Design of microfluidic channels to prevent negative filtration in implantable hemofiltration devices

In order to improve the quality of life of dialysis patients, our group have been developing an implantable hemofiltration device (IHFD) composed of multiple layers of dialysis membranes and microfluidic channels. To improve the hemodialysis performance of IHFD, preventing the negative filtration, which is caused by the oncotic pressure of blood, is mandatory. In this study, we fabricated IHFDs with five different microchannel designs and experimentally investigated the performance of each device in in vitro experiment. In addition, the successful IHFD was further evaluated by ex vivo experiments with a beagle dog. The experiments verified the effectiveness of the microchannel design, which will be used for the IHFD for in vivo experiments with pigs in the future.

Heparin affects the induction of regulatory T cells independent of anti-coagulant activity and suppresses allogeneic immune responses

Heparin is a widely used anti-coagulant that enhances anti-thrombin (AT) activity. However, heparin also suppresses immune and inflammatory responses in various rodent models and clinical trials, respectively. The mechanism by which heparin suppresses immune responses is unclear. The effect of heparin on regulatory T cells (T_regs ) in allogeneic immune responses was analysed using an acute graft-versus-host disease (aGVHD) mouse model and mixed lymphocyte reactions (MLRs). In-vitro culture systems were utilized to study the effects of heparin on T_regs . Heparin administration reduced mortality rates and increased the proportion of T_regs in the early post-transplantation period of aGVHD mice. In both murine and human MLRs, heparin increased T_regs and inhibited responder T cell proliferation. Heparin promoted functional CD4⁺ CD25⁺ forkhead box protein 3 (FoxP3)⁺ T_reg generation from naive CD4⁺ T cells, increased interleukin (IL)-2 production and enhanced the activation of pre-existing T_regs with IL-2. Heparin-induced T_reg increases were not associated with anti-coagulant activity through AT, but required negatively charged sulphation of heparin. Importantly, N-acetyl heparin, a chemically modified heparin without anti-coagulant activity, induced T_regs and decreased mortality in aGVHD mice. Our results indicate that heparin contributes to T_reg -mediated immunosuppression through IL-2 production and suggest that heparin derivatives may be useful for immunopathological control by efficient T_reg induction.

P3578Determinants of visual-functional mismatches as assessed by coronary angiography and 3-D angiography-based quantitative flow ratio

Background

Quantitative flow ratio (QFR) is a novel three-dimensional quantitative coronary angiography (QCA)-based computational index that can estimate fractional flow reserve (FFR) without pharmacologically induced hyperemia or the use of a pressure wire.

Purpose

We aimed to evaluate the determinants of visual-functional mismatches between conventional two-dimensional QCA and QFR.

Methods

A total of 504 de novo intermediate-to-severe lesions from 504 patients with stable angina who underwent angiographical and physiological assessments were analyzed. All lesions were divided into four groups based on the significance of visual (QCA-diameter stenosis [DS] >50% and ≤50%) and functional (QFR <0.80 and ≥0.80) stenosis severity. Patient characteristics, angiographic findings, QFR computations, and physiological indices were compared among the four groups.

Results

Among 504 lesions, 153 lesions (30.4%) showed concordantly negative (DS ≤50% and QFR >0.80) and 170 lesions (33.7%) showed concordantly positive (DS >50% and QFR ≤0.80) visual and functional assessments. Among 181 lesions (35.9%) with discordant results, 75 lesions (14.9%) showed a mismatch (DS >50% and QFR >0.80) and 106 lesions (21.0%) showed a reverse mismatch (DS ≤50% and QFR ≤0.80), respectively. Reverse mismatch was associated with smaller reference diameter (odds ratio [OR] 0.561; P=0.036), greater DS (OR 1.039, P=0.013), lower coronary flow reserve (CFR) (OR 0.571, P<0.001, non-diabetes mellitus (OR 2.141, P=0.013) and lower ejection fraction (OR 0.961, P=0.011). Mismatch was associated with smaller DS (OR 0.914, P<0.001), shorter lesion length (OR 0.894, P=0.001), higher CFR (OR 1,633, P<0.001), and lower estimated glomerular filtration rate (OR, 0.968, P=0.001). Lesion location and the index of microcirculatory resistance was not associated with the prevalence of reverse mismatch or mismatch.

Conclusions

There was a high prevalence of visual-functional mismatches between QCA-DS and QFR, and CFR was an important functional factor of mismatches. Our results suggested the difference between predictors of reported visual-functional mismatches of QCA/FFR and those of QCA/QFR.

P2705Hybrid QFR-FFR decision making strategy for revascularization

Background

Measurement of the fractional flow reserve (FFR) has become a standard practice for revascularization decision-making in evaluating the functional significance of angiographically intermediate epicardial coronary stenosis. The quantitative flow ratio (QFR) is a novel method for rapid computational estimation of FFR without pressure wire and vasodilator drugs.

