BACKGROUND:Physics-informed neural networks (PINNs) are increasingly being used to model cardiovascular blood flow. The accuracy of PINNs is dependent on flow complexity and could deteriorate in the presence of highly-dynamical blood flow conditions, but the extent of this relationship is currently unknown. Therefore, we investigated the accuracy and performance of PINNs under a range of blood flow conditions, from laminar to turbulent-like flows. METHODS:A stenosis was virtually induced in the thoracic segment of a patient's aorta to represent aortic coarctation. Stenosis severity was varied from 0% to 70% in increments of 5% (NCFD=15 cases), corresponding to stenotic Reynolds number that ranged from 1000 to 3333. CFD simulations at high spatial and temporal resolutions (6.9 million mesh, 10,000 time-steps) were performed for all NCFD=15 cases to obtain ground-truth velocity data. Fourier-based activation function in feed-forward PINNs with dynamic loss coefficients were trained to reconstruct CFD velocity field. Losses included those from physical equations, boundary conditions and sensor data sampled evenly from CFD simulations. Number of sensor points were increased from 200-1600 in increments of 200. This resulted in a total of 8 sensor point variations for each stenotic model (Nsens=8). Hence, a total of 120 (NCFDxNsens) cases were trained in this study. The PINNs architecture and data have been made open-sourced. RESULTS:PINNs errors increased substantially for stenosis severity >50% (stenotic Reynolds numer > 2000) due to the presence of complex turbulent-like flow features. When using 400 sensor points, PINNs velocity magnitude errors ranged from 30% for no-stenosis model to 57% for the model with 70% stenosis, and dropped to 10% and 20%, respectively when the number of sensor points were increased to 1600. PINNs velocity magnitude errors increased monotonically with turbulent intensity, particularly beyond stenosis severity of 50%. CONCLUSIONS:Our findings indicate that the accuracy of PINNs is dependent on the complexity of blood flow conditions. Using conventional PINNs architecture, the errors in trained velocity can increase substantially in the presence of turbulent-like blood flows that are typically found in various vascular pathologies.

BACKGROUND AND OBJECTIVES:Physics-informed neural networks (PINNs) can be used to inversely model complex physical systems by encoding the governing partial differential equations and training data into the neural network. However, neural networks are known to be biased towards learning less complex functions, called spectral bias. This has important implications in modeling cardiovascular flows, where spatial frequencies can vary substantially across anatomies and pathologies (e.g., aneurysms or stenoses). Recent evidence suggests that Fourier-based activation functions have desirable properties, and can potentially reduce spectral bias; however, the performance and adequacy of such Fourier activation functions have not yet been evaluated in patient-specific cardiovascular flow applications. METHODS:The performance of sine activation function was evaluated against tanh and swish activation functions in a 1D advection-diffusion problem, an eccentric 2D stenosis model (Re=5000), and a patient-specific 3D aortic model (Re=823) under pulsatile flow conditions. CFD simulations were performed at high spatio-temporal resolution and data points were extracted for training the neural network. The number of training data points were normalized by L/D. The performance of the PINNs framework was evaluated with increasing number of training data points and across all three activation functions. RESULTS:Our results demonstrate that sine activation function presents desirable characteristics, such as monotonic reduction in errors, relatively faster convergence, and accurate eigen spectra at higher modes, compared to tanh and swish activation functions. Interestingly, for all activation functions, the domain-averaged errors tended to asymptote at ≈15-20% despite substantial increase in training point density. For 2D eccentric stenosis, errors asymptoted at a sensor point density of 40L/D. For 3D patient-specific aorta, this asymptote was achieved at 180L/D for all three activation functions with an error of ≈15% although sine activation function demonstrated relatively faster convergence. CONCLUSIONS:We have demonstrated that Fourier-based activation functions have higher performance in terms of accuracy and convergence properties for cardiovascular flow applications; however, inherent challenges of neural networks (e.g., spectral bias) can limit the accuracy to ≈15% under physiological, 3D patient-specific blood flow conditions.

