Variation in the frozen lesion size according to the non-occluded application duration and technique for cryoballoon ablation.

OBJECTIVE: The frozen lesion formation created by cryoballoon ablation, especially with non-occluded applications, has not been fully evaluated. This study aimed to validate the lesion size under different cryoballoon ablation settings: application duration, push-up technique, and laminar flow. METHODS: The frozen lesion size was evaluated immediately after ending the freezing with three different application durations (120, 150, and 180 seconds) in porcine hearts (N = 24). During the application, the push-up technique was applied at 10, 20, and 30 seconds after starting the freezing with or without laminar flow. RESULTS: The lesion size was significantly correlated with the nadir balloon temperature (P<0.001). The lesion volume became significantly larger after 150 seconds than 120 seconds (1272mm3 versus 1709mm3, P = 0.004), but not after 150 seconds (versus 1876mm3 at 180 seconds, P = 0.29) with a comparable nadir balloon temperature. Furthermore, the lesion volume became significantly larger with the push-up technique with the largest lesion size with a 20-second push-up after the freezing (1193mm3 without the push-up technique versus 1585mm3 with a push-up at 10 seconds versus 1808mm3 with a push-up at 20 seconds versus 1714mm3 with a push-up at 30 seconds, P = 0.04). Further, the absence of laminar flow was not associated with larger lesion size despite a significantly lower nadir balloon temperature. CONCLUSION: The frozen lesion size created by cryoballoon ablation became larger with longer applications at least 150 seconds and with a push-up technique especially at 20 seconds after the freezing.

Reliable focal and rotational activations in CARTOFINDER mapping using the OctaRay catheter.

INTRODUCTION: The aim of the current study was to elucidated the reliable atrial fibrillation (AF) drivers identified by CARTOFINDER using OctaRay catheter. METHODS AND RESULTS: The reliability of focal and rotational activations identified by CARTOFINDER using OctaRay catheter was assessed by the sequential recordings in each site of both atrium before and after pulmonary vein isolation (PVI) in 10 persistent AF patients. The outcome measures were the reproducibility rate during the sequential recordings and the stability rate between pre- and post-PVI as reliable focal and rotational activations. The study results were compared with those under use of PentaRay catheter (N = 18). Total 68928 points of 360 sites in OctaRay group and 24 177 points of 311 sites in PentaRay were assessed. More focal activation sites were identified in OctaRay group than PentaRay group (7.9% vs. 5.7%, p < .001), although the reproducibility rate and the stability rate were significantly lower in OctaRay group (45.3% vs. 58.9%, p < .001; 11.2% vs. 28.4%, p < .001). Meanwhile, the prevalence of reproducible focal activation sites among overall points was comparable (3.6% vs. 3.3%, p = .08). Regarding rotational activation, more rotational activation sites were identified in OctaRay group (5.1% vs. 0.2%, p < .001), and the reproducibility rate and the stability rate were significantly higher in OctaRay group (45.2% and 12.5% vs. 0.0%, p < .001). Both reliable focal and rotational activation sites were characterized by significantly shorter AF-cycle length (CL) and higher repetition of focal and rotational activations during the recordings compared with the sites of non or unreliable focal and rotational activations. CONCLUSION: In CARTOFINDER, OctaRay catheter could identify reliable focal activation with high resolution and reliable rotational activation compared with PentaRay catheter. The repetitive focal and rotational activations with short AF-CL could be the potential target during ablation.

Intracardiac energy inefficiency during atrial fibrillation rhythm with heart failure: Assessment by echo-vector flow mapping.

