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Patients with chronic coronary syndrome (CCS), even when they have complete revascularization and normal left ventricular (LV) systolic function, experience subsequent cardiovascular disease (CVD), highlighting the importance of surrogate markers to prevent adverse consequences. Speckle-tracking echocardiography-derived left atrial (LA) reservoir strain has emerged as a sensitive marker for CVD in various clinical settings. The present study investigated the prevalence, determinants, and prognostic value of LA dysfunction in CCS. We included 278 consecutive patients with CCS with completed percutaneous coronary intervention and preserved LV ejection fraction who underwent follow-up echocardiography. Speckle-tracking analysis was performed to assess LA reservoir strain, and LA dysfunction was defined as LA reservoir strain ≤24%. The primary outcome comprised new-onset atrial fibrillation, heart failure hospitalization, acute coronary syndrome, stroke, or all-cause death. At baseline, 28 patients (10.1%) had LA dysfunction. Multivariable analysis identified age, hypertension, LV ejection fraction, and multivessel disease as independent determinants of LA reservoir strain (all p0.05). During a median follow-up of 4.8 years, the primary outcome occurred in 60 patients (21.6%). LA dysfunction carried a significant risk for primary outcome independent of traditional risk factors, LV parameters, and LA size (adjusted hazard ratio 3.10, p = 0.003); the risk increase remained significant even after excluding atrial fibrillation from the primary outcome (adjusted hazard ratio 2.27, p = 0.043). In conclusion, approximately 10% of patients with CCS with normal LV ejection fraction had LA dysfunction associated with adverse cardiovascular outcomes. Further studies are needed to explore whether therapeutic interventions affecting LA remodeling may help prevent CVD events.

Aims Aortic valve sclerosis (AVS) without haemodynamically significant obstruction is related to cardiovascular morbidity and mortality independent of left ventricular (LV) hypertrophy, although the underlying mechanisms remain unknown. This study investigated the prevalence of AVS and its association with subclinical LV systolic and diastolic dysfunction in individuals with normal LV geometry free of cardiovascular disease. Methods and results We examined 962 participants with normal LV geometry and free from significant AV stenosis who underwent standard and speckle-tracking echocardiography. AVS was categorized into four groups as follows: no AVS, AV thickening, calcification on one leaflet, and calcification on ≥2 leaflets. Among the 962 participants, 767 (79.7%) individuals were classified as no AVS, 74 (7.7%) as AV thickening, 87 (9.0%) as calcification on one leaflet, and 34 (3.5%) as calcification on ≥2 leaflets. The prevalence of subclinical LV diastolic dysfunction (E/e′ ratio ≥13) and systolic dysfunction [LV global longitudinal strain (GLS) > −17.0% for men and > −18.0% for women] were greater in AVS groups than those in no AVS group. Subclinical LV diastolic impairment was evident from AV thickening and systolic dysfunction was observed at AV calcification. Multivariable logistic regression analysis demonstrated that AV thickening as well as calcification were independently associated with subclinical LV diastolic impairment (all P < 0.05), while only AV calcification on ≥2 leaflets conferred significant increased risk of impaired LVGLS. Conclusion AVS was observed in approximately 20% individuals without cardiac disease and was associated with subclinical LV diastolic and systolic function even in the absence of LV morphological change.

Arterial structural and functional remodeling is recognized as a key determinant of incident heart failure, although the contribution of arterial properties on left ventricular (LV) remodeling is not fully studied. Aortic dilatation is an early manifestation of arterial remodeling and estimated pulse wave velocity (ePWV) is emerging as a simple measure of arterial stiffness. This study aimed to characterize the association of aortic size and ePWV with LV morphology and function.The study cohort consisted of 539 participants without overt cardiac disease who underwent extensive cardiovascular examination. Aortic root diameter was measured by two-dimensional echocardiography and ePWV was calculated from a regression equation using age and mean blood pressure. LV global longitudinal strain (LVGLS) was obtained by speckle-tracking echocardiography.Aortic root diameter and ePWV were correlated with LV mass index and LVGLS, while only ePWV was related to E / e' ratio. In multivariable analysis, aortic root diameter and ePWV were significantly related to LV mass index and LVGLS (all P 0.05), and the association of aortic root size and ePWV with LVGLS was independent of LV mass index and E / e' ratio. Individuals with both aortic root enlargement and increased ePWV had significantly larger LV mass index and reduced LVGLS compared with those either or those with normal aortic size and ePWV (both P 0.05).Aortic root size and ePWV were independently associated with unfavorable LV remodeling in individuals free of cardiac disease, which might provide useful information into the pathogenesis-linking arterial remodeling and heart failure.

