1.Asia's first successful minimally invasive transapical transcatheter mitral valve-in-valve implantation.
Jia Lin SOON ; Yeow Leng CHUA ; Victor Tt CHAO ; Paul Tl CHIAM ; See Hooi EWE ; Ving Yuen SEETHO ; Chung Yin LEE ; Swee Yaw TAN ; Tian Hai KOH ; Kenny Yk SIN
Annals of the Academy of Medicine, Singapore 2013;42(2):85-87
2.Pulmonary endarterectomy and balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension: The Singapore experience.
Wen RUAN ; Jonathan YAP ; Kevin QUAH ; Foong Koon CHEAH ; Ghee Chee PHUA ; Duu Wen SEWA ; Aidila Binte ISMAIL ; Alicia CHIA ; David JENKINS ; Ju Le TAN ; Victor CHAO ; Soo Teik LIM
Annals of the Academy of Medicine, Singapore 2021;50(3):270-273
3.Impact of Chronic Kidney Disease on Outcomes in Transcatheter Aortic Valve Implantation.
Jonathan Jl YAP ; Julian Ck TAY ; See Hooi EWE ; Nishanth THIAGARAJAN ; Shaw Yang CHIA ; Mohammed Rizwan AMANULLAH ; Soo Teik LIM ; Victor Tt CHAO ; Kay Woon HO
Annals of the Academy of Medicine, Singapore 2020;49(5):273-284
INTRODUCTION:
Chronic kidney disease (CKD) is a significant comorbidity in aortic stenosis (AS) patients. We examined the impact of baseline CKD, postoperative acute kidney injury (AKI) and CKD progression on clinical outcomes in patients who underwent transcatheter aortic valve implantation (TAVI).
MATERIALS AND METHODS:
Consecutive patients with severe AS who underwent TAVI were classified into CKD stages 1-2 (≥60 mL/min/1.72m), 3 (30-59 mL/min/1.73m) and 4-5 (<30 mL/min/1.73m or dialysis) based on estimated glomerular filtration rate (eGFR). Primary outcome was mortality and secondary outcomes included 1-year echocardiographic data on aortic valve area (AVA), mean pressure gradient (MPG) and aortic regurgitation (AR).
RESULTS:
A total of 216 patients were included. Higher eGFR was associated with lower overall mortality (adjusted hazards ratio [AHR] 0.981, 95% confidence interval [CI] 0.968-0.993, = 0.002). CKD 4-5 were associated with significantly higher mortality from non-cardiovascular causes ( <0.05). Patients with CKD 3-5 had higher incidence of moderate AR than those with CKD 1-2 ( = 0.010); no difference in AVA and MPG was seen. AKI patients had higher mortality ( = 0.008), but the effect was attenuated on multivariate analysis (AHR 1.823, 95% CI 0.977-3.403, = 0.059). Patients with CKD progression also had significantly higher mortality (AHR 2.969, 95% CI 1.373-6.420, = 0.006).
CONCLUSION
CKD in severe AS patients undergoing TAVI portends significantly higher mortality and morbidity. Renal disease progression impacts negatively on outcomes and identifies a challenging subgroup of patients for optimal management.
4.Comparison of the Haemodynamic Parameters of Venous and Arterial Coronary Artery Bypass Conduits.
Jun Mei ZHANG ; Clement Jh CHAN ; Ning KANG ; Jia Lin SOON ; Kenny Yk SIN ; Victor Tt CHAO ; Teing Ee TAN ; Chong Hee LIM ; Mathew J CHAKARAMAKKIL ; Adrian Sw OOI ; Yeow Leng CHUA ; Ru San TAN ; Liang ZHONG
Annals of the Academy of Medicine, Singapore 2016;45(8):369-372
Aged
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Atherosclerosis
;
Case-Control Studies
;
Coronary Artery Bypass
;
methods
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Coronary Artery Disease
;
surgery
;
Female
;
Hemodynamics
;
physiology
;
Humans
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Male
;
Mammary Arteries
;
physiology
;
transplantation
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Middle Aged
;
Pulsatile Flow
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Radial Artery
;
physiology
;
transplantation
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Rheology
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Saphenous Vein
;
physiology
;
transplantation
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Shear Strength
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Stress, Mechanical
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Vascular Patency
;
physiology
5.Clinical Updates on the Diagnosis and Management of Chronic Thromboembolic Pulmonary Hypertension.
