The utility of zebrafish cardiac arrhythmia model to predict the pathogenicity of KCNQ1 variants.

Genetic testing for inherited arrhythmias and discriminating pathogenic or benign variants from variants of unknown significance (VUS) is essential for gene-based medicine. KCNQ1 is a causative gene of type 1 long QT syndrome (LQTS), and approximately 30% of the variants found in type 1 LQTS are classified as VUS. We studied the role of zebrafish cardiac arrhythmia model in determining the clinical significance of KCNQ1 variants. We generated homozygous kcnq1 deletion zebrafish (kcnq1del/del) using the CRISPR/Cas9 and expressed human Kv7.1/MinK channels in kcnq1del/del embryos. We dissected the hearts from the thorax at 48 h post-fertilization and measured the transmembrane potential of the ventricle in the zebrafish heart. Action potential duration was calculated as the time interval between peak maximum upstroke velocity and 90% repolarization (APD90). The APD90 of kcnq1del/del embryos was 280 ± 47 ms, which was significantly shortened by injecting KCNQ1 wild-type (WT) cRNA and KCNE1 cRNA (168 ± 26 ms, P < 0.01 vs. kcnq1del/del). A study of two pathogenic variants (S277L and T587M) and one VUS (R451Q) associated with clinically definite LQTS showed that the APD90 of kcnq1del/del embryos with these mutant Kv7.1/MinK channels was significantly longer than that of Kv7.1 WT/MinK channels. Given the functional results of the zebrafish model, R451Q could be reevaluated physiologically from VUS to likely pathogenic. In conclusion, functional analysis using in vivo zebrafish cardiac arrhythmia model can be useful for determining the pathogenicity of loss-of-function variants in patients with LQTS.

The Association Between Serum Uric Acid and Mortality in Patients with Acute Coronary Syndrome After Percutaneous Coronary Intervention.

This study aims to explore the associations between uric acid (UA) and long-term outcomes among patients with acute coronary syndrome (ACS). A total of 1068 consecutive patients with ACS who underwent percutaneous coronary intervention (PCI) were analyzed retrospectively. The patients were divided into 3 groups based on the levels of serum UA upon admission (bottom quintile, middle 3 quintiles, and top quintile). The primary endpoint was all-cause mortality. The patients in the higher UA groups were associated with younger age (71 ± 11 versus 68 ± 12 versus 67 ± 14 years; P < 0.05) and were more likely to be male (57.6 versus 76.9 versus 84.7%; P < 0.001). Furthermore, these patients had lower estimated glomerular filtration rates (83 ± 27 versus 74 ± 23 versus 59 ± 24 mL/minute/1.73 m2; P < 0.001) and lower left ventricular ejection fractions (58 ± 14 versus 57 ± 14 versus 53 ± 15%; P < 0.001). During the median 4-year follow-up, there were 158 incidents of all-cause death. Patients in the top quintile, followed by patients in the bottom quintile, had greater all-cause mortality compared with patients in the middle quintile (16.5 versus 11.4 versus 23.8%; P < 0.001). When the middle of the 3 quintiles was assigned as the reference group, the adjusted hazard ratios for all-cause mortality for the top and bottom quintiles were 1.72 (95% confidence interval [CI] 1.16-2.53, P < 0.05) and 1.57 (95% CI 1.03-2.36, P < 0.05), respectively. These results demonstrate that UA levels upon admission in patients with ACS who underwent PCI exhibited a 'J-shaped' association with all-cause mortality.

Impact of concomitant peripheral artery disease on contrast-induced acute kidney injury and mortality in patients with acute coronary syndrome after percutaneous coronary intervention.