Aims To investigate the exact prevalence of glucose metabolism disorders, and their impact on left atrial (LA) remodelling and reversibility in patients with atrial fibrillation (AF). Methods and results We examined 204 consecutive patients with AF who underwent their first catheter ablation (CA). Oral glucose tolerance test was used to evaluate glucose metabolism disorders in 157 patients without known diabetes mellitus (DM). Echocardiography was performed before and 6 months after CA. Oral glucose tolerance test identified abnormal glucose metabolism in 86 patients [11 with newly diagnosed DM, 74 with impaired glucose tolerance (IGT) and 1 with impaired fasting glucose (IFG)]. Ultimately, 65.2% of patients had abnormal glucose metabolism. Diabetes mellitus group had the worst LA reservoir strain and LA stiffness (both P < 0.05), while there was no significant difference in baseline LA parameters between normal glucose tolerance (NGT) group and IGT/IFG group. The prevalence of LA reverse remodelling (≥15% decrease in the LA volume index at 6 months after CA) was significantly higher in NGT group compared with IGT/IFG and DM group (64.1 vs. 38.6 vs. 41.5%, P = 0.006). Both DM and IFG/IGT carry a significant risk of lack of LA reverse remodelling independent of baseline LA size and AF recurrence. Conclusion Approximately 65% of patients with AF who underwent their first CA had abnormal glucose metabolism. Patients with DM had significantly impaired LA function compared with non-DM patients. Impaired glucose tolerance/IFG as well as DM carries significant risk of unfavourable LA reverse remodelling. Our observations may provide valuable information regarding the mechanisms and therapeutic strategies of glucose metabolism-related AF.

AimsPatients with chronic coronary syndrome (CCS) suffer from subsequent cardiovascular events, even after complete revascularization; thus, elucidation of the underlying pathophysiological mechanisms is required. Epicardial adipose tissue (EAT) is increasingly recognized as a metabolically active organ with a key role in the pathogenesis of metabolic-related cardiac diseases. The present study investigated the association between EAT burden and left heart remodelling in patients with CCS.Methods and resultsWe studied 267 CCS patients (210 men; 71 ± 9 years) with complete revascularization and normal left ventricular (LV) ejection fraction who underwent follow-up echocardiography. All patients underwent the measurement of EAT thickness and speckle-tracking analysis to evaluate LV global longitudinal strain (LVGLS) and left atrial (LA) phasic strain. The mean EAT thickness was 5.0 ± 1.8 mm. Age, sex, body mass index, and diabetes mellitus were independently associated with EAT thickness (all P < 0.05). Multivariable linear regression analysis demonstrated that EAT thickness was significantly associated with LV mass index, early diastolic mitral annular velocity, and LA conduit strain independent of age, sex, and cardiovascular risk factors (all P < 0.05). On the other hand, there was no relationship between EAT thickness and LV systolic parameters including LV ejection fraction and LVGLS.ConclusionCCS patients with increased EAT thickness had unfavourable left heart remodelling. The assessment of EAT thickness by echocardiography may have clinical utility as a simple surrogate to aid in risk stratification for impaired left heart function in CCS patients.

