Tomokazu Ikemoto

Minimizing the inhibitory effect of neutralizing antibody for efficient gene expression in the liver with adeno-associated virus 8 vectors.

Neutralizing antibodies (NAbs) against adeno-associated viruses (AAVs) are known to interfere with AAV vector-mediated gene transfer by intravascular delivery. Evading the inhibitory effects of antibodies against AAV vectors is necessary for efficient transfer of therapeutic genes clinically. For this purpose, we tested the efficacy of saline flushing in order to avoid contact of vectors with NAbs present in blood. Direct injection of the AAV8 vector carrying the factor IX (FIX) gene into the portal vein of macaques using saline flushing achieved transgene-derived FIX expression (4.7 ± 2.10-10.1 ± 5.45% of normal human FIX concentration) in the presence of NAbs. Expression was as efficient as that (5.43 ± 2.59-12.68 ± 4.83%) in macaques lacking NAbs. We next tested the efficacy of saline flushing using less invasive balloon catheter-guided injection. This approach also resulted in efficient expression of transgene-derived FIX (2.5 ± 1.06-9.0 ± 2.37%) in the presence of NAbs (14-56× dilutions). NAbs at this range of titers reduced the efficiency of transduction in the macaque liver by 100-fold when the same vector was injected into mesenteric veins without balloon catheters. Our results suggest that portal vein-directed vector delivery strategies with flushing to remove blood are efficacious for minimizing the inhibitory effect of anti-AAV antibodies.

Catheter‐Based Renal Denervation Reduces Hypoxia‐Triggered Nocturnal Blood Pressure Peak in Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with an increased risk of cardiovascular events during sleep. Patients with OSAS are likely to be nondippers with diminished nocturnal blood pressure (BP) falls during sleep or risers with higher nocturnal BP than daytime BP. Increased BP surge and variability may be triggers of a cardiovascular event, and the exaggerated nocturnal BP surge triggered by periodic hypoxiainduced sympathetic overdrive may contribute to sleep-onset cardiovascular events in OSAS patients. However, conventional ambulatory BP monitoring, which measures nocturnal BP at 30-minute intervals, cannot always detect nocturnal BP surges at the time of apneic episodes in OSAS patients. Initially, the BP-lowering effect of catheter-based renal denervation (RDN) was demonstrated in the SYMPLICITY HTN-1 and SYMPLICITY HTN-2 trials; however, SYMPLICITY HTN-3, a randomized controlled trial with a sham group, did not demonstrate the effectiveness of RDN on office systolic BP, a primary endpoint, in the entire group with drug-resistant hypertension. The pathophysiology of resistant hypertension is quite heterogeneous. In patients with hypertension caused by increased sympathetic overdrive, such as patients with OSAS, RDN may provide greater BP reduction. This idea is supported by a substudy of the SYMPLICITY HTN-2 trial that demonstrated a significant office BP–lowering effect in 10 hypertensive patients with OSAS. A previous experimental study demonstrated that the BP surge caused by apneic episodes was suppressed by RDN. However, in humans it remains unclear whether catheter-based RDN could successfully suppress the hypoxia-induced nocturnal BP surge in patients with OSAS. Recently, we developed IT-based trigger nocturnal BP monitoring (ITNP), which can selectively measure hypoxia-induced BP peaks. Using this BP monitoring device, we tested the hypothesis that the sympatholytic effect of catheter-based RDN significantly suppresses hypoxia-induced peaks of nocturnal BP in patients with OSAS. This study involved two patients with drug-resistant hypertension and mild OSAS who were not being treated with continuous positive airway pressure (CPAP), were already enrolled in the Sleep Pressure and Disordered Breathing in Resistant Hypertension and Cardiovascular Disease (SPREAD) study, and had had their nocturnal BP monitored before RDN. The SPREAD study is an ongoing nationwide prospective registry trial of high-risk patients with a history of cardiovascular events or OSAS and resistant hypertension. The purpose of this study is to clarify whether hypoxia-induced nocturnal BP peaks are independently associated with cardiovascular risk, especially with sleep-onset events in high-risk hypertensive patients with OSAS. In the SPREAD study, we ask study patients to place the cuff on the upper arm and the pulse oximeter on a finger of the opposite hand just before going to bed. The ITNP device automatically measures hypoxia-triggered nocturnal BP peaks along with nocturnal BPs at 30-minute fixed time intervals and sends the data to a cloud-based computer. Renal denervation was performed on the two patients using the Symplicity system (Medtronic, Minneapolis, MN) according to the protocol of SYMPLICITY HTNJapan by one of the authors (T.I.), an expert in this procedure. SYMPLICITY HTN-Japan was the first prospective, randomized controlled trial comparing RDN with standard pharmacotherapy for treatment of resistant hypertension (systolic BP ≥160 mm Hg on ≥3 antihypertensive drugs including a diuretic for ≥6 weeks) in Asia. Patient 1 (a 65-year-old hypertensive man with diabetes and OSAS) was taking valsartan (80 mg twice daily, morning/evening), cilnidipine (10 mg twice daily, morning/evening), carvedilol (20 mg once daily, morning), eplerenone (50 mg once daily, morning), trichlormethiazide (2 mg once daily, morning), and insulin (NovoRapid 50, Diagramma AG, Dietikon, Switzerland; breakfast 8 U, lunch 4 U, dinner 6 U). Patient 2 (a 53-year-old man with diabetes and OSAS) was taking amlodipine (5 mg once daily, morning), eplerenone (25 mg once daily, bedtime), carvedilol (20 mg once daily, bedtime), and candesartan (8 mg/ hydrochlorothiazide 6.25 mg combination once daily, morning). Both study patients met the enrollment criteria of HTN-Japan. In our university hospital, nine cases were enrolled in HTN-Japan. Nocturnal BP monitoring was performed using ITNP for 3 months (1 month before and 2 months after catheter-based RDN) (Table I and Table II). Nocturnal BP data were successfully obtained by ITNP from 19 nights before, 22 nights during the first month after, and 20 nights during the second month after RDN for patient 1 and from 13 nights, 15 nights, and 16 nights, respectively, for patient 2. This study demonstrated that catheter-based RDN significantly reduced hypoxia-induced nocturnal systolic BP peaks by 10 mm Hg (Table I and Table II). The hypoxia-induced peak nocturnal BP could be only selectively detected by this new ITNP device with the trigger function of BP measurement. Oxygen saturation is continuously monitored by pulse oximetry, and the device sends a signal for cuff inflation when the oxygen is below the variable thresholds of hypoxia. The hypoxia-induced peak nocturnal BP would be triggered by the sympathetic overdrive associated with each apneic episode. In fact, studies performed in hypertensive patients with OSAS have shown that bedtime dosing of sympatholytic drugs, such as doxazosin and carvedilol, significantly reduce hypoxia-induced peak doi: 10.1111/jch.12759

