1.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
2.Help-seeking patterns and funding strategies in patients with pulmonary arterial hypertension on phosphodiesterase-5 inhibitors: an orphan disease with effective but costly treatment.
Yinghao LIM ; Siti Munawarah Bte MAAROOF ; Ting Ting LOW ; Ivandito KUNTJORO ; James Wl YIP ; Edgar TAY
Singapore medical journal 2021;62(4):199-203
INTRODUCTION:
Pulmonary arterial hypertension (PAH) is associated with high medical and pharmaceutical costs. Phosphodiesterase type 5 (PDE5) inhibitors have been found to be beneficial but costly. They are not subsidised in Singapore except via the Medication Assistance Fund (MAF) Plus scheme. In this study, we described the help-seeking behaviour of patients and funding strategies for Singaporean patients on PDE5 inhibitors in our registry.
METHODS:
We consecutively recruited all patients with PAH who presented to our pulmonary hypertension specialty centre between 1 January 2003 and 29 December 2016. Singaporean patients on PDE5 inhibitors were included. Data recorded and analysed for this study included baseline demographics, whether the patients received MAF Plus funding, percentage of funding, and any additional source of subsidies.
RESULTS:
114 (77.0%) of 148 patients in the registry were Singapore citizens on PDE5 inhibitors. 75 (65.8%) of these 114 patients had been seen by a medical social worker, of whom 16 were on MAF Plus funding. 14 of the remaining 59 patients were subsidised by MediFund, whereas the remainder were self-paying. 30 (26.3%) patients in total were on some form of subsidy, and 28 (24.6%) patients were on combination therapy. Of this group, nine were receiving MAF Plus subsidies.
CONCLUSION
Fewer than expected patients were found to be receiving drug subsidies for PAH. This was partly due to insufficient referrals and lack of requests for financial assistance. Patients on combination therapy had greater financial challenges. This study should spur us on to study funding gaps further and address them.
3.Chronic thromboembolic pulmonary hypertension: a review.
Cheryl Zhiya CHONG ; Edgar Lik Wui TAY ; Ching Hui SIA ; Kian Keong POH
Singapore medical journal 2021;62(7):318-325
Chronic thromboembolic pulmonary hypertension (CTEPH) is a unique form of pulmonary hypertension resulting from obstruction of the pulmonary artery by fibrotic thromboembolic material, usually initiated by recurrent or incomplete resolution of pulmonary embolism. This distinct form of pulmonary hypertension is classified under Group 4 of the World Health Organization classification. Further investigations are usually initiated, with transthoracic echocardiography followed by right heart catheterisation and pulmonary angiography as the gold standard. Definitive treatment is usually in the form of surgical pulmonary endarterectomy. Inoperable CTEPH is medically treated with pharmacological agents such as phosphodiesterase Type 5 inhibitors, endothelin receptor antagonists, soluble guanylate cyclase stimulators and prostacyclin. Recent developments have made balloon pulmonary angioplasty a viable option as well.
4.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.Electrocardiography findings and clinical presentation in Ebstein's anomaly.
Mayank DALAKOTI ; Devinder SINGH ; Wee Tiong YEO ; Lik Wui Edgar TAY ; Kian Keong POH
Singapore medical journal 2019;60(11):560-564
Ebstein's anomaly is a congenital malformation characterised by tricuspid valve pathology with right heart enlargement. Cases of Ebstein's anomaly can vary widely in severity, anatomy and presentation. In this article, we presented three cases of Ebstein's anomaly and discussed the presentation as well as electrocardiographic (ECG) changes. Patients may first present to their primary care physicians with cardiac symptoms such as reduced effort tolerance together with an abnormal ECG. ECG changes suggestive of right heart enlargement are important in the initial consideration and eventual formal diagnosis of the condition.
7.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.
9.Mid-term study of transcatheter aortic valve implantation in an Asian population with severe aortic stenosis: two-year Valve Academic Research Consortium-2 outcomes.
Nicholas CHEW ; Jimmy Kim Fatt HON ; Wei Luen James YIP ; Siew Pang CHAN ; Kian-Keong POH ; William Kok-Fai KONG ; Kristine Leok Kheng TEOH ; Tiong Cheng YEO ; Huay Cheem TAN ; Edgar Lik Wui TAY
Singapore medical journal 2017;58(9):543-550
INTRODUCTIONTranscatheter aortic valve implantation (TAVI) is an effective treatment for high-risk or inoperative patients with severe aortic stenosis. Given the unique characteristics of Asian populations, questions regarding mid-term outcomes in Asians undergoing TAVI have yet to be addressed. We evaluated the two-year clinical outcomes of TAVI in an Asian population using Valve Academic Research Consortium-2 definitions.
METHODSThis prospective study recruited 59 patients from a major academic medical centre in Singapore. The main outcomes were two-year survival rates, peri-procedural complications, symptom improvement, valvular function and assessment of learning curve.
RESULTSMean age was 76.8 years (61.0% male), mean body surface area 1.6 mand mean logistic EuroSCORE 18.7%. Survival was 93.2%, 86.0% and 79.1% at 30 days, one year and two years, respectively. At 30 days post TAVI, the rate of stroke was 1.7%, life-threatening bleeding 5.1%, acute kidney injury 25.0%, major vascular complication 5.1%, and new permanent pacemaker implantation 6.8%. 29.3% of TAVI patients were rehospitalised (47.1% cardiovascular-related) within one year. These composite outcomes were measured: device success (93.2%); early safety (79.7%); clinical efficacy (66.1%); and time-related valve safety (84.7%). Univariate analysis found these predictors of two-year all-cause mortality: logistic EuroSCORE (hazard ratio [HR] 1.07; p < 0.001); baseline estimated glomerular filtration rate (HR 0.97; p = 0.048); and acute kidney injury (HR 5.33; p = 0.022). Multivariate analysis identified non-transfemoral TAVI as a predictor of cardiovascular-related two-year mortality (HR 14.64; p = 0.008).
CONCLUSIONDespite the unique clinical differences in Asian populations, this registry demonstrated favourable mid-term clinical and safety outcomes in Asians undergoing TAVI.

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