Subclinical peripheral artery disease (PAD) might be associated with pathophysiology of contrast-induced acute kidney injury (CI-AKI). We hypothesized that concomitant PAD in patients with the acute coronary syndrome (ACS) would represent a high-risk subgroup with a greater incidence of CI-AKI, both of which lead to higher mortality after percutaneous coronary intervention (PCI). Six hundred and seventy-five consecutive patients with ACS who underwent PCI and examination of ankle-brachial index (ABI) were analyzed retrospectively. The presence of PAD was defined as an ABI < 0.9. We investigated whether (1) PAD was an independent predictor of CI-AKI (≥ 0.3 mg/dL or ≥ 50% relative increase in serum creatinine within 48 h after PCI) and (2) PAD and CI-AKI were independently associated with long-term mortality. Of the 675 patients with ACS, 114 (17%) exhibited PAD. The incidence of CI-AKI was significantly higher in PAD patients, compared with the remaining patients (12% vs. 4%, p < 0.001). Multivariate logistic regression analysis revealed that the presence of PAD was an independent predictor for the development of CI-AKI [odds ratio 2.50, 95% confidence interval (CI) 1.07-5.73, p < 0.05]. During the median 4-year follow-up, there were 65 incidents of all-cause death. In the multivariate Cox proportional hazard regression analysis, the presence of PAD [hazard ratio (HR) 2.08, 95% CI 1.17-3.65, p < 0.05] and CI-AKI (HR 2.23, 95% CI 1.08-4.26, p < 0.05) were associated with an increased risk of all-cause mortality. Assessment of ABI provides useful information for predicting CI-AKI and long-term mortality in patients with ACS after PCI.

Impact of decreased ankle-brachial index on 30-day bleeding complications and long-term mortality in patients with acute coronary syndrome after percutaneous coronary intervention.

BACKGROUND: Although concomitant peripheral artery disease in patients with acute coronary syndrome (ACS) has been considered as a high-risk subgroup with a greater incidence of bleeding after percutaneous coronary intervention (PCI), few data exist regarding the clinical utility of the ankle-brachial index (ABI) for predicting bleeding complications, which affects the subsequent outcome. METHODS: Eight hundred and twenty-four consecutive patients with ACS who underwent PCI and ABI examination were analyzed retrospectively. Decreased-ABI was defined as ABI <0.9. The primary outcome was bleeding complications within 30 days, which was defined according to the Bleeding Academic Research Consortium classification grade ≥3. The secondary endpoint was all-cause death during follow-up. RESULTS: Of the 824 patients with ACS, 137 (16.6%) exhibited decreased-ABI. The incidence of bleeding complications was significantly higher in patients with decreased-ABI, compared with the remaining patients (21.9% vs. 6.0%, p<0.001). In multivariate analysis, anemia [odds ratio (OR) 2.14], estimated glomerular filtration rate<60mL/min/1.73m2 (OR 2.14), femoral access (OR 3.31), use of an intra-aortic balloon pump (OR 3.16), and decreased-ABI (OR 2.58) were independent predictors of 30-day bleeding complications. Assigning 1 point for each variable, we developed a new bleeding risk score (range, 0-5). The area under the receiver-operating characteristic curve for the probability of 30-day bleeding for the new risk score was significantly superior than that of the traditional one (0.82 vs. 0.76, p<0.05). During the median 4-year follow-up, there were 98 incidents of all-cause death. Multivariate Cox-proportional hazard analysis revealed that decreased-ABI [hazard ratio (HR) 1.91, 95% confidence interval (CI) 1.15-3.13, p<0.05] and 30-day bleeding (HR 3.00, 95% CI 1.76-4.97, p<0.001) were associated with an increased risk of all-cause mortality. CONCLUSIONS: Assessment of ABI provides useful information for predicting 30-day bleeding complications and long-term mortality in patients with ACS after PCI.

Self-Expanding Nitinol Stent vs Percutaneous Transluminal Angioplasty in the Treatment of Femoropopliteal Lesions: 3-Year Data From the SM-01 Trial.

PURPOSE: To report the midterm outcomes of a trial comparing self-expanding nitinol stents to percutaneous transluminal angioplasty (PTA) with provisional stenting in the treatment of obstructive disease in the superficial femoral and popliteal arteries. MATERIALS AND METHODS: The SM-01 study ( ClinicalTrials.gov identifier NCT01183117), a single-blinded, multicenter, randomized controlled trial in Japan, enrolled 105 consecutive patients with de novo or postangioplasty restenotic femoropopliteal lesions; after removing protocol violations (1 from each group), 51 patients (mean age 74±8 years; 36 men) in the stent group and 52 patients (mean age 73±8 years; 35 men) in the PTA group were included in the intention-to-treat analysis. The groups were well-matched at baseline. Patients were followed to 36 months with duplex imaging. Three-year primary patency was assessed based on a duplex-derived peak systolic velocity ratio <2.5. Freedom from clinically-driven target vessel revascularization (TVR) and target lesions revascularization (TLR) were estimated using the Kaplan-Meier method. RESULTS: The technical success rate was higher (100% vs 48%, p<0.001) and the frequency of vascular dissection was lower (4% vs 31%, p<0.001) in the stent group. The S.M.A.R.T stent group had a higher 3-year primary patency rate (73% vs 51%, p=0.033). Freedom from clinically-driven TVR and TLR were not significantly different between the groups. CONCLUSION: The S.M.A.R.T. stent maintained a higher primary patency rate than PTA at 3 years in this randomized trial; the need for clinically-driven revascularization was similar for both therapies.