Purpose

Nevertheless, the evidence was shown the clinical better outcome of coronary revascularization stratified by FFR, the adoption of FFR remains low. We hypothesized that combined QFR and FFR hybrid strategy could improve the physiological assessment without pressure wire and drugs.

Methods and results

We performed a post-hocanalysis of 549 vessels with angiographically intermediate stenosis in 549 patients who underwent measurement of FFR. The median FFR and QFR values were 0.81 (0.73–0.87) and 0.79 (0.74–0.87), respectively.The ischemic threshold was defined as 0.80 for both QFR and FFR measures. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the QFR for predicting an FFR of ≤0.80 were 86.2%, 71.9%, 78.9%, 74.5%, and 84.5%, respectively. The area under the receiver operating characteristic curve using the cut-off threshold of ≤0.80 for the FFR was 0.85 (95% confidence interval [CI], 0.81–0.88) for the QFR.In total, 433 (78.9%) and 116 (21.1%) lesions showed concordant and discordant FFR and QFR functional classifications, respectively. A hybrid QFR-FFR strategy was developed, by allowing deferral when QFR values providing negative predictive value greater than 90% and treat others when QFR values greater than that showing 90% positive predictive value, with adenosine being given only to patients with QFR in between those values. For the FFR cut-off (0.8), an QFR of <0.73 could be used to confirm treatment (PPV of 90.7%), while an QFR value of >0.83 could be used to defer revascularization (NPV of 90.0%). When QFR values fall between 0.73 and 0.84, adenosine is given for hyperemic induction and the FFR cut-off of 0.8 is used to guide revascularization. This hybrid QFR-FFR approach has a 95% agreement with an FFR-only decision making, and 285 lesions (51.9%) would have obviated the need of a pressure wire and adenosine.

Hybrid QFR-FFR strategy

Conclusions

A hybrid QFR-FFR strategy for coronary revascularization could reduce the need of a pressure wire and vasodilator drugs, which may increase the penetration of functional assessment of coronary lesions.

P5619Comparison of different resting physiological indices: are diastolic pressure ratio and resting full-cycle ratio equal?

Background

Previous reports showed all diastolic resting indexes tested were virtually identical to the instantaneous wave-free ratio (iFR). Although RFR has been also reported to be diagnostically equivalent to iFR, no comparisons have been reported about the prevalence and characteristics of discordance in diagnosis between diastolic pressure ratio (dPR) and resting full-cycle ratio (RFR).

Purpose

This study sought to determine the coronary pressure characteristics of lesions classified as discordant between dPR and RFR in angiographically intermediate stenoses.

Methods

We recruited 532 patients with 668 intermediate (angiographically stenosis between 30% to 70% severity) coronary lesions undergoing FFR assessment and analyzed DICOM pressure tracings of resting state (dPR and RFR) using a fully automated off-line software algorithm in a blind fashion. Diagnostic performance of dPR and RFR was evaluated using FFR as a reference. Furthermore, we investigated similarity and difference between dPR and RFR.

Results

Median FFR was 0.81 with an interquartile range of 0.74 to 0.87. RFR was highly correlated to dPR (R2=0.94, p<0.001), with a mean bias of 0.012 (95% limits of agreement −0.008 to 0.031). The diagnostic performance of RFR versus dPR was diagnostic accuracy 95.4%, sensitivity 100.0%, specificity 91.6%, positive predictive value 90.6%, negative predictive value 100.0%). Using the binary cut-off of dPR ≤0.89 as a cut-off value, RFR showed near identical agreement according to ROC curve analysis (AUC: 0.996, 95% CI: 0.994–0.999, p<0.001). Although dPR and RFR demonstrated equivalent performance against FFR ≤0.8 (79.5% vs. 79.3% accuracy; p=0.960; area under the receiver-operating characteristic curve: 0.869 vs. 0.870; p=0.528), RFR disagreed with dPR in 4.6% (31 of 668). When all lesions (668 vessels) were divided into groups according to the concordance and discordance between dPR and RFR: RFR+/dPR+ (298 vessels, n=240), RFR+/dPR– (31 vessels, n=31 patients), RFR-/dPR- (339 vessels, n=259). There was no lesion showing RFR-/dPR+. The prevalence of ischemia was tended to be higher in lesions evaluated by RFR (49.3% vs 44.6%, P=0.100) when using FFR ≤0.80 as a reference standard. An overall significant difference in the prevalence of FFR ≤0.80 and the FFR values were detected among these 3 groups. Furthermore, pairwise comparison also revealed the prevalence of FFR >0.80 and the FFR values were significantly lower in RFR+/dPR– than in RFR-/dPR-, and significantly higher in RFR+/dPR– than in RFR+/dPR+. (P<0.001 and P<0.001, respectively)

Conclusion

Significant difference in FFR values was observed according to dPR/RFR agreement and disagreement. Revascularization decision making might defer according to the resting index used. Compared with RFR, lesions might be more frequently deferred when dPR was used to assess physiological significance.

