Testing mosses exposed in bags as biointerceptors of airborne radiocaesium after the Fukushima Dai-ichi Nuclear Power Station accident

Eight years after the Fukushima nuclear accident, mosses exposed in bags were used to investigate their ability to accumulate radiocaesium and therefore to act as biointerceptors of ¹³⁴Cs and ¹³⁷Cs in the evacuated area of the Fukushima territory. Bags were filled with 3 widely studied moss species (Sphagnum palustre, Hypnum cupressiforme, and Hypnum plumaeforme) and exposed for 3, 6 or 9 weeks at 5 former residential sites within the Fukushima area and, for comparison, at three background sites located 700 km away. The radiocaesium activity concentrations found in moss bags were evaluated as function of exposure time, site conditions and moss species. In the Fukushima area, the moss bags accumulated ¹³⁷Cs at all exposure sites and in all exposure periods, with S. palustre having the highest ¹³⁷Cs accumulation ability. The ¹³⁷Cs activity concentrations (from 28 to 4700 Bq kg^-1) measured in moss bags increased with the exposure time and were consistent with the decontamination status of each exposure site, highlighting the big potential of moss bags to discriminate among exposure sites. Time dependency of ¹³⁷Cs activity concentrations measured in mosses allowed the calculation of location-specific and species-specific factors, which can be used to predict radiocaesium accumulation trends in future biomonitoring surveys performed in the same area with the same experimental design. Autoradiography and electron microscopy analyses of the moss surfaces revealed a prevalence of soil-derived particulate form of radiocaesium, suggesting the use of moss bags as warning sensors of resuspended particles potentially harmful for local residents.

Additional clinical impact of plaque analysis for on-site CT-derived FFR in coronary CT angiography on midterm prognosis

Background

We previously reported that per-patient on-site computed tomography-fractional flow reserve (CT-FFR), which can be acquired on-site workstation using fluid structure interaction during the multiple optimal diastolic phases measured 1 to 2 cm distal to a target lesion may be feasible for risk stratification based on future cardiac events for patients who did not undergo planned revascularization. However, per-vessel CT-FFR and the additional impact of plaque analysis on CT-FFR have not been evaluated.

Purpose

The aim of this study is to assess the clinical and additional impact of novel plaque analysis using labeling method for per-vessel CT-FFR on midterm prognosis.

Methods

A total of 254 consecutive patients with 354 vessels showing 50–90% stenosis but not revascularized within 90 days from coronary CT angiography (CCTA) on 320-row CT were retrospectively analyzed and followed during a median follow up 3.6 years. Plaque characteristics by labeling method (necrotic core/total plaque volume (% necrotic core), non-calcified plaque (NCP)/vessel volume (%NCP), and total plaque/vessel volume (%total plaque) for both total vessel volume (mm3) and at minimum lumen area (MLA, mm2)), positive remodeling (PR) and CT-FFR were analyzed on per-target vessels. The endpoint was vessel oriented-composite outcome (VOCO), including cardiac death, non-fatal MI, and unplanned revascularization.

Results

The incidence of VOCO occurred in 6.8% (24/354). In the cox proportional hazard model, a multivariate analysis identified CT-FFR≤0.80 was the most associated factor with VOCO (all values <0.01 for other plaque morphologies), but %necrotic core, %NCP, %total plaque at MLA and PR were significantly independent of CT-FFR≤0.80. (%necrotic core HR; 3.43 (p<0.01 [95% confidence interval (CI) 1.42–8.29]), %NCP HR; 4.05 (p=0.03 [95% CI 1.19–13.71]), %total plaque at MLA HR; 2.82 (p=0.02 [95% CI 1.18–6.76]), and PR HR; 2.90 (p<0.01 [95% CI 1.30–6.51]), respectively.)

Conclusion

From a view point of clinical outcomes for vessels with moderate to severe stenosis but not revascularized at initial CCTA, CT-FFR demonstrated the significant impact on per-vessel analysis. Moreover, %necrotic core, %NCP and %total plaque at MLA analyzed by labeling method provided better prognostic value in addition to CT-FFR.

Funding Acknowledgement

Type of funding sources: None.

Clinical trajectory and outcomes of patients with heart failure with preserved ejection fraction with normal or indeterminate diastolic function

Background

Heart failure (HF) with preserved ejection fraction (HFpEF) is a chronic and progressive disease, but limited therapeutic strategies are currently available. Although left ventricular diastolic dysfunction (DD) is a prominent mechanism of HFpEF, a certain number of patients with HFpEF have a normal diastolic function (ND) or indeterminate diastolic function (ID). With the progressive nature of HFpEF, diastolic function may change over time. However, the change of diastolic function, its predictor and prognosis in patients with clinically established HFpEF remains unknown.

Purpose

To investigate the clinical trajectory and outcomes of patients with HFpEF with ND or ID and to identify factors associated with progression from ND or ID at discharge to DD at 1-year follow-up.

Methods

Using data from a prospective multicenter observational study of patients with HFpEF, we extracted 289 patients with HFpEF with ND or ID at discharge who had echocardiographic data at 1-year follow-up for the re-evaluation of diastolic function. Diastolic function was assessed according to the 2016 American Society of Echocardiography recommendations. Patients were classified according to the absence or presence of progression from ND or ID to DD at 1 year. The primary endpoint was a composite of all-cause death and HF rehospitalization.

Results

Median age was 81 years, and 138 (47.8%) patients were female. At 1 year, 107 (37%) patients progressed to DD. During a median follow-up of 709 days, the composite endpoint occurred in 90 (31.1%) patients. Compared to patients without progression to DD, those with progression to DD had a significantly higher cumulative incidence rate of the composite endpoint (incidence rate: 11.7/100 person-year versus 23.3/100 person-year, P<0.001). Progression to DD (adjusted HR: 2.014, 95% CI: 1.239–3.273, P=0.005) was independently associated with the composite endpoint. Age (adjusted OR: 1.046, 95% CI: 1.008–1.087, P=0.018), body mass index (BMI) (adjusted OR: 1.107, 95% CI: 1.029–1.192, P=0.006), and serum albumin (adjusted OR: 0.459, 95% CI: 0.216–0.974, P=0.042) were independently associated with progression from ND or ID to DD at 1 year.

Conclusion

More than one-third of patients with HFpEF with ND or ID progressed to DD at 1 year and had poor clinical outcomes. Age, BMI, and serum albumin were independently associated with this progression.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants from Japan Society for the Promotion of Science KAKENHI (No. JP 17K09496) and Japan Agency for Medical Research and Development (No. JP16lk1010013).

Association between prognosis and the use of angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blocker in frail patients with heart failure with preserved ejection fraction

Background

The effectiveness of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARB) has not been demonstrated in patients with heart failure with preserved ejection fraction (HFpEF). We recently reported significant interaction between the use of ACE-I and/or ARB (ACE-I/ARB) and frailty on prognosis in patients with HFpEF.

Purpose

In the present study, we examined the association between ACE-I/ARB and prognosis in patients with HFpEF stratified by the presence or absence of frailty.

Methods

We examined the association between the use of ACE-I/ARB and prognosis according to the presence (Clinical Frailty Scale (CFS) ≥5) or absence (CFS ≤4) of frailty in patients with HFpEF in a post-hoc analysis of registry data. Primary endpoint was the composite of all-cause mortality and heart failure admission. Secondary endpoints were all-cause mortality and heart failure admission.