Percutaneous transluminal angioplasty for central venous stenosis or occlusion in hemodialysis patients.

The objectives of central venous percutaneous transluminal angioplasty are to dilate the venous lesion and to extend the life of arteriovenous fistula for hemodialysis. It is reasonable to perform percutaneous transluminal angioplasty for central venous lesions if this interventional therapy is required to maintain stable dialysis therapy. However, the presence of large fresh thrombus at central venous lesion site represents a contraindication to percutaneous transluminal angioplasty unless the thrombus can first be removed by thrombectomy. Balloon angioplasty is a basic treatment for central venous lesion, but stent implantation is sometimes required. The self-expandable or balloon-expandable stent is chosen by the lesion location and characteristics. The lesion in subclavian vein is generally treated by self-expandable stent and right brachiocephalic vein is treated by balloon-expandable stent. The organic lesion of innominate vein with plaque is treated by self-expandable stent. Note that the innominate venous stenosis is sometimes caused by compression between the right brachiocephalic artery and the sternum, and this lesion is treated by balloon-expandable stent because the radial force of balloon-expandable stent is stronger than self-expandable stent. It is important to understand the indication and stent selection for central venous percutaneous transluminal angioplasty.

Impact of stent deformity induced by the kissing balloon technique for bifurcating lesions on in-stent restenosis after coronary intervention.

OBJECTIVES: To investigate the impact of stent deformity induced by final kissing balloon technique (KBT) for coronary bifurcation lesions on in-stent restenosis (ISR). BACKGROUND: In experimental models, the detrimental effects of KBT have been clearly demonstrated, but few data exists regarding the impact of proximal stent deformity induced by KBT on clinical outcomes. METHODS: We examined 370 coronary lesions where intravascular ultrasound (IVUS)-guided second-generation drug-eluting stent (DES) implantation for coronary bifurcation lesions was performed. Based on IVUS analysis, the stent symmetry index (minimum/maximum stent diameter) and stent overstretch index (the mean of stent diameter/the mean of reference diameter) were calculated in the proximal main vessel. RESULTS: The stent symmetry index was significantly lower (0.75 ± 0.07 vs 0.88 ± 0.06, P < 0.0001) and the stent overstretch index was significantly higher (1.04 ± 0.08 vs 1.01 ± 0.06, P = 0.0007) in lesions with KBT (n = 174) compared to those without KBT (n = 196). The number of two-stent technique in lesions with KBT was 31 (18%). In multivariate analysis, the degree of stent deformity indices was not associated with ISR in lesions with KBT; however, two-stent technique use was the only independent predictor of ISR at 8 months (hazard ratio: 3.96, 95% confidence interval: 1.25-12.5, P = 0.01). CONCLUSIONS: Second-generation DES deformity induced by KBT was not associated with mid-term ISR.

Paradoxical impact of decreased low-density lipoprotein cholesterol level at baseline on the long-term prognosis in patients with acute coronary syndrome.

Although statin therapy is beneficial in the setting of acute coronary syndrome (ACS), a substantial proportion of patients with ACS still do not receive the guideline-recommended lipid management in contemporary practice. We hypothesize that the low-density lipoprotein cholesterol (LDL-C) level at the time of admission might affect patient management and the subsequent outcome. Nine-hundred and forty-two consecutive patients with ACS who underwent percutaneous coronary intervention were analyzed retrospectively. The study patients were first divided into two groups based on the LDL-C level on admission: group A (n = 267), with LDL-C < 100 mg/dL; and group B (n = 675), with LDL-C ≥ 100 mg/dL. Each group was then further divided into those who were prescribed statins or not at the time of discharge from the hospital. The primary endpoint was all-cause death. In addition, we analyzed the serial changes of LDL-C within 1 year. Patients in group A were significantly older and more likely to have multiple comorbidities compared with group B. The proportion of patients who were prescribed statin at discharge was significantly smaller in group A compared with group B (57.7 vs. 77.3%, p < 0.001). During the median 4-year follow-up, there were 122 incidents of all-cause death. Multivariate Cox proportional hazard analysis revealed that LDL-C < 100 mg/dL on admission [hazard ratio (HR), 1.61; 95% confidence interval (CI), 1.09-2.39; p < 0.05] and prescription of statins at discharge (HR, 0.52; 95% CI, 0.36-0.76; p < 0.001) were associated significantly with all-cause death. Under these conditions, increasing LDL-C levels were documented during follow-up in those patients in group A when no statins were prescribed at discharge (79 ± 15-96 ± 29 mg/dL, p < 0.001), whereas these remained unchanged when statins were prescribed at discharge (79 ± 15-77 ± 22 mg/dL, p = 0.30). These results demonstrate that decreased LDL-C on admission in ACS led to less prescription for statins, which could result in increased death, probably due to underestimation of the baseline LDL-C.