Acknowledgement/Funding

None

P2704The association between global coronary flow reserve and coronary inflammation assessed by attenuation index on computed tomography in patients with stable angina pectoris

Background

Impaired global coronary flow reserve (G-CFR) is known to predict worse outcomes in patients with coronary artery disease. Phase contrast cine-magnetic resonance imaging (PC-CMR) of the coronary sinus (CS) is a promising approach for quantifying coronary sinus flow (CSF) and G-CFR without the need for ionizing radiation, radioactive tracers, or intravascular catheterization. Although G-CFR impairment is previously reported to be linked with endothelium dysfunction and progression of atherosclerosis, the association of perivascular adipose tissue inflammation with myocardial coronary flow remains to be determined.

Purpose

We evaluated the association between G-CFR by quantifying CSF using PC-CMR and the extent of coronary inflammation evaluated by perivascular adipose tissue inflammatory status using CT to assess if coronary inflammation is linked with G-CFR in patients with stable angina pectoris (SAP) treated with elective percutaneous coronary intervention (PCI).

Methods

The study enrolled 74 SAP patients with single denovo lesion who underwent coronary CT angiography and PC-CMR within 90 days before coronary intervention. Proximal 40-mm segments of all three major epicardial coronary vessels were traced and examined. Coronary inflammation was assessed by the CT fat attenuation index of perivascular adipose tissue (FAI-PVAT) defined as the mean attenuation of the perivascular adipose tissue (−190 to −30 Hounsfield units (HU)) in a layer of tissue within a radial distance from the outer coronary artery wall equal to the diameter of the vessel. CMR images were also acquired to assess absolute CSF at rest and during maximum hyperemia before elective PCI. The patients were divided into 4 groups according to the number of inflamed vessels as defined by showing FAI ≥−70.1 HU.

Results

In the final analysis of 69 patients (mean age 67, Male 45 (65.2%)), 18, 19, 20, 12 patients exhibited none, 1, 2, 3 inflamed vessels with FAI ≥−70.1 HU, respectively. Rest and maximal hyperemic CSF and corrected G-CFR were 1.28 [0.76,1.55] vs 1.47 [1.11, 1.81] vs 1.30 [0.94, 1.64] vs 1.27 [1.11, 2.00] ml/min/g; P=0.49, 3.50 [2.84, 5.25] vs 3.28 [2.62, 4.31] vs 3.11 [2.16, 3.63] vs 2.37 [1.40, 2.98] ml/min/g; P=0.049, 3.57 [2.17, 4.54] vs 2.25 [1.73, 3.49] vs 2.26 [1.64, 3.38] vs 1.89 [0.89, 2.32]; P=0.023, respectively. G-CFR and hyperemic CSF were both significantly lower in the group with larger number of inflamed vessels.

Conclusions

In SAP patients with significant coronary artery stenosis, G-CFR obtained by PC-CMR significantly associated with the prevalence of inflamed vessels detected by coronary CT. The extent of coronary inflammation may influence global coronary endothelium dysfunction, resulting in decreased G-CFR.

P5617Repeatability of instantaneous wave-free ratio in comparison with fractional flow reserve

Background

Instantaneous wave-free ratio (iFR) has been recently introduced as an adenosine free alternative for fractional flow reserve (FFR) to assess the functional significance of epicardial coronary stenosis. Little is known, however, regarding the repeatability and stability of iFR in comparison with FFR.

Purpose

The aim of this study was to evaluate the repeatability of iFR and compare it to that of FFR.

Methods

Patients with stable coronary artery disease who underwent physiological assessment twice within 90 days were enrolled. Repeated measurements were performed at diagnostic and therapeutic catheterization in about 70% of studied population. The remaining patients were measured twice for non-culprit lesion assessment at primary PCI and subsequent non-culprit and ischemia-documented lesion PCI. The calculation of iFRmatlab from DICOM pressure tracing data of resting state was performed using a fully automated off-line software algorithm in a blind fashion. FFR values were also measured by a fully automated algorithm in the same core laboratory by using hyperemic pressure tracing data. The repeatability of the two indices were evaluated and compared. The inter-rater agreement between iFRmatlab and FFR values of two measurements was assessed by κ coefficient. The pressure rate product during each assessment was also documented and evaluated.

Results

Ninety-three lesions from 92 patients were included in the study. The time interval between the two assessments was 38.4±19.0 days. iFRmatlab and FFR both showed significant correlation within the two assessments (iFRmatlab: r=0.75, 95% confidence interval, 0.64 to 0.83; mean difference, −0.006 [−0.18 to −0.01], FFR: r=0.86, 95% confidence interval, 0.79 to 0.90; mean difference, 0.004 [−0.07 to 0.03]). The inter-rater agreement of functional ischemia for iFRmatlab and FFR were κ=0.449 and κ=0.732, respectively. Although the prevalence of functional ischemia during the first and second assessment were consistent for both indices (iFRmatlab: 70.0%/67.7%, FFR: 86.0%/ 86.0%), significant difference was observed in the prevalence of clinical disagreement on the diagnosis of functional ischemia (FFR=0.80, iFR=0.89 used as cut-off values, respectively) between the first and second assessment among the two indices (iFRmatlab: 6.5%, FFR: 23.7%, p=0.002). iFRmatlab was significantly associated with pressure rate product during the examination compared to FFR (iFRmatlab: r= −0.25, 95% confidence interval, −0.43 to −0.04, P=0.018, FFR: r=−0.08, 95% confidence interval, −0.28 to −0.13, p=0.467).