High-sensitivity troponin T is a prognostic marker for patients with aortic stenosis after valve replacement surgery

BACKGROUND Aortic stenosis (AS) is recognized as a cause of sudden cardiac death. Recently, the measurement of high-sensitivity troponin T (hs-TnT) has become possible. Several studies have clarified that hs-TnT is a marker to indicate mortality of cardiovascular diseases. OBJECTIVES To examine whether hs-TnT can be used as a prognostic marker to predict the operative outcome of AS. METHODS We enrolled 60 patients with AS (mean age=68.7 ± 9.6 years, male/female=30/30). Cardiac catheterization and echocardiography were performed to evaluate the severity of AS. Aortic valve replacement surgery was performed in all patients. We defined major adverse cardiac events (MACE) as composite events of heart failure, fatal arrhythmia, and all causes of death. RESULTS We followed up the patients for 922 ± 800 days. Mean left ventricular ejection fraction was 60.0 ± 1.8%. Mean aortic valve area was 0.61 ± 0.03 cm(2). MACE occurred in 11 patients (18%), including 5 sudden cardiac deaths. We divided the patients into three groups based on the percentile of the plasma levels of hs-TnT. Kaplan-Meier curve revealed a statistically significant difference in MACE rate among the groups (log-rank test, χ(2)=13.0, p=0.002). We conducted a Cox proportional hazard analysis with a model including age, sex, estimated glomerular filtration rate, and hs-TnT tertile as explanatory variables to predict MACE. We found that hs-TnT tertile to be a significant factor to predict MACE (hazard ratio: 3.71, p=0.03). CONCLUSIONS hs-TnT can be a prognostic marker for patients with AS after valve replacement surgery.

