The combined application of the contrast-to-noise index and 80 kVp for cardiac CTA scanning before atrial fibrillation ablation reduces radiation dose exposure

INTRODUCTION

To compare the radiation dose, diagnostic accuracy, and the resultant ablation procedures using 80 and 120-kVp cardiac computed tomography angiography (CCTA) protocols with the same contrast-to-noise ratio in patients scheduled for atrial fibrillation (AF) ablation.

METHODS

This retrospective study was performed following institutional review board approval. We divided 140 consecutive patients who had undergone CCTA using a 64-MDCT scanner into two equal groups. Standard deviation (SD) of the CT number was set at 25 Hounsfield units (HU) for the 120-kVp protocol. To facilitate a reduction in radiation dose it was set at 40 HU for the 80 kVp protocol. We compared the two protocols with respect to the radiation dose, the diagnostic accuracy for detecting left atrial appendage (LAA) thrombi, matching for surface registration, and the resultant ablation procedures.

RESULTS

At 120 kVp, the dose length product (DLP) was 2.2 times that at 80 kVp (1269.0 vs 559.0 mGy cm, p < 0.01). The diagnostic accuracy for thrombus detection was 100% using both protocols. There was no difference between the two protocols with respect to matching for surface registration. The protocols did not differ with respect to the subsequent time required for the ablation procedures and the ablation fluoroscopy time, and the radiation dose (p = 0.54, 0.33, and 0.32, respectively).

CONCLUSION

For the same CNR, the DLP at 80 kVp (559.0 mGy cm) was 56% of that delivered at 120 kVp (1269.0 mGy cm). There was no reduction in diagnostic accuracy.

IMPLICATIONS FOR PRACTICE

Maintaining CNR allows for a reduction in the radiation dose without reducing the image quality.

Activation of Hepatic Stellate Cells Requires Dissociation of E-Cadherin-Containing Adherens Junctions with Hepatocytes

Hepatic stellate cells (HSCs) are resident mesenchymal cells in the space of Disse interposed between liver sinusoidal endothelial cells and hepatocytes. Thorn-like microprojections, or spines, project out from the cell surface of HSCs, crossing the space of Disse, to establish adherens junctions with neighboring hepatocytes. Although HSC activation is initiated largely from stimulation by adjacent cells, isolated HSCs also activate spontaneously in primary culture on plastic. Therefore, other unknown HSC-initiating factors apart from paracrine stimuli may promote activation. The dissociation of adherens junctions between HSCs and hepatocytes as an activating signal for HSCs was explored, establishing epithelial cadherin (E-cadherin) as an adhesion molecule linking hepatocytes and HSCs. In vivo, following carbon tetrachloride-induced liver injury, HSCs lost their spines and dissociated from adherens junctions in the early stages of injury, and were subsequently activated along with an increase in YAP/TAZ expression. After abrogation of liver injury, HSCs reconstructed their spines and adherens junctions. In vitro, reconstitution of E-cadherin-containing adherens junctions by forced E-cadherin expression quiesced HSCs and suppressed TAZ expression. Additionally, increase of TAZ expression leading to the activation of HSCs by autocrine stimulation of transforming growth factor-β, was revealed as a mechanism of spontaneous activation. Thus, we have uncovered a critical event required for HSC activation through enhanced TAZ-mediated mechanotransduction after the loss of adherens junctions between HSCs and hepatocytes.

Recent progress in space weather research for cosmic radiation dosimetry

The radiation environment in space is a complex mixture of particles of solar and galactic origin with a broad range of energies. In astronaut dose estimation, three sources must be considered: galactic cosmic radiation, trapped particles, and solar energetic particles (SEPs). The astronaut dose due to SEP exposure during a space mission is more difficult to estimate than the other components because the occurrence of a large solar particle event cannot be predicted by the current space weather research. Thus, several models have been proposed to estimate the worst-case scenario and/or the probability of the integral SEP fluence during a particular space mission, considering the confidence level, solar activity, and duration of the mission. In addition, recent investigations of the cosmogenic nuclide concentrations in tree rings and ice cores have revealed that the sun can cause solar particle events much larger than the largest event recorded in the modern solar observations. If such an extreme event occurs during a mission to deep space, astronauts may suffer from radiation doses in excess of the threshold value for some tissue reactions (0.5 Gy) and their career limit (0.6-1.2 Sv). This article reviews the recent progress made in space weather research that is useful for cosmic radiation dosimetry.