Conclusion

Our results suggested that iFRmatlab showed lower repeatability and reliability for decision making compared to FFR. The instability of iFRmatlab potentially derives at least in part from its association with heart rate and blood pressure product.

P2703Impact of subtended myocardial mass on the assessment of functional ischemia as evaluated by FFR and QFR

Background

The fractional flow reserve (FFR) becomes a standard practice for revascularization decision-making in evaluating the functional significance of angiographically intermediate epicardial coronary stenosis. The quantitative flow ratio (QFR) is a novel method for rapid computational estimation of FFR without pressure wire and hyperemic induction. FFR has been reported to be associated with not only epicardial stenosis but also subtended myocardial mass (Vsub). In contrast, the relationship between QFR and Vsub has not been clarified.

Purpose

We sought to examine if subtended myocardial mass (Vsub) assessed by coronary computed tomography showed a significant relationship with QFR in comparison with FFR.

Methods and results

We performed a post-hoc analysis of 152 territories (LAD 116, RCA 25 and LCX 11 lesions) with angiographically intermediate-to-severe stenosis in 152 patients who underwent FFR assessment. The median FFR and QFR values were 0.76 (0.64–0.84) and 0.76 (0.72–0.83), respectively. The median diameter stenosis (%DS) and minimum lumen diameter (MLD) were 54.5 (43.9–64.2) and 1.2 (0.9–1.6), respectively. In total, 123 (80.9%) and 29 (19.1%) lesions showed concordant and discordant FFR and QFR functional classifications, respectively. The ability of Vsub/MLD2 to discriminate lesions with FFR≤0.80 and QFR≤0.80 was assessed compared with QCA data. FFR values were associated with Vsub (R=0.37, P<0.001). In contrast, a trend albeit no significant linear relationshipwas detected between QFR and Vsub (R=0.15, P=0.060). The area under the curve (AUC) of Vsub/MLD2 predicting FFR≤0.80 (0.88: 95% confidence interval [CI], 0.83–0.94)was significantly better than that of MLD (0.80: 95% [CI], 0.72–0.88) (P<0.001). On the other hand, the AUC of Vsub/MLD2 predicting QFR≤0.80 (0.82: 95% [CI], 0.75–0.90) was similar to that of MLD (0.80: 95% [CI], 0.72–0.87) (P=0.276). Multivariate analysis showed that the value of Vsub/MLD2 was an independent predictor of FFR≤0.80 (odds ratio [OR]: 1.09, 95% [CI]: 1.03–1.15, P=0.002), whereas it was not an independent predictor of QFR≤0.80.

Conclusions

Subtended cardiac mass volume derived from CT segmentation improved the diagnostic performance of angiography-derived parameters to identify ischemia-producing lesions when FFR used as a reference standard, whereas QFR showed non-significant relationship with subtended cardiac mass.

6113Gender differences in long-term outcomes in patients with deferred revascularization following fractional flow reserve assessment: international collaboration registry of physiologic evaluation

Background

Studies of sex differences in fractional flow reserve (FFR) measurements have shown that in comparison with men, angiographic lesions of similar visual severity are less likely to be ischemia producing in women. Gender specific differences may influence revascularization decision making and prognosis after deferred revascularization following FFR measurement.

Purpose

This study sought to investigate the gender difference in long-term prognosis of patients of deferred revascularization following FFR assessment.

Methods

A total of 879 patients (879 vessels) with deferred revascularization with FFR >0.75 who underwent FFR and CFR measurements were enrolled from 3 countries (Korea, Japan, and Spain). Long-term outcomes were assessed in 649 men and 230 women by the patient-oriented composite outcome (POCO, a composite of any death, any myocardial infarction [MI], and any revascularization). We applied inverse-probability weighting (IPW) based on propensity scores to account for differences at baseline between women and men (age, hypertension, hyperlipidemia, diabetes mellitus, lesion location, clinical status, FFR, Reference diameter, Diameter stenosis, lesion length). The median follow-up duration was 1855 days (745–1855 days).

Results

Median FFR values were 0.88 (0.83–0.93) in men and 0.89 (0.85–0.94) in women, respectively. The occurrences of POCO were significantly high in men compared with that in women (10.5% vs 4.2%, P=0.007). Kaplan–Meier analysis revealed that women had a significantly lower risk of POCO (χ2=7.2, P=0.007). Multivariate COX regression analysis revealed that age, male, diabetes mellitus, diameter stenosis, lesion length, and coronary flow reserve were independent predictors of POCO. After applying IPW, the hazard ratio of male for POCO was 2.20 (95% confidence interval: 1.12 to 4.33, P=0.023).