Results

Of 1059 patients, median age was 83 years and 45% were male. Kaplan-Meier analysis showed that the risk of composite endpoint (log-rank P=0.001) and all-cause death (log-rank P=0.005) in patients with ACE-I/ARB was lower in those with CFS ≥5, but similar between patients with and without ACE-I/ARB in patients with CFS ≤4 (composite endpoint: log-rank P=0.830; all-cause death: log-rank P=0.192). In a multivariable Cox proportional hazards model, use of ACE-I/ARB was significantly associated with lower risk of the composite endpoint (hazard ratio = 0.52, 95% CI: 0.33–0.83, P=0.005) and heart failure admission (hazard ratio = 0.45, 95% CI: 0.25–0.83, P=0.010) in patients with CFS ≥5, but not in patients with CFS ≤4 (composite endpoint: hazard ratio = 1.41, 95% CI: 0.99–2.02, P=0.059; heart failure admission: hazard ratio = 1.43, 95% CI: 0.94–2.18, P=0.091). The association between ACE-I or ARB and prognosis did not significantly differ by CFS (CFS ≤4: log-rank P=0.562; CFS ≥5: log-rank P=0.100, for with ACE-I vs. ARB, respectively). Adjusted HRs for CFS 1–4 were higher than 1.0, but were less than 1.0 at CFS 5.

Conclusions

In patients with HFpEF, use of ACE-I/ARB was associated with better prognosis in patients with frailty as assessed with the CFS, but not in those without frailty.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Roche

Premature atrial contraction on Holter electrocardiogram predicts the recurrence of atrial fibrillation after catheter ablation

Introduction

It is important to detect the recurrence of atrial fibrillation (AF) after catheter ablation (CA) early, but the method of detection has not been established. The purpose of this study is to determine whether 24-h Holter electrocardiogram (ECG) can predict the recurrence of AF after CA.

Methods

We studied 336 patients of 497 patients enrolled in EARNEST-PVI trial to investigate whether the total number of premature atrial contraction (PAC) and the maximum number of PAC run by 24-h Holter ECG at 6 months after CA predicted AF recurrence after 6 months. We excluded 86 patients with recurrence by 6 months after CA and 75 patients without Holter ECG at 6 months after CA.

Results

Median age was 66 years, male were 77% and median follow-up period was 1138 days. Receiver operating characteristic curve analysis identified the total number of PAC ≥270 beats and the maximum number of PAC run ≥8 beats as the optimal cutoff for prediction of AF recurrence. Kaplan-Meier analysis showed patients with the total number of PAC ≥270 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 34% vs. 17%, Log-rank P=0.001) and patients with the maximum number of PAC run ≥8 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 33% vs. 20%, Log-rank P=0.006). Multivariate analysis revealed that the total number of PAC ≥270 beats and the maximum number of PAC run were significantly associated with AF recurrence (hazard ratio [95% confidence interval] 1.83 [1.16–2.91], P=0.01 and 1.01 [1.01–1.02], P=0.001, respectively)

Conclusion

The total number of PAC and the maximum number of PAC run on the Holter ECG may be useful in predicting AF recurrence after CA.

Funding Acknowledgement

Type of funding sources: None.

Impact of heart rate reduction on recurrence after catheter ablation of persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Johnson & Johnson KK

OnBehalf

OCVC Arrhythmia Investigators

Background

Predicting heart rate (HR) after restoration of sinus rhythm (SR) remains one of the challenges when performing catheter ablation (CA) of persistent atrial fibrillation (AF).

Purpose

To evaluate the association between pre-ablation HR during AF and post-ablation HR during SR, and whether the HR reduction is associated with AF recurrence.

Methods

The analysis was performed from the EARNEST-PVI trial, a randomized controlled trial designed to assess a CA strategy for persistent AF, which was conducted in the Osaka region of Japan. After excluding patients with beta-blocker prescription, a total of 216 patients (median age, 67 years; 20% female; 23% long-standing persistent AF) with AF rhythm at baseline and SR at discharge were enrolled in this study. Baseline HR during AF and post-ablation HR during SR was measured on admission and at discharge using the 12-lead electrocardiograms, respectively.

Results

There was a mild correlation between baseline HR (median 82 [interquartile range 72-95] bpm) and post-ablation HR (78 [48-117] bpm) (r = 0.27, p <0.001). Reduction in HR was positively associated with baseline HR (r = 0.79, p <0.001) and was negatively associated with post-ablation HR (r = - 0.37, p <0.001). During the follow-up of 1 year, 56 patients (25.9%) experienced AF recurrence. HR reduction had the higher diagnostic accuracy in predicting AF recurrence than HR at baseline and HR after CA (area under the curve, 0.625; 95% confidence interval, 0.557–0.690; p = 0.003). AF recurrence rate was significantly higher in 141 patients with smaller HR reduction (cut-off, <14bpm) than those with larger HR reduction (31.9% vs. 14.7%, p = 0.009). After adjustment of age, gender, long-standing persistent AF, and CA strategy, HR reduction of <14 bpm was a significant predictor of AF recurrence (hazard ratio, 2.32; 95% confidence interval, 1.20–4.51; p = 0.013).

Conclusions

There was a mild correlation between HR during AF and HR after restoration of SR in patients underwent CA of persistent AF. HR reduction after restoration of SR predicted AF recurrence.

Comparison of clinical effect of living alone between urban area and rural area in patient with acute coronary syndrome

Background and objective

Living alone is reported as an independent risk factor for worse clinical outcomes after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Manifestations of psychological stress such as depression and anxiety in patients living alone is thought to be associated with subsequent cardiovascular events. The impact of living alone on the psychological factors of patients may be differ depending on their living environment. However, comparison of the effects of living alone in different living environment on the prognosis of patients with ACS has not been reported.

Purpose

The aim of the present study was to compare the clinical effect of living alone on clinical outcomes in patients with ACS between urban area and rural area.

Methods

Data from a multi-center, observational study of consecutive patients who underwent emergency PCI for ACS between January 2012 and December 2016 were analyzed. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE). MACCE was defined as composite of cardiovascular death, ACS, and stroke.

Results

In this study, 1349 patients were enrolled and divided into two population according to their living environment: urban area population (n=417), and rural area population (n=932). In urban area population, 87 patients (20.9%) were living alone, and 330 (79.1%) were living together. In rural area population, 169 (18.1%) were living alone, and 763 (81.9%) were living together. There are no significant differences in baseline characteristics between the living alone group and the living together group in both urban area population and rural area population. During a median follow-up period of 2.1 years, Kaplan-Meier curves showed the living alone group had higher risk of MACCE than the living together group in urban area population (log-rank, p=0.01). On the other hands, there are no significant differences in the incidences of MACCE between two groups in rural area population (p=0.86). After adjustment for other covariates, the living alone was significantly associated with MACCE (hazard ratio [HR], 2.83; 95% confidential interval [CI], 1.16–6.91; p=0.02) compared with the living together group in urban area population. However, in rural area population, the living alone group was not significantly associated with MACCE (HR, 1.02; 95% CI, 0.66–1.57; p=0.92) compared with the living together group.

Conclusion

Living alone was significantly associated with worse clinical outcomes after emergency PCI of ACS in urban area but not in rural area.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Reappraising the role of baseline plasma C-reactive protein levels on recurrence after catheter ablation of persistent atrial fibrillation: insight from EARNEST-PVI trial

Background

Subclinical inflammation is an important pathogenesis of developing and sustaining atrial fibrillation (AF). Because AF itself contribute to the inflammatory response, the role of baseline subclinical inflammation on AF recurrence after catheter ablation (CA) remains controversial in patients with persistent AF.

Purpose

To evaluate whether baseline plasma C-reactive protein (CRP) levels, a sensitive marker of inflammation, are associated with AF recurrence following CA.

Methods

The analysis was performed from the EARNEST-PVI trial, a randomized controlled trial designed to assess a CA strategy for persistent AF, which was conducted in the Osaka region of Japan. A total of 441 patients (median age, 67 years; 26% female; 25% long-standing persistent AF) whose plasma CRP levels were measured at baseline were included in this study.