Coronary computed tomography angiography (cCTA) has poor specificity to identify coronary stenosis that limit blood flow to the myocardial tissue. Integration of dynamic CT myocardial perfusion imaging (CT-MPI) can potentially improve the diagnostic accuracy. We propose a method that integrates cCTA and CT-MPI to identify culprit coronary lesions that limit blood flow to the myocardium. Coronary arteries and left ventricle surfaces were segmented from cCTA and registered to CT-MPI. Myocardial blood flow (MBF) was derived from CT-MPI. A ray-casting approach was developed to project volumetric MBF onto the left ventricle surface. MBF volume were divided into coronary-specific territories based on proximity to the nearest coronary artery. MBF and normalized MBF were computed for the entire myocardium and each of the coronary artery. Projection of MBF onto cCTA allowed for direct visualization of perfusion defects. Normalized MBF had higher correlation with ischemic myocardial territory compared to MBF (MBF: R2=0.81 and Index MBF: R2=0.90). There were 18 vessels that showed angiographic disease (stenosis >50%); however, normalized MBF demonstrated only 5 coronary territories to be ischemic. These findings demonstrate that cCTA and CT-MPI can be integrated to visualize myocardial defects and detect culprit coronary arteries responsible for perfusion defects. These methods can allow for non-invasive detection of ischemia-causing coronary lesions and ultimately help guide clinicians to deliver more targeted coronary interventions.

Traditionally, strokes are characterized by negative symptoms, including contralateral hemiparesis, facial paralysis, and sensory loss in the upper face and upper extremities. Strokes rarely cause movement disorders such as ballismus, a severe chorea characterized by brief, sudden dance-like movements. Early identification of non-traditional stroke symptoms and risk factors for cerebrovascular disease is vital in providing timely treatment and improving patient outcomes. Our case highlights an uncommon complication of stroke and the need to use advanced imaging modalities, including MRI, to identify brain lesions when other testing is negative. This report adds to the body of literature highlighting ballismus, a rare presentation of stroke, and the lessons learned from managing this case.

Acquired ventricular septal rupture (VSR) is a rare but potentially fatal complication of late-presenting myocardial infarction (MI). In the era of revascularization and reperfusion therapy, the incidence of VSR has significantly decreased. Ruptures occur predominantly in patients with late-presenting ST elevation MI. Patients may present with a wide variety of symptoms ranging from chest pain and mild hemodynamic instability to profound cardiogenic shock. Inotropes, vasopressors, and mechanical support with intra-aortic balloon pumps and extracorporeal membrane oxygenation can be used to bridge patients to surgery. Despite treatment with ventricular septal repair, postsurgical mortality remains high. There is a wide variety of complications that can occur in the postoperative period. A multidisciplinary approach is vital in these patients who develop VSR. Improving awareness among healthcare professionals regarding the symptoms of acute coronary syndrome can hopefully help prevent delayed presentation of patients to healthcare facilities.

Background Prodromal symptoms are warning signs of an impending acute myocardial infarction (AMI). However, they are often overlooked by both patients and primary clinicians, and little is known about them. Therefore, this study aims to assess the frequency and types of prodromal symptoms in patients with AMI. Methodology This descriptive cross-sectional study was conducted at a tertiary care cardiac center. Consecutive patients diagnosed with AMI within the last week were evaluated for prodromal symptoms. The prodromal symptoms included chest pain, chest heaviness, chest burning, palpitations, fatigue, sleep disturbance, shortness of breath (SOB), dizziness, anxiety, sudden heat or cold, back pain, and vomiting. Results In a sample of 242 patients, 79.6% were males, with a mean age of 54.7 ± 12.2 years, and 179 (74%) were diagnosed with ST-segment elevation myocardial infarction (STEMI). Among the participants, 142 (58.7%) showed no prodromal symptoms. Among those with prodromal symptoms, chest pain was the predominantly reported prodromal symptom with a frequency of 68%, followed by chest heaviness at 44%, palpitations at 42%, shortness of breath at 34%, and chest burning at 27%. Unusual fatigue in 23% and sleep disturbance in 22% of the patients were also reported. Conclusion The findings from this study revealed that prodromal symptoms were present in a significant proportion of acute myocardial infarction (MI) cases, with more than four in 10 patients reporting these early warning signs. The most commonly observed prodromal symptoms were chest pain, chest heaviness, palpitations, shortness of breath, and chest burning. The timely identification of these symptoms can help prevent infarction, thereby reducing the burden of heart failure and other related mortalities.