Conclusion

This large multinational study reveals that long-term outcome differs between women and men in favour of women after FFR-guided revascularization deferral.

Acknowledgement/Funding

None

P2239The association between global coronary flow reserve and coronary inflammation assessed by fat attenuation index on computed tomography in patients with acute coronary syndrome

Background

Impaired global coronary flow reserve (G-CFR) is known to predict worse outcomes in patients with coronary artery disease. Phase contrast cine-magnetic resonance imaging (PC-CMR) of the coronary sinus (CS) is a promising approach for quantifying coronary sinus flow (CSF) and global coronary flow reserve (G-CFR) without the need for ionizing radiation, radioactive tracers, or intravascular catheterization. Although G-CFR impairment has been previously reported to be linked with endothelium dysfunction and subsequent atherosclerosis, the relationship between coronary inflammation and absolute coronary blood flow volume or coronary flow reserve remains elusive.

Purpose

We evaluated the association between G-CFR by quantifying CSF using PC-CMR and the extent of coronary inflammation in patients with ACS treated with emergent percutaneous coronary intervention (PCI).

Methods

The study enrolled 107 ACS patients who underwent uncomplicated emergent PCI within 48 hours of symptom onset and coronary CT angiography were performed before PCI. Proximal 40-mm segments of all three major epicardial coronary vessels were examined. Coronary inflammation was assessed by the CT fat attenuation index of perivascular adipose tissue (FAI−PVAT) defined as the mean attenuation of the perivascular adipose tissue (−190 to −30 Hounsfield units (HU)) in a layer of tissue within a radial distance from the outer coronary artery wall equal to the diameter of the vessel, as previously reported. CMR images were acquired to assess absolute CSF at rest and during maximum hyperemia within 30 days after emergent PCI and revascularization of non-culprit significant lesions. The patients were divided into 4 groups according to the number of inflamed vessels (defined as 0, 1, 2, 3 vessels with FAI ≥−70.1 HU).

Results

In the final analysis of 102 patients (mean age 64, Male 65 (63.7%)) including 77 patients with non-ST-segment elevation myocardial infarction (NSTEMI) (75.5%) and 25 patients with unstable angina pectoris (UAP), 25, 30, 26, 21 patients exhibited none, 1, 2, 3 inflamed vessels with FAI ≥−70.1 HU, respectively. Rest and maximal hyperemic CSF and corrected G-CFR were 1.17 [0.63, 1.71] vs 1.36 [1.05, 1.67] vs 1.21 [0.83, 1.94] vs 1.35 [0.96, 1.67] ml/min/g; P=0.61, 3.26 [2.62, 2.99] vs 3.50 [2.60, 4.03] vs 3.34 [1.78, 4.20] vs 2.48 [1.54, 3.43]; P=0.061, 2.95 [2.05, 4.30] vs 2.63 [1.80, 3.56] vs 2.15 [1.37, 2.91] vs 2.18 [1.46, 2.42]; P=0.018, respectively. G-CFR was significantly lower in group with increased number of inflamed vessels.

Conclusions

In ACS patients successfully revascularized within 48 hours of onset, G-CFR obtained by noninvasive PC-CMR significantly associated with the prevalence of inflamed vessels detected by coronary CT. Further large population study is warranted to test the hypothesis that the extent of coronary inflammation before coronary revascularization in patients with ACS might provide prognostic information.

P5251Prognostic value of unrecognized myocardial infarction detected by cardiac magnetic resonance imaging in patients presenting with first acute myocardial infarction

Background

Unrecognized myocardial infarction (UMI) has been reported to be strongly associated with worse outcome in patients with cardiovascular disease. Cardiac magnetic resonance (CMR) imaging is a useful instrument for the assessment of pathological and functional conditions.

Purpose

This study sought to evaluate the prognostic value of the presence of unrecognized non-infarct-related late gadolinium enhancement (non-IR LGE) evaluated by cardiac magnetic resonance imaging in patients presenting with a first acute myocardial infarction (AMI).

Methods

We studied 311 AMI patients including 213 STEMI and 98 NSTEMI patients without the history of prior MI who underwent uncomplicated primary or emergent PCI within 48 hours of symptom onset between October, 2012 and June, 2017. CMR images were acquired at 28 [21, 32] days after primary/emergent PCI. UMI was defined as having LGE separately in the different and remote area from the perfused territory by infarct-related artery. In case of multiple LGE areas of infarction, the coronary angiography findings were used to support identification of the area corresponding to the culprit artery of AMI. The association of CMR variables and other clinical characteristics with major adverse cardiac events (cardiac death, nonfatal myocardial infarction, nonfatal stroke) were investigated.

