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Dive into the research topics where Gerald Yong is active.

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Featured researches published by Gerald Yong.


Catheterization and Cardiovascular Interventions | 2012

Left atrial appendage closure with Amplatzer cardiac plug for stroke prevention in atrial fibrillation: Initial Asia‐Pacific experience

Yat-Yin Lam; Gabriel Wai-Kwok Yip; Cheuk-Man Yu; Wilson W.M. Chan; Boron Cheung Wah Cheng; Bryan P. Yan; R. Clugston; Gerald Yong; Tim Gattorna; Vincent Paul

Background: Left atrial appendage (LAA) is the main source of left atrial thrombus that causes stroke in patients with non‐valvular atrial fibrillation (NVAF). This study reported the initial safety, feasibility, and 1‐yr clinical outcomes following AMPLATZER cardiac plug (ACP) implantation in Asia‐Pacific region.Methods: Twenty NVAF patients (16 males, age 68 ± 9 yr) with high risk for developing cardioembolic stroke (CHADS2 score: 2.3 ± 1.3) and contraindications to warfarin received ACP implants from June 2009 to May 2010. Patients received general anesthesia (n = 9) or controlled propofol sedation (n = 11) and the procedures were guided by fluoroscopy and transesophageal echocardiography (TEE). Clinical follow‐up was arranged at 1 month and then every 3 months after implantation, whereas, a TEE was scheduled at 1 month upon completion of dual anti‐platelet therapy.Results: The LAA was successfully occluded in 19/20 patients (95%) at two Asian centers. One procedure was abandoned because of catheter‐related thrombus formation. Other complications included coronary artery air embolism (n = 1) and TEE‐attributed esophageal injury (n = 1). The median procedural and fluoroscopic times were 79 (IQR: 59–100) and 18 (IQR 12–27) minutes, respectively. The mean size of implant was 23.6 ± 3.1 mm. The average hospital stay was 1.8 ± 1.1 days. Follow‐up TEE showed all the LAA orifices were sealed without device‐related thrombus formation. No stroke or death occurred at a mean follow‐up of 12.7 ± 3.1 months. Conclusions: Our preliminary data suggested LAA closure with ACP is safe, feasible with encouraging 1‐yr clinical outcomes. Further large‐scaled trials are needed to confirm the efficacy of this device.


Jacc-cardiovascular Interventions | 2011

Outcome of Patients After Transcatheter Aortic Valve Embolization

E. Tay; Ronen Gurvitch; Namal Wijeysinghe; Fabian Nietlispach; Jonathon Leipsic; David A. Wood; Gerald Yong; Anson Cheung; Jian Ye; Samuel V. Lichtenstein; Ronald G. Carere; Christopher R. Thompson; John G. Webb

OBJECTIVES This study aims to assess the mid- to long-term follow-up of patients after valve embolization at the time of transcatheter aortic valve implantation (TAVI). BACKGROUND Transcatheter heart valve (THV) embolization is a rare but serious complication during TAVI. Although various techniques have been developed to manage acute complications and reduce periprocedural morbidity/mortality, long-term clinical and hemodynamic consequences after these events are unknown. METHODS Patients who developed THV embolization after TAVI were prospectively assessed. Clinical and echocardiographic characteristics were recorded at baseline and after successful TAVI/surgical aortic valve replacement. The THV migration and strut fractures/degeneration were assessed by computed tomography. RESULTS A total of 7 patients had THV embolization, all of which occurred immediately after valve deployment. The embolized THV was repositioned in the aortic arch proximal to the left subclavian artery (n = 2), immediately distal to the left subclavian artery (n = 2), and in the abdominal aorta (n = 3). A second THV was implanted successfully at the same sitting in 4 patients and at the time of a second procedure in 2 patients. Elective conventional aortic valve replacement was performed in 1 patient. Median follow-up was 1,085 days. One patient died during follow-up from an unrelated cause. The remaining 6 survivors were in New York Heart Association functional class I or II at final follow-up. Mid-term computed tomography follow-up (n = 4,591 to 1,548 days) showed that the leaflets of the embolized THV remain open in all phases of the cardiac cycle. There was also no strut fracture or migration of these valves. CONCLUSIONS Clinical outcomes remain good when THV embolization is managed effectively. There are no apparent hemodynamic consequences of a second valve placed in the series. These embolized valves remain in a stable position with no evidence of strut fractures at mid-term follow-up.