Patients with myocardial bridges (MBs) have a higher prevalence of atherosclerosis. Wall shear stress (WSS) has previously been correlated with plaque in coronary artery disease patients, but such correlations have not been investigated in symptomatic MB patients. The aim of this paper was to use a multi-scale computational fluid dynamics (CFD) framework to simulate hemodynamics in MB patient, and investigate the co-localization of WSS and plaque. We identified N = 10 patients from a previously reported cohort of 50 symptomatic MB patients, all of whom had plaque in the proximal vessel. Dynamic 3D models were reconstructed from coronary computed tomography angiography (CCTA), intravascular ultrasound (IVUS) and catheter angiograms. CFD simulations were performed to compute WSS proximal to, within and distal to the MB. Plaque was quantified from IVUS images in 2 mm segments and registered to CFD model. Plaque area was compared to absolute and patient-normalized WSS. WSS was lower in the proximal segment compared to the bridge segment (6.1 ± 2.9 vs. 16.0 ± 7.1 dynes/cm2, p value < 0.01). Plaque area and plaque burden measured from IVUS peaked at 1–3 cm proximal to the MB entrance, coinciding with the first diagonal branch. Normalized WSS showed a statistically significant moderate correlation with plaque area (r = 0.41, p < 0.01). WSS may be obtained non-invasively in MB patients and provides a surrogate marker of plaque area. Using CFD, it may be possible to non-invasively assess the extent of plaque area, and identify patients who could benefit from frequent monitoring or medical management.

Objectives: Anomalous aortic origin of the right coronary artery (AAORCA) may cause ischemia and sudden death. However, the specific anatomic indications for surgery are unclear, so dobutamine-stress instantaneous wave-free ratio (iFR) is increasingly used. Meanwhile, advances in fluid–structure interaction (FSI) modeling can simulate the pulsatile hemodynamics and tissue deformation. We sought to evaluate the feasibility of simulating the resting and dobutamine-stress iFR in AAORCA using patient-specific FSI models and to visualize the mechanism of ischemia within the intramural geometry and associated lumen narrowing. Methods: We developed 6 patient-specific FSI models of AAORCA using SimVascular software. Three-dimensional geometries were segmented from coronary computed tomography angiography. Vascular outlets were coupled to lumped-parameter networks that included dynamic compression of the coronary microvasculature and were tuned to each patient's vitals and cardiac output. Results: All cases were interarterial, and 5 of 6 had an intramural course. Measured iFRs ranged from 0.95 to 0.98 at rest and 0.80 to 0.95 under dobutamine stress. After we tuned the distal coronary resistances to achieve a stress flow rate triple that at rest, the simulations adequately matched the measured iFRs (r = 0.85, root-mean-square error = 0.04). The intramural lumen remained narrowed with simulated stress and resulted in lower iFRs without needing external compression from the pulmonary root. Conclusions: Patient-specific FSI modeling of AAORCA is a promising, noninvasive method to assess the iFR reduction caused by intramural geometries and inform surgical intervention. However, the models’ sensitivity to distal coronary resistance suggests that quantitative stress-perfusion imaging may augment virtual and invasive iFR studies.