Results

Forty-six patients (14.8%) showed UMI defined by the presence of non-IR LGE (27 STEMI and 19 NSTEMI). During the follow up for 830 [385, 1309] days, cardiovascular death occurred in 7 patients (2.3%), and non-fatal MI and non-fatal stroke occurred in 10 and 1 patients, respectively (3.2%, 0.3%, respectively). There was no significant difference in the prevalence of UMI and incidence of MACE between the patients with STEMI and NSTEMI (p=0.13, p=0.11, respectively). Event-free survival was significantly worse in patients with UMI (log-rank χ2=16.3, P=0.001) in a total cohort. Cox proportional hazards analysis showed that UMI was independent predictors of adverse cardiac events during follow-up in patients with first MI (hazard ratio, 7.60, 95% confidence interval, 2.78–20.8, p=0.0001).

Conclusions

In first AMI patients, UMI defined by non-IR LGE obtained by noninvasive CMR provides significant prognostic information. Early detection of UMI by CMR may help risk stratification of patients with AMI and support adjunctive aggressive patient management such as strong statin therapy and life style intervention.

P6393Differences in coronary inflammation between the culprit and non-culprit vessels assessed by fat attenuation index on computed tomography in patients with acute coronary syndromes

Background

Inflammation is linked with progression of coronary atherosclerosis. Recent studies have reported the association between elevated perivascular fat attenuation index (FAI) on computed tomography (CT) and worse cardiac outcomes in patients with coronary artery disease.

Purpose

We aimed to investigate the differences in FAI-defined peri-coronary inflammation status between the culprit and non-culprit vessels in patients with acute coronary syndromes (ACS).

Methods

A total of 78 ACS patients with left anterior descending coronary arteries (LAD) as a culprit vessel who underwent coronary CT angiography and invasive coronary angiography were studied. Proximal 40-mm segments of the LAD and the right coronary artery (RCA) were traced. Coronary inflammation was assessed by the FAI defined as the mean CT attenuation value of perivascular adipose tissue (−190 to −30 Hounsfield units [HU]) in a layer of tissue within a radial distance from the outer coronary artery wall equal to the diameter of the vessel. All patients were divided into two groups according to the values of FAI in the LAD: high FAI group (FAI-LAD > median; n=39) and low FAI group (FAI-LAD ≤ median; n=39). Patient characteristics, angiographic and CT findings were compared between the two groups.

Results

In a total of 78 patients, median FAI in the LAD was −70.20 (interquartile range, −74.81 to −64.58) HU. High FAI group was associated with male sex and lower left ventricular ejection fraction compared with Low FAI group. Minimal lumen diameter, reference diameter, diameter stenosis, and lesion length on quantitative coronary angiography analysis and coronary artery calcium score on CT was not different between the groups. FAI in the RCA was also higher in High FAI group than that in Low FAI group (−67.64±8.31 vs. −76.47±6.25 HU, P<0.001). Paired t-test comparison demonstrated that culprit vessel showed higher FAI than the non-culprit vessel (−69.85±7.74 vs. −72.11±8.54 HU, P=0.013).

Conclusions

In ACS patients with culprit LAD lesions, FAI-defined peri-coronary inflammation status is higher in the culprit vessel than in the non-culprit vessel.

P3585Prognostic value of the assessment of coronary sinus flow by phase contrast cine-magnetic resonance imaging in patients with acute coronary syndrome

Background

Phase contrast cine-magnetic resonance imaging (PC-CMR) of the coronary sinus (CS) is a promising approach for quantifying global coronary sinus flow (CSF) and global coronary flow reserve (G-CFR) without the need for ionizing radiation, radioactive tracers, or intravascular catheterization.

Purpose

We evaluated the prognostic value of G-CFR by quantifying CSF using PC-CMR in patients with ACS treated with primary or emergent percutaneous coronary intervention (PCI).

Methods

The study prospectively enrolled 387 ACS patients who underwent uncomplicated primary or emergent PCI within 48 hours of symptom onset. Breath-hold PC-CMR images of CS were acquired to assess absolute CSF at rest and during maximum hyperemia within 30 days after primary PCI and revascularization of functionally significant non-culprit lesions of ACS. The association of G-CFR and baseline clinical characteristics with major adverse cardiac events (cardiac death, nonfatal myocardial infarction, late revascularization, or hospitalization for congestive heart failure) was investigated.

Results

In the final analysis of 366 patients (Male 294 (80.3%), mean age 65) including 233 patients (63.7%) with ST-segment elevation myocardial infarction (STEMI) and 133 patients (36.3%) with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), rest and maximal hyperemic CSF and corrected G-CFR were 1.24 [0.83, 1.71] ml/min/g, 2.56 [1.87, 3.66] ml/min/g, and 2.20 [1.53, 3.17], respectively. During a median follow-up of 16 months, MACE occurred in 84 patients (cardiac death: 9, nonfatal myocardial infarction: 11, late revascularization: 59, hospitalization for congestive heart failure: 5). Cardiac event-free survival was significantly worse in patients with a corrected G-CFR <2.00 (log-rank χ2=20.2, P<0.001). Cox proportional hazards analysis showed that corrected G-CFR were independent predictors of adverse cardiac events during follow-up in patients with STEMI (hazard ratio, 0.66, 95% confidence interval, 0.51–0.85, p=0.001) and NSTE-ACS (hazard ratio, 0.64, 95% confidence interval, 0.43–0.95, p=0.026), respectively.

