CRT almost never experienced cardiac events (P &lt; 0.05).

Conclusions

The improved LV coordination by CRT also resulted in resynchronization of discoordinated LA wall motion and a consecutive improvement of LA reservoir function, which ultimately lead to the favorable outcome for HFrEF patients with wide-QRS complex.

Abstract Figure.

preoperative right ventricular overwork is a major determinant of residual pulmonary arterial hypertension in patients with repaired arterial septal defect

Funding Acknowledgements

Type of funding sources: None.

Background

The haemodynamic effect of atrial septal defect (ASD) is a chronic volume overload of the right heart and pulmonary vasculature. Pulmonary overcirculation is generally compensated for by the right ventricular (RV) and pulmonary arterial (PA) reserve. However, in a subset of patients, prolonged pulmonary overcirculation insidiously induces obstructive pulmonary vasculopathy, which results in postoperative residual pulmonary arterial hypertension (PAH) after ASD closure. Postoperative PAH is a major concern because it is closely associated with poor outcomes and impaired quality of life. However, to date, no clinically robust predictors of postoperative residual PAH have been clearly identified.

Purpose

This study sought to assess the haemodynamic characteristics of ASD patients in terms of mechano-energetic parameters and to identify the predictors of postoperative residual PAH in these patients.

Methods

A total of 120 ASD patients (age: 58 ± 17 years) and 46 normal controls were recruited. As previously reported, the simplified RV contraction pressure index (sRVCPI) was calculated as an index of RV external work by multiplying the tricuspid annular plane systolic excursion (TAPSE) by the pressure gradient between the RV and right atrium. RV- PA coupling was evaluated using TAPSE divided by PA systolic pressure as an index of the RV length-force relationship. These parameters were measured both at baseline and 6 months after ASD closure.

Results

As expected, baseline sRVCPI was significantly greater in patients with ASD than in controls (775 ± 298 vs. 335 ± 180 mm Hg • mm, P &lt; 0.01), which indicated significant "RV overwork". As a result, RV-PA coupling in ASD patients was significantly impaired compared to that in controls (0.9 ± 0.8 vs. 3.5 ± 1.7 mm/mm Hg, P &lt; 0.01). All 120 ASD patients underwent transcatheter or surgical shunt closure; 15 of them had residual PAH after closure. After 6 months, RV-PA coupling index significantly improved in patients without residual PAH, from 0.96 ± 0.81 to 1.27 ± 1.24 mm/mm Hg (P = 0.02). Furthermore, RV load was markedly reduced, with sRVCPI falling from 691 ± 258 to 434 ± 217 mm Hg • mm, P &lt; 0.01). However, in patients with residual PAH, RV-PA coupling index deteriorated from 0.64 ± 0.23 to 0.53 ± 0.12 mm/mm Hg (P &lt; 0.01). As a result, RV overload was not significantly relieved (sRVCPI; from 971 ± 382 to 783 ± 166 mm Hg • mm, P = 0.22). In a multivariate analysis, baseline pulmonary vascular resistance (hazard ratio 1.009; P &lt; 0.01) and preoperative sRVPCI (hazard ratio 1.003; P &lt; 0.01) revealed to be independent predictors of residual PAH.

Conclusion

In terms of mechano-energetic function, preoperative "RV overwork" can be used as a robust predictor of an impaired RV-PA relationship in ASD patients. Moreover, periodic assessment of sRVPCI may contribute to the better management for patients with unrepaired ASD.

Abstract Figure.

An analysis of osteoporosis in patients with hereditary multiple exostoses

We analyzed osteoporosis in 20 HME patients. According to the T-score of BMD, 30% and 67.5% of the patients fell in the range of osteopenia in the lumbar spine and femoral neck. Our results indicate HME patients have low bone mass. They do not have abnormal bone metabolism.

INTRODUCTION

There are few reports of osteoporosis in hereditary multiple exostoses (HME) patients. Therefore, the purpose of this study was to analyze osteoporosis in HME patients.

METHODS

This retrospective cohort study included 20 patients diagnosed with HME. Patients underwent bone mineral density (BMD) measurement of the lumbar spine (n = 20) and femoral neck (n = 40). Bone metabolic parameters, including serum osteocalcin and urinary cross-linked N-telopeptide of type 1 collagen (NTx), were analyzed in all subjects. EXT1 and EXT2 genes were sequenced using genomic DNA. We also examined the correlation between genotype and BMD Z-score and T-score.

RESULTS

The mean BMD values of the lumbar spine were 1.085 ± 0.116 g/cm² (n = 11) in male and 1.108 ± 0.088 g/cm² (n = 9) in female. The mean BMD values of the femoral neck area were 0.759 ± 0.125 g/cm² (n = 22) in male and 0.749 ± 0.115 g/cm² (n = 18) in female. Z-score of most HME patients show < 0, indicating that these patients tend to have low bone mass compared with the age-matched population. According to the T-score of BMD, 30% (6 of 20) and 67.5% (27 of 40) of the patients fell in the range of osteopenia in the lumbar spine and femoral neck areas, respectively. Serum osteocalcin and urinary NTx were in the normal range in most patients. There was no significant correlation between genotypes and Z-score.