Aortic valve sclerosis (AVS) without hemodynamically significant obstruction is related to cardiovascular morbidity and mortality independent of left ventricular (LV) hypertrophy, although the underlying mechanisms remain unknown. This study investigated the prevalence of AVS and its association with subclinical LV systolic and diastolic dysfunction in individuals with normal LV geometry free of cardiovascular disease.We examined 962 participants with normal LV geometry and free from significant AV stenosis who underwent standard and speckle-tracking echocardiography. AVS was categorized into 4 groups as follows: no AVS, AV thickening, calcification on one leaflet and calcification on ≥2 leaflets.Among the 962 participants, 767 (79.7%) individuals were classified as no AVS, 74 (7.7%) as AV thickening, 87 (9.0%) as calcification on one leaflet, and 34 (3.5%) as calcification on ≥2 leaflets. The prevalence of subclinical LV diastolic dysfunction (E/e' ratio ≥13) and systolic dysfunction (LV global longitudinal strain (GLS) -17.0% for men and -18.0% for women) were greater in AVS groups than those in no AVS group. Subclinical LV diastolic impairment was evident from AV thickening and systolic dysfunction was observed at AV calcification. Multivariable logistic regression analysis demonstrated that AV thickening as well as calcification were independently associated with subclinical LV diastolic impairment (all p 0.05), while only AV calcification on ≥2 leaflets conferred significant increased risk of impaired LVGLS.AVS was observed in approximately 20% individuals without cardiac disease and was associated with subclinical LV diastolic and systolic function even in the absence of LV morphological change.We investigated the prevalence of aortic valve sclerosis (AVS) and its association with subclinical left ventricular (LV) systolic and diastolic dysfunction in 962individuals with normal LV geometry free of cardiac disease. In this study population, AVS characterized by thickening or calcification was present in 20% of individuals. Subclinical LV diastolic dysfunction appeared from AV thickening and systolic dysfunction by LV global longitudinal strain was observed at calcification on ≥2 leaflets; these associations were independent of age, sex and cardiovascular risk factors.

Balloon pulmonary angioplasty (BPA) has been recognized as an alternative therapeutic approach for patients with inoperative chronic thromboembolic pulmonary hypertension and those with residual pulmonary hypertension after pulmonary endarterectomy. However, the safe and successful treatment rate for a total occlusion lesion (TOL) using BPA is low, mainly because vessels distal to the occlusion are invisible by angiogram. Here, we present the case of a 53-year-old woman with chronic thromboembolic pulmonary hypertension with successfully recanalization of a TOL by use of BPA with the aid of intracardiac echocardiography. The intracardiac echocardiography–assisted wire passage technique may be a promising method for safe and reliable TOL treatment using BPA.

Porcelain aorta, defined as extensive calcification of the ascending aorta or aortic arch, is a reported risk factor for embolic stroke during cardiac surgery. However, the time course of the progression of aortic calcification leading to porcelain aorta has not been elucidated. We herein describe a 70-year-old woman who was followed up for systemic lupus erythematosus and antiphospholipid syndrome for approximately 20 years. A routine computed tomography scan revealed progression of ascending aortic calcification to porcelain aorta. The calcification was absent during the preceding 12 years, partial 6 years later, and total after another 3 years. Computed tomography also demonstrated aortic and mitral valve calcification in the development of porcelain aorta. During the 3 years prior to the last admission, annual echocardiography examinations showed progression of calcific aortic stenosis with symptoms. The patient was admitted to our institution for aortic valve replacement. Considering the high risk of perioperative stroke associated with porcelain aorta, transcatheter aortic valve implantation was performed. Postoperative transthoracic echocardiography revealed improvement of the aortic stenosis with no symptoms. The present case revealed aortic calcific progression to porcelain aorta during an approximately 10-year period with deterioration of aortic stenosis within a short time. The aortic and valvular calcification could be attributed to the inflammatory process of systemic lupus erythematosus and antiphospholipid syndrome. The presence of aortic and mitral annular calcification in the serial imaging can provide information on aortic and valvular atherosclerotic progression, which may be modifiable by early steroid-lowering therapy.

