Singapore Heart Research Articles

Distinguishing heart failure with reduced ejection fraction from heart failure with preserved ejection fraction: A phenomics approach.

Pathophysiological differences between patients with heart failure with preserved (HFpEF) and reduced (HFrEF) ejection fraction (EF) remain unclear. Therefore we used a phenomics approach, integrating selected proteomics data with patient characteristics and cardiac structural and functional parameters, to get insight into differential pathophysiological mechanisms and identify potential treatment targets. We report data from a representative subcohort of the prospective Singapore Heart Failure Outcomes and Phenotypes (SHOP), including patients with HFrEF (EF <40%, n = 217), HFpEF (EF ≥50%, n = 213), and age- and sex-matched controls without HF (n = 216). We measured 92 biomarkers using a proximity extension assay and assessed cardiac structure and function in all participants using echocardiography. We used multi-block projection to latent structure analysis to integrate clinical, echocardiographic, and biomarker variables. Candidate biomarker targets were cross-referenced with small-molecule and drug databases. The total cohort had a median age of 65 years (interquartile range 60-71), and 50% were women. Protein profiles strongly discriminated patients with HFrEF (area under the curve [AUC] = 0.89) and HFpEF (AUC = 0.94) from controls. Phenomics analyses identified unique druggable inflammatory markers in HFpEF from the tumour necrosis factor receptor superfamily (TNFRSF), which were positively associated with hypertension, diabetes, and increased posterior and relative wall thickness. In HFrEF, interleukin (IL)-8 and IL-6 were possible targets related to lower EF and worsening renal function. We identified pathophysiological mechanisms related to increased cardiac wall thickness parameters and potentially druggable inflammatory markers from the TNFRSF in HFpEF.

Strategies to prevent cardiovascular disease in Singapore: A call to action from Singapore Heart Foundation, Singapore Cardiac Society and Chapter of Cardiologists of the Academy of Medicine, Singapore.

In 2022, the Minister for Health of Singapore launched Healthier SG, a national strategy in championing the shift towards a population health approach. The Singapore Heart Foundation conducted a series of roundtable discussions, also attended by representatives of the Singapore Cardiac Society and the Chapter of Cardiologists of the Academy of Medicine Singapore. During the meetings, the authors formulated interventions supportive of Healthier SG that specifically aimed to uplift the state of cardiovascular (CV) preventive care in Singapore. In line with Healthier SG, the authors propose a 3-pronged approach ("Healthier Heart SG") to augment the success of Healthier SG in achieving good CV outcomes. This proposal includes the following components: (1) a call to update the standards of care in addressing the 5 main modifiable risk factors of cardiovascular disease (CVD); (2) patient education through cooperation between healthcare professionals and community partners for a whole-of-system approach; and (3) support for integrated care, including access to cardiac rehabilitation in the community, improved referral processes and access to nutrition/dietetics counselling and tobacco cessation, optimal use of information technology, and continued CV research. Healthier Heart SG would bring the standards of care and CV care delivery in Singapore closer to achieving the vision of proactive prevention of CVD and CV morbidity and mortality. This can only be achieved through the concerted efforts of healthcare professionals, policymakers and community partners, coupled with the cooperation of community members.

The Singapore Heart Failure Risk Score: Prediction of Survival in Southeast Asian Patients

Numerous heart failure risk scores have been developed but there is none for Asians. We aimed to develop a risk calculator, the Singapore Heart Failure Risk Score, to predict 1- and 2-year survival in Southeast Asian patients hospitalised for heart failure. Consecutive patients admitted for heart failure were identified from the Singapore Cardiac Databank Heart Failure registry. The follow-up was 2 to 4 years and mortality was obtained from national registries. The derivation (2008-2009) and 2 validation cohorts (2008-2009, 2013) included 1392, 729 and 804 patients, respectively. Ten variables were ultimately included in the risk model: age, prior myocardial infarction, prior stroke, atrial fibrillation, peripheral vascular disease, systolic blood pressure, QRS duration, ejection fraction and creatinine and sodium levels. In the derivation cohort, predicted 1- and 2-year survival was 79.1% and 68.1% compared to actual 1- and 2-year survival of 78.2% and 67.9%. There was good agreement between the predicted and observed mortality rates (Hosmer-Lemeshow statistic = 14.36, P = 0.073). C-statistics for 2-year mortality in the derivation and validation cohorts were 0.73 (95% CI, 0.70-0.75) and 0.68 (95% CI, 0.64-0.72), respectively. We provided a risk score based on readily available clinical characteristics to predict 1- and 2-year survival in Southeast Asian patients hospitalised for heart failure via a simple online risk calculator, the Singapore Heart Failure Risk Score.