Plasma granzyme B as a predicting factor of coronary artery disease—-Clinical significance in patients with chronic renal failure

OBJECTIVES To elucidate the role of granzyme B in coronary artery disease (CAD) in patients with chronic kidney disease (CKD). We hypothesized that granzyme B plays an important role in the formation of coronary artery lesions in patients with CKD. PATIENTS AND METHODS We studied 141 patients (116 men and 25 women; mean age, 64.2±9.6 years) and 16 control subjects. Diagnosis of CAD was confirmed by selective coronary angiography. CKD was defined as a sustained decrease in the estimated glomerular filtration (eGFR) rate less than 60 mL/min/1.73 m(2) over 3 months. We assigned patients to three groups: CAD without CKD (CAD group, n=46), CKD without CAD (CKD group, n=18), and CAD with CKD (CAD/CKD group, n=77). Plasma granzyme B was measured by enzyme-linked immunosorbent assay. Factors contributing to the severity of CAD were analyzed by multiple regression analysis in patients with CAD. RESULTS Plasma levels of high-sensitivity CRP (hs-CRP) and granzyme B in the CAD/CKD group were significantly higher than in other groups. A significant positive correlation was observed between plasma hs-CRP and granzyme B levels. A significant negative correlation was observed between eGFR and granzyme B levels. Multiple regression analysis revealed that granzyme B and hs-CRP levels were independent predicting variables of the number of stenoses in major coronary arteries. CONCLUSIONS These results indicate that granzyme B might be a novel risk factor for the formation of coronary atherosclerosis by inducing apoptosis of vascular tissues in patients with CKD.

Lack of association between serum paraoxonase-1 activity and residual platelet aggregation during dual anti-platelet therapy

High residual platelet aggregability during thienopyridine treatment occurs because of low levels of the active drug metabolite, and is associated with an increased rate of major adverse cardiovascular events. Recent findings suggest that paraoxonase-1 (PON1) is a major determinant for clopidogrel efficacy. The aim of this study was to assess the impact of serum PON1 activity on platelet aggregability in thienopyridine-treated patients. In 72 patients receiving treatment with aspirin and ticlopidine after acute coronary syndrome, various laboratory data including the formation of platelet aggregations induced by agonists were compared with serum PON1 activities, measured as paraoxonase and homocysteine thiolactone hydrolase (HTLase). Serum paraoxonase activity was significantly associated with HTLase activity (R=0.4487, P<0.0001). These PON1 activities were not correlated with any parameters for platelet aggregation, hypertension, sleep apnea, and diabetes mellitus. In contrast, serum PON1 activities seemed to be involved in cardiac function, with brain natriuretic peptide and ejection fraction being significantly correlated with serum HTLase activity (R=-0.2767, P=0.0214) and paraoxonase activity (R=0.2558, P=0.0339), respectively. Paraoxonase activity also demonstrated a significant association with increased levels of ankle-brachial index (R=0.267, P=0.0255). Serum PON1 activities did not influence platelet aggregability during treatment with thienopyridine. However, they might modulate cardiac function after acute coronary syndrome and progression of atherosclerosis.

Impact of Introducing Catheter-based Renal Denervation into Japan for Hypertension Management: Estimation of Number of Target Patients and Clinical Relevance of Ambulatory Blood Pressure Reduction

BACKGROUND New medical approaches to the autonomic nervous system, such as catheterbased renal denervation, have been introduced into clinical practice in the recent years for patients who have resistant hypertension. OBJECTIVES AND METHODS We estimate the number of subjects in Japan who would benefit from renal denervation when this treatment is introduced into Japan, based on data from the Jichi Medical University clinical trials. We also discuss the logical basis of changing the formerly used primary endpoint, i.e., office BP, to 24-hr ambulatory BP in future clinical trials. RESULTS Among JAMP registry data, the total number of hypertensives was 5,858 and the patients who were prescribed ≥ 3 drugs including diuretics were 749. The poorly controlled hypertension rate was 32% in the group prescribed ≥ 3 drugs including diuretics and it constitutes 4.1% of the total hypertensive patients. We also analyzed the data of JMS ABPM cohort study wave 1 (811 patients). The hazard ratios (HRs) for each 10-mmHg increase in BP was 1.38 (95%CI 1.17-1.63, p<0.001) for 24-hr BP and 1.18 (95%CI 1.05-1.33, p=0.006) for office BP. However, the significance for office BP was lost once the 24-hr, daytime and nighttime ambulatory BP data were added to the covariates. CONCLUSION The prevalence of resistant hypertensive patients among all of the hypertensive patients is 4.1%. Based on this prevalence, the number of resistant hypertensive individuals in Japan would be 1,870,000 patients. In future renal denervation clinical studies in Japan, we should set the primary endpoint as a 24-hr systolic BP reduction measured by ABPM.