Ventricular free wall rupture (VFWR) is a catastrophic complication of myocardial infarction that poses an imminent surgical emergency. Early recognition is essential as it can expedite the process for a life-saving surgical intervention. We present a case of an acute left VFWR resulting from an underlying myocardial infarction which showed a "milking-like effect" during diagnostic angiography. "Milking-like effect" is an angiographic phenomenon typically seen in myocardial bridging, which occurs due to the compression of the intramyocardial coronary segments during systole. The presence of this phenomenon is believed to occur due to the extrinsic compression of the coronary by the evolving hemopericardium.

Vein grafts, the most commonly used conduits in multi-vessel coronary artery bypass grafting surgery, have high intermediate-and long-term failure rates. The abrupt and marked increase in hemodynamic loads on the vein graft is a known contributor to failure. Recent computational modeling suggests that veins can more successfully adapt to an increase in mechanical load if the rate of loading is gradual. Ap-plying an external wrap or support at the time of surgery is one way to reduce the transmural load, and this approach has improved performance relative to an unsupported vein graft in several animal studies. Yet, a clinical trial in humans has shown benefits and drawbacks, and mechanisms by which an exter-nal wrap affects vein graft adaptation remain unknown. This study aims to elucidate such mechanisms using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, hemodynamics using computational fluid dynamics, structure using histology, and transcriptional changes using bulk RNA-sequencing in an ovine carotid-jugular interposition vein graft model, without and with an external biodegradable wrap that allows loads to increase gradually. We show that a biodegradable external wrap promotes luminal uniformity, physiological wall shear stress, and a consistent vein graft phenotype, namely, it prevents over-distension, over-thickening, intimal hyperplasia, and inflammation, and it preserves mechanotrans-duction. These mechanobiological insights into vein graft adaptation in the presence of an external sup-port can inform computational growth and remodeling models of external support and facilitate design and manufacturing of next-generation external wrapping devices. Statement of significance External mechanical support is emerging as a promising technology to prevent vein graft failure follow-ing coronary bypass graft surgery. While variants of this technology are currently under investigation in clinical trials, the fundamental mechanisms of adaptation remain poorly understood. We employ an ovine carotid-jugular interposition vein graft model, with and without an external biodegradable wrap to provide mechanical support, and probe vein graft adaptation using a multimodal experimental and computational data collection pipeline. We quantify morphometry using magnetic resonance imaging, mechanics using biaxial testing, fluid flow using computational fluid dynamics, vascular composition and structure using histology, and transcriptional changes using bulk RNA sequencing. We show that the wrap mitigates vein graft failure by promoting multiple adaptive mechanisms (across biological scales). (c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Background Emergency department overutilization is a known contributor to the high per-capita healthcare cost in the United States. There is a knowledge gap regarding the substitution effect of walk-in clinic availability in primary care provider (PCP) offices and emergency department utilization (EDU). This study evaluates associations between PCP availability and EDU and analyzes the potential cost savings for health systems. Methods A retrospective cohort analysis compared low acuity EDU rates in established patients at a family medicine residency's PCP office before and after walk-in clinic implementation. The practice had 12 providers, 12 residents, and a patient panel of approximately 7,000-8,000. Inclusion criteria were met if patients were: (1) established with the PCP office, (2) had a low acuity emergency department (ED) visit (emergency index score level 4 or 5) OR had a walk-in clinic visit at the family practice. ED visits were tracked from January 2018 to January 2020 and encounters were compared numbers to pre and post-implementation of a walk-in clinic. Cost savings for comparable management was estimated with average price differences for low acuity encounters in the ED versus clinic. Results Over the two-year timeframe, there were 10,962 total visits to the ED by family practice patients, 4,250 of these visits were low acuity. Despite gross monthly increases of EDU from 2018-2020, after implementation of a walk-in clinic in 2019, rates of total EDU decreased by 1.5% and low acuity utilization rates also decreased. The average annual patient census nearly doubled from 5,763 to 8,042. T-tests confirmed statistical significance with p-values <0.05. Average low acuity ED visits ($437) cost 4.9 times more than comparable PCP office visits ($91). Managing 2,387 patients in the walk-in clinic resulted in an estimated annual cost savings of $ 825,902. Conclusion Extended walk-in availability in primary care offices provides non-ED capacity for low acuity management and might mitigate low acuity ED utilization while providing more cost-effective care. This study supports similarly described pre-hospital diversions in reducing ED over-utilization by increasing access to care. Higher levels of evidence are needed to establish causality.

