Publications by authors named "Aaron Sung Lung Wong"

Aim: Physician visual assessment (PVA) in invasive coronary angiography (ICA) is clinically used to determine stenosis severity and guide coronary intervention. However, PVA provides limited information regarding the haemodynamic significance of stenosis. This prospective study aimed to develop a model combining visual diameter stenosis (DS) and quantitative coronary angiography (QCA)-derived parameters to diagnose ischaemic lesions using invasive fractional flow reserve (FFR) with pharmacologically induced maximal hyperaemia as the gold standard.

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Purpose To develop a new coronary CT angiography (CCTA)-based index, α×LL/MLD, that considers lesion entrance angle (α) in addition to lesion length (LL) and minimal lumen diameter (MLD) and to evaluate its efficacy in predicting hemodynamically significant coronary stenosis compared with invasive coronary angiography (ICA)-derived fractional flow reserve (FFR). Materials and Methods This prospective study enrolled participants (September 2016-March 2020) from two centers who underwent CCTA followed by ICA (ClinicalTrials.gov identifier: NCT03054324).

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Patients with chronic kidney disease (CKD) have traditionally been excluded from randomized trials. We aimed to compare percutaneous coronary intervention versus conservative management, and early intervention (EI; within 24 hours of admission) versus delayed intervention (DI; after 24 to 72 hours of admission) in patients with non-ST-segment elevation myocardial infarction (NSTEMI) and concomitant CKD. An electronic literature search was performed to search for studies comparing invasive management to conservative management or EI versus DI in patients with NSTEMI with CKD.

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Background: Physician visual assessment (PVA) in invasive coronary angiography (ICA) is the current clinical method to determine stenosis severity and guide percutaneous coronary intervention. This study sought to evaluate the effect of sex differences in assessing coronary stenosis severity between PVA and quantitative coronary angiography (QCA).

Methods: 209 patients with coronary artery disease (288 coronary lesions) underwent ICA and fractional flow reserve (FFR).

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Article Synopsis
  • This study evaluated a new method for non-invasive fractional flow reserve (FFR) calculation to diagnose coronary artery disease (CAD) using CT scans.
  • Researchers compared this new method with traditional computational fluid dynamics (CFD) and invasive measurement techniques on a group of 108 patients.
  • Results showed that the new method offers comparable accuracy in diagnosing ischemic lesions while being significantly faster in computation time.*
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Article Synopsis
  • The study aimed to analyze how the COVID-19 pandemic impacted primary percutaneous coronary intervention (PPCI) procedures and patient outcomes for those with ST elevation myocardial infarction (STEMI) compared to the period before the pandemic.
  • It involved a retrospective analysis of data from 16,674 patients across various regions, showing a significant decrease in PPCI procedures during the pandemic (16% reduction) along with increases in treatment delays and mortality rates.
  • Findings highlight that older adults were particularly affected, and the increased time to treatment likely contributed to both in-hospital and 30-day mortality rates rising during the pandemic.
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Introduction: Early reperfusion of ST-segment elevation myocardial infarction (STEMI) results in better outcomes. Interventions that have resulted in shorter door-to-balloon (DTB) time include prehospital cardiovascular laboratory activation and prehospital electrocardiogram (ECG) transmission, which are only available for patients who arrive via emergency ambulances. We assessed the impact of mode of transport on DTB time in a single tertiary institution and evaluated the factors that affected various components of DTB time.

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Objectives: To assess the clinical and angiographic outcomes of coronary intravascular lithotripsy (IVL) use in an all-comers population with moderate-to-severely calcified coronary lesions.

Background: IVL has been shown to modify coronary calcific plaques with minimal vascular complications.

Methods: This was a retrospective, observational study of patients treated with IVL.

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Proper inlet boundary conditions are essential for accurate computational fluid dynamics (CFD) modeling. We developed methodology to derive noninvasive FFR using CFD and computed tomography coronary angiography (CTCA) images. This study aims to assess the influence of brachial mean blood pressure (MBP) and total coronary inflow on FFR computation.

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Background: Computed tomography coronary angiography (CTCA) image analysis enables plaque characterization and non-invasive fractional flow reserve (FFR) calculation. We analyzed various parameters derived from CTCA images and evaluated their associations with ischemia.

Methods: 49 (61 lesions) patients underwent CTCA and invasive FFR.

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Background: To evaluate the combined diagnostic accuracy of coronary computed tomography angiography (CCTA) and computed tomography derived fractional flow reserve (FFRct) in patients with suspected or known coronary artery disease (CAD).

Methods: PubMed, The Cochrane library, Embase and OpenGray were searched to identify studies comparing diagnostic accuracy of CCTA and FFRct. Diagnostic test measurements of FFRct were either extracted directly from the published papers or calculated from provided information.

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Invasive fractional flow reserve (FFR) is the gold standard to assess the functional coronary stenosis. The non-invasive assessment of diameter stenosis (DS) using coronary computed tomography angiography (CTA) has high false positive rate in contrast to FFR. Combining CTA with computational fluid dynamics (CFD), recent studies have shown promising predictions of FFRCT for superior assessment of lesion severity over CTA alone.

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Background: Timely reperfusion in ST-segment elevation myocardial infarction (STEMI) improves outcomes. System delay is that between first medical contact and reperfusion therapy, comprising prehospital and hospital components. This study aimed to characterize prehospital system delay in Singapore.

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Local hemodynamic parameters, such as wall shear stress (WSS), oscillatory shear index and relative resident time (RRT), have been linked to coronary plaque initiation and progression. In this study, a left coronary artery tree model was reconstructed from computed tomography angiography images of a patient with multiple stenoses. The geometry of the coronary artery tree model was virtually restored by eliminating the lesions, essentially re-creating the virtually healthy artery anatomy.

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Article Synopsis
  • Fractional flow reserve (FFR) is crucial for guiding coronary interventions but currently requires invasive procedures to obtain.
  • This study introduces a noninvasive method to estimate fractional flow reserve computed tomography (FFRCT) by combining CTA images with computational fluid dynamics (CFD).
  • Results show that FFRCT decreases as diameter stenosis increases, with specific stenosis characteristics impacting its value, and simulations align well with invasive angiography results, suggesting this method could enhance CAD diagnosis.
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Study Objective: Reducing door-to-balloon times for acute ST-segment elevation myocardial infarction (STEMI) patients has been shown to improve long-term survival. We aim to reduce door-to-balloon time for STEMI patients requiring primary percutaneous coronary intervention by adoption of out-of-hospital 12-lead ECG transmission by Singapore's national ambulance service.

Methods: This was a nationwide, before-after study of STEMI patients who presented to the emergency departments (ED) and required percutaneous coronary intervention.

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To characterize prehospital delays in patients presenting with acute ST-elevation myocardial infarction to the emergency department of a tertiary hospital in Asia. A retrospective review of 273 patients with diagnosis of ST-elevation myocardial infarction; symptom to door (S2D) time was described in two ways, time from first onset of symptoms; and time from the onset of the worst episode to presentation at emergency department. The median first onset S2D time was 173 min (interquartile range 80-350 min); and median worst episode S2D time was 131 min (interquartile range 70-261 min).

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Coronary stent infection is exceedingly rare, with only 23 reported cases. We present a patient with an everolimus-coated stent infection that led to an infected pseudoaneurysm in the left anterior descending artery. Medical therapy failed and the patient underwent emergent surgical intervention; however, he died of multiorgan failure after the operation.

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