Results

At baseline, a median (interquartile range) of plasma CRP level was 0.10 [0.06–0.19] mg/dl. Plasma CRP levels significantly increased at discharge (0.83 [0.21–1.84] mg/dl, p<0.001) and decreased 1 year after CA (0.10 [0.05–0.20] mg/dl, p=0.040) compared to the baseline value. During the follow-up of 1 year, 115 patients (26%) experienced AF recurrence, and the incidence was significantly higher in 124 patients with low CRP levels at baseline (cut-off ≤0.06 mg/dl) than the other 317 patients (33.9% vs. 23.0%, p=0.017). After adjustment of age, gender, body mass index, long-standing persistent AF, CA strategy, and plasma brain natriuretic peptide levels, low plasma CRP levels was a significant predictor of AF recurrence (hazard ratio, 1.51; 95% confidence interval, 1.02–2.24; p=0.042).

Conclusions

Low plasma CRP levels at baseline predicted AF recurrence in the EARNEST-PVI trial. Reappraising the role of CRP on AF recurrence may be needed in patients with persistent AF.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Johnson & Johnson KK

Comparison of clinical outcomes between percutaneous coronary intervention for the de novo lesion versus in-stent restenosis lesion

Background and objective

Percutaneous coronary intervention (PCI) with metallic coronary stent (bare-metal stents [BMS] and drug-eluting stents [DES]) implantation is most frequently performed therapeutic procedures for coronary artery disease. In-stent restenosis (ISR) is a critical drawback of metallic coronary stents. Incidence of ISR has been reported in up to 30% after BMS implantation. The use of DES has greatly reduced the proportion of restenosis compared with the BMS. However, ISR still remains the primary concern after PCI even in the contemporary DES era, and thought to be associated with worse clinical outcomes. However, comparative data on ISR and de novo lesions are rare.

Purpose

The aim of the present study was to compare the clinical outcomes after PCI for the de novo lesion and the ISR lesion.

Methods

We performed a retrospective analysis of patients who underwent PCI between 2013 and 2020. The incidences of major adverse cardiac and cerebrovascular events (MACCE) and all-cause death were evaluated. MACCE was defined as composite of cardiovascular death, non-fatal myocardial infarction, and stroke.

Results

In this study, 1538 patients were enrolled and divided into two groups: PCI for de novo lesion group (n=1258, 81.8%), and PCI for ISR lesion group (n=280, 18.2%). Patients in the ISR lesion group were significantly older and had higher prevalence of hypertension, diabetes mellitus, dyslipidemia and chronic kidney disease than patients in the de novo lesion group. During a median follow-up period of 1.9 years, Kaplan-Meier curves showed no significant differences in the incidences of MACCE (log-rank, p=0.86) and all-cause death (p=0.84) between two groups. After adjustment for other covariates, PCI for ISR lesion were not significantly associated with MACCE (hazard ratio [HR], 1.10; 95% confidential interval [CI], 0.61–1.97; p=0.76) and all-cause death (HR, 0.93; 95% CI, 0.56–1.56; p=0.79)

Conclusion

PCI for the ISR lesion was not associated with worse clinical outcomes compared with PCI for the de novo lesion.

Funding Acknowledgement

Type of funding sources: None.

Optimal measurement location of on-site based CT-derived FFR on midterm prognosis

Background

Fractional Flow Reserve (FFR) derived from coronary computed tomography angiography (CCTA) enables anatomical and hemodynamical assessment of coronary artery disease. CT-FFR, which can be acquired on-site workstation using fluid structure interaction during the multiple optimal diastolic phase, has an incremental diagnostic value over conventional CCTA. However, few studies are focused on investigating the appropriate measurement location of CT-FFR, considering the prognosis, using CCTA as a standalone modality.

Purpose

The aim of this study is to assess the clinical impact on CT-FFR with an appropriate measurement.

Methods

A total of 370 consecutive patients who underwent CCTA in a single-heartbeat scan with a phase window of 70% to 99% of the R-R interval, showing 50–90% stenosis of at least one major epicardial vessel measuring ≥1.8 mm in diameter on CCTA were retrospectively analyzed and followed during a median follow up 2.9 years. CT-FFR values were measured at three points: 1, 2 cm distal to a target lesion (CT-FFR1cm, 2cm) and the vessel terminus (CT-FFRlowest), and a CT-FFR value ≤0.80 was considered abnormal. The endpoint was MACE, a composite of cardiac death, non-fatal MI, and unplanned revascularization.

Results

The incidence of MACE occurred in 8.4% (31/370) of the whole patients, including four cardiac deaths, ten all cause deaths, two non-fatal MI, and twenty unplanned revascularization. The Kaplan-Meier survival analysis demonstrated a significantly higher cumulative MACE rate in patients with positive CT-FFR1cm and 2cm than those with negative CT-FFR1cm and 2cm, while there was no significant difference between negative and positive in CT-FFRlowest, among patients with negative CT-FFR1cm and 2cm (Figure 1). Among 221 patients, who did not perform early revascularization within 90 days from CCTA, there was no significant difference in CT-FFRlowest in the incidence of MACE. In contrast, the risk of MACE was significantly higher in both positive CT-FFR1cm and CT-FFR2cm (Figure 2).

Conclusion

From a view point of clinical outcome for patients with moderate to severe stenosis on CCTA, a CT-FFR value when measured at 1-to-2 cm distal to a target lesion could be feasible for the deferral of unnecessary invasive coronary angiography safely. Moreover, CT-FFR1–2cm showed better risk stratification measurement rather than CT-FFRlowest, based on future adverse cardiac event.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Canon Medical Systems Corporation Kaplan-Meier 1Kaplan-Meier 2

The relationship among extent of lipid-rich plaque, factors associated with a reduction of lipid-rich plaque and late lumen loss: a near-infrared spectroscopy and intravascular ultrasound study

Background

Near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) are useful imaging modalities to identify lipid-rich plaque (LRP) which is associated with an increased risk of future cardiovascular events in individuals undergoing PCI. Pathological studies have raised concerns that treating LRP with stents may impair vascular healing. However, the impact of stent implantation to LRP lesions was less known. Moreover, little information is available about changes in the extent of LRP at before and after PCI.

Purpose

The aim of this study was to investigate changes in LRP by NIRS between pre- and post-stent implantation, and to evaluate an association among impact of LRP by NIRS at pre- and post-stenting and late lumen loss (LLL) by angiography.

Methods

We studied 175 lesions in 149 patients who underwent PCI under NIRS-IVUS guidance and follow-up angiography at 8-month later from 2017 to 2020. Plaque characteristics on IVUS, the extent of LRP [defined as a long segment with a 4-mm maximum lipid core burden index (maxLCBI4mm)] on NIRS, and quantitative coronary angiography measurements were analyzed. We evaluated a change of the extent of LRP between pre- and post-stenting at index PCI procedure, and association between the extent of LRP and a 8-month LLL at follow-up coronary angiography. A large LRP was defined as maxLCBI4mm>400 at pre-stenting.

Results

Mean age was 64.5 years old, and 123 (82%) patients were male. The prevalence of large LRP was 51% and median plaque burden at minimum lumen area was 81%. The extent of LRP at culprit lesion significantly decreased from pre- to post-stenting (median maxLCBI4mm [interquartile range (IQR)]: 407 [199, 580] to 133 [13, 319], p<0.001) (Figure 1). In multivariable liner regression analysis, independent predictors for the reduction of LRP were a pre-stenting LRP (β coefficient = −57.0, 95% confidence interval (CI) [−65.1 to −48.8], p<0.001) and plaque burden (β coefficient = −30.0, 95% CI [−56.6 to −3.4], p<0.001), respectively. On the other hands, patient comorbidities, lipid profile and inflammatory markers were not associated with the reduction of LRP (all p>0.05). Median LLL at follow-up angiogram was 0.17 [0.07–0.35] mm. Both the extent of pre- and post-stenting LRP were not associated with LLL (r=0.018, p=0.80 and r=0.022, p=0.76, respectively) (Figure 2). In addition, there was no significant difference in LLL between the post-stenting large and non-large LRP (median [IQR] 0.18 [0.08–0.35] vs. 0.17 [0.07–0.35]; P=0.95).