Adjuvant management of locally advanced oral squamous cell carcinoma - real-world challenges and opportunities

Patients with locally advanced oral squamous cell cancer (LAOSCC) are treated with adjuvant radiotherapy (RT) or chemoradiotherapy (CRT) following surgical ablation. This depends on the pathological risk factors and aims to reduce the risk of local recurrence and improve survival. Delivery of these aggressive treatments is, however, challenging particularly following major surgery. To inform the adaptations necessary to deliver gold-standard therapy, we aimed to describe real-world delivery of multimodality treatment in LAOSCC, in a UK population with high levels of disease incidence and low socioeconomic status. Patients with LAOSCC (T1-4 N1-3/T3-4 N0) who were treated between October 2014 and October 2016 and had a minimum follow up of 24 months were included. They were identified using the Somerset Cancer Register and data were collected through retrospective case note review. Approval was obtained from the audit departments at the relevant NHS institutions, and data were analysed using IBM SPSS Statistics for Windows version 24 (IBM Corp). The analysis included 129 patients with 82% having an initial performance status (PS) of 0-1. The most frequent change in PS was a one point drop (46%). Twenty of the 93 eligible patients (22%) underwent adjuvant CRT. A total of 37 (40%) began adjuvant CRT/RT within 42 days, and 79 (85%) within 56 days. A delay in initiating adjuvant therapy was associated with higher rates of complications and a longer postoperative hospital stay. Concordance between imaging and pathological nodal staging was poor (cK 0.223). PS frequently declines after complex surgical procedures and long postoperative recovery periods, leading to difficulties providing adjuvant treatments within the national guidance of 42 days. Frequent deviation from planned adjuvant therapies highlights the need for improved treatment strategies.

Validity of ultrasound arterial wall vascularization for assessment of vascular inflammation

Background

Vascular inflammation plays a fundamental role in most vascular diseases including atherosclerosis and vasculitis syndrome, in which arterial wall vascularization (AWV) frequently develops. Visualization of AWV is informative in detecting the vascular inflammation but is challenging. A new ultrasound technique (superb micro-vascular imaging [SMI]) allows the detection of extremely low-velocity flows. We examined an availability of SMI for assessment of the instability of atherosclerotic plaques and the activity of Takayasu arteritis (TA).

Methods and results

The study consists of two independent and consecutive parts A and B, examined in carotid stenosis (A) and TA (B), respectively. In part A, 12 patients with symptomatic severe carotid stenosis (CS group) scheduled for carotid endarterectomy were enrolled. In six of 12 patients, preoperative ultrasonography with SMI showed intraplaque neovascularization at the plaque shoulder. Postoperatively, histopathology confirmed the neovessels at the corresponding sites of visualized AWV. SMI had a sensitivity of 67%, specificity of 90% for detection of AWV in CS group. In SMI analysis, false positive findings were caused by motion artifact and arterial wall calcification, and a false negative finding is attributed by intraplaque hemorrhage. In part B, 10 patients with TA were enrolled. All patients underwent 18F-FDG-PET/CT, and its vascular uptake were compared with AWV detected by SMI. Bilateral common carotid arteries (CCA), internal carotid arteries and common iliac arteries were examined by SMI. Active vascular 18F-FDG uptake (max SUV &gt;2.1) were found at five sites in three patients, which were not significantly correlated with the prevalence of macaroni sign, increase in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Of note, SMI revealed AWV at five sites corresponding to uptake of 18F-FDG, with a sensitivity/specificity of 100% and 98%, positive predictive value 71%, and a negative predictive value 100%.

Conclusion

SMI enables visualization of AWV at vulnerable plaque in CS patients and at 18F-FDG positive sites in TA patients. SMI has potential as a modality to detect the vascular inflammation.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Scientific Research, Japan

Inhibition of xanthine oxidase ameliorates functional and metabolic impairment in type 2 diabetic hearts under pressure overload

Background

We recently reported that upregulated AMP deaminase (AMPD), via reduction in the tissue adenine nucleotide pool, contributes to exacerbation of diastolic dysfunction under pressure overload in OLETF, a rat model of obese type 2 diabetes (T2DM). Upregulated AMPD also possibly promotes xanthine oxidase (XO)-mediated ROS production, since AMPD deaminases AMP to IMP, which is further converted to inosine, providing substrates of XO, hypoxanthine and xanthine. Here, we examined the hypothesis that inhibition of XO ameliorates the pressure overload-induced diastolic dysfunction by suppression of ROS-mediated mitochondrial dysfunction and/or vascular dysfunction in T2DM rats.