Initial and late efficacy of everolimus-eluting stents for small and non-small coronary lesions from evaluating delayed late loss study.

The aim of the present study was to evaluate the long-term outcomes at 2 years in patients in whom everolimus-eluting stents (EESs) were implanted in small and non-small vessels. A small vessel is an important risk factor for restenosis with BMSs, even in the first generation DESs. The 690 patients with 690 lesions implanted with an EES were enrolled and divided into two groups by vessel reference diameter (RD): >2.5 mm for non-small vessels (Non-S-group) and ≤2.5 mm for small vessels (S-group). Two years later, the 365 patients with no restenosis at 8 months who underwent angiography were enrolled into the late catch-up study. At the initial 8-month follow-up, the rates of restenosis and target lesion revascularization (TLR) of both groups were not significantly different (restenosis 3.9 vs 6.5%, p = 0.17; TLR 3.9 vs 6.5%, p = 0.17). At the late 2-year follow-up, there were no significant differences in the late loss (0.36 ± 0.66 vs 0.34 ± 0.50 mm, p = 0.14), net gain (1.50 ± 0.75 vs 1.26 ± 0.60 mm, p = 0.39), late catch-up restenosis rate (5.1 vs 3.4%, p = 0.38), TLR (4.9 vs 2.7%, p = 0.40), and delayed late loss (0.14 ± 0.58 vs 0.15 ± 0.49 mm, p = 0.10) between both groups. There is no correlation between delayed late loss and RD in all patients(r = -0.009) and in AMI patients (r = -0.004). These results demonstrate that the initial and late catch-up restenosis rates of small coronary vessels with EES placement were excellent, the same as for non-small coronary vessels. We suggest that involvement of small coronary arteries may not be a risk factor for restenosis and results of stenting for small coronary arteries with EES placement were excellent.

Impact of Baseline Angiographic Complexities Determined by Coronary Artery Bypass Grafting SYNTAX Score on the Prediction of Outcome After Percutaneous Coronary Intervention.

Although Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) score based on angiographic scoring system was developed in patients with previous coronary artery bypass grafting (CABG), few data exist regarding its prognostic utility in patients undergoing percutaneous coronary intervention (PCI). We examined 272 patients with previous CABG (217 men; mean age, 70.4 ± 9.7 years) undergoing PCI. Severity of the coronary anatomy was evaluated using CABG-SYNTAX score. The primary end point of this study was cardiovascular death. The baseline CABG-SYNTAX score ranged from 2 to 53.5, with an average of 26.0 ± 10.2. In the index procedures, PCI for the native coronary accounted for nearly all patients (88%). During follow-up (median 4.1 years), 40 cardiovascular deaths had occurred. In multivariate analysis, age >75 years (hazard ratio [HR] 2.82, 95% CI 1.45 to 5.52), left ventricular ejection fraction <40% (HR 2.99, 95% CI 1.39 to 6.07), end-stage renal disease (HR 2.90, 95% CI 1.15 to 6.75), peripheral artery disease (HR 2.20, 95% CI 1.10 to 4.64), and CABG-SYNTAX score >25 (HR 2.37, 95% CI 1.19 to 5.05) were independent predictors of cardiovascular death. After creating a composite risk score in consideration of identified predictors, the freedom from cardiovascular death at 5 years was 98%, 86%, and 58% in the low (0 to 1), medium (2), and high (3 to 5) scores, respectively (p <0.001). The area under the receiver-operating characteristic curve for cardiovascular death for the CABG-SYNTAX and composite risk scores were 0.66 and 0.77, respectively (p <0.05). In conclusion, the combination of angiographic and clinical characteristics is useful for risk stratification in patients with previous CABG undergoing PCI.