Conclusions

This study showed coronary stent implantation significantly reduced the NIRS-derived LRP in patients undergoing PCI. Although the extent of pre-stenting LRP and IVUS plaque burden predicted the reduction of LRP, the extent of pre- and post-stenting LRP were not associated with LLL. These findings suggest that stent implantation for LRP, even in a large LRP, is safe and does not affect LLL.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Scatter plotsFigure 2. CENTRAL Figure

Renal function and arrhythmia outcomes in persistent atrial fibrillation patients after catheter ablation: subanalysis of the EARNEST-PVI trial

Background

Atrial fibrillation (AF) reduces the renal function. Renal dysfunction and AF often coexist. Catheter ablation (CA) of persistent AF can maintain a sinus rhythm and may improve the renal function.

Purpose

We sought to elucidate whether the estimated glomerular filtration rate (eGFR) in patients with persistent AF was increased after CA, especially with the presence of an AF recurrence.

Methods

We enrolled 487 persistent AF patients whose eGFR data were available both before and 1-year after the CA out of 512 patients in the EARNEST-PVI trial.

Results

The mean age was 65±9 year and 113 patients (24.8%) had long-standing persistent AF. We compared the eGFR at baseline with that 1-year after the CA. AF recurrences were recognized in 118 patients (25.8%). The eGFR was similar between the group without recurrence and that with recurrence at baseline (without AF recurrence vs. with AF recurrence; 63.8±14.3 vs. 62.7±13.6 mL/min/1.73m2, p=0.46). In patients without AF recurrence, the G1, G2, G3a, G3b, G4, and G5 were 13 (3.8%), 198 (58.4%), 98 (28.9%), 26 (7.7%), 3 (0.9%), and 1 (0.3%), respectively at baseline. In the patients with AF recurrence, the G1, G2, G3a, G3b, G4, and G5 were 3 (2.5%), 68 (57.8%), 38 (32.2%), 6 (5.1%), 3 (2.5%), and 0 (0%), respectively at baseline. The ΔeGFR was significantly higher in the patients without AF recurrence than in those with AF recurrence (without AF recurrence vs. with AF recurrence; 5.1 [−0.3, 10.8] vs. 3.0 [−3.0, 7.6], p=0.0033). In the patients without AF recurrence, a better eGFR class at 1-year after the CA than in those before the CA was recognized in 75 patients (22.1%), while it was recognized in 19 patients (16.1%) with AF recurrences.

Conclusion

Successful catheter ablation in patients with persistent AF led to a better renal outcome.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): This study was funded by Medtronic, Johnson & Johnson, and Abbott.

Coronary lipid-rich plaque characteristics with acute coronary syndrome and chronic coronary syndrome: a near infrared spectroscopy and intravascular ultrasound study

Background

Asians have a much lower incidence of adverse coronary events than Caucasians, and the characteristics of vulnerable plaque might be different among the ethnics.

Purpose

The aim of this study was to investigate the clinical characteristics of lipid-rich plaque (LRP) in the Asian population and we also aimed to distinguish the characteristics of an acute coronary syndrome (ACS) culprit lesion and a chronic coronary syndrome (CCS) culprit lesion. Furthermore, we evaluated the association between lipid core burden index (LCBI) and cardiovascular risk factors, lipid profiles, and inflammatory biomarkers, as determined in vivo by near infrared spectroscopy intravascular ultrasound (NIRS-IVUS) imaging in patients undergoing percutaneous coronary intervention (PCI).

Methods

We evaluated 207 patients (ACS, n=75; CCS, n=132) who underwent PCI under NIRS-IVUS. Plaque characteristics and the extent of LRP [defined as a long segment with a 4-mm maximum LCBI (maxLCBI4mm)] on NIRS in de-novo culprit and non-culprit segments were analyzed.

Results

The mean age was 65 years old and 82% of patients were male. The ACS culprit lesions had a significantly higher maxLCBI4mm (median [interquartile range (IQR)]: 533 [385–745] vs. 361 [174–527], p<0.001) than the CCS culprit lesions. Whereas, no significant difference was seen in maxLCBI4mm between ACS and CCS non-culprit lesion segments (246 [53, 342] vs. 185 [37, 350], p=0.47) (Figure 1). Receiver-operating characteristic analysis showed that the NIRS maxLCBI4mm could distinguish the ACS culprit segment from the CCS culprit segment, with a sensitivity of 73% and a specificity of 69% (c-statistic = 0.69; p<0.001, cut-off value of max LCBI4mm = 408) (Figure 2). On multivariate logistic analysis, a large LRP (defined as maxLCBI4mm ≥400) was the strongest independent predictor of the ACS culprit segment (odds ratio, 3.87; 95% confidence interval, 1.95–8.02). In non-culprit segments, 19.8% of patients had at least one large LRP without a small lumen. No significant correlation was found between the extent of LRP and circulating lipid profiles and inflammatory makers biomarkers (hs-CRP, IL-6, TNF-α) in both the culprit and non-culprit lesion segments, whereas the extent of LRP was positively correlated with IVUS plaque burden (r=0.24, p<0.001).

Conclusions

We confirmed that NIRS-IVUS plaque assessment could be useful to differentiate ACS from CCS culprit lesions, and that a threshold maxLCBI4mm ≥400 was clinically suitable in Japanese patients. No systemic surrogate markers were found to be associated with the extent of LRP by NIRS in culprit and non-culprit segments. Consequently, we believe that direct intravascular evaluation of coronary plaque characteristics remains important for identification of high-risk LRP.

Funding Acknowledgement

Type of funding sources: None. Figure 1. The difference of maxLCBI4mmFigure 2. ROC curve

Differences in quality of life improvement with pulmonary vein isolation alone vs. more extensive ablation of persistent atrial fibrillation: insights from the EARNEST-PVI trial

Background

Improving the quality of life (QoL) is one of the main purposes of catheter ablation (CA) of persistent atrial fibrillation (AF). QoL improvement in persistent AF patients has not been fully clarified. The EARNEST-PVI trial was a multi-center randomized trial comparing clinical outcomes of pulmonary vein isolation (PVI) alone and more intensive ablation in addition to PVI including complex fractionated atrial electrogram (CFAE) and linear ablation (PVI plus).

Purpose

To investigate the QoL change after persistent AF ablation and the differences between the PVI-alone strategy and the PVI plus strategy.

Methods

In the EARNEST-PVI trial, patients with persistent AF who underwent an initial catheter ablation (n=512) were randomly assigned in a 1:1 ratio to either PVI alone or PVI plus. Quality of life was assessed at baseline and at 12 months after ablation for AF using the 36-Item Short Form Health Survey. Scores were also converted to a physical health component summary (PCS), a mental health component summary (MCS) and a role/social component summary (RCS).

Results

In the EARNEST-PVI trial, the PVI alone strategy was associated with higher recurrence rate compared with the PVI plus additional ablation strategy. After excluding 68 patients for whom preoperative or postoperative QoL assessment was not available, 222 patients were evaluated respectively. Overall, significant improvements in PCS (46.2±11.4 to 48.7±11.4]), MCS (50.1±8.8 to 54.3±8.6) and RCS (44.6±13.3 to 48.6±11.3) occurred 12 months after ablation (P<0.001, respectively). Although significant QoL improvement occurred in both PVI alone and PLI plus strategies, the changes in PCS was greater in the PVI-plus than that in PVI-alone (3.5±10.3 vs 1.5±10.6, P=0.04).

Conclusions

Ablation for persistent atrial fibrillation improved both physical and mental quality of life. The PVI-plus strategy showed greater improvement in physical QoL.