Conclusions

In ACS patients successfully revascularized within 48 hours of onset, G-CFR obtained by noninvasive PC-CMR provided significant prognostic information independent of infarction size and conventional risk scores.

Enfold-type connecting system of artificial blood vessels for micro implantable dialysis device

This paper reports the connecting mechanism for the artificial blood vessels along with the recent development of the micro implantable dialysis device. Our group has been studying the micro implantable dialysis device, which will drastically improve the quality of life of dialysis patients. We expect to replace the device every couple of years, which will involve surgery. In order to simplify the surgery to reduce the load to the patients, we develop a connector for the artificial vessels, which allows the exchange of the device by low invasive surgery. The connector needs to be designed not to induce blood coagulation. We designed a connecting mechanism that enfolds the artificial vessels to allow blood to contact only to the surface of the artificial vessels. In order to verify effectiveness of the proposed connecting mechanism, we investigated the connector surfaces with SEM after blood circulation tests. Then, we evaluated blood coagulation capacity of the connecting system as well as the set of the connecting system and the micro dialysis device with respect to the activated partial thromboplastin time (APTT). No remarkable increase of blood coagulation at the connecting point was observed after 72 hours of blood circulation tests. Short-term experiments for 120 minutes to evaluate APTT showed a small decrease of APTT, which needs to be further investigated in a longer-term experiments.

Evaluation of biofouling for implantable micro dialysis system

Implantable artificial kidney can drastically improve the quality of life of the renal disease patients. In previous study, our group has developed a multi-layered micro dialysis device which is composed of micro stainless steel channels and nano-porous polyethersulfone (PES) membranes. The device conducts hemofiltration without dialysis fluids, which is advantageous in miniaturization. We investigated the water-permeability of the PES membrane through in vivo experiments using rat model of renal disease for 5 hours and verified the effectiveness of the device. We investigated the permeability of PES membrane via in vitro experiments for 24 days. Biofouling on the PES membrane was found and caused deterioration of dialysis performance of the membrane. In this research, we investigated the biofouling such as thrombus, coagulation and protein adhesion on the sidewall of the micro fluidic channels. We investigated the micro fluidic channel geometry and surface condition associated with the processing methods. Conducting in vitro experiment for 7 days, biofouling was found to be mainly caused by the surface conditions. The mirror surface formed by electrolytic etching could substantially prevent biofouling.

Does the Age of Donor Kidneys Affect Nocturnal Polyuria in Patients With Successful Real Transplantation?

BACKGROUND

We investigated whether the age of donor kidneys influences the incidence of nocturnal polyuria in patients with successful renal transplantation (RTX).

METHODS

Eighty-five patients (45 men and 40 women) undergoing RTX (median age, 47 years) were included in this study. Twenty-four-hour bladder diaries were kept for 3 days, and nocturnal polyuria was defined as a nocturnal polyuria index (nocturnal urine volume/24-hour urine volume) of >0.33. Risk factors for nocturnal polyuria were analyzed in patients with RTX by means of the Mann-Whitney U test, χ² test, and a logistic regression analysis.

RESULTS

End-stage renal disease (ESRD) developed from diabetes mellitus in 16 patients (19%). Sixty-five patients (76%) received pre-transplant dialysis, with a median duration of 5 years. The median serum creatinine level and body mass index at the most recent visit were 1.2 mg/dL and 21.2 kg/m², respectively. On the basis of the 24-hour bladder diaries, nocturnal polyuria was identified in 48 patients (56%). A logistic regression analysis revealed that diabetes mellitus as the original disease for ESRD was the only risk factor for nocturnal polyuria (odds ratio, 8.95; 95% confidence interval, 2.01-65.3; P = .0028). The age of donor kidneys at examination did not affect the incidence of nocturnal polyuria (P = .9402).

CONCLUSIONS

Nocturnal polyuria was not uncommon in patients with successful RTX. Diabetes mellitus as the original disease for ESRD was the only risk factor for nocturnal polyuria, whereas the age of donor kidneys at examination did not affect the incidence of nocturnal polyuria. Thus, nocturnal polyuria is caused by recipient factors but not donor factors.