Repeated occurrence of slow flow phenomenon during and late after sirolimus-eluting stent implantation.

A 78-year-old man with unstable angina showed 90% stenosis in the proximal left anterior descending artery. Pre-procedural intravascular ultrasound revealed ruptured plaque and attenuated plaque in the lesion. Under these conditions, two overlapping sirolimus-eluting stent (SES) implantation in this lesion resulted in slow flow which was recovered by intracoronary nitrates, nicorandil, and nitroprusside without further complications. When the patient showed up again 5 years later with recurrence of angina pectoris, angiography revealed a hazy ulcerated in-stent restenosis (ISR) at the site of the SES. Pre-procedural optical coherence tomography (OCT) imaging revealed multiple intimal ruptures, cavity formation behind the stent struts, a thin-cap fibroatheroma containing neointima surrounded by signal-poor, lipid-rich area in the proximal SES, suggesting the progression of neoatherosclerosis within SES. Importantly, there occurred slow flow again after balloon angioplasty for this lesion. We would suggest careful OCT examination is warranted to confirm development of neoatherosclerosis within the stent, and distal protection device should be considered to prevent slow flow phenomenon even in a patient with very late ISR.

Serial changes in glucose-loaded 18F-fluoro-2-deoxyglucose positron emission tomography, 99mTc-tetrofosmin and 123I-beta-methyl-p-iodophenyl-penta-decanoic acid myocardial single-photon emission computed tomography images in patients with anterior acute myocardial infarction.

BACKGROUND: (18)F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) is assumed to be the most useful method for evaluating the viability of the myocardium. However, there are few reports regarding serial changes in (18)F-FDG-PET images of acute myocardial infarction (AMI). We evaluated serial changes in glucose-loaded (18)F-FDG-PET, (123)I-ß-methyl-p-iodophenyl-penta-decanoic acid (BMIPP) single-photon emission computed tomography (SPECT) and (99m)Tc-Tetrofosmin (TF) gated SPECT images in patients with AMI. METHODS AND RESULTS: We enrolled 7 consecutive patients with first anterior AMI who successfully underwent percutaneous coronary intervention (PCI). (18)F-FDG-PET images were obtained in the acute, subacute, chronic, mid-term and long-term phases. (123)I-BMIPP and (99m)Tc-TF SPECT images were obtained in the subacute, chronic, mid-term and long-term phases. We determined the total defect score (TDS) for each image. The TDS of the glucose-loaded (18)F-FDG-PET, (123)I-BMIPP and( 99m)Tc-TF SPECT images indicated significant serial decrease (P<0.001). Comparing these images, the TDS of the glucose-loaded (18)F-FDG-PET images was larger than that of the (123)I-BMIPP and (99m)Tc-TF SPECT images, and the TDS indicated (18)F-FDG-PET>(123)I-BMIPP>(99m)Tc-TF in all phases. CONCLUSIONS: The defect areas of glucose-loaded (18)F-FDG-PET images were significantly larger than those of (123)I-BMIPP and( 99m)Tc-TF SPECT images during 9 months follow-up of patients with successful PCI for anterior AMI. Additionally, the impairment of glucose metabolism was prolonged.

Serial cardiac influence of volume overload induced by interventional therapy for central venous stenosis or occlusion in chronic hemodialysis patients.