Funding Acknowledgement

Type of funding sources: None. QoL improvement

Combined impact of residual inflammatory risk and chronic kidney disease on long-term clinical outcomes in patients undergoing percutaneous coronary intervention

Background

Inflammatory status pre-percutaneous coronary intervention (PCI) and post-PCI has been reported not only associated with poor prognosis, but also to impair renal function. Statins reduce cardiovascular events by lowering lipids and have anti-inflammatory impacts, but residual inflammatory risk (RIR) exists. It remains unclear that the synergistic effect of RIR and chronic kidney disease (CKD) on long-term clinical outcome in stable coronary artery disease (CAD) patients undergoing PCI in statin era.

Aim

The aim of this study was to investigate the long-term combined impact of RIR evaluating hs-CRP at follow-up and CKD among stable CAD patients undergoing PCI in statin era.

Methods

This is a single-center, observational, retrospective cohort study assessing consecutive 2,984 stable CAD patients who underwent first PCI from 2000 to 2016. We analyzed 2,087 patients for whom hs-CRP at follow-up (6–9 months later) was available. High residual inflammatory risk was defined as hs-CRP >0.6 mg/L according to the median value at follow up. Patients were assigned to four groups as Group1 (high RIR and CKD), Group2 (low RIR and CKD), Group3 (high RIR and non-CKD) or Group4 (low RIR and non-CKD). We evaluated all-cause death and major adverse cardiac events (MACE), defined as a composite of cardiovascular (CV) death, non-fatal myocardial infarction (MI) and non-fatal stroke.

Results

Of patients (83% men; mean age 67 years), there were 299 (14.3%) patients in group 1, 201 (9.6%) patients in group 2, 754 (36.1%) patients in group 3, and 833 (39.9%) patients in group 4. The median follow-up period was 5.2 years (IQR, 1.9–9.9 years). In total, 189 (frequency, 16.1%) cases of all-cause death and 128 (11.2%) MACE were identified during follow-up, including 53 (4.6%) CV deaths, 27 (2.4%) MIs and 52 (4.8%) strokes. The rate of all-cause death and MACE in group 1 was significantly higher than other groups (p<0.001, respectively). There was a stepwise increase in the incidence rates of all-cause death and MACE. After adjustment for important covariates, the presence of high RIR and/or CKD were independently associated with higher incidence of MACE and higher all-cause mortality. (shown on figure).

Conclusion

The presence of both high RIR and CKD conferred a synergistic adverse effect on the risk for long-term adverse cardiac events in patients undergoing PCI.

Kaplan-Meier curve

Funding Acknowledgement

Type of funding source: None

Cardiac factors as well as non-cardiac factors were associated with frailty in patients with heart failure with preserved ejection fraction

Background

Frailty is associated with malnutrition and poor prognosis in patients with heart failure with preserved ejection fraction (HFpEF). However, the cardiac factors associated with frailty have not been fully examined in patients with HFpEF.

Purpose

The purpose of this study is to clarify the cardiac factors related to frailty in patients with HFpEF.

Methods

Of the 756 patients who registered prospective, multicenter, observational study of patients with HFpEF (PURSUIT-HFpEF) registry, 481 cases with clinical frailty score (CFS) and prognosis after discharge were examined. Frailty was defined as CFS ≥5. Outcomes were composite endpoint of all-cause death and heart failure readmission, and all-cause mortality. We compared outcomes between patients without and with frailty, and sought to identify factors which were associated with increase in clinical frailty score by the correlation analysis and linear regression analysis.

Results

Of 481 patients, 131 patients (27.2%) were frail. Male gender was less in patients with frailty than those without frailty (26.7% vs 73.3%, P<0.001). Frail patients had higher age (85.2±7.3 vs 78.7±9.4 years, P<0.001). During follow-up period of 396 [343, 697] days, composite endpoint (Kaplan-Meier event rate estimates, 77% vs. 60%; log-rank P<0.001), and all-cause mortality (Kaplan-Meier event rate estimates, 57% vs. 28%; log-rank P<0.001) was higher in patients with frailty than those without frailty. Multivariate Cox regression analysis revealed frailty was significantly and independently associated with mortality (HR=1.40, 95% CI=1.17–1.68, P<0.001). CFS was significantly correlated with age (r=0.401, P<0.001), sex (r=0.223, P<0.001), body mass index (r=−0.146, P=0.001), hemoglobin (r=−0.148, P=0.001), albumin (r=−0.222, P<0.001), left ventricular diastolic diameter (r=−0.184, P<0.001), interventricular septum thickness (r=−0.124, P=0.008), left ventricular mass (r=−0.217, P<0.001), tricuspid annular plane systolic excursion (r=−0.165, P=0.001), and tricuspid regurgitation pressure gradient (TRPG) (r=0.189, P<0.001). Multivariate linear regression analysis using these factors as covariates revealed age (standardized β: 0.337, P<0.001), sex (standardized β: 0.120, P=0.014), albumin (standardized β: −0.151, P=0.003) and TRPG (standardized β: 0.129, P=0.005) were significantly and independently associated with increase in clinical frailty score.

Conclusion

Our results suggest that not only nutritional factors but also a cardiac factor were associated with frailty, and frailty was associated with mortality in patients with HFpEF. Improvement of hemodynamics in HFpEF patients as well as improvement of nutrition might contribute to alleviation of frail in HFpEF patients.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnostics K.K.; Fuji Film Toyama Chemical Co. Ltd.

P1745Clinical characteristics and long-term outcome in patients with helicopter-transported acute coronary syndrome after primary percutaneous coronary intervention

Background

Reducing delay to percutaneous coronary intervention improves functional outcome and reduces long-term mortality. Transportation by helicopter is often quicker than ground transport and thus may improve overall prognosis through reduced ischemic injury and infarction size. Our hospital is located on the medically-depopulated peninsula surrounded by mountain. The journey from the southern tip of the peninsula to the critical care medical center of our hospital take 1.5 hour by a ground ambulance but only 15 minutes by helicopter.

We compared the clinical characteristics and long-term mortality between air and ground transport of ACS patients for primary PCI.

Methods

We conducted an observational cohort study evaluating 2324 patients (mean age 68.5±12.0, male 75.2%) with ACS underwent primary PCI between April 2004 and December 2017 at our hospital.

We divided into three groups according to transportation system type (air, ground, walk-in).

The primary outcome was defined as all-cause death during the long-term follow-up.

Results

Among the entire cohort, 577 patients (24.8%) were transported by air. 1326 (57.1%) patients by ambulance, 421 (18.1%) patients by walk. Baseline characteristics were comparable, but patients by air had a higher prevalence of ST-elevation myocardial infarction.

The rate of long-term mortality was comparable during the median follow up of 6 years (air, 21.1% vs. ground, 21.4% vs. walk-in, 21.1%, respectively, log-rank p=0.72). Multivariate Cox regression analysis showed no significant association between air transportation and long-term mortality (Adjusted HR [vs ground] 1.05, 95% CI 0.60–1.78, p=0.85 and [vs walk-in] 0.94, 95% CI 0.62–1.43, respectively, p=0.77).

Kaplan-Meier curve

Conclusions

The rate of long-term mortality in patients with ACS transported by air was comparable with those transported by ground.

P5734The outcome of intra-aortic balloon pumping support for acute myocardial infarction with extracorporeal membrane oxygenation therapy

Background

It has been reported that intra-aortic balloon pumping (IABP) support for acute myocardial infarction (AMI) with cardiogenic shock did not reduce short and long-term mortality. However, the significance of IABP support for AMI patients with extracorporeal membrane oxygenation (ECMO) therapy remains unclear. The aim of this study was to investigate the effect of IABP support for the short and long-term outcome in AMI patients who received ECMO.

