1.Clinical and echocardiographic differences between rheumatic and degenerative mitral stenosis.
Ryan LEOW ; Ching-Hui SIA ; Tony Yi-Wei LI ; Meei Wah CHAN ; Eng How LIM ; Li Min Julia NG ; Tiong-Cheng YEO ; Kian-Keong POH ; Huay Cheem TAN ; William Kf KONG
Annals of the Academy of Medicine, Singapore 2025;54(4):227-234
INTRODUCTION:
Degenerative mitral stenosis (DMS) is frequently cited as increasing in prevalence in the developed world, although comparatively little is known about DMS in comparison to rheumatic mitral stenosis (RMS).
METHOD:
A retrospective observational study was conducted on 745 cases of native-valve mitral stenosis (MS) with median follow-up time of 7.25 years. Clinical and echocardiographic parameters were compared. Univariate and multivariate Cox regression analyses were performed for a composite of all-cause mortality and heart failure hospitalisation.
RESULTS:
Patients with DMS compared to RMS were older (age, mean ± standard deviation: 69.6 ± 12.3 versus [vs] 51.6 ± 14.3 years, respectively; P<0.001) and a greater proportion had medical comorbidities such as diabetes mellitus (78 [41.9%] vs 112 [20.0%], P<0.001). The proportion of cases of degenerative aetiology increased from 1.1% in 1991-1995 to 41.0% in 2016-2017. In multivariate analysis for the composite outcome, age (hazard ratio [HR] 95% confidence interval [CI] of 1.032 [1.020-1.044]; P<0.001), diabetes mellitus (HR 1.443, 95% CI 1.068-1.948; P=0.017), chronic kidney disease (HR 2.043, 95% CI 1.470-2.841; P<0.001) and pulmonary artery systolic pressure (HR 1.019, 95% CI 1.010- 1.027; P<0.001) demonstrated significant indepen-dent associations. The aetiology of MS was not independently associated with the composite outcome.
CONCLUSION
DMS is becoming an increasingly common cause of native-valve MS. Despite numerous clinical differences between RMS and DMS, the aetiology of MS did not independently influence a composite of mortality or heart failure hospitalisation.
Humans
;
Mitral Valve Stenosis/etiology*
;
Male
;
Female
;
Retrospective Studies
;
Middle Aged
;
Aged
;
Rheumatic Heart Disease/mortality*
;
Echocardiography
;
Hospitalization/statistics & numerical data*
;
Heart Failure/epidemiology*
;
Singapore/epidemiology*
;
Proportional Hazards Models
;
Diabetes Mellitus/epidemiology*
2.Clinical profile and outcomes in patients with moderate to severe aortic stenosis with or without concomitant chronic kidney disease.
Jinghao Nicholas NGIAM ; Ching-Hui SIA ; Nicholas Wen Sheng CHEW ; Tze Sian LIONG ; Zi Yun CHANG ; Chi Hang LEE ; Wen RUAN ; Edgar Lik-Wui TAY ; William Kok-Fai KONG ; Huay Cheem TAN ; Tiong-Cheng YEO ; Kian Keong POH
Singapore medical journal 2024;65(11):624-630
INTRODUCTION:
Management of aortic stenosis (AS) in patients with chronic kidney disease (CKD) may often be overlooked, and this could confer poorer outcomes.
METHODS:
Consecutive patients ( n = 727) with index echocardiographic diagnosis of moderate to severe AS (aortic valve area <1.5 cm 2 ) were examined. They were divided into those with CKD (estimated glomerular filtration rate < 60 mL/min) and those without. Baseline clinical and echocardiographic parameters were compared, and a multivariate Cox regression model was constructed. Clinical outcomes were compared using Kaplan-Meier curves.
RESULTS:
There were 270 (37.1%) patients with concomitant CKD. The CKD group was older (78.0 ± 10.3 vs. 72.1 ± 12.9 years, P < 0.001), with a higher prevalence of hypertension, diabetes mellitus, hyperlipidaemia and ischaemic heart disease. AS severity did not differ significantly, but left ventricular (LV) mass index (119.4 ± 43.7 vs. 112.3 ± 40.6 g/m 2 , P = 0.027) and Doppler mitral inflow E to annular tissue Doppler e' ratio (E: e' 21.5 ± 14.6 vs. 17.8 ± 12.2, P = 0.001) were higher in the CKD group. There was higher mortality (log-rank 51.5, P < 0.001) and more frequent admissions for cardiac failure (log-rank 25.9, P < 0.001) in the CKD group, with a lower incidence of aortic valve replacement (log-rank 7.12, P = 0.008). On multivariate analyses, after adjusting for aortic valve area, age, left ventricular ejection fraction and clinical comorbidities, CKD remained independently associated with mortality (hazard ratio 1.96, 95% confidence interval 1.50-2.57, P < 0.001).