CONCLUSION

HME patients have low bone mass, especially in the femoral neck area. They do not have abnormal bone metabolism, and there was no correlation between genotypes and Z-score.

Caprylic acid enhances hydroxyhexylitaconic acid production in Aspergillus niger S17-5

AIM

Aspergillus niger S17-5 produces two alkylitaconic acids, 9-hydroxyhexylitaconic acid (9-HHIA) and 10-hydroxyhexylitaconic acid (10-HHIA), which have cytotoxic and polymer building block properties. In this study, we characterized the production of 9-HHIA and 10-HHIA by addition of their expected precursor, caprylic acid, to a culture of A. niger S17-5, and demonstrated batch fermentation of 9-HHIA and 10-HHIA in a jar fermenter with DO-stat.

METHODS AND RESULTS

Production titres of 9-HHIA and 10-HHIA from 3% glucose in a flask after 25 days cultivation were 0·35 and 1·01 g l^-1 respectively. Addition of 0·22 g l^-1 of caprylic acid to a suspension of resting cells of A. niger S17-5 led to 32% enhancement of total 9-HHIA and 10-HHIA production compared to no addition. No enhancement of the production of 9-HHIA or 10-HHIA by the addition of oxaloacetic acid was observed. Addition of caprylic acid to the culture at mid-growth phase was more suitable for 9-HHIA and 10-HHIA production due to less cell growth inhibition by caprylic acid. DO-stat batch fermentation with 3% glucose and 14·4 g l^-1 of caprylic acid in a 1·5 l jar fermenter resulted in the production titres of 9-HHIA and 10-HHIA being 0·48 and 1·54 g l^-1 respectively after 10 days of cultivation.

CONCLUSIONS

Addition of caprylic acid to the culture of A. niger S17-5 enhances 9-HHIA and 10-HHIA production.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results suggest that 9-HHIA and 10-HHIA are synthesized with octanoyl-CoA derived from caprylic acid, and that the supply of octanoyl-CoA is a rate-limiting step in 9-HHIA and 10-HHIA production. To the best of our knowledge, this is the first report regarding the fermentation of naturally occurring itaconic acid derivatives in a jar fermenter.

Toll-like receptor 9 is a novel therapeutic target to prevent atrial fibrillation

Background

Atrial fibrillation (AF) is the most common type of arrhythmia seen in clinical practice. Recent studies suggest that inflammation contributes to the pathogenesis of AF. On the other hand, several evidence suggests that toll-like receptor (TLR) 9 recognizes bacterial DNA, activating innate immunity, whereas it also provokes inflammation in response to fragmented DNA released from mammalian cells. Recently, we have reported that TLR 9 plays a pivotal role in the development of vascular inflammation and atherogenesis through proinflammatory activation of macrophages.

Purpose

This study aimed to assess whether TLR9 contributes to the AF arrhythmogenesis.

Methods

TLR9 deficient (TLR9−/−) and wild-type mice were infused with angiotensin II (Ang II) or vehicle via an osmotic minipump for 4 weeks. Blood pressure and body weight were measured serially. Then, we examined AF inducibility by intracardiac electrophysiological study and the inflammation-induced atrial remodeling by biochemical analysis after 4 weeks of Ang II infusion.

Results

There was no significant difference in blood pressure and pulse rate between TLR9−/− and wild-type mice both before and after Ang II infusion. Ang II-treated TLR9−/− mice showed lower incidence of AF compared with wild-type mice treated with Ang II. Genetic deletion of TLR9 significantly reduced the interstitial fibrosis in atrium of Ang II-treated mice. TLR9−/− mice also showed less mRNA expressions of inflammatory and fibrosis-related biomarkers (TNF-α, interleukin-6, TGF-β, collagen-1, collagen-3) in atrium compared with wild-type mice.

Conclusions

TLR9 might contribute to the AF arrhythmogenesis associated with atrial inflammation. TLR9 might serve as a potential therapeutic target for AF.

Funding Acknowledgement

Type of funding source: None

Association between clinical risk factors and left ventricular function in patients with breast cancer following chemotherapy

Background

The sequential or concurrent use of two different types of agents such as anthracyclines and trastuzumab may increase myocardial injury and cancer therapeutics-related cardiac dysfunction (CTRCD), which is often the result of the combined detrimental effect of the two therapies for breast cancer patients. For risk stratification to detect the development of CTRCD, the current position paper from the European Society of Cardiology (ESC) lists several factors associated with risk of cardiotoxicity following treatment with chemotherapy. However, the association between clinical risk factors and left ventricular (LV) function in breast cancer patients is currently unclear.