Methods

Using the database of the Osaka Acute Coronary Insufficiency Study (OACIS), 12,093 consecutive AMI patients were enrolled in this analysis. Among these, we analyzed 520 patients with ECMO. We classified the patients into two groups, patients who received IABP support [IABP group (n=460)] and patients who did not [no IABP group (n=60)]. Primary outcome was all-cause death.

Results

Study patients had following baseline clinical characteristics, age: 66.8±12.0 year old, male: 78.3%, diabetes mellitus: 41.0%, Killip class≥II: 66.2%, multi-vessel disease: 72.3%, peak creatine phosphokinase >3000IU/L: 68.1%. During a mean follow-up period of 349±625 days, Kaplan-Meier analysis revealed that the all-cause death was significantly lower in IABP group than no IABP group for 30-day (45.5% vs 72.7%, log-rank p<0.001) and long-term (66.2% vs 78.4%, Log rank p=0.005) follow-up period. Cox multivariate analysis revealed that IABP support was significantly associated with a reduced risk of mortality (Hazard ratio 0.445, 95% confidence interval 0.289 to 0.687, p<0.001).

Conclusions

IABP support for AMI patients with ECMO was significantly associated with reduced risks of the short and long-term mortality, suggesting that IABP support might contribute to improvement of the survival in AMI patients with ECMO.

P6173Plaque characteristics on coronary CT angiography in case of discordance between fractional flow reserve (FFR) and instantaneous wave-free ratio (IFR)

Background

The usefulness of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) evaluation has been confirmed in the determination of revascularization of coronary artery disease. When FFR≤0.8 and iFR≤0.89 were regarded as the criteria for positivity, the discordance was noted in approximately 20%, but this cause has not been well established.

Purpose

The purpose of this study was to investigate the patient background and features on coronary CT angiography (CCTA) showing the discordance between FFR≤0.8 and iFR≤0.89.

Methods

The subjects were consecutive 85 cases with 108 vessels in which stenosis of 30–90% was detected at one vessel of at least 2mm or more in the major epicardial vessels and FFR and iFR was performed within subsequent 90 days, among suspected cases of coronary arterial diseases which underwent CCTA. The factors showing the discordance between FFR and iFR (patient background, coronary artery calcification score, high risk plaque features on CCTA (positive remodeling, low attenuation plaque), plaque characteristics by a plaque analysis software using a new algorithm called labeling method (vessel volume, plaque volume, lumen volume, plaque length, maximum plaque burden, necrotic core area, fibrous area and calcium area) were evaluated using logistic regression analysis on per-patient and per-vessel basis.

Results

There were no significant both FFR and iFR positive definite factors on per-patient basis. The lumen volume/vessel volume (OR: 0.93, 95% CI: 0.88–0.98, P=0.0032) (OR: 0.90, 95% CI: 0.85–0.95, P<0.0001),minimum lumen area (MLA) (OR: 0.59, 95% CI: 0.41–0.85, P=0.0006) (OR: 0.64, 95% CI: 0.44–0.92, P=0.0047), the plaque volume/vessel volume (OR: 1.05, 95% CI: 1.01–1.10, P=0.0114) (OR: 1.09, 95% CI: 1.04–1.15, P=0.0002) and maximum plaque burden (OR: 1.08, 95% CI: 1.01–1.15, P=0.0095) (OR: 1.06, 95% CI: 1.00–1.13, P=0.0406) were significant both FFR and iFR positive definite factors on per-vessels basis. Discordance between FFR≤0.8 and iFR≤0.89 was observed in 23 vessels (21.3%) of 19 patients. In FFR positive and iFR negative group (15 vessels, 13.9%), positive remodeling (PR) (OR: 4.38, 95% CI: 1.13–17.00, P=0.0294) was only significant predictor. In FFR negative and iFR positive group, there was no significant predictors.

Conclusions

In both FFR and iFR, only lumen volume /vessel volume, MLA, plaque volume/vessel volume and plaque burden were significant positive definite factors. As for the discordance between FFR and iFR, PR is significant predictor in FFR positive and iFR negative group.

Long-term clinical impact of serum albumin in coronary artery disease patients with preserved renal function

BACKGROUND AND AIMS

Low serum albumin level is reportedly associated with worse clinical outcomes in patients with chronic kidney disease (CKD). However, associations between decreased serum albumin level and outcomes in non-CKD patients with coronary artery disease (CAD) remain unclear. Therefore, we aimed to evaluate the prognostic value of serum albumin concentrations in stable CAD patients with preserved renal function.

METHODS AND RESULTS

We studied 1316 patients with CAD and preserved renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m²) who underwent their first PCI between 2000 and 2011 and had data available for pre-procedural serum albumin. Patients were assigned to quartiles based on pre-procedural albumin concentrations. The incidence of major adverse cardiac events (MACE), including all-cause death and non-fatal myocardial infarction, was evaluated. Mean albumin concentration was 4.1 ± 0.4 g/dL. During the median follow-up of 7.5 years, 181 events occurred (13.8%). Kaplan-Meier curves revealed that patients with decreased serum albumin concentrations showed a higher event rate for MACE (log-rank, p < 0.0001). Using the highest tertiles (>4.3 g/dL) as reference, adjusted hazard ratios were 1.97 (95% CI, 1.12-3.55), 1.77 (95% CI, 0.99-3.25), and 1.19 (95% CI, 0.68-2.15) for serum albumin concentrations of <3.9, 3.9-4.0, and 4.1-4.3 g/dL, respectively. Decreased serum albumin concentration was associated with MACE even after adjusting for other independent variables (HR, 2.21 per 1-g/dL decrease; 95% CI, 1.37-3.56, p = 0.001).

CONCLUSION

Decreased serum albumin concentration independently predicted worse long-term prognosis in non-CKD patients after PCI. Pre-procedural serum albumin concentration could offer a useful predictor for patients with CAD and preserved renal function.

TWEAK/Fn14 pathway promotes a T helper 2-type chronic colitis with fibrosis in mice

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a TNF superfamily member, induces damage of the epithelial cells (ECs) and production of inflammatory mediaters through its receptor Fn14 in a model of acute colitis. In our current study of chronic colitis induced by repeated rectal injection of a hapten, we found that inflammation, fibrosis, and T helper 2 (Th2)-type immunity were significantly reduced in Fn14 gene knockout (KO) mice when compared with wild-type (WT) control mice. Expression of thymic stromal lymphopoietin (TSLP) was lower in Fn14 KO colon ECs than in WT ECs. TWEAK potentiates the induction of TSLP by interleukin-13 (IL-13) in colon explants from WT but not in Fn14 KO tissue. TSLP receptor KO mice exhibit milder chronic colitis, similar to that in Fn14 KO mice. TWEAK and IL-13 synergistically promote fibroblast proliferation. Thus we propose an IL-13-TWEAK/Fn14-TSLP axis as a key mechanism underlying chronic colitis with fibrosis.

A grasping forceps with a triaxial MEMS tactile sensor for quantification of stresses on organs

This paper reports on a grasping forceps with a triaxial Micro Electro Mechanical Systems (MEMS) tactile sensor on a tip. The laparoscopic surgery is minimally invasive because the incisions are smaller than the open surgery. This results in fast recovery. However, it is a problem in the laparoscopic surgery to damage an organ by localized stress generated by grasping with a thin forceps. To avoid excessive stress applying to the organ, real time evaluation of the stress is important. However, there is no acceptable tool to measure the stress. We propose a grasping forceps with a triaxial MEMS tactile sensor on a tip for a measurement tool. We attached a triaxial MEMS tactile sensor which we have developed on a tip of a grasping forceps. The MEMS sensor can measure not only the pressure but also two directional shear stresses applied to the sensor surface. The sensor size is 7 mm × 7 mm × 2 mm. It is enough small to attach the sensor to the tip of a forceps 12 mm in diameter. In this paper, the characteristics of the forceps with the MEMS sensor during grasping, pushing and pulling actions were evaluated. In these experiments, output of each sensor for pressure and shear stress was proportional to the applied stresses, respectively. Moreover, as an in vivo experiment, we measured the shear stress applied to a pig liver block when it is lifted after being grasped with the forceps. We obtained that the shear stress applied to the liver block increased with the increase of the weight of the liver block.