N‐terminal pro‐B‐type natriuretic peptide and prognosis in Caucasian vs. Asian patients with heart failure

AimsN‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) is the most frequently used biomarker in heart failure (HF), but its prognostic utility across ethnicities is unclear.Methods and resultsThis study included 546 Caucasians with HF from the Coordinating Study Evaluating Outcomes of Advising and Counseling in Heart Failure and 578 Asians with HF from the Singapore Heart Failure Outcomes and Phenotypes study. NT‐proBNP was measured at discharge after HF hospitalization. The studied outcome was a composite of all‐cause mortality and HF hospitalization at 18 months. Compared with Caucasian patients, Asian patients were younger (63 ± 12 vs. 71 ± 11 years); less often female (26% vs. 39%); and had lower body mass index (26 vs. 27 kg/m2), better renal function (61 ± 37 vs. 54 ± 20 mL/min/1.73 m2), lower rates of atrial fibrillation (25% vs. 46%), strikingly higher rates of diabetes (59% vs. 30%), and higher rates of hypertension (76% vs. 44%). Despite these clear inter‐group differences in individual drivers of NT‐proBNP, average levels were similar in Asians [2709 (1350, 6302) pg/mL] and Caucasians [2545 (1308, 5484) pg/mL] (P = 0.514). NT‐proBNP was strongly associated with outcome [hazard ratio 1.28 (per doubling), 95% confidence interval 1.18–1.39, P < 0.001], regardless of ethnicity (P interaction = 0.719). NT‐proBNP was similarly associated with outcome in HF with reduced and preserved ejection fraction in Asian (P interaction = 0.776) and Caucasian patients (P interaction = 0.558).ConclusionsNT‐proBNP has similar prognostic performance in Asians and Caucasians with HF despite ethnic differences in known clinical determinants of plasma NT‐proBNP.

The association between distance to public amenities and cardiovascular risk factors among lower income Singaporeans.

Existing evidence on the association between built environment and cardiovascular disease (CVD) risk factors focused on the general population, which may not generalize to higher risk subgroups such as those with lower socio-economic status (SES). We examined the associations between distance to 5 public amenities from residential housing (public polyclinic, subsidized private clinic, healthier eatery, public park and train station) and 12 CVD risk factors (physical inactivity, medical histories and unhealthy dietary habits) among a study sample of low income Singaporeans aged ≥ 40 years (N = 1972). Using data from the Singapore Heart Foundation Health Mapping Exercise 2013–2015, we performed a series of logistic mixed effect regressions, accounting for clustering of respondents in residential blocks and multiple comparisons. Each regression analysis used the minimum distance (in km) between residential housing and each public amenity as an independent continuous variable and a single risk factor as the dependent variable, controlling for demographic characteristics. Increased distance (geographical inaccessibility) to a train station was significantly associated with lower odds of participation in sports whereas greater distance to a subsidized private clinic was associated with lower odds of having high cholesterol diagnosed. Increasing distance to park was positively associated with higher odds of less vegetable and fruits consumption, deep fried food and fast food consumption in the preceding week/month, high BMI at screening and history of diabetes, albeit not achieving statistical significance. Our findings highlighted potential effects of health-promoting amenities on CVD risk factors in urban low-income setting, suggesting gaps for further investigations.

The prognostic value of highly sensitive cardiac troponin assays for adverse events in men and women with stable heart failure and a preserved vs. reduced ejection fraction.

Circulating biomarkers are important in the diagnosis, risk stratification and management of patients with heart failure (HF). Given the current lack of biomarkers in HF with preserved ejection fraction (HFpEF), we aimed to investigate the prognostic performance of the newly developed high-sensitivity (hs) assays for cardiac troponin I (hsTnI) compared with troponin T (hsTnT) for adverse events in HFpEF vs. HF with reduced ejection fraction (HFrEF). Findings in these two HF subgroups were also compared with those in the recently defined HF with mid-range ejection fraction (HFmrEF) subgroup. Both hsTnI and hsTnT were measured in 1096 patients with HFrEF [left ventricular ejection fraction (LVEF) <50%; n = 853] or HFpEF (LVEF ≥50%; n = 243) enrolled in the Singapore Heart Failure Outcomes and Phenotypes (SHOP) study. Both troponin assays were more strongly associated with the composite endpoint (all-cause mortality or first rehospitalization for HF) in HFpEF than in HFrEF. The hsTnT assay provided the greatest additional prognostic value in HFpEF in comparison with hsTnI and NT-proBNP. TnI was more strongly associated with composite events in men with HFpEF [hazard ratio (HR) 3.33, 95% confidence interval (CI) 1.82-6.09; P < 0.001 per standard deviation (SD) increase in log-transformed hsTnI] than in women with HFpEF (HR 1.35, 95% CI 0.94-1.93; P = 