Methods and results

Metabolomic analyses revealed that levels of xanthine and uric acid in the LV myocardium were significantly higher by 37% and 51%, respectively, in OLETF than in LETO, non-diabetic control rats, under the condition of phenylephrine-induced pressure overloading (200–230 mmHg). Myocardial XO activity in OLETF was 57.9% higher than that in LETO, which may be attributed to 31% higher level of inosine, a positive regulator of XO, in OLETF than in LETO. The activity of XO was significantly attenuated by administration of topiroxostat, an XO inhibitor at 0.5 mg/kg/day for 14 days. Pressure volume loop analyses showed that the pressure overloading resulted in significantly higher LVEDP in OLETF than in LETO (18.3±1.5 vs. 12.2±1.3 mmHg, p&lt;0.05, n=7), though LVEDPs at baseline were comparable in OLETF and LETO (5.6±0.4 vs. 4.7±0.7 mmHg). Treatment with topiroxostat significantly suppressed the pressure overload-induced elevation of LVEDP in OLETF (18.3±1.5 vs. 11.3±1.1 mmHg, p&lt;0.05) but not in LETO. Under the condition of pressure overloading, Ea/Ees, an index for ventricular-arterial coupling, was higher in OLETF than in LETO (2.3±0.3 vs. 1.6±0.3, p&lt;0.05), and it was also improved by topiroxostat in OLETF (1.2±0.2, p&lt;0.05). Myocardial ATP content was lower in OLETF than in LETO (2966±400 vs. 1818±171 nmol/g wet tissue, p&lt;0.05), and treatment with topiroxostat significantly restored the ATP level (2629±307 nmol/g wet tissue). The LV myocardium of OLETF under pressure overload showed significantly higher level of malondialdehyde and 4-hydroxynonenal, an indicator of lipid peroxidation, than that of LETO. Measurement of oxygen consumption rate by Seahorse XFe96 Analyzer in mitochondria isolated from LV tissues revealed that state 3 respiration was significantly suppressed in OLETF by 43% compared to LETO, and it was restored by treatment with topiroxostat.

Conclusion

Both activity and substrates of XO are increased in T2DM hearts, in which upregulation of AMPD may play a role. Inhibition of XO ameliorates pressure overload-induced diastolic dysfunction and improves ventricular-arterial coupling in diabetic hearts, most likely through protection of mitochondrial function from ROS-mediated injury.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in-aid for Scientific Research (#26461132, #17K09584) from the Japanese Society for the Promotion of Science

Utility of superb microvascular imaging for assessment of foot perfusion in patients with critical limb ischemia

Background

Recently, an increasing attention has been paid to foot microcirculation in critical limb ischemia (CLI). Although skin perfusion pressure (SPP) is the most frequently used marker of microcirculation, SPP is often unmeasurable at the most ischemic site in the foot. A new ultrasound technique (superb micro-vascular imaging [SMI]) allows the detection of extremely low velocity flows and enables the quantitative verification as vascular index (VI). We examined the diagnostic value of SMI-based VI in assessing foot perfusion when planning endovascular treatment (EVT).

Methods

Consecutive 50 patients with CLI were enrolled. All cases underwent EVT for superficial femoral arteries. SMI-based VI of plantar, dorsal, medial heel, lateral heel and toe's area were obtained before and after EVT, and those were compared with SPP (plantar and dorsal) or ankle-brachial index (ABI) representing macrocirculation.

Results

Based on the six angiosomes concept, SMI enabled to visualize microcirculation in all subjects, but SPP was not feasible in 13% of all subjects at the most ischemic site. After EVT, ABIs were significantly increased from 0.64±0.19 to 0.85±0.27 (P=0.0003). Plantar SPP also increased from 39.6±20.4 mmHg to 58.5±27.1 mmHg (p=0.002). SMI-based VI significantly increased in each sites based on the six angiosomes concept. Of note, plantar SMI-based VI significantly increased from 5.1±3.2% to 10.6±6.6% (p&lt;0.0001), suggesting improvement of foot perfusion. Plantar SMI-based VI was well correlated with plantar-SPP both before and after EVT (p=0.002, r=0.663). Plantar VI was also informative in showing a rapid improvement of foot perfusion during EVT.