BACKGROUND: Upper arm swelling and venous hypertension at arteriovenous fistula sites, and insufficiency of hemodialysis are induced by central venous lesions in chronic hemodialysis patients. Percutaneous transluminal angioplasty (PTA) for central venous lesions is first-choice treatment. Cardiac function can be evaluated by measuring the acute increase in venous return volume after PTA. METHODS: We studied 6 cases of successful PTA for central venous stenotic or occluded lesions, and evaluated cardiac function by Swan-Ganz (SG) catheter and ultrasound echocardiography (UCG) at pre-, post-PTA, and on the following day. RESULTS: Ejection fraction (EF) in 6 cases was 71.0 ± 5.5% on UCG. Two cases of subclavian venous stenosis, one case of subclavian venous occlusion, and three cases of brachiocephalic venous occlusion were enrolled. The reference diameter (RD) was 10.2 ± 4.9 mm, % diameter-stenosis (%DS) was 92.2 ± 12.2% at pre-PTA, and %DS at post-PTA was 21.7 ± 20.7%. There were no significant differences in pulmonary capillary-wedge, pulmonary artery, and right ventricular end-diastolic pressure in SG at pre- and post-PTA. The pressure of right atrium (RA) and cardiac output (CO) were significantly increased by PTA (RA pressure at pre-/post-PTA, 9.7 ± 2.9/11.7 ± 3.6 mmHg, p<0.05, CO at pre-/post-PTA 5.09 ± 2.07/5.45 ± 2.25 l/min, p<0.05). There were no significant differences in serial EF, left atrial and left ventricular diameters on UCG. However, the short-diameter of right ventricle (RV) and RA were significantly increased at post-PTA and recovered on the following day (RV short-diameter at pre-/post-/following-day PTA, 26.7 ± 3.5/32.5 ± 1.9/29.1 ± 1.7 mm, p<0.05; RA short-diameter at pre-/post-/following-day PTA, 30.2 ± 4.2/36.3 ± 2.4/32.1 ± 3.6mm, p<0.05). CONCLUSIONS: Volume overload after PTA for central venous stenotic or occluded lesions in chronic hemodialysis patients resulted in increased RA and RV diameters. These changes were transient and completely recovered by the following day. PTA for central venous lesions in patients with normal EF can be performed without clinical cardiac problems.

Which DES is the most appropriate for very small target vessels? Experimental study of stent expandable performance with SES, PES, ZES and EES.

The restenosis rate of coronary stent has significantly decreased by implantation of the drug-eluting stent (DES). We often experienced the DES implantation for very small target vessels. The minimum size of DES in Japan and USA is 2.5 mm-diameter, but there were no reports of the expandability of DESs for the very small target vessels with reference diameter <2.2 mm. We clarify the expandable performance of 2.5 mm-DESs for very small target vessels with reference diameter <2.2 mm in vitro and vivo study. We studied 3 pieces in each kind of DES (Sirolimus-eluting stent; SES, Paclitaxel-eluting stent; PES, Zotarolimus-eluting stent; ZES and Everolimus-eluting stent; EES) in vitro and vivo study of the porcine coronary artery with reference diameter <2.2 mm. By using the delivery balloon, each stent was initially dilated with 3.5 atm. And the pressure of 0.5 atm. was applied until it reached the maximum pressure of 12 atm. The minimum pressure of the full expanded stent balloon was estimated as the minimum expandable pressure. The stent-inner diameter and area on each pressure were measured by IVUS. The average minimum expandable pressure (atm.) in vitro/vivo was 4.7/4.5 in SES, 7.2/6.8 in PES, 4.3/4.5 in ZES and 3.8/3.8 in EES. The inner diameter (mm) in vitro/vivo at minimum expandable pressure was 1.81 ± 0.07/1.84 ± 0.05 in SES, 2.31 ± 0.10/2.13 ± 0.13 in PES, 2.41 ± 0.13/1.98 ± 0.31 in ZES and 2.13 ± 0.11/1.88 ± 0.22 in EES. The stent inner-diameter (mm) of DESs at 8 atm. in vivo was 2.16/2.21/2.45/2.25 in SES/PES/ZES/EES. All kinds of DES could be delivered to very small target vessels with reference diameter <2.2 mm at the minimum expandable pressure in vivo study, but the stent which presented adequate stent inner-diameter at 8 atm. was only SES. We have to implant the 2.5 mm-DESs for very small target vessels according to the data based on this expandability of DESs to bail out threatening occlusion due to coronary dissection or elastic recoil.

Development of a novel catheter preventing the outflow of debris and thrombus on percutaneous transluminal angioplasty for hemodialysis access fistulas.

If a large amount of debris or thrombus dislodges from a lesion because of dilation of the stenotic or occluded lesion in the hemodialysis access fistula when angioplasty is performed, it may move into the pulmonary artery via the central vein, resulting in pulmonary embolism. A novel sheath has been developed to prevent the outflow of debris or thrombus to the central vein. The catheter consists of a 5 F sheath introducer and a silicone balloon attached at the tip of the sheath. The silicon balloon is inflated via small inflation lumen on the shaft wall of the sheath. In the case of percutaneous transluminal angioplasty (PTA), the silicone balloon is inflated to block the blood flow by a mixture of contrast medium and physiological saline, and then dilate a stenotic or occluded lesion by PTA balloon. Next, the debris and thrombus are aspirated using the flush-lumen of this device. Finally, the silicone balloon is deflated and the dilation of the lesion is confirmed. A case of hemodialysis access fistula graft with massive thrombotic occlusion was presented. This device enabled Fogarty procedure using PTA balloon and the blood flow of the graft was completely improved and a large amount of thrombus was removed. This novel device is useful to prevent the embolic complication of the intervention for hemodialysis access fistula.