Aortopulmonary fistula caused by an infected thoracic aortic false aneurysm rupturing after endovascular stent placement

We report a case of 74-year-old man presenting with a rupture of a thoracic aortic false aneurysm after undergoing conventional total arch replacement for aortic arch aneurysm (62 mm) and endovascular stent placement for descending aortic aneurysm (70 mm). His chief complaints at the present admission were fever and sensation of dyspnea and we put him on a course of antibiotics for stent graft infection. However he died of massive hemoptysis. From a standpoint of autopsy findings, a thoracic aortic false aneurysm formed at the just proximal landing zone owing to type Ia endoleak, and simultaneously stent graft infection lead to make fistula formation between the false aneurysm and the lung. We examined ourselves that stent graft infection and aortopulmonary fistula caused by an infected thoracic aortic false aneurysm rupturing into the lung should be promptly treated such as complete removal of the stent and another revascularization in a reasonable period of time except if there are complications such as comorbid1ities or withholding of consent. We experienced and reported one rare case associated with a rupture of thoracic aortic false aneurysm caused by stent graft infection and the fistulization between the lung and the stent graft.

miR-296 regulation of a cell polarity-cell plasticity module controls tumor progression

The expression of small, non-coding RNA, or microRNAs (miR), is frequently deregulated in human cancer, but how these pathways affect disease progression is still largely elusive. Here, we report on a microRNA, miR-296, which is progressively lost during tumor progression, and correlates with metastatic disease in colorectal, breast, lung, gastric, parathyroid, liver and bile ducts cancers. Functionally, miR-296 controls a global cell motility gene signature in epithelial cells by transcriptionally repressing the cell polarity-cell plasticity module, Scrib. In turn, loss of miR-296 causes aberrantly increased and mislocalized Scrib in human tumors, resulting in exaggerated random cell migration, and tumor cell invasiveness. Re-expression of miR-296 in MDA-MB231 cells inhibits tumor growth, in vivo. Finally, miR-296 or Scrib levels predict tumor relapse in hepatocellular carcinoma patients.

These data identify miR-296 as a global repressor of tumorigenicity, and uncover a previously unexplored exploitation of Scrib in tumor progression in humans.

Cardiac intervention using high-intensity focused ultrasound: creation of interatrial communication in beating heart of an anesthetized rabbit

OBJECTIVE

Current fetal cardiac intervention for restrictive atrial septum is invasive and technically demanding. We investigated the feasibility of computer-assisted high-intensity focused ultrasound (HIFU) for cardiac intervention on the atrial septum of a beating heart.

METHODS

To create an interatrial communication in the beating heart of nine anesthetized rabbits, the heart was exposed surgically and placed under a water-filled tank, in contact with the tank's membranous base. A HIFU transducer (3.3 MHz) coupled with a diagnostic ultrasound probe (10.0 MHz) was placed in the tank over the beating heart. The focus of the HIFU transducer was set so that it could create a hole in the target area on the atrial septum during the early diastolic phase. HIFU delivery was controlled based on ultrasound images captured with real-time image-recognition software. We attempted to create interatrial communication using HIFU and assessed the cardiac tissue specimen pathologically.

RESULTS

In eight of nine rabbits, small holes in the atrial septum were successfully created. Serious complications occurred in two animals: a fatal atrioventricular block in one and a cardiac tamponade in the other.

CONCLUSION

HIFU combined with a computer-assisted imaging system might be useful to create interatrial communication in beating hearts. This procedure may be helpful for making current fetal cardiac intervention less invasive.

Implantable telemetry capsule for monitoring arterial oxygen saturation and heartbeat

In this study, we have developed an implantable telemetry capsule for monitoring heartbeat. The capsule has three main functions, monitoring vital signs, transmitting the vital signs, and receiving energy for driving the capsule without wires. We used two wavelengths of LEDs and a photodiode sensitive to the two wavelengths for heartbeat sensor. The arterial oxygen saturation is calculated from the amplitude of the heartbeat signal. We fabricated an FM transmitter whose carrier frequency was 80 MHz. Though the GHz range frequency is generally used in transmission, the attenuation in the human body is large. The size of a common linear antenna is about a quarter of its operating wavelength. We employed a coil-based antenna which can reduce size below the quarter of the wavelength. We fabricated a miniaturized transmitter with the coil-based antenna at lower frequency. Our capsule was driven intermittently. We used a rechargeable battery. When the battery ran down, the battery was charged by wireless using the induced electromotive force. This means that the capsule is capable of monitoring vital signs over the long term. We measured the heartbeat from the middle finger of hand in a water tank as a model of a human body.

Control of fracture reduction robot using force/torque measurement

We have developed a surgical robotic system for femoral fracture reduction employing indirect traction. Indirect traction in fracture reduction is a generally used surgical method for preventing complications such as bone splits caused by high stress on bones. For traction, a patient's foot is gripped by a jig and pulled to the distal side. Indirect traction has the advantage of distributing bone stress by utilizing a strong traction force; however, this procedure does not accurately control the proper positioning of fractured fragments when a surgical robot is used. The human leg has knee and an ankle joints, and thus robotic motion presents problems in not being able to directly propagate reduction motion to a fractured femoral fragment, rendering control of bone position difficult. We propose a control method for fracture reduction robots using external force/torque measurements of the human leg to achieve precise fracture reduction. Results showed that the proposed method reduced repositioning error from 6.8 mm and 15.9 degrees to 0.7 mm and 5.3 degrees, respectively.

Down-regulation of norepinephrine transporter expression on membrane surface induced by chronic administration of desipramine and the antagonism by co-administration of local anesthetics in mice

We have previously shown that chronic administration of the antidepressant desipramine, a norepinephrine transporter (NET) inhibitor to mice markedly enhanced convulsions induced by local anesthetics and that behavioral sensitization may be relevant to decreased [(3)H]norepinephrine uptake by the isolated hippocampus. The co-administration of local anesthetics with desipramine reversed the behavioral sensitization and down-regulation of NET function induced by desipramine. The present study aimed to elucidate whether chronic treatment with desipramine regulates the expression of NET protein examined in membrane fractions in various brain regions and whether co-administration of local anesthetics affects the desipramine-induced alteration of NET expression. Desipramine with or without local anesthetics was injected intraperitoneally once a day for 5 days. The animals were decapitated 48 h after the last administration of drugs and the whole cell fraction, membrane fraction and cell-surface protein fraction were prepared. [(3)H]nisoxetine binding was significantly reduced in the P2 fraction of the hippocampus by chronic administration of desipramine, and the reduction was overcome by co-administration of lidocaine with desipramine. Immunoreactive NET was detected by SDS-PAGE and immunoblotting in the murine hippocampus. NET protein expression in the whole cell fraction and membrane fraction was not affected by treatment with any drugs. However, administration of desipramine significantly reduced the amount of immunoreactive NET in the cell-surface protein fraction. This reduction was blocked by simultaneous injection of lidocaine, bupivacaine or tricaine. These results indicate that the NET down-regulation indicated by the reduction of [(3)H]nisoxetine binding was induced by administration of desipramine via decrease of NET localization on the cell surface. The antagonistic actions of local anesthetics against NET down-regulation by desipramine were related to alterations of the cell-surface localization of NET.