Complications after intraoral vertical ramus osteotomy: relationship to the shape of the osteotomy line

Intraoral vertical ramus osteotomy (IVRO) is used widely to correct mandibular prognathism. However, several disadvantages of this procedure have been reported, such as condylar luxation and bony interference at the osteotomy site. The aim of this study was to survey the incidence of complications (condylar luxation and bony interference) based on the shape of the osteotomy line. One hundred and eighty-five rami in 118 patients with jaw deformities, which were treated with IVRO, were examined retrospectively. The shape of the osteotomy line and the postoperative complications were examined on panoramic radiographs. Osteotomy lines were classified into three types: vertical, C-shaped, and oblique. Of the 185 osteotomy sites, 98 were vertical, 37 C-shaped, and 50 oblique. Condylar luxation was found in six rami (3.2%); four had undergone vertical osteotomy and two had undergone C-shaped osteotomy. Bony interference occurred in seven rami (3.8%), all with vertical type osteotomy lines. Most complications occurred in the vertical type cases and no complications were found in oblique type cases. Condylar luxation was found mainly in unilateral IVRO cases and bony interference was found in bilateral IVRO cases. These results suggest that the oblique type of osteotomy line has the advantage of avoiding complications.

Development of implantable hemodialysis system using PES membranes with high water-permeability

This paper presents development of high water-permeable dialysis membranes. We proposed the system that does not use dialysis fluid for the implantable micro dialysis treatment and development of such membranes is crucial. We developed micro dialysis system composed by nanoporous membranes and microfluidic channels in our prior work. The membranes were made of nanoporous polyethersulfone (PES), which was not water-permeable. By not using dialysate, our device can be simplified because the pumps and storage tanks for the dialysis fluid are not necessary. This treatment is termed as hemofiltration. We measured the water permeability of PES membrane with respect to the concentrations of the PES, the additives, and the solvents in the casting solution. We could find the membranes with sufficiently high water permeability through in vitro experiments using a syringe pomp and whole cow blood, and the membrane had enough mechanical strength. We conducted experiments with multi-layered device in in vitro and in vivo using rats, where the system was connected to the vein and artery. We successfully collected the filtrate beyond target line, which was set by a medical doctor, without any leakage of blood from the device. The results verified that the filtration device can be scaled-up by increasing a number of the layer. We connected the device to a rat for 5h. It was verified the device maintained almost constant water permeability beyond our target line.

Simple Resistance Exercise helps Patients with Non-alcoholic Fatty Liver Disease

To date, only limited evidence has supported the notion that resistance exercise positively impacts non-alcoholic fatty liver disease. We evaluated the effects of resistance exercise on the metabolic parameters of non-alcoholic fatty liver disease (NAFLD) in 53 patients who were assigned to either a group that performed push-ups and squats 3 times weekly for 12 weeks (exercise group; n=31) or a group that did not (control; n=22). Patients in the control group proceeded with regular physical activities under a restricted diet throughout the study. The effects of the exercise were compared between the 2 groups after 12 weeks. Fat-free mass and muscle mass significantly increased, whereas hepatic steatosis grade, mean insulin and ferritin levels, and the homeostasis model assessment-estimated insulin resistance index were significantly decreased in the exercise group. Compliance with the resistance exercise program did not significantly correlate with patient background characteristics such as age, sex, BMI and metabolic complications. These findings show that resistance exercise comprising squats and push-ups helps to improve the characteristics of metabolic syndrome in patients with non-alcoholic fatty liver disease.

Genetic diversity of Mycobacterium tuberculosis isolates from foreign-born and Japan-born residents in Tokyo

Sequences of the full genomes of 259 clinical isolates of Mycobacterium tuberculosis, obtained from foreign-born and Japan-born patients in Tokyo, Japan, were determined, and a phylogenetic tree constructed by concatenated single-nucleotide polymorphism (SNP) sequences. The 259 isolates were clustered into four clades: Lineage 2 (East Asian or "Beijing" genotype; n = 182, 70.3%), Lineage 4 (Euro-American, n = 46, 17.8%), Lineage 1 (Indo-Oceanic, n = 23, 8.9%), and Lineage 3 (East African-Indian, n = 8, 3.1%). Of the 259, 36 (13.9%) were resistant to at least one drug. There was no multi-drug-resistant isolate. Drug resistance was greater for the strains in Lineage 2 than the non-Lineage 2. The proportion of Lineage 2 isolates was significantly smaller in foreign-born (n = 43/91, 47.3%) than in Japan-born (n = 139/168, 82.7%) patients, whereas the proportion of Lineage 1 isolates was significantly larger in foreign-born (n = 19/91, 20.9%) than in Japan-born (n = 4/168, 2.4%) patients. We also found eight SNPs specific to the typical Beijing sub-genotype in Lineage 2, including 4 non-synonymous SNPs. Of the 259 isolates, 244 had strain-specific SNP(s) and small (1-30-bp) insertions and deletions (indels). The numbers of strain-specific SNPs and indels per isolate were significantly larger from foreign-born (median 89, range 0-520) than from Japan-born (median 23, range 0-415) (p 3.66E-15) patients. These results suggested that M. tuberculosis isolates from foreign-born patients had more genetic diversity than those from Japan-born patients.