Congenital anomalous origin of the coronary arteries is a rare but well-described cause of myocardial ischemia and sudden cardiac death. Anomalous origin of the right coronary artery from the ascending aorta is an extraordinarily rare occurrence. We report a case of anomalous origin of the right coronary artery from the ascending aorta posteriorly above the left sinus of Valsalva found during coronary angiography for evaluation of newly diagnosed cardiomyopathy.

High-fidelity computational fluid dynamics (HF-CFD) has revealed the potential for high-frequency flow instabilities (aka "turbulent-like" flow) in intracranial aneurysms, consistent with classic in vivo and in vitro reports of bruits and/or wall vibrations. However, HF-CFD has typically been performed on limited numbers of cases, often with unphysiological inflow conditions or focused on sidewall-type aneurysms where flow instabilities may be inherently less prevalent. Here we report HF-CFD of 50 bifurcation aneurysm cases from the open-source Aneurisk model repository. These were meshed using quadratic finite elements having an average effective spatial resolution of 0.065 mm, and solved under physiologically-pulsatile flow conditions using a well-validated, minimally-dissipative solver with 20,000 time-steps per cardiac cycle Flow instability was quantified using the recently introduced spectral power index (SPI), which quantifies, from 0 to 1, the power associated with velocity fluctuations above those of the driving inflow waveform. Of the 50 cases, nearly half showed regions within the sac having SPI up to 0.5, often with non-negligible power into the 100's of Hz, and roughly 1/3 had sac-averaged SPI > 0.1. High SPI did not significantly predict rupture status in this cohort. Proper orthogonal decomposition of cases with highest SPIavg revealed time-varying energetics consistent with transient turbulence. Our reported prevalence of high-frequency flow instabilities in HF-CFD modelling of aneurysms suggests that care must be taken to avoid routinely overlooking them if we are to understand the highly dynamic mechanical forces to which some aneurysm walls may be exposed, and their prevalence in vivo.

Background In underdeveloped countries, coronary artery disease (CAD) has developed into a serious health issue due to the high rates of risk factors such as obesity and smoking amongst the population. This study has been performed to find the rate of multivessel CAD (MVD) and subsequent thrombolysis in myocardial infarction (TIMI) flow grade III in patients undergoing primary percutaneous coronary intervention (PCI). Methods This transverse study was carried out involving 110 patients from the emergency department of the National Institute of Cardiovascular Diseases, Karachi, Pakistan, from August 2015 to March 2016. All patients were diagnosed as ST-segment elevation myocardial infarction (STEMI) and had gone through primary PCI. Pre-procedure angiographic findings regarding the number of vessels involved and post-procedure TIMI flow grade were assessed and analysed. Results The average age of the study sample was 56.3 ± 11.4 years. The proportion of male patients was 81.8% (n=90), and hypertension was the most prevalent risk factor followed by type II diabetes with a frequency of 67.3% (n=74) and 40.0% (n=44), respectively. Coronary angiography showed MVD in 50.0% (n=55) of the patients, of whom 34 patients had two-vessel disease, and the remaining 21 had three-vessel disease. Ninety percent (n=99) of the patients exhibited TIMI flow grade III after the procedure with no significant difference between patients with MVD and those with single-vessel disease with a rate of 87.3% (n=48/55) versus 92.7% (n=51/55, P=0.527), respectively. Conclusion Post-procedure TIMI flow grade III was accomplished in almost 90% of the subjects with or without MVD. It can be concluded that primary PCI has a significant role in the early restoration of myocardial blood flow following STEMI regardless of the vessels involved.