Wen RUAN ; Jonathan Jl YAP ; Kevin Kh QUAH ; Foong Koon CHEAH ; Ghee Chee PHUA ; Duu Wen SEWA ; Aidila Binte ISMAIL ; Alicia Xf CHIA ; David JENKINS ; Ju Le TAN ; Victor Tt CHAO ; Soo Teik LIM
Annals of the Academy of Medicine, Singapore 2020;49(5):320-330
INTRODUCTION:
Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela after acute pulmonary embolism (PE). It is a debilitating disease, and potentially fatal if left untreated. This review provides a clinically relevant overview of the disease and discusses the usefulness and limitations of the various investigational and treatment options.
METHODS:
A PubMed search on articles relevant to PE, pulmonary hypertension, CTEPH, pulmonary endarterectomy, and balloon pulmonary angioplasty were performed. A total of 68 articles were found to be relevant and were reviewed.
RESULTS:
CTEPH occurs as a result of non-resolution of thrombotic material, with subsequent fibrosis and scarring of the pulmonary arteries. Risk factors have been identified, but the underlying mechanisms have yet to be fully elucidated. The cardinal symptom of CTEPH is dyspnoea on exertion, but the diagnosis is often challenging due to lack of awareness. The ventilation/perfusion scan is recommended for screening for CTEPH, with other modalities (eg. dual energy computed tomography pulmonary angiography) also being utilised in expert centres. Conventional pulmonary angiography with right heart catheterisation is important in the final diagnosis of CTEPH.
CONCLUSION
Operability assessment by a multidisciplinary team is crucial for the management of CTEPH, as pulmonary endarterectomy (PEA) remains the guideline recommended treatment and has the best chance of cure. For inoperable patients or those with residual disease post-PEA, medical therapy or balloon pulmonary angioplasty are potential treatment options.
6.Impact of aortic annular size and valve type on haemodynamics and clinical outcomes after transcatheter aortic valve implantation.
Samuel Ji Quan KOH ; Jonathan YAP ; Yilin JIANG ; Julian Cheong Kiat TAY ; Kevin Kien Hong QUAH ; Nishanth THIAGARAJAN ; Swee Yaw TAN ; Mohammed Rizwan AMANULLAH ; Soo Teik LIM ; Zameer Abdul AZIZ ; Sivaraj GOVINDASAMY ; Victor Tar Toong CHAO ; See Hooi EWE ; Kay Woon HO
Annals of the Academy of Medicine, Singapore 2022;51(10):605-618
INTRODUCTION:
Data on patients with small aortic annuli (SAA) undergoing transcatheter aortic valve implantation (TAVI) are limited. We aim to describe the impact of aortic annular size, particularly SAA and TAVI valve type on valve haemodynamics, durability and clinical outcomes.
METHOD:
All patients in National Heart Centre Singapore who underwent transfemoral TAVI for severe symptomatic native aortic stenosis from July 2012 to December 2019 were included. Outcome measures include valve haemodynamics, prosthesis-patient mismatch (PPM), structural valve degeneration (SVD) and mortality.
RESULTS:
A total of 244 patients were included. The mean Society of Thoracic Surgeons score was 6.22±6.08, with 52.5% patients with small aortic annulus (<23mm), 33.2% patients with medium aortic annulus (23-26mm) and 14.3% patients with large aortic annulus (>26mm). There were more patients with self-expanding valve (SEV) (65.2%) versus balloon-expandable valve (BEV) (34.8%). There were no significant differences in indexed aortic valve area (iAVA), mean pressure gradient (MPG), PPM, SVD or mortality across all aortic annular sizes. However, specific to the SAA group, patients with SEV had larger iAVA (SEV 1.19±0.35cm2/m2 vs BEV 0.88±0.15cm2/m2, P<0.01) and lower MPG (SEV 9.25±4.88 mmHg vs BEV 14.17±4.75 mmHg, P<0.01) at 1 year, without differences in PPM or mortality. Aortic annular size, TAVI valve type and PPM did not predict overall mortality up to 7 years. There was no significant difference in SVD between aortic annular sizes up to 5 years.
CONCLUSION
Valve haemodynamics and durability were similar across the different aortic annular sizes. In the SAA group, SEV had better haemodynamics than BEV at 1 year, but no differences in PPM or mortality. There were no significant differences in mortality between aortic annular sizes, TAVI valve types or PPM.
Humans
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Transcatheter Aortic Valve Replacement
;
Heart Valve Prosthesis
;
Aortic Valve Stenosis/surgery*
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Aortic Valve/surgery*
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Prosthesis Design
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Postoperative Complications/surgery*
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Treatment Outcome
;
Hemodynamics
7.Isolation and Identification of Human Umbilical Cord and Placenta-derived Stem Cells and Their Component Analysis.