CONCLUSION
Concomitant CKD in patients with moderate to severe AS was associated with increased mortality, more frequent admissions for cardiac failure and a lower incidence of aortic valve replacement.
Humans
;
Aortic Valve Stenosis/surgery*
;
Male
;
Female
;
Renal Insufficiency, Chronic/complications*
;
Aged
;
Aged, 80 and over
;
Middle Aged
;
Severity of Illness Index
;
Glomerular Filtration Rate
;
Proportional Hazards Models
;
Echocardiography
;
Kaplan-Meier Estimate
;
Retrospective Studies
;
Aortic Valve/surgery*
;
Echocardiography, Doppler
3.Association of face mask use with self-reported cardiovascular symptoms during the COVID-19 pandemic.
Nicholas Wen SHENG CHEW ; Raymond Ching CHIEW WONG ; Andie Hartanto DJOHAN ; Jinghao Nicholas NGIAM ; Ping CHAI ; Tiong-Cheng YEO ; Huay-Cheem TAN ; Ching-Hui SIA
Singapore medical journal 2023;64(10):609-615
INTRODUCTION:
Countries are mandating the use of face masks to stem the spread of coronavirus disease 2019 (COVID-19). Face mask use has been associated with discomfort due to its effects on thermoregulation, breathing and oxygenation. We evaluated the prevalence and severity of self-reported cardiovascular symptoms before and during face mask use.
METHODS:
This was a cross-sectional study of 1,001 participants residing in Singapore, who participated in a self-administered questionnaire between 25 April 2020 and 4 May 2020. Symptom severity before and during mask use, and health-seeking behaviour information were collected. The study outcome was self-reported worsening of cardiovascular symptoms and its association with the type of mask worn, duration of mask worn per day, and intensity of physical activities during mask use.
RESULTS:
The most common symptom reported during mask use was dyspnoea. Independent predictors for self-reported cardiovascular symptoms during mask use were moderate-high physical activity during mask use (odds ratio [OR] 1.634, 95% confidence interval [CI] 1.176-2.270, P = 0.003), duration of mask use for ≥3 h (OR 1.672, 95% CI 1.189-2.352, P = 0.003) and type of mask used, after adjusting for age, sex, healthcare-based worker status and presence of comorbidities. N95 mask was associated with worse symptoms when compared to surgical mask. Participants with ≥3 worsening symptoms or worsening dyspnoea, palpitations, fatigue and dizziness were more likely to seek medical help.
CONCLUSION
Face mask use has been proven to be an effective way in curbing COVID-19 transmission. However, participants in this study had concerns regarding its use and these concerns should be urgently addressed to enable mask use policies to be enacted.
Humans
;
COVID-19/epidemiology*
;
Pandemics
;
Masks/adverse effects*
;
Self Report
;
Cross-Sectional Studies
;
Dyspnea/etiology*
4.Rare
Nicholas W S CHEW ; Raymond C WONG ; William W F KONG ; Adrian LOW ; Huay Cheem TAN
Annals of the Academy of Medicine, Singapore 2021;50(8):655-656
5.Cost-Effectiveness of Transcatheter Aortic Valve Implantation in Intermediate and Low Risk Severe Aortic Stenosis Patients in Singapore.
Ivandito KUNTJORO ; Edgar TAY ; Jimmy HON ; James YIP ; William KONG ; Kian Keong POH ; Tiong Cheng YEO ; Huay Cheem TAN ; Michael George CALEB ; Nan LUO ; Pei WANG
Annals of the Academy of Medicine, Singapore 2020;49(7):423-433
INTRODUCTION:
Singapore has the world's second most efficient healthcare system while costing less than 5% GDP. It remains unclear whether transcatheter aortic valve implantation (TAVI) is cost-effective for treating intermediate-low risk severe aortic stenosis (AS) patients in a highly efficient healthcare system.