Arterial Remodeling and Endothelial Shear Stress Exhibit Significant Longitudinal Heterogeneity Along the Length of Coronary Plaques

Atherosclerosis is determined by both systemic risk factors and local vascular mechanisms. The arterial remodeling in response to plaque development plays a key role in atherosclerosis. Compensatory expansive remodeling is an adaptive mechanism that maintains lumen patency as a plaque develops. In

Relationship between Fibroblast Growth Factor 21 and Extent of Left Ventricular Remodeling after Acute Myocardial Infarction

Background: Fibroblast growth factor 21 (FGF21) is a novel myokine released from skeletal muscle. Recent studies have showed that FGF21-transgenic mice had low plasma levels of insulin-like growth factor-1, a potent tissue survival factor, in ischemic myocardium following acute myocardial infarction (AMI). Objective: To examine a role of FGF21 in subsequent complication after AMI. Methods: Patients experiencing their first AMI (n=71, mean age 62.4±10.1 years old) was employed. Successful coronary reperfusion was accomplished within 12 hours in all patients. Plasma FGF21 levels were measured on admission, and 7 days and 6 months after onset. Left ventricular (LV) remodeling was assessed by left ventriculography on the day of admission and 6 months after AMI. Results: Levels of FGF21 in plasma peaked on admission and had declined by 6 months (admission: 611±40, day 7: 246±23, 6 months: 316±24 pg/ml, P<0.001). The FGF21 levels were correlated with plasma lactate levels on admission (r=+0.26, P=0.03). The LV end-diastolic volume index (LVEDVI) significantly increased 6 months after AMI (admission: 79.5±2.4, 6 months: 84.5±2.9 ml/m 2 , P=0.004). The FGF 21 levels on admission were positively correlated with the changes in LVEDVI (r=+0.23, P=0.04). The multivariate regression analysis showed that the plasma FGF21 levels on admission was a significant explanatory variable for the changes in LVEDVI (β=+0.232, P=0.041). Conclusions: These results suggest that a novel myokine, FGF21, reflects circulatory insufficiency and could be a marker for late-stage LV remodeling after AMI.

Thrombus just beneath a retrievable inferior vena cava filter in a pregnant woman with deep vein thrombosis: Its removal requiring catheter thrombus fragmentation with fibrinolysis

Recently, transient inferior vena cava (IVC) filters have been employed to protect against pulmonary embolism (PE) in pregnant women with deep vein thrombosis. A 34‐year‐old primiparous Japanese woman with a history of myomectomy was diagnosed with deep vein thrombosis by ultrasound at 27 weeks of gestation. Unfractionated heparin was administered, which soon ameliorated swelling in the right thigh. A transient IVC filter was implanted just before cesarean section. An enhanced computed tomography scan 2 days after cesarean section revealed a wide thrombus just distal to the filter. We performed catheter thrombus fragmentation with fibrinolysis just before the removal of the IVC filter, resulting in re‐canalization of blood flow. No significant PE occurred. Although a transient IVC filter may work well for the prophylaxis of PE during labor and delivery, catheter fragmentation with fibrinolysis may become necessary at removal of the filter.

Roles of ghrelin in left-ventricular remodelling after acute myocardial infarction

Objective The purpose of this study was to elucidate the role of ghrelin after acute myocardial infarction (AMI) in left ventricular (LV) remodelling. Design Prospective observational study. Setting Jichi Medical University Hospital. Patients Fifty consecutive patients experiencing their first AMI. Interventions Ghrelin was measured on the day of admission, day 7, day 14 and 6 months after AMI. Patients were treated by percutaneous coronary intervention, and successful myocardial reperfusion was accomplished within 12 h after onset. To analyse LV remodelling, the authors performed left ventriculographies on the day of admission and 6 months after AMI. Main outcome measures Changes in LV volume. Results Plasma ghrelin increased significantly after AMI (admission: 40.9±7.3; day 7: 89.5±11.0; day 14: 92.6±11.8 fmol/ml, p<0.0001). There was a significant correlation between ghrelin on day 14 and changes in LV volume over 6 months (r=+0.46, p<0.001). Multivariate regression analysis showed that ghrelin on day 14 is a significant predictor of LV remodelling after AMI (β=+0.44, p=0.001). Conclusion To our knowledge, this is the first report that shows a relation between circulating ghrelin after AMI and the progression of LV remodelling in the chronic phase. The elevation of ghrelin after AMI might be a compensatory mechanism to attenuate LV remodelling.