AIMS: Intracardiac dynamics during atrial fibrillation(AF) complicated by heart failure(HF) are not fully understood. The aim of this study was to evaluate the impact of intracardiac dynamics assessed by echo-vector flow mapping on AF complicated by HF. METHODS AND RESULTS: We enrolled 76 AF patients receiving sinus restoration therapy and assessed energy loss(EL) by echo-vector flow mapping during both AF rhythm and sinus rhythm. Patients were divided into 2 groups according to serum NT-proBNP level: high NT-proBNP group(≥1800 pg/ml during AF rhythm: N = 19), and low NT-proBNP group(N = 57). Outcome measures were average ELs/stroke volume(SV) in left ventricle(LV) and left atrium(LA). Average EL/SVs during AF rhythm in the LV and LA were significantly larger in the high NT-proBNP group than the low NT-proBNP group(54.2 mE/m·L versus 41.2 mE/m·L, P = 0.02; 3.2 mE/m·L versus 1.9 mE/m·L, P = 0.01). The significantly larger EL/SV in the high NT-proBNP group was recorded for maximum EL/SVs. In patients with high NT-proBNP, large vortex formation with extreme EL was detected in the LV and LA during the diastolic phase. After sinus restoration, the average decrease of EL/SV in the LV and LA was larger in the high NT-proBNP group(-21.4 mE/m·L versus +2.6 mE/m·L, P = 0.04; -1.6 mE/m·L versus -0.3 mE/m·L, P = 0.02). Average EL/SV during sinus rhythm did not significantly differ between the high and low NT-proBNP groups in the LV and LA. CONCLUSIONS: High EL during AF rhythm as intracardiac energy inefficiency was associated with high serum NT-proBNP levels and improved after sinus restoration.

Effects of a new 75 g glucose- and high fat-containing cookie meal test on postprandial glucose and triglyceride excursions in morbidly obese patients.

A new meal tolerance test (MTT) using a 75 g glucose- and high fat-containing meal was applied to classify glucose intolerance in morbidly obese patients. According to the MTT data, the concordance rate of diagnosis was 82.5% compared to the 75 g oral glucose tolerance test (OGTT) in patients with normal glucose tolerance (NGT, n = 40). In the NGT patients, the insulinogenic index (r = 0.833), Matsuda index (r = 0.752), and disposition index (r = 0.845) calculated from the MTT data were each significantly (p < 0.001) correlated with those derived from the OGTT data. However, in patients with impaired glucose tolerance (IGT, n = 23) or diabetes mellitus (DM, n = 17), the postprandial glucose levels post-MTT were significantly lower than those post-OGTT, without increases in the postprandial insulin levels post-MTT. Thus, the severity of glucose intolerance measured by the MTT was milder than that indicated by the OGTT. Plasma levels of both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were increased at the postprandial state, but only the GIP levels post-MTT were significantly higher than those post-OGTT. The enhancement of glucose disposal rates in patients with NGT or IGT after the MTT was associated with increased GIP levels. The postprandial hypertriglyceridemia induced by the MTT was associated with insulin resistance, but it was not associated with the impaired insulinogenic index or the disposition index. These results indicate that the new MTT is clinically useful to evaluate both abnormal glucose and triglyceride excursions caused by abnormal insulin sensitivity and secretions of insulin and gut hormones in morbidly obese patients.

A Prospective, Open-Label Short-Term Pilot Study on Modification of the Skin Hydration Status During Treatment With a Sodium-Glucose Cotransporter-2 Inhibitor.

INTRODUCTION: Various types of skin lesions with pruritus have been reported in participants of Asian clinical trials on sodium-glucose cotransporter-2 (SGLT2) inhibitors. The aim of this study was to determine whether the diuretic effect of a SGLT2 inhibitor could modify skin hydration status in patients with type 2 diabetes mellitus. METHODS: A prospective, short-term, open-label, two-parallel-arm, pilot study was conducted. Eligible patients were assigned to either a SGLT2 inhibitor (50 mg ipragliflozin once daily) group or to a dipeptidyl peptidase-4 inhibitor (50 mg sitagliptin once daily) group (control). The biophysical characteristics of the skin were measured and blood chemistry tests were run in all participants 1 day prior to medication initiation (pre-treatment values) and 14 days thereafter (post-treatment values). RESULTS: Fourteen patients were enrolled in the study, of whom eight were in the ipragliflozin group and six in the sitagliptin group. Compared to the pre-treatment values, the glycated hemoglobin (HbA1c) levels were slightly but significantly reduced in the ipragliflozin group (p = 0.02), but the changes in HbA1c from the pre-treatment to post-treatment time points did not significantly differ between the two treatment groups. Serum 3-hydroxy butyrate levels were significantly higher in the ipragliflozin group than in the sitagliptin group (p < 0.02). Neither electrical capacitance nor electrical conductance of the stratum corneum (SC), parameters that reflect skin water content, was reduced by 14 days of ipragliflozin treatment; similarly, no changes in these parameters were found in the sitagliptin control group. There was also no difference in the changes in water barrier function of the SC between the two treatment groups. There was a significant linear correlation (p < 0.01) in skin water content at pre-treatment and that 14 days after treatment with each drug, respectively. CONCLUSION: Ipragliflozin treatment for 14 days did not significantly affect the skin hydration status in patients with well-controlled type 2 diabetes mellitus.