Purpose Although subclinical hypothyroidism (SCH) is a common clinical entity and carries independent risk for incident heart failure (HF), its possible association with subclinical cardiac dysfunction is unclear. Left ventricular global longitudinal strain (LVGLS) and left atrial (LA) phasic strain can unmask subclinical left heart abnormalities and are excellent predictors for HF. This study aimed to investigate the association between the presence of SCH and subclinical left heart dysfunction in a sample of the general population without overt cardiac disease. Methods We examined 1078 participants who voluntarily underwent extensive cardiovascular health check-ups, including laboratory tests and 2-dimensional speckle-tracking echocardiography to assess LVGLS and LA reservoir, conduit, and pump strain. SCH was defined as an elevated serum thyroid-stimulating hormone level with normal concentration of free thyroxine. Results Mean age was 62 ± 12 years, and 56% were men. Seventy-eight (7.2%) participants exhibited SCH. Individuals with SCH had significantly reduced LA reservoir (37.1 ± 6.6% vs 39.1 ± 6.6%; P = 0.011) and conduit strain (17.3 ± 6.3% vs 19.3 ± 6.6%; P = 0.012) compared with those with euthyroidism, whereas there was no significant difference in left ventricular ejection fraction, LA volume index, LVGLS, and LA pump strain between the 2 groups. In multivariable analyses, SCH remained associated with impaired LA reservoir strain, independent of age, traditional cardiovascular risk factors, and pertinent laboratory and echocardiographic parameters. including LVGLS (standardized β −0.054; P = 0.032). Conclusions In an unselected community-based cohort, individuals with SCH had significantly impaired LA phasic function. This association may be involved in the higher incidence of HF in subjects with SCH.

This study aimed to clarify the usefulness of the Ikari-curve left (IL) guiding catheter for balloon pulmonary angioplasty (BPA).The current BPA strategy for chronic thromboembolic pulmonary hypertension is dilation of as many branches as possible to normalize hemodynamics and oxygenation. The shape of the guiding catheter is a major factor in achieving this. However, conventional guiding catheters are difficult to introduce into particular branches. The IL guiding catheter may be suitable; however, its utility remains unclear.We retrospectively analyzed 202 consecutive BPA sessions of 40 patients from November 2016 to October 2019 and divided these sessions into two groups: the IL group where the IL guiding catheter was used and the non-IL group where other catheters were utilized. The occurrence of lung injury was determined by the presence of bloody sputum. We compared the rates of successful introduction into target vessels and assessed for the occurrence of lung injury.The average age of enrolled patients was 60.3 ± 14.4 years, with females comprising 65%. There were 99 sessions in the IL group. The median treated branches per session differed between the 2 groups (IL group: 15 versus non-IL group: 10, P < 0.05). The occurrence of lung injury was lower in the IL group (4.0% versus 11.7%, P = 0.07). The IL group had more successful vessel insertions than the non-IL group (78.8% versus 42.7%, P < 0.01).The IL guiding catheter may be introduced into branches that cannot be accessed by conventional guiding catheters.

A 4b-quantized convolutional neural network (CNN) inference engine for edge-AI is presented featuring a Cartesian-product MAC array and pipelined activation aligners targeting deep-/random-pruned models. A 40nm prototype with 32x32 MACs and 5Mb SRAM runs at 534 MHz, 1.07 TOPS, 352 mW at 1.1V, and attains 5.30 dense TOPS/W, 234 MHz at 0.8V. Sparse TOPS/W reaches 26.5 when running a randomly pruned model (after 88% pruning). Training algorithms for obtaining highly efficient sparse/quantized models are also proposed.