Conclusion

SMI enabled to visualize the foot microcirculation on the basis of angiosomes concept. SMI has potential as an alternative to SPP.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Grant-in -Aid for Scientific Reseach, Japan

Plaque erosion is associated with less systemic atherosclerosis than other plaque types of acute coronary syndrome

Background

Previous studies have demonstrated that plaque erosion is associated with less atheromatous plaque at both culprit and non-culprit lesion than other plaque types of acute coronary syndrome (ACS). However, the status of systemic atherosclerosis in patients with plaque erosion remains to be elucidated.

Purpose

To clarify if plaque erosion is associated with less systemic atherosclerosis than other plaque types of ACS.

Methods

A total of 239 consecutive patients with ACS who underwent optical coherence tomography (OCT) imaging of the culprit lesion were enrolled. Patients were classified into either plaque erosion (PE, n=45) or non-plaque erosion (non-PE, n=194) including plaque rupture and calcified nodule based on OCT findings of the culprit lesions. The status of systemic atherosclerosis was assessed by the findings of carotid echography, the severity of aortic arch calcification (AAC; grade 0–3) on chest X-ray, brachial-ankle pulse wave velocity (baPWV) and ankle-brachial pressure index (ABPI).

Results

The maximum intima media thickness (IMT) was significantly thinner in the PE group than in the non-PE group (1.9±0.8 vs. 2.3±0.9 mm, p=0.023) (Panel A). The prevalence of heterogeneous plaque and calcified plaque was significantly lower in the PE group than in the non-PE group (25.0 vs. 50.4%, p=0.010, 18.8 vs. 38.5%, p=0.037, respectively). The prevalence of AAC grade was significantly different between the two groups with a tendency toward lower AAC grade in the PE group than the non-PE group (Panel B). The mean baPWV (1588.1±420.6 vs. 1686.5±363.5 cm/sec, p=0.186) and ABPI (1.1±0.1 vs. 1.1±0.1, p=0.270) was comparable between the two groups.

Conclusion

Plaque erosion was associated with less atherosclerosis in carotid artery and aortic arch than non-plaque erosion. These findings may help further clarify the distinct pathophysiology of plaque erosion.

Funding Acknowledgement

Type of funding source: None

Lower levels of low-density lipoprotein cholesterol are associated with lower prevalence of thin-cap fibroatheroma in statin-treated patients with coronary artery disease

Background

Lowering low-density lipoprotein cholesterol (LDL-C) with statins slows progression of atherosclerotic plaques and reduces cardiovascular events. The 2019 European Society of Cardiology guideline for the management of dyslipidaemias recommends the absolute LDL-C treatment target as &lt;55mg/dL for very high-risk patients, &lt;70 mg/dL for high-risk patients and &lt;100 mg/dL for moderate-risk patients. However, the difference in plaque composition of coronary lesions according to these LDL-C levels remains to be elucidated.

Purpose

To investigate plaque morphologies according to LDL-C levels in statin-treated patients with coronary artery disease (CAD).

Methods

A total of 685 consecutive statin-treated patients with CAD, who underwent optical coherence tomography (OCT) imaging of culprit lesions were enrolled. The prevalence of vulnerable compositions in culprit plaques evaluated by OCT was compared among the groups of patients classified by LDL-C levels (&lt;55, 55–70, 70–100, ≥100 mg/dL).

Results

LDL-C levels &lt;55 mg/dL, &lt;70 mg/dL and &lt;100 mg/dL were observed in 6.3%, 21.8% and 63.9% of patients, respectively. The prevalence of thin-cap fibroatheroma was significantly different among the groups (P=0.014, Figure) with a trend toward lower prevalence in the lower two LDL-C groups than in the higher two LDL-C groups. A gradient with lower prevalence of thrombus in lower LDL-C groups was observed, although the statistical significance was not demonstrated (Figure). There was no significant difference in the prevalence of macrophage or cholesterol crystal among the groups.

Conclusions

Lower LDL-C level was associated with a trend toward lower prevalence of thin-cap fibroatheroma and thrombus in statin-treated patients with CAD.