MATERIALS AND METHODS:
A two-phase economic model combining decision tree and Markov model was developed to assess the costs, effectiveness, and the incremental cost-effectiveness ratio (ICER) of transfemoral (TF) TAVI versus surgical aortic valve replacement (SAVR) in intermediate-low risk patients over an 8-year time horizon. Mortality and complications rates were based on PARTNER 2 trial cohort A and Singapore life table. Costs were mainly retrieved from Singapore National University Health System database. Health utility data were obtained from Singapore population based on the EuroQol-5D (EQ-5D). A variety of sensitivity analyses were conducted.
RESULTS:
In base case scenario, the incremental effectiveness of TF-TAVI versus SAVR was 0.19 QALYs. The ICER of TF-TAVI was S$33,833/QALY. When time horizon was reduced to 5 years, the ICER was S$60,825/QALY; when event rates from the propensity analysis was used, the ICER was S$21,732/QALY and S$44,598/QALY over 8-year and 5-year time horizons, respectively. At a willingness to pay threshold of S$73,167/QALY, TF-TAVI had a 98.19% probability of being cost-effective after 100,000 simulations. The model was the most sensitive to the costs of TF-TAVI procedure.
CONCLUSION
TF-TAVI is a highly cost-effective option compared to SAVR for intermediate-low risk severe AS patients from a Singapore healthcare system perspective. Increased procedure experience, reduction in device cost, and technology advance may have further increased the cost-effectiveness of TF-TAVI per scenario analysis.
6.Percutaneous pulmonary valve implantation as an alternative to repeat open-heart surgery for patients with pulmonary outflow obstruction: a reality in Singapore.
Lik Wui Edgar TAY ; Wei Luen James YIP ; Ting Ting LOW ; Chin Ling William YIP ; Kok Fai William KONG ; Tiong Cheng YEO ; Huay Cheem TAN ; Shakeel Ahmed QUERESHI ; Swee Chye QUEK
Singapore medical journal 2019;60(5):260-264
Right ventricle to pulmonary artery (RV-PA) conduits have been used for the surgical repair of congenital heart defects. These conduits frequently become stenosed or develop insufficiency with time, necessitating reoperations. Percutanous pulmonary valve implantation (PPVI) can delay the need for repeated surgeries in patients with congenital heart defects and degenerated RV-PA conduits. We presented our first experience with PPVI and described in detail the procedural methods and the considerations that are needed for this intervention to be successful. Immediate and short-term clinical outcomes of our patients were reported. Good haemodynamic results were obtained, both angiographically and on echocardiography. PPVI provides an excellent alternative to repeat open-heart surgery for patients with congenital heart defects and degenerated RV-PA conduits. This represents a paradigm shift in the management of congenital heart disease, which is traditionally managed by open-heart surgery.
7.Ethnic Differences and Trends in ST-Segment Elevation Myocardial Infarction Incidence and Mortality in a Multi-Ethnic Population.
Huili ZHENG ; Pin Pin PEK ; Andrew Fw HO ; Win WAH ; Ling Li FOO ; Jessie Q LI ; Vasuki UTRAVATHY ; Terrance Sj CHUA ; Huay Cheem TAN ; Marcus Eh ONG
Annals of the Academy of Medicine, Singapore 2019;48(3):75-85
INTRODUCTION:
This study aimed to compare the incidence and mortality of ST-segment elevation myocardial infarction (STEMI) across the 3 main ethnic groups in Singapore, determine if there is any improvement in trends over the years and postulate the reasons underlying the ethnic disparity.
MATERIALS AND METHODS:
This study consisted of 16,983 consecutive STEMI patients who sought treatment from all public hospitals in Singapore from 2007 to 2014.
RESULTS:
Compared to the Chinese (58 per 100,000 population in 2014), higher STEMI incidence rate was consistently observed in the Malays (114 per 100,000 population) and Indians (126 per 100,000 population). While the incidence rate for the Chinese and Indians remained relatively stable over the years, the incidence rate for the Malays rose slightly. Relative to the Indians (30-day and 1-year all-cause mortality at 9% and 13%, respectively, in 2014), higher 30-day and 1-year all-cause mortality rates were observed in the Chinese (15% and 21%) and Malays (13% and 18%). Besides the Malays having higher adjusted 1-year all-cause mortality, all other ethnic disparities in 30-day and 1-year mortality risk were attenuated after adjusting for demographics, comorbidities and primary percutaneous coronary intervention.
CONCLUSION
It is important to continuously evaluate the effectiveness of existing programmes and practices as the aetiology of STEMI evolves with time, and to strike a balance between prevention and management efforts as well as between improving the outcome of "poorer" and "better" STEMI survivors with finite resources.

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