The American Journal of Gastroenterology | 2007

Predictive and protective factors associated with upper gastrointestinal bleeding after percutaneous coronary intervention: a case-control study.

Marcus W. Chin; Gerald Yong; Max Bulsara; Jamie Rankin; Geoffrey M. Forbes

BACKGROUND:Hemorrhagic complications of acute coronary syndromes and percutaneous coronary intervention (PCI) are associated with increased mortality. Upper gastrointestinal (UGI) bleeding after PCI is a potential target for preventative strategies.OBJECTIVE:To evaluate the risk factors for UGI bleeding in a large cohort of contemporary PCI patients and assess the outcomes of medical and endoscopic management.METHOD:A case-control study evaluating UGI bleeding in the 30 days following PCI for stable angina and acute coronary syndromes, at one institution between 1998 and 2005. Cases were identified and outcomes assessed using linkage analysis of data from institutional PCI and endoscopy databases, statewide vital statistics and hospital discharge registries, and a detailed review of medical notes for each case and three matched controls. Analysis of the case and control groups for risk and protective factors was performed using the χ2 test with Fishers exact P value and logistic regression.RESULTS:The incidence of UGI bleeding following PCI was 1.2% (70 of 5,673 patients). The etiologies of these bleeds were diverse. Risk factors for UGI bleeding were primary PCI (OR 27.80, 95% CI 6.28–123.05, P < 0.001), cardiac arrest (OR 6.17, 95% CI 1.82–20.84, P = 0.003), inotropic requirement (OR 5.85, 95% CI 1.98–17.27, P = 0.001), thienopyridine use before PCI (OR 2.40, 95% CI 1.04–5.53, P = 0.02), and advanced age (OR 1.08, 95% CI 1.04–1.12, P < 0.001). Proton pump inhibitor use after PCI (OR 0.08, 95% CI 0.02–0.40, P = 0.002) was accompanied by a reduced risk of UGI bleeding. Endoscopy provided therapeutic intervention in 33% of patients. There were no serious complications of endoscopy. The 30-day mortality for cases was 11.9% and 0.5% for controls (P = 0.001).CONCLUSION:UGI bleeding after PCI is relatively common and associated with increased mortality. Those undergoing PCI for acute myocardial infarction or in the presence hemodynamic instability are at highest risk. Proton pump inhibition following PCI may reduce the bleeding risk, though when UGI bleeding occurs, therapeutic endoscopy is safe.


Nephrology | 2012

Incidence, risk factors and prognosis of acute kidney injury after transcatheter aortic valve implantation

Wai Y Kong; Gerald Yong; Ashley Irish

Aim:  Transcatheter aortic valve implantation (TAVI) poses a significant risk of acute kidney injury (AKI). Little is known of the impact of TAVI and AKI on long‐term kidney function and health cost. We explored the predictive factors and prognostic implications of AKI following TAVI.


Journal of Vascular Surgery | 2013

Incidence and prognosis of vascular complications after transcatheter aortic valve implantation.