Computational scalability allows neural networks on embedded systems to provide desirable inference performance while satisfying severe power consumption and computational resource constraints. This paper presents a simple yet scalable inference method called ProgressiveNN, consisting of bitwise binary (BWB) quantization, accumulative bit-serial (ABS) inference, and batch normalization (BN) retraining. ProgressiveNN does not require any network structure modification and obtains the network parameters from a single training. BWB quantization decomposes and transforms each parameter into a bitwise format for ABS inference, which then utilizes the parameters in the most-significant-bit-first order, enabling progressive inference. The evaluation result shows that the proposed method provides computational scalability from 12.5% to 100% for ResNet18 on CIFAR-10/100 with a single set of network parameters. It also shows that BN retraining suppresses accuracy degradation of training performed with low computational cost and restores inference accuracy to 65% at 1-bit width inference. This paper also presents a method to dynamically adjust the bit-precision of the ProgressiveNN to achieve a better trade-off between computational resource use and accuracy for practical applications using sequential data with proximity resemblance. The evaluation result indicates that the accuracy increases by 1.3% with an average bit-length of 2 compared with only the 2-bit BWB network.

QUEST is a programmable multiple instruction, multiple data (MIMD) parallel accelerator for general-purpose state-of-the-art deep neural networks (DNNs). It features die-to-die stacking with three-cycle latency, 28.8 GB/s, 96 MB, and eight SRAMs using an inductive coupling technology called the ThruChip interface (TCI). By stacking the SRAMs instead of DRAMs, lower memory access latency and simpler hardware are expected. This facilitates in balancing the memory capacity, latency, and bandwidth, all of which are in demand by cutting-edge DNNs at a high level. QUEST also introduces log-quantized programmable bit-precision processing for achieving faster (larger) DNN computation (size) in a 3-D module. It can sustain higher recognition accuracy at a lower bitwidth region compared to linear quantization. The prototype QUEST chip is integrated in the 40-nm CMOS technology, and it achieves 7.49 tera operations per second (TOPS) peak performance in binary precision, and 1.96 TOPS in 4-bit precision at 300-MHz clock.

Obesity increases the risk for atrial fibrillation (AF), although the impact of abdominal fat distribution on left atrial (LA) morphology and functional remodeling remains unclear. This study aimed to investigate whether increased abdominal adiposity is independently associated with impaired LA function and/or LA enlargement in a sample of the general population and to evaluate the role of adipokines in this association.The study cohort consisted of 527 participants (362 men; 57 ± 10 years) without overt cardiac disease who underwent laboratory testing, abdominal computed tomographic examination and echocardiography. Abdominal adiposity was quantitatively assessed as visceral fat area (VFA) and subcutaneous fat area (SFA) at the level of the umbilicus. Speckle-tracking echocardiography was performed to assess LA phasic function including reservoir, conduit and pump strain. LA reservoir and conduit strain decreased with increasing VFA quartiles (both p 0.05), whereas no significant differences were observed in LA volume index and pump strain. When stratified by SFA, there were no significant differences in LA size and function across the quartiles. In multivariable analysis, VFA was significantly associated with LA conduit strain independent of cardiovascular risk factors, and pertinent laboratory and echocardiographic parameters (standardized β = -0.136, p = 0.019). VFA was correlated with serum adiponectin level (r = -0.51, p 0.001), but there was no association between adiponectin level and three LA phasic strains.In a sample of the general population, VFA accumulation was independently associated with worse LA conduit strain, which may be involved in the pathophysiological mechanism of obesity-related AF.

Background Insulin resistance carries increased risk of heart failure, although the pathophysiological mechanisms remain unclear. LV global longitudinal strain (LVGLS) assessed by speckle-tracking echocardiography has emerged as an important tool to detect early LV systolic abnormalities. This study aimed to investigate the association between insulin resistance and subclinical left ventricular (LV) dysfunction in a sample of the general population without overt cardiac disease. Methods We investigated 539 participants who voluntarily underwent extensive cardiovascular health check including laboratory test and speckle-tracking echocardiography. Glycemic profiles were categorized into 3 groups according to homeostatic model assessment of insulin resistance (HOMA-IR): absence of insulin resistance (HOMA-IR − 16.65%). Results Forty-five (8.3%) participants had DM and 66 (12.2%) had abnormal HOMA-IR. LV mass index and E/e′ ratio did not differ between participants with and without abnormal HOMA-IR, whereas abnormal HOMA-IR group had significantly decreased LVGLS (− 17.6 ± 2.6% vs. − 19.7 ± 3.1%, p Conclusions In the general population without overt cardiac disease, insulin resistance carries independent risk for subclinical LV dysfunction, especially in normal weight individuals.