Funding Acknowledgement

Type of funding source: None

Higher level of high sensitivity C-reactive protein is associated with more fibrocalcific plaque and longer lesion in patients with acute coronary syndrome

Background

The association between the level of high sensitivity C-reactive protein (hsCRP) and coronary plaque characteristics in patients with acute coronary syndrome (ACS) remains to be elucidated.

Purpose

To clarify the morphological characteristics of culprit lesion in patients with ACS according to the hsCRP levels using optical coherence tomography (OCT).

Methods

A total of 215 consecutive patients with ACS, who underwent OCT imaging of culprit lesions were included. The patients were classified into either the higher hsCRP group (hsCRP ≥0.14 mg/dL, n=108) or the lower hsCRP group (hsCRP &lt;0.14 mg/dL, n=107) according to the median preprocedural hsCRP level. The morphological characteristics of culprit lesion assessed by OCT were compared between the two groups.

Results

The higher hsCRP group had higher prevalence of insulin therapy (14 vs. 6%, p=0.037) and current smoker than the lower hsCRP group (37 vs. 18%, p=0.002). The prevalence of long lesion (≥25 mm, 67 vs. 53%, p=0.041) and fibrocalcific plaque (53 vs. 33%, p=0.003) was significantly higher in the higher hsCRP group than in the lower hsCRP group (Figure). On the other hand, the prevalence of plaque rupture (36 vs. 46%, p=0.174) and lipid-rich plaque (47 vs. 64%, p=0.011) was rather lower in the higher hsCRP group than in the lower hsCRP group (Figure). In a multivariate analysis, fibrocalcific plaque (odds ratio [OR]: 2.098, 95% confidence interval [CI]: 1.125–3.913, p=0.019), lesion length (mm, OR: 1.036, 95% CI: 1.010–1.061, p=0.004) and current smoker (OR: 2.757, 95% CI: 1.388–5.476, p=0.003) was independently associated with higher hsCRP level.

Conclusions

ACS patients with high hsCRP levels had more fibrocalcific plaque and longer lesion than those with low hsCRP levels. The association between high hsCRP levels and vulnerable characteristics of culprit plaque was not demonstrated.

Funding Acknowledgement

Type of funding source: None

Remote monitoring can predict lethal arrhythmic events through time-domain analysis of heart rate variability in patients with implantable cardioverter defibrillator

Background

We prospectively collected device and heart rate data, i.e. heart rate variability (HRV), through remote monitoring (RM) of patients with implantable cardioverter defibrillator (ICD). Several studies have demonstrated usefulness of RM in implanted device patients, however, reports concerning the predictors of lethal ventricular arrhythmias are limited.

Purpose

The objective was to identify the predictors of lethal arrhythmic events (VT/VF).

Methods

Thirty-three patients (mean age: 50 years) with ICDs [with functionality of HRV analysis] were divided into 2 groups [VT/VF(+), VT/VF(−)]. Clinical, device (ventricular lead impedance; amplitude of ventricular electrogram), and HRV data were compared between the 2 groups. As the index of time-domain HRV analysis, NN intervals-index (SDNNi) was calculated for every 5 minutes, and the mean, maximum, and minimum SDNNi during the 24-hour period were used.

Results

During the observation period (median 12 months), 10 patients experienced VT/VF events. In HRV data, the mean, max, and min SDNNi were higher in VT/VF(+) than VT/VF(−) group (132.9±9.3 v.s. 93.5±6.1, p=0.0013; 214.6±10.6 v.s. 167.0±7.0, p=0.0007; 71.2±7.5 v.s. 43.9±4.9, p=0.0047). The other parameters did not exhibit significant difference. On logistic regression analysis, the mean SDNNi of 100.1, max SDNNi of 185.0 and min SDNNi of 52.0 as cut-off values for prediction of VT/VF event demonstrated significant receiver operating characteristics (ROC) curves (AUC=0.86, p=0.0007; AUC=0.84, p=0.0005; AUC=0.78, p=0.0030). Furthermore, in cases of VT/VF(+) group, the max ΔSDNNi, i.e., difference from baseline SDNNi, and min ΔSDNNi in 7 and 28 days preceding VT/VF events exhibited time course changes in comparison with baseline values. They were significant predictors of VT/VF events (max ΔSDNNi cut-off: 46.8, AUC=0.91, p=0.0002; min ΔSDNNi cut-off: −42.4, AUC=0.88, p=0.0014).