Bibombe P. Mwipatayi; Alarick Picardo; Taolo Vijay Masilonyane-Jones; Robert Larbalestier; Shannon D. Thomas; Jennifer Turner; Vikram Vijayan; Gerald Yong

OBJECTIVE Transcatheter aortic valve implantation (TAVI) has gained increasing global popularity as a minimally invasive option for high-risk cardiac patients. However, this operation is not without risk, particularly of significant vascular complications that increase the morbidity, mortality, and overall cost of the procedure. We aim to present our experience of TAVI-related vascular complications, including the morbidity and cost impacts of these events. METHODS A case-series study was performed for all patients undergoing TAVI at our center. Vascular complications were defined according to the 2011 Valve Academic Research Consortium standardized end points. The data were prospectively collected from February 2009 to April 2012, and the outcomes were entered into a database and cross-checked with the hospital notes. RESULTS TAVI was performed on 100 patients in our center during the study period, and the 30-day mortality was 6%. Access approaches included 81 transfemoral, 18 transapical, and one trans-subclavian access. The average patient age was 84.9 years, and 65% of the patients were male. Among the transfemoral procedures, there were 16 vascular access-related complications (VAC), including nine major and seven minor complications. The major complications included aortic dissection, iliac arterial rupture, femoral dissection, false aneurysms, and distal embolization, all of which required surgical or endovascular repair. An apical false aneurysm and an apical tear were major VAC of the transapical group, with the latter resulting in death. Patients with VAC had higher blood transfusion requirements (4.1 ± 4.5 units vs 0.9 ± 2.2 units; P = .004), greater length of hospital stay (16.4 ± 10.7 days vs 6.5 ± 5.1 days; P = .001), and increased cost (A


American Heart Journal | 2009

Randomized trial comparing 600- with 300-mg loading dose of clopidogrel in patients with non–ST elevation acute coronary syndrome undergoing percutaneous coronary intervention: Results of the Platelet Responsiveness to Aspirin and Clopidogrel and Troponin Increment after Coronary intervention in Acute coronary Lesions (PRACTICAL) Trial

Gerald Yong; Jamie Rankin; Louise Ferguson; Jim Thom; John K. French; David Brieger; Derek P. Chew; Ronald Dick; David Eccleston; Bernard Ef Hockings; D. Walters; Alan Whelan; John W. Eikelboom

93,448 ± 21,435 vs A


The Annals of Thoracic Surgery | 2015

Transapical Versus Transaortic Transcatheter Aortic Valve Implantation: A Systematic Review

Ben Dunne; Darren Tan; Daniel Chu; Victor Yau; Jinguo Xiao; Kwok M. Ho; Gerald Yong; Robert Larbalestier

69,932 ± 15,007; P = .002) compared with the non-VAC group. The predictors of vascular complications using multivariate analysis included European System for Cardiac Operative Risk Evaluation (odds ratio, 1.06; 95% confidence interval, 1.02-1.10; P = .001) and diabetes mellitus (odds ratio, 5.07; 95% confidence interval, 1.17-21.88; P = .03). Occurrence of major VAC did not affect in-hospital or 30-day mortality rates and was not associated with poorer survival. CONCLUSIONS Vascular complications affect perioperative management and outcomes following TAVI. Our findings show that these complications often require urgent surgical or endovascular repair and result in increased blood transfusions, greater length of hospital stay, and significantly increased costs. Diabetes mellitus and logistic European System for Cardiac Operative Risk Evaluation may be predictive of VAC and should be considered during TAVI patient selection.


International Journal of Laboratory Hematology | 2009

A rapid flow cytometric technique for the detection of platelet-monocyte complexes, activated platelets and platelet-derived microparticles

Laura Pearson; Jim Thom; Mj Adams; R Oostryck; Rom G. Krueger; Gerald Yong; Ross Baker