Introduction Primary percutaneous coronary intervention (PPCI) is now a well-established treatment of acute ST-elevation myocardial infarction (STEMI). For the first time in Pakistan, various off-site satellite centers are established to perform PPCI 24-hours. Our population mainly resides in the rural area with low literacy rate and poor socioeconomic conditions. The majority of the patients who are presented in the satellite center had either never received any long-term treatment plan or were non-compliant to their medication. The objective of this study was to determine the outcome of patients at six months who underwent primary PCI at a rural satellite center of Sindh, Pakistan. Methods This study was conducted at Larkana satellite center of National Institute of Cardiovascular Diseases, Karachi. Patients who underwent PPCI for STEMI from October 2017 to March 2018 were enrolled in the study. In case of death of the patient, data were obtained from the attendant of the deceased. Patients, on follow-up visits, were interrogated for post-procedure symptoms. Results A total of 271 patients were enrolled in the study. The mean age ± standard deviation of patients was 54.84 ± 10.64 years. The most common culprit artery was left anterior descending (LAD) artery with 161 (59.4%) patients, followed by right coronary artery (RCA) with 98 (36.2%) patients. Only 41 (15%) patients had a three-vessel disease, while 141 (52%) patients had single-vessel disease. On follow-up, 70 (25.8%) patients complained of chest pain grade II, 20 (7.4%) complained of shortness of breath (SOB) grade II, 44 (16.2%) complained of vertigo, and 16 (5.9%) complained of nonspecific weakness. The mortality rate of 6.3% (17) was observed after six months of PPCI. The mortality rate was found to be lower for patients with LAD disease (p = 0.036) and higher among patients with RCA as the culprit artery (p = 0.045). The mortality rate was significantly associated with the number of diseased vessels and the type of stent deployed. Conclusion Primary PCI, at a rural satellite center, has an overall positive outcome. Steps should be taken to provide free medication along with encouragement towards compliance of dual antiplatelet medication. Furthermore, the facility for subsequent procedures should be provided at the same set-up.

In the past decade, high-fidelity computational fluid dynamics (CFD) has uncovered the presence of high frequency flow instabilities (on the order of 100 s of Hz) in a variety of cardiovascular applications. These fluctuations are typically reported as pulsatile velocity-time traces or fast-Fourier-transformed power frequency spectra, often from a single point or at most a handful of points. Originally inspired by its use in spectral Doppler ultrasound, here we demonstrate the utility of the simplest form of time-frequency representation - the spectrogram - as a more comprehensive yet still-intuitive means of visualizing the potential harmonic complexity of pulsatile cardiovascular flows. After reviewing the basic theory behind spectrograms, notably the short-time Fourier transform (STFT), we discuss the choice of input parameters that inform the appearance and trade-offs of spectrograms. We show that spectrograms using STFT were able to highlight spectral features and were representative of those obtained from more complex methods such as the Continuous Wavelet transforms (CWT). While visualization properties (colourmap, filtering, smoothing/interpolation) are shown to affect the conspicuity of spectral features, the window properties (function, size, overlap) are shown to have the greatest impact on the resulting spectrogram appearance. Using a set of cerebral aneurysm CFD cases, we show that spectrograms can readily reveal the case specific nature of the time-varying flow instabilities, whether broadband, suggesting intermittent turbulent-like flow, or narrowband, suggesting laminar vortex shedding, or some combination thereof. (c) 2020 Elsevier Ltd. All rights reserved.