Conclusion

Time-domain analysis of HRV through RM may help identify patients at high risk of lethal arrhythmic events, and predict occurrence of such arrhythmic events.

Funding Acknowledgement

Type of funding source: None

Long-term prognostic significance of dispersion of ventricular repolarization in patients with cardiac sarcoidosis

Background

Although the presence of cardiac involvement is recognised as a determinant of worse clinical outcomes in sarcoidosis patients, the determinants of adverse outcomes in patients with cardiac sarcoidosis (CS) have not been well understood. T-peak to T-end interval (TpTe) on the surface electrocardiogram (ECG) was proposed as a marker of dispersion of ventricular repolarisation. Prolonged TpTe to QT interval ratio (TpTe/QT) represents a period of potential vulnerability to reentrant ventricular arrhythmias. Notably, prolonged TpTe/QT has been associated with increased risk of mortality in hypertrophic cardiomyopathy, congenital long-QT syndrome, and Brugada syndrome. However, its prognostic implication in patients with CS is unclear.

Purpose

We sought to investigate whether TpTe/QT was associated with long-term clinical outcomes in patients with CS.

Methods

A total of 108 consecutive CS patients between August 1986 and March 2019 in two academic hospitals who had ECG data before initiation of immunosuppressive therapy were examined. We excluded patients who received pacemaker (n=15) or cardiac resynchronization therapy (n=3) at the time of ECG. Ultimately, 90 CS patients were included in this study. All standard 12-lead ECGs were recorded at 25 mm/s with an amplification of 10 mm/mV. TpTe was measured from the peak of T wave to the end of T wave which defined as the intersection of the tangent to the down slope of the T wave and the isoelectric line. Lead V5 was selected for the analyses. If V5 is not suitable for analyses, V4 was selected. The primary outcome was the composite of advanced atrioventricular block (AVB), ventricular tachycardia or ventricular fibrillation (VT/VF), heart failure hospitalisation and all-cause death.

Results

During a median follow-up period of 4.70 (interquartile range [IQR] 2.06–7.23) years, adverse events occurred in 21 patients (23.3%), including 2 advanced AVB, 12 VT/VF, 4 heart failure hospitalisation and 3 all-cause death. Events group had higher TpTe/QT compared to no events group (0.231 [IQR 0.193–0.261] vs. 0.282 [IQR 0.263–0.304] P&lt;0.001). Kaplan-Meier analyses revealed that the primary outcome, especially VT/VF or sudden cardiac death more frequently occurred in patients with higher TpTe/QT (≥0.242, the median) compared to those with lower TpTe/QT (Figure 1). Multivariable Cox regression analysis showed that higher TpTe/QT was independently associated with increased subsequent risk of adverse events (hazard ratio 1.09, 95% confidence interval [CI] 1.02–1.17, P=0.014) even after adjustment for age, sex and left ventricular ejection fraction. Furthermore, the optimal cut-off value of TpTe/QT for the discriminatory of primary outcome was 0.257, and c-index was 0.77 (95% CI 0.64–0.89).

Conclusions

Higher TpTe/QT was associated with worse long-term clinical outcomes in patients with CS. Our findings indicate the importance of assessing TpTe/QT for risk stratification in patients with CS.

Figure 1

Funding Acknowledgement

Type of funding source: None

Prognostic impact of right ventricular overload in patients with acute coronary syndrome

Background

Right ventricular (RV) overload is associated with adverse outcome in patients with chronic heart failure. However, its prognostic value in acute coronary syndrome (ACS) patients remains unknown.

Purpose

The purpose of this study was to investigate the prevalence and prognostic impact of right ventricular overload in ACS patients.

Methods

We studied 2797 ACS patients from Mie ACS registry, a prospective and multicenter registry in Japan. They were divided into 4 subgroups according to the severity of RV overload and the extent of Left Ventricle Ejection Fraction (LVEF) assessed by echocardiography before hospital discharge. High RV overload was defined as trans-tricuspid pressure gradient (TRPG) ≥40mmHg and preserved LVEF was defined as ≥50%. The primary outcome was defined as 2-year all-cause mortality. Median follow up duration was 730 days (1–2215 days).