Miniature bending manipulator for fetoscopic intrauterine laser therapy to treat twin-to-twin transfusion syndrome

BACKGROUND

Recent typical therapy for twin-to-twin transfusion syndrome (TTTS) is selective laser photocoagulation of anastomotic communicating vessels on the placenta using the fetoscopic approach. The difficulty of a conventional laser device approach for this procedure depends significantly on the placental location, so a new robotized device is required to bend the direction of laser irradiation flexibly within the narrow uterus.

METHODS

The authors designed a miniature bending mechanism impelled by a wire-guided linkage driving method that provides a stable procedure for bending laser irradiation from -90 degrees to 90 degrees . Using this bending mechanism, the authors developed a bending manipulator with a diameter of 3.5 mm and a hollow central channel with a diameter of 0.8 mm for passing a glass fiber for neodymium:yttrium-aluminum-garnet (Nd:YAG) laser photocoagulation. The bending mechanism is motorized by an electrical actuator and controlled by a grip-type interface with a small joystick. The robotized tip's part and the actuator's part are easily separable for cleaning and sterilization.

RESULTS

In performance evaluations of the manipulator, the bending characteristics with a glass fiber were examined. The bending range was -52.6 degrees to 80 degrees, with a very small hysteresis error, and the bending repeatability error was 0.5 degrees +/- 0.2 degrees, which corresponds with the high accuracy of 0.2 +/- 0.1-mm positioning error at the glass fiber's tip. In the evaluation of Nd:YAG laser photocoagulation, the study confirmed that the manipulator performed effective laser photocoagulation of the placental phantom surface (underwater chicken liver). The large bending range, reaching 80 degrees, enabled a flexible approach from various directions with a high irradiation efficiency of no less than 96.6%.

CONCLUSIONS

The authors' original miniature bending manipulator can change the laser irradiating direction with highly repeatable positioning accuracy for speedy, safe, and effective vessel occlusion in clinical practice.

An Er:YAG laser bone cutting manipulator for precise rotational acetabular osteotomy

Rotational acetabular osteotomy (RAO) has an important advantage in that surgical bony defects are reconstructed with a patients' own tissue. We propose a surgical robot for the RAO using Er:YAG laser irradiating mounted on iliac bone to operate RAO precisely and to reduce recovery and trauma. A water-cooling Er:YAG laser (30 J/cm/sup 2/, l=2.94 mum, 20 Hz, 200 msec) that used optical fiber was operated 4-8 irradiation-overlapping ratio. We kept the distance between the laser and the bone at 0.25 mm using force sensor and spring to maintain effective ablation. Swine scapulae were ablated and performance was evaluated. The manipulator was operated mounting on iliac bone to get a filed position whereby resulting in precise bone cutting. The precision of the manipulator was within 0.3 mm and the efficiency of laser bone ablations per unit time optimized to 0.21 mm/sup 3//secW at the overlapping ratio of the irradiation area was 0.8, meaning a given ablated area was irradiated five times. The troughs showed m charring at this condition and the temperature of the surface was raised to 41.3 degrees C and it lasted only 5 seconds. We are sure that this research will be applied to orthopedics in the near future.

Antigen-presenting cells expressing glutamate decarboxylase 67 were identified as epithelial cells in glutamate decarboxylase 67-GFP knock-in mouse thymus

Glutamate decarboxylase (GAD), which has two isoforms, GAD65, and GAD67, is responsible for synthesis of the major inhibitory neurotransmitter, gamma-aminobutyric acid. GAD is expressed predominantly in the central nervous system; recent reports suggest that GAD is also expressed in non-neuronal organs including the pancreas. In the pancreatic islets, GAD serves as one of the autoantigens in type I diabetes mellitus. Recent flow cytometric analyses have shown that a variety of self-antigens, including GAD, are ectopically transcribed and expressed in particular cell populations of the thymus, although consensus concerning the cellular phenotype has not been obtained. The aim of this study was to clarify the localization and cellular phenotype of GAD67-expressing cells in the thymus at a cellular level with a novel approach using GAD67-green fluorescent protein (GFP) knock-in mice, in which GFP is expressed specifically in GAD67-positive cells. GFP-positive cells were detected in the thymic medulla and were identified as epithelial cells by immunohistochemistry. Almost all GFP-positive cells were positive for major histocompatibility complex (MHC) class II antigen staining and were positive for both cytokeratin and Ulex Europaeus Agglutinin I, markers of medullary thymic epithelial cells, but were negative for CD11c, Gr-1, and CD45, markers of dendritic cells, macrophages, and B-lymphocytes, respectively.

Laparoscopic cholecystectomy using a newly developed laparoscope manipulator for 10 patients with cholelithiasis

BACKGROUND

Laparoscopic surgery has continued to gain popularity in almost all fields of abdominal surgery, and robotic systems have been introduced in general surgery. Naviot is a new remote-controlled laparoscope manipulator system controlled by the operator's hand. This study assessed its introduction into clinical practice.

METHODS

A group of 10 consecutive patients with cholelithiasis underwent laparoscopic cholecystectomy assisted by the Naviot system (Naviot group). Another group of 41 patients who underwent laparoscopic cholecystectomy with a conventional human camera holder (human camera group) were selected for a comparison of their operative results with those of the Naviot group.

RESULTS

The operative time of 89.3 +/- 27.1 min for the Naviot group was significantly longer than that of 74.8 +/- 28.1 min for the human camera group (p < 0.05). However, when the setup time for the Naviot system was excluded, the operative time was not significantly different from that for the human camera group. Other operative results showed no significant difference between the two groups.

CONCLUSIONS

The authors believe that the new Naviot system is feasible for clinical use, and that it enables surgeons to perform solo gastrointestinal surgery.

Transport of dopamine and levodopa and their interaction in COS-7 cells heterologously expressing monoamine neurotransmitter transporters and in monoaminergic cell lines PC12 and SK-N-SH

The present study investigated the effects of levodopa, a precursor of dopamine (DA) therapeutically used for the treatment of Parkinson's disease, on DA transport in the two different systems, COS-7 cells heterologously expressing rat monoamine transporter cDNA and in monoaminergic cell lines PC12 and SK-N-SH. Levodopa enhanced uptake of [3H]DA and [3H]norepinephrine (NE) but not [3H]serotonin in the transfected COS-7 cells in a concentration-dependent manner. On the other hand, in PC12 and SK-N-SH cells where NET is functionally expressed, levodopa enhanced [3H]DA and [3H]NE uptake at low concentrations and inhibited the uptake at higher concentrations. The effects of levodopa on catecholamine transporters in the opposite direction suggest a different mechanism at the intra- and extracellular sites in a levodopa transport-dependent and independent manner.

A robotic wide-angle view endoscope using wedge prisms

BACKGROUND

The aim was to develop a new type of robotic wide-angle view endoscope that does not require rotation or bending of the endoscope to move the field of view. This endoscope allows the surgeon to make extensive observations in a small space. It is safe because it avoids the possibility of hitting organs accidentally.

METHODS

The system consists of an endoscope with a zoom facility and two wedge prisms at the tip. Each prism is set on its own sleeve at the end of the endoscope, and both prisms rotate independently about the axis of the endoscope.

RESULTS

In the in vivo experiment, the high quality of the image was confirmed, and almost whole liver could be observed without the observer moving the endoscope itself.

CONCLUSIONS

This system provides safe robotic endoscopic surgery because of the high quality of the image. It has great significance for future clinical use.

An ultrasound-driven needle-insertion robot for percutaneous cholecystostomy

A real-time ultrasound-guided needle-insertion medical robot for percutaneous cholecystostomy has been developed. Image-guided interventions have become widely accepted because they are consistent with minimal invasiveness. However, organ or abnormality displacement due to involuntary patient motion may undesirably affect the intervention. The proposed instrument uses intraoperative images and modifies the needle path in real time by using a novel ultrasonic image segmentation technique. In phantom and volunteer experiments, the needle path updating time was 130 and 301 ms per cycle, respectively. In animal experiments, the needle could be placed accurately in the target.