Observation of p.R4810K, a Polymorphism of the Mysterin Gene, the Susceptibility Gene for Moyamoya Disease, in Two Female Japanese Diabetic Patients with Familial Partial Lipodystrophy 1.

Mysterin, which was recently shown to play an important role in maintaining cellular fat storage, has been identified to be the susceptibility gene for moyamoya disease (MMD). We encountered some female Japanese patients with partial lipodystrophy and MMD-like vascular lesions. This prompted us to examine whether mysterin variants may be present in these patients. We identified a mysterin variant, p.R4810K in two patients with MMD-like vascular lesions, who may fit the category of familial partial lipodystrophy (FPLD) 1. Our cases suggest the possibility that p.R4810K, in addition to atherogenic risk factors, might thus play a role in the development of atherosclerotic lesions in patients with FPLD1 and p.R4810K.

Association of relative wall thickness of left ventricle with incidence of thromboembolism in patients with non-valvular atrial fibrillation: The Fushimi AF Registry.

AIMS: Atrial fibrillation (AF) increases the risk of thromboembolism, such as ischaemic stroke or systemic embolism (SE). The aim of this study was to investigate the relationship between left ventricular relative wall thickness (RWT) and the risk of thromboembolism in patients with non-valvular AF. METHODS AND RESULTS: The Fushimi AF Registry is a community-based prospective survey of the patients with AF in Japan. Analyses were performed on 3067 non-valvular AF patients, in which RWT values determined by transthoracic echocardiography were available at the baseline. The high-RWT group (RWT above the median) was more often female, older, and had higher systolic blood pressure, CHADS2 and CHA2DS2-VASc scores, as compared with low-RWT group. During the median follow-up period of 1309 days, there was a higher incidence of ischaemic stroke/SE in the high-RWT group [unadjusted hazard ratio (HR), 1.91; 95% confidence interval (CI), 1.42-2.59]. On multivariate Cox regression analysis, including the components of CHA2DS2-VASc score, left atrial diameter, oral anticoagulant prescription at baseline, and type of AF, high RWT was independently associated with ischaemic stroke/SE (adjusted HR, 1.81; 95% CI, 1.34-2.47). Stratified analysis demonstrated no significant interaction for any subgroups. In Kaplan-Meier analysis, ordinal RWT quartiles stratified the incidence of ischaemic stroke/SE. Finally, addition of RWT to CHA2DS2-VASc score increased the performance of risk stratification for the incidence of stroke/SE. CONCLUSION: Relative wall thickness was independently associated with ischaemic stroke/SE among Japanese patients with non-valvular AF, suggesting the importance of left ventricular morphology in contributing to adverse outcomes, particularly thromboembolism.

Clinical characteristics in two patients with partial lipodystrophy and Type A insulin resistance syndrome due to a novel heterozygous missense mutation in the insulin receptor gene.