Background The aim of this study was to determine the frequency of coronary artery anomalies (CAAs) in Tetralogy of Fallot (TOF) patients undergoing computed tomography (CT)-angiography in a tertiary care hospital. Methodology In this observational study, we included consecutive TOF patients undergoing CT-angiography without prior history of cardiac surgery or congenital heart disease. CAAs were defined based on either origin or course of the artery. Results Out of 441 TOF patients, the prevalence of CCAs was 3.6% (16), of which 13 were below 18 years of age. Anomalous left main artery was observed in six (1.4%) patients, followed by left anterior descending artery and right coronary artery, observed in four (0.9%) patients each, and two (0.5%) patients had a single coronary artery originating from the left coronary cusp with an interarterial course. Conclusions CAAs were observed in a significant number (3.6%) of TOF patients. A CT-angiographic assessment before surgical correction would help identify the exact anatomy for better surgical planning to minimize complications.

Background Acute myocardial infarction (MI) is the leading cause of worldwide cardiac morbidities and mortalities. Mitral regurgitation (MR) is a common complication of MI. The severity of ischemic MR (IMR) can range widely, both clinically and hemodynamically. Mitral valve (MV) repair by lifting annuloplasty is a surgical procedure used to correct the pathology of IMR. The immediate outcomes of this technique have not yet been determined. The present study, therefore, evaluated the immediate results of MV annuloplasty performed to complement MV repair in patients with IMR. Methodology All adult patients with IMR who underwent lifting posterior mitral annuloplasty (LPMA) plus concomitant coronary artery bypass grafting (CABG) were included. Immediate outcomes were evaluated by transesophageal color Doppler echocardiography. The frequency of successful outcomes was compared in patients with different baseline characteristics. Results Posterior mitral annuloplasty was successful in 93.1% of patients, including in 92.8% of men and 94.1% of women. The percentages of successful immediate outcomes differed significantly in patients with and without diabetes and hypertension, and in patients with two- and three-vessel disease. Conclusion LPMA resulted in a high percentage of successful immediate outcomes in patients with IMR. Further studies should compare rates of immediate, intermediate, and late outcomes of this technique.

OBJECTIVE Aneurysm wall enhancement (AWE) on 3D vessel wall MRI (VWMRI) has been suggested as an imaging biomarker for intracranial aneurysms (IAs) at higher risk of rupture. While computational fluid dynamics (CFD) studies have been used to investigate the association between hemodynamic forces and rupture status of IAs, the role of hemodynamic forces in unruptured IAs with AWE is poorly understood. The authors investigated the role and implications of abnormal hemodynamics related to aneurysm pathophysiology in patients with AWE in unruptured IAs. METHODS Twenty-five patients who had undergone digital subtraction angiography (DSA) and VWMRI studies from September 2016 to September 2017 were included, resulting in 22 patients with 25 IAs, 9 with and 16 without AWE. High-resolution CFD models of hemodynamics were created from DSA images. Univariate and multivariate analyses were performed to investigate the association between AWE and conventional morphological and hemodynamic parameters. Normalized MRI signal intensity was quantified and quantitatively associated with wall shear stresses (WSSs) for the entire aneurysm sac, and in regions of low, intermediate, and high WSS. RESULTS The AWE group had lower WSS (p < 0.01) and sac-averaged velocity (p < 0.01) and larger aneurysm size (p < 0.001) and size ratio (p = 0.0251) than the non-AWE group. From multivariate analysis of both hemodynamic and morphological factors, only low WSS was found to be independently associated with AWE. Sac-averaged normalized MRI signal intensity correlated with WSS and was significantly different in regions of low WSS compared to regions of intermediate (p = 0.018) and high (p < 0.001) WSS. CONCLUSIONS The presence of AWE was associated with morphological and hemodynamic factors related to rupture risk. Low WSS was found to be an independent predictor of AWE. Our findings support the hypothesis that low WSS in IAs with AWE may indicate a growth and remodeling process that may predispose such aneurysms to rupture; however, a causality between the two cannot be established.