Sheng-Li ZHOU ; Chao ZHENG ; Jian-Qiang SU ; Yuan-Hong QI ; Zheng-Kai SI
Journal of Experimental Hematology 2015;23(6):1684-1691
OBJECTIVEClinical transplantation evidence has been indicated that umbilical cord blood (UCB) can be useful in the hematopoietic reconstitution in the children, but can not be well in the adult hematopoietic transplantation because of the low count. This study was to evaluate a new method for collecting stem cells from human placenta and umbilical cord, and to comparatively analyze the similarity and difference of quality and quantity of the cells.
METHODSThe UCB was collected, in same time the placental tissue was sterily collected; the umbilical placenta was collected by perfusing the blood (UPB) cord arterial and venous vascules with 0.9% saline; the mesenchymal stem cells (MSC) from same source of umbilical cord and placental tissues were isolated and cultured. The cell colony assay and flow cytometry were performed to determine the proliferation capacities and cell markers of UMSC and PMSC.
RESULTSThe total nuclear cells (NC) and hematopoietic stem cells (CD34(+)) from UPB and UCB were (17.45 ± 16.86) × 10(8), (6.9 ± 4.61) × 10(8) and (2.97 ± 2.25) × 10(6), (1.91 ± 1.7) × 10(6), respectively. Furthermore, the UPB contained more early precursor of hematopoietic stem cells (CD33(+) CD34(-)) (6.2 ± 13.5) × 10(5), (0.2 ± 0.8) × 10(5) ; and high proportion of MSC to NC (25.21 ± 18.69, 0.05 ± 0.10)%, respectively in 62 samples. There were no difference of the MSC level in UPB and UCB, as well as in the morphology and cell markers.
CONCLUSIONUPB has rich hematopoietic stem cells and mesenchymal stem cells. Placenta may offer another source for hematopoietic stem cells in research of hematopoietic stem cells and regeneration medicine.
Adult ; Antigens, CD34 ; Cell Separation ; Female ; Fetal Blood ; Flow Cytometry ; Hematopoietic Stem Cells ; Humans ; Mesenchymal Stromal Cells ; Placenta ; Pregnancy ; Umbilical Cord
8.Comparison of the clinical profile of patients with glaucoma between private and government clinics in the Philippines.
Edgar Felipe U LEUENBERGER ; James Paul S GOMEZ ; Robert Edward T ANG ; Maria Imelda YAP-VELOSO ; Joseph Anthony J TUMBOCON ; Jose Maria D MARTINEZ ; John Mark S DE LEON ; Nilo Vincent FLORCRUZ ; Rainier Victor A COVAR ; Irene R FELARCA ; Denise Polly CHAO-PO ; Shalam SIAO-MARIANO ; Marie Joan Therese D BALGOS ; Noel D ATIENZA
Philippine Journal of Ophthalmology 2019;44(2):45-53
OBJECTIVE: To describe the demographic and clinical characteristics of patients with glaucoma managed at private and government institutions in the Philippines between 2009 and 2014.
METHODS: A research team from two private and two government institutions in the Philippines reviewed the case records of 1246 patients seen who met the following criteria: intraocular pressure of >21 mmHg, optic nerve and nerve fiber layer abnormalities, and visual field defects. For bilateral cases, we selected the eye with worse glaucoma parameters.
RESULTS: There were 600 and 646 patients in the private and government groups (mean age at presentation, 60.51 and 55.88 years), respectively, with the majority being Filipino (91%). Patients with visual acuity (VA) of 20/20 to 20/40 were more frequently observed in private centers (58.7% vs. 41.3%), while a VA worse than counting fingers was more frequently observed in government centers (66.1% vs. 33.9%). Within-group analysis showed that primary angle-closure glaucoma was the most frequent glaucoma subtype in both private (27.3%) and government institutions (37.8%). In between-group analysis showed the following to be more common in private than government centers: primary open-angle glaucoma (61.3% vs. 38.7%), normal-tension glaucoma (63.9% vs. 36.1%), ocular hypertension (92.3% vs. 7.7%), and glaucoma suspects (80.4% vs. 19.6%) while government institutions registered a larger number of primary angle-closure glaucoma (59.8% vs. 40.2%) and secondary glaucoma (70.3% vs. 29.7%) cases. Medical treatment using a single drug and multiple drugs was employed for 245 (23%) and 825 (77%) patients, respectively. Within-group analysis showed that laser iridotomy and trabeculectomy were the most commonly performed laser and surgical procedures in both institution types.
CONCLUSION: There is a contrasting profile of glaucoma between clinical institutions in the Philippines with openangle glaucoma being more predominant in private centers while closed-angle glaucoma and secondary glaucoma being more frequent in government centers. Our findings may provide important preliminary information that can aid future health studies or training programs.
Human ; Glaucoma ; Patients