AIMS: The present report aimed to clarify the clinical characteristics in a girl at the age of 12 and her mother with partial lipodystrophy and Type A insulin resistance syndrome. METHODS: We examined fat distribution in the patients using dual-energy X-ray absorptiometry, magnetic resonance imaging, and computed tomography. We performed genetic analysis to examine the causal gene for lipodystrophy and insulin resistance. RESULTS: Both patients had partial lipodystrophy and a novel heterozygous missense mutation (Asn1137 → Lys1137) in the insulin receptor gene. Because Asn1137 in the catalytic loop is conserved in all protein kinases, this mutation was thought to impair insulin receptor function. By whole-exome sequencing, we found the proband had neither mutations in candidate genes known to be associated with familial partial lipodystrophy nor novel likely candidate causal genes. Taken together, we thought that fat loss in these two patients might be caused by insulin receptor dysfunction. The proband had amenorrhea due to polycystic ovary syndrome. Her menstruation improved, as fat loss was restored during adolescence. This might be caused by improving insulin resistance due to increased levels of leptin and fat mass. CONCLUSIONS: This case might help to understand the mechanisms insulin receptor dysfunction that cause lipodystrophy.

Incidence and Risk Factors of Stroke or Systemic Embolism in Patients With Atrial Fibrillation and Heart Failure　- The Fushimi AF Registry.

BACKGROUND: Heart failure (HF) is a heterogeneous syndrome, but the effect of the type and severity of HF on the incidence of stroke or systemic embolism (SE) in atrial fibrillation (AF) patients is unclear.Methods and Results:The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Kyoto, Japan. Follow-up data were available for 3,749 patients. We defined pre-existing HF as having one of the following: prior hospitalization for HF, presence of HF symptoms (NYHA ≥2), or reduced ejection fraction (<40%). At baseline, 1,008 (26.9%) patients had pre-existing HF. On multivariate analysis, the incidence of stroke/SE was not associated with pre-existing HF (hazard ratio (HR), 1.24; 95% confidence interval (CI), 0.92-1.64) or each criterion for the definition of pre-existing HF, but was associated with high B-type natriuretic peptide (BNP) or N-terminal proBNP levels (above the median of the pre-existing HF group) at baseline (HR, 1.65; 95% CI, 1.06-2.53). Stroke/SE was markedly increased in the initial 30-day period following hospital admission for HF (HR, 12.0; 95% CI, 4.59-31.98). CONCLUSIONS: The effect of HF on the incidence of stroke/SE may depend on the stage or severity of HF in patients with AF. The incidence of stroke/SE was markedly increased in the 30 days after admission for HF, but compensated 'stable' HF did not appear to confer an independent risk.

Sex-Related Differences in the Clinical Events of Patients With Atrial Fibrillation　- The Fushimi AF Registry.

BACKGROUND: Female sex is considered a risk factor for thromboembolism in patients with atrial fibrillation (AF), and is included in the risk stratification scheme, CHA2DS2-VASc score. The purpose of the present study was to investigate the clinical outcomes of female Japanese AF patients.Methods and Results:The Fushimi AF Registry is a community-based prospective survey of the AF patients in Fushimi-ku, Kyoto. Follow-up data were available for 3,878 patients. Female AF patients (n=1,551, 40.0%) were older (77.0 vs. 71.4 years; P<0.001) than male patients (n=2,327, 60.0%). Female patients were more likely to have heart failure (31.1% vs. 23.7%; P<0.001). Previous stroke incidence (19.2% vs. 21.4%; P=0.083) was comparable between male and female patients. During the median follow-up period of 1,102 days, Cox regression analysis demonstrated that female sex was not independently associated with a risk of stroke or systemic embolism (adjusted hazard ratio [HR] 0.74; 95% confidence interval [CI]: 0.54-1.00, P=0.051). However, female sex showed an association with a lower risk of intracranial hemorrhage (adjusted HR 0.54; 95% CI: 0.30-0.95, P=0.032) and all-cause death (adjusted HR 0.56; 95% CI: 0.46-0.68, P<0.001). CONCLUSIONS: We demonstrated that female sex is not independently associated with an increased risk of thromboembolism, but is associated with a decreased risk of intracranial hemorrhage and all-cause death in Japanese AF patients enrolled in the Fushimi AF Registry.