Usefulness of fluorine-18-fluorodeoxyglucose positron emission tomography in a patient with Takayasu's arteritis associated with antiphospholipid syndrome.

A 36-year-old woman was admitted for recurring chest pain and hemoptysis. Blood pressure in the right and left arms was equal, and no murmurs or bruits were heard. Body temperature was normal on admission and remained within the normal range during the hospital stay. C-reactive protein was slightly elevated (2.3 mg/dL) and lupus anticoagulant was positive. Angiography showed no abnormality of the aorta or its branches, but the left pulmonary artery showed occlusion at the proximal portion. Computed tomography (CT) revealed segmental wall thickening of the thoracic aorta. Fluorine-18-fluorodeoxyglucose positron emission tomography (18FDG PET) showed high uptake in the proximal portion of the left pulmonary artery and in the thoracic aorta with wall thickening on CT. Based on these findings, a diagnosis of Takayasu's arteritis associated with antiphospholipid syndrome was made and high-dose steroid therapy (prednisolone 30 mg/day) was started. Two months later, the C-reactive protein level had decreased from 2.3 mg/dL to 1.1 mg/dL, and both the focal wall thickening and (18)FDG uptake of the thoracic aorta were decreased. 18FDG PET was useful for evaluating the efficacy of the steroid therapy in addition to making a diagnosis of Takayasu's arteritis associated with antiphospholipid syndrome.

Abnormal sympathetic innervation of the heart in a patient with Emery-Dreifuss muscular dystrophy.

A 33-year-old man was admitted for general malaise and vomiting. An electrocardiogram showed a complete atrioventricular block and an echocardiogram showed right atrial dilatation and normal wall motion of left ventricle (LV). Gene analysis showed nonsense mutation in the STA gene, which codes for emerin, and Emery-Dreifuss muscular dystrophy was diagnosed. An endomyocardial biopsy of right ventricle showed mild hypertrophy of myocytes. Myocardial scintigraphic studies with Tc-99m methoxyisobutylisonitrile (MIBI) and I-123-betamethyl-p-iodophenylpentadecanoic acid (BMIPP) scintigrams showed no abnormalities. In contrast, I-123 metaiodobenzylguanidine (MIBG) scintigrams showed a diffuse and severe decrease in accumulation of MIBG in the heart. Six months later, his LV wall motion on echocardiograms developed diffuse hypokinesis. These results suggest that the abnormality on I-123 MIBG myocardial scintigrams may predict LV dysfunction in Emery-Dreifuss muscular dystrophy.

Self-vasodilating ability at the spastic site of patients with vasospastic angina: estimation by acetylcholine delayed phase.

Deficient nitric oxide (NO) release is thought to be the principal mechanism of coronary spasm, however, the precise mechanisms are unknown. Although acetylcholine (ACh) is used for provocation of coronary spasm, ACh is also used for the augmentation of blood flow and flow-mediated vasodilation is induced. We estimated the self-vasodilating ability (endothelial function) at the spastic site of coronary arteries in patients with vasospastic angina (VSA) during the provocation test of coronary spasm by ACh. This study included 93 patients with VSA and 77 patients with atypical chest pain (ACP). Intracoronary injection of ACh (20, 50, and 100 microg) was performed over 30 seconds and the coronary artery diameter of the spastic site was measured 3 to 4 minutes after ACh injection (delayed phase). The ability of dilation (AOD) was calculated as: ([diameter of delayed phase-baseline diameter]/[diameter after isosorbide dinitrate-baseline diameter]) x 100 (%). No significant difference was noted between the AOD in patients with ACP and VSA (28 +/- 36 vs 15 +/- 60%, respectively). The AOD values of 49% of patients with VSA were greater than the mean value of AOD of patients with ACP. At least almost half of the patients with VSA may have preserved self-vasodilating ability at the spastic site, and an abnormality other than endothelial dysfunction is involved in the mechanism of coronary spasm in these patients.