BACKGROUND There is uncertainty about the benefit of a higher loading dose (LD) of clopidogrel in patients with non-ST elevation acute coronary syndrome (NSTEACS) undergoing early percutaneous coronary intervention (PCI). METHODS We compared the effects of a 600- versus a 300-mg LD of clopidogrel on inhibition of platelet aggregation, myonecrosis, and clinical outcomes in patients with NSTEACS undergoing an early invasive management strategy. Patients with NSTEACS (n = 256, mean age 63 years, 81.6% elevated troponin) without thienopyridine for at least 7 days were randomized to receive 600- or 300-mg LD of clopidogrel. Percutaneous coronary intervention was performed in 140 patients, with glycoprotein IIb/IIIa inhibitor use in 68.6%. Adenosine diphosphate (ADP)-induced platelet aggregation was measured by optical platelet aggregometry immediately before coronary angiography. RESULTS Post-PCI myonecrosis was defined as a next-day troponin I greater than 5 times the upper limit of reference range and greater than baseline levels. Clopidogrel 600-mg LD compared with 300-mg LD was associated with significantly reduced ADP-induced platelet aggregation (49.7% vs 55.7% with ADP 20 micromol/L) but did not reduce post-PCI myonecrosis or adverse clinical outcomes to 6 months. There was no association between preprocedural platelet aggregation and outcome. CONCLUSIONS These data confirm a modest incremental antiplatelet effect of a 600-mg clopidogrel LD compared with 300-mg LD but provide no support for a clinical benefit in patients with NSTEACS managed with an early invasive strategy including a high rate (69%) of glycoprotein IIb/IIIa inhibitor use during PCI.


Eurointervention | 2009

Rapid pacing rotational angiography with three-dimensional reconstruction: use and benefits in structural heart disease interventions

Stéphane Noble; Joaquim Miro; Gerald Yong; Raoul Bonan; Jean-Claude Tardif; Reda Ibrahim

Two alternative approaches for transcatheter aortic valve implantation (TAVI) exist for patients unsuitable for the transfemoral approach; the transapical and the transaortic approaches. It is unclear as to which approach has superior short-term outcomes. A systematic review and meta-analysis was performed to answer this question. Mortality was equivalent in the 2 groups. There was a trend toward a lower rate of stroke in the transaortic group (0.9% vs 2.1%) but this was not statistically significant. Conversion to surgical aortic valve replacement, paravalvular leak, pacemaker requirement, and major bleeding occurred at equivalent rates.


Thrombosis and Haemostasis | 2015

Vascular risk levels affect the predictive value of platelet reactivity for the occurrence of MACE in patients on clopidogrel: Systematic review and meta-analysis of individual patient data

Jean-Luc Reny; Pierre Fontana; Willibald Hochholzer; Franz Josef Neumann; Jurriën M. ten Berg; Paul W.A. Janssen; Tobias Geisler; Meinrad Gawaz; Rossella Marcucci; Anna Maria Gori; Thomas Cuisset; Marie Christine Alessi; P. Berdagué; Paul A. Gurbel; Gerald Yong; Dominick J. Angiolillo; Dániel Aradi; Roy Beigel; Gianluca Campo; Christophe Combescure

Platelet activation occurs in a variety of clinical situations in which it directly contributes to the pathology. This study reports a simple flow cytometric assay for platelet activation which measures platelet‐derived microparticles, activated platelets and platelet–monocyte complexes. Pre‐ and post analytical conditions were investigated and optimized and a normal range established on 20 healthy controls. Twenty patients pre‐ and post percutaneous coronary intervention (PCI) were tested with the technique. Soluble activation markers sCD40 ligand and sP‐selectin and plasma phospholipid levels were measured in both groups. There was a significant increase in activated platelets and platelet–monocyte complexes between normal and pre‐PCI (P = 0.005 and 0.0275, respectively) suggesting an activated state. There was a significant fall in activated platelets post‐PCI (P = 0.0027) which was mirrored by a fall in soluble CD40 ligand, soluble P‐selectin and plasma phospholipid levels (P = 0.0066, <0.0001 and 0.0032, respectively) consistent with antiplatelet therapy administered during the process. This is a reliable and rapid method for the assessment of ex vivo platelet activation which may be an aid in diagnosis and help guide therapy for patients with thrombotic disease.

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D. Walters

University of Queensland

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A. Sinhal

Flinders Medical Centre

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