Purpose

Our purpose was to investigate the impact of baseline risk factors on LV function in patients with preserved LV ejection fraction (LVEF) who have undergone anthracycline or trastuzumab chemotherapy for breast cancer.

Methods

We studied 86 breast cancer patients treated with anthracyclines, trastuzumab, or both. Mean age was 59±13 years and LVEF was 67±5%. In accordance with the current definition, CTRCD was defined as a decline in LVEF of &gt;10% to an absolute value of &lt;53% after chemotherapy. Based on the 2016 ESC position paper, clinical risk factors for CTRCD were defined as: (1) a cumulative total doxorubicin dose of ≥240 mg/m2, (2) age ≥65-year-old, (3) body mass index ≥30 kg/m2, (4) a previous history of radiation therapy to chest or mediastinum, (5) B-type natriuretic peptide ≥100pg/mL, (6) a previous history of cardiovascular disease, (7) atrial fibrillation, (8) hypertension, (9) diabetes mellitus, (10) current or ex-smoker.

Results

The relative decrease in LVEF after chemotherapy for patients with more than four risk factors was significantly greater than that for patients without (−9.3±10.8% vs. −2.2±10.2%; p=0.02). However, this finding did not apply to patients with more than one, two or three risk factors. Patients with more than four risk factors also tended to show a higher prevalence of CTRCD than those without (14.3% vs. 2.8%, p=0.12). Moreover, patients with more than four risk factors were more likely to have higher LV mass index (109.3±29.0 g/m2 vs. 83.2±21.0g /m2, p&lt;0.001), lower global longitudinal strain (18.4±2.8% vs. 20.0±2.6%, p=0.06) and higher E/e' (10.4 (8.9–13.0) vs. 9.0 (7.4–10.9), p=0.06) compared to those without.

Conclusions

Association between clinical risk factors and LV dysfunction following chemotherapy became stronger with an increase in the number of risk factors in breast cancer patients, and was especially strong for patients treated with chemotherapy who had more than four risk factors. Our findings can thus be expected to have clinical implications for better management of patients with breast cancer referred for chemotherapy.

Funding Acknowledgement

Type of funding source: None

Consideration of non-valvular atrial fibrillation with left atrial appendage thrombus formation despite under appropriate oral anticoagulation therapy

Background

Atrial fibrillation (AF) is the most frequently sustained cardiac arrhythmia, with a prevalence of about 2–3% in the general population. In accordance with CHADS2 or CHA2DS2-VASc score, appropriate oral anticoagulation therapy such as warfarin or direct oral anticoagulants (DOAC) significantly reduced the risk of thromboembolic events. However, left atrial (LA) thrombus can be detected in the LA appendage (LAA) in AF patients despite appropriate oral anticoagulation therapy.

Purpose

Our purpose was to investigate the associated factors of LAA thrombus formation in non-valvular atrial fibrillation (NVAF) patients despite under appropriate oral anticoagulation therapy.

Methods

We retrospectively studied consecutive 286 NVAF patients for scheduled catheter ablation or electrical cardioversion for AF in our institution between February 2017 and September 2019. Mean age was 67.1±9.4 years, 79 patients (29.5%) were female, and 140 (52.2%) were paroxysmal AF. All patients underwent transthoracic and transesophageal echocardiography before catheter ablation or electrical cardioversion. All patients received appropriate oral anticoagulation therapy including warfarin or DOAC for at least 3 weeks prior to transesophageal echocardiography based on the current guidelines. LAA thrombus was defined as an echodense intracavitary mass distinct from the underlying endocardium and not caused by pectinate muscles by at least three senior echocardiologists.

Results

Of 286 NVAF patients with under appropriate oral anticoagulation therapy, LAA thrombus was observed in 9 patients (3.3%). Univariate logistic regression analysis showed that age, paroxysmal AF, CHADS2 score ≥3, left ventricular end-diastolic volume index (LVEDVI), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI), LA volume index (LAVI), mitral inflow E and mitral e' annular velocities ratio (E/e'), and LAA flow were associated with LAA thrombus formation. It was noteworthy that multivariate logistic regression analysis showed that LAA flow was independent predictor of LAA thrombus (OR: 0.72, 95% CI: 0.59–0.89, p&lt;0.005) as well as LVEF. Furthermore, receiver operating characteristic (ROC) curve analysis identified the optimal cutoff value of LAA flow for predicting LAA thrombus as ≤15cm/s, with a sensitivity of 88%, specificity of 93%, and area under the curve (AUC) of 0.95.

Conclusions

LAA flow was strongly associated with LAA thrombus formation even in NVAF patients with appropriate oral anticoagulation therapy. According to our findings, further strengthen of oral anticoagulation therapy or percutaneous transcatheter closure of the LAA may be considered in NVAF patients with appropriate oral anticoagulation therapy but low LAA flow, especially &lt;15cm/s.

Funding Acknowledgement

Type of funding source: None