Results

High RV overload was detected in 76 patients (2.7%). In basic patients characteristics, high RV overload patients were significantly older and higher killip classification than low RV overload patients (P&lt;0.01, respectively). Laboratory data in high RV overload patients showed lower hemoglobin level and higher serum creatinine level than those in low RV overload patients (P&lt;0.01, respectively).

Echocardiographic findings in high RV overload represented lower LVEF, higher rate of moderate or severe mitral regurgitation and left atrial enlargement than those in low RV overload patients (P&lt;0.01, respectively).

During the follow-up periods (median 730 days), 260 (9.3%) patients experienced all-cause death. Multivariate cox hazard regression analysis for all-cause mortality demonstrated that high RV overload was an independent poor prognostic factor in the entire study population. Among patients with preserved LVEF, high RV overload resulted in an increased risk of all-cause mortality compared to low RV overload (P&lt;0.0001).

Conclusion

In ACS patients, high RV overload strongly contributes to worsening of prognosis regardless of the extent of LVEF.

Kaplan-Meier survival curve

Funding Acknowledgement

Type of funding source: None

Impact of hinge motion on stent edge restenosis after new generation drug-eluting-stent implantation in RCA

Background

Edge restenosis still occurs after stent implantation, even by using new generation drug-eluting stents (DES) considered to have favorable biomechanical properties. Mechanical stress imposed on the stent edge are thought to be aggravated by hinge motion at a point between the stented and unstented segments, inducing chronic local inflammation and neointimal overgrowth.

Purpose

The aim of this study was to investigate the association between the development of edge restenosis and hinge motion in right coronary artery (RCA) where the excessive vessel movement is commonly observed.

Methods

Among consecutive 650 lesions in RCA where new generation DESs were implanted between 2009 and 2019, 427 serial lesions with sets of angiographies at baseline and follow-up (6–18 month) were included. In addition to conventional quantitative angiography analysis, hinge angle at stent edges was measured (Fig. 1). All the appropriate data for intravascular imaging were analyzed for both stent edges and reference segments.

Results

Binary restenosis occurred in 43 lesions, and 39 of them were referred to re-intervention. Fifty five percent of them were related to stent edges (15 at proximal and 9 at distal edges). Classical risk factors including diabetes and hemodialysis were more prevalent in the restenosis group (p&lt;0.05). Hinge angle was statistically larger in edge restenosis group than body restenosis or no restenosis group (17.3° vs 11.6° vs 10.6°, p&lt;0.001, Fig. 2). In per-edge analysis, hinge angle, dissection and residual plaque ratio were the independent predictors for binary restenosis (Table 1) with the optimal cut-off value of hinge angle 11.5°. The coexistence of excessive hinge angle and residual plaque burden had an amplified effect on the angiographic stenotic progression at stent edge (p for interaction &lt;0.001) and the incidents of binary restenosis (16.7% vs 1.7% p&lt;0.01, Figs. 3,4).

Conclusion

Substantial stress determined by angulation at the stent edge and its interaction with residual plaque can be considered as one of the plausible mechanisms for edge restenosis. For tortuous RCA lesions, it would be important to decide the stent-landing zone for minimizing hinge motion and optimize the future stent design.

Funding Acknowledgement

Type of funding source: None

Effects of laundry-hanging motion on oxygen uptake and ventilation in healthy young women

Many patients with chronic obstructive pulmonary disease (COPD) experience problems during performance of activities of daily living. These problems may lead to reduced physical activity. The purpose of this study was to reveal the influence on the oxygen uptakes in motion methods of hanging on laundry. Eighteen healthy females were recruited for participation in this study. They performed three kinds of movement to hang on laundry. Participants performed the following three actions: (1) hanging some towels on bars with a low stand in a sitting position (Action 1), (2) hanging some towels on bars with a low stand in a standing position (Action 2) and (3) hanging some towels on bars with a high stand in a standing position (Action 3). We measured metabolic and ventilatory requirements during these actions by use of an expires gas analyser. Mutual comparison of the three different types action showed significant differences in the oxygen uptake (VO2), carbon dioxide output (VCO2), minute ventilation (VE), and metabolic equivalents (METs). On the other hands, the differences in respiratory rate (RR) among these three actions were not significant. Action 3 tended to have the most increased values in VO2, VCO2, VE and METs. The Action 1 tended to behave the lowest value. The oxygen uptake and ventilation variables may be influenced by the methods used in hanging laundry.