Percutaneous coronary intervention (PCI) is sometimes considered as an alternative therapeutic strategy to surgical revascularization in patients with coronary artery disease (CAD) and reduced left ventricular ejection fraction (LVEF). However, the types or conditions of patients that receive the clinical benefit of left ventricular reverse remodelling (LVRR) remain unknown. The purpose of this study was to investigate the determinants of LVRR following PCI in CAD patients with reduced LVEF. From 4394 consecutive patients who underwent PCI, a total of 286 patients with reduced LV systolic function (LVEF

A 28.8-GB/s 96-MB 3D-stacked SRAM is presented. A total of eight SRAM dies, designed in a 40-nm CMOS process, are vertically stacked and connected using an inductive coupling wireless link with a low-voltage NMOS push-pull transmitter that reduces the power of the link by 45% with a 0.4-V power supply. The SRAM utilizes an inverted bit insertion scheme that compensates the degradation of the first signal, a coil termination scheme that aims to eliminate the noise of 3D inductive coupling bus, and a 12:1 SerDes. The data density of the SRAM should reach 12.3-MB/mm3, which extends beyond that of state-of-the-art stacked DRAMs.

Energy-constrained neural network processing is in high demanded for various mobile applications. Binary neural network aggressively enhances the computational efficiency, and in contrast, it suffers from degradation of accuracy due to its extreme approximation. We propose a novel accurate neural network model based on binarization and "dithering" that distributes the quantization error to neighboring pixels. The quantization errors in the binarization are distributed in the plane, so that a pixel in the multi-level source expression more accurately represented in the resulting binarized plane by multiple pixels. We designed a low-overhead binary-based hardware architecture for the proposed model. The evaluation results show that this method can be realized with a few additional lightweight hardware components.

In the remarkable evolution of deep neural network (DNN), development of a highly optimized DNN accelerator for edge computing with both less hardware resource and high computing performance is strongly required. As a well-known characteristic, DNN processing involves a large number multiplication and accumulation operations. Thus, low-precision quantization, such as binary and logarithm, is an essential technique in edge computing devices with strict restriction of circuit resource and energy. Bit-width requirement in quantization depends on application characteristics. Variable bit-width architecture based on the bit-serial processing has been proposed as a scalable alternative that allows different requirements of performance and accuracy balance by a unified hardware structure. In this paper, we propose a well-optimized DNN hardware architecture with supports of binary and variable bit-width logarithmic quantization. The key idea is the distributed-and-shared accumulator that processes multiple bit-serial inputs by a single accumulator with an additional low-overhead circuit for the binary mode. The evaluation results show that the idea reduces hardware resources by 29.8% compared to the prior architecture without losing any functionality, computing speed, and recognition accuracy. Moreover, it achieves 19.6% energy reduction using a practical DNN model of VGG 16.

A key consideration for deep neural network (DNN) inference accelerators is the need for large and high-bandwidth external memories. Although an architectural concept for stacking a DNN accelerator with DRAMs has been proposed previously, long DRAM latency remains problematic and limits the performance [1]. Recent algorithm-level optimizations, such as network pruning and compression, have shown success in reducing the DNN memory size [2]; however, since networks become irregular and sparse, they induce an additional need for agile random accesses to the memory systems.

Hardware-oriented approaches to accelerate deep neural network processing are very important for various embedded intelligent applications. This paper is a summary of our recent achievements for efficient neural network processing. We focus on the binarization approach for energy- and area-efficient neural network processor. We first present an energy-efficient binarized processor for deep neural networks by employing inmemory processing architecture. The real processor LSI achieves high performance and energy-efficiency compared to prior works. We then present an architecture exploration technique for binarized neural network processor on an FPGA. The exploration result indicates that the binarized hardware achieves very high performance by exploiting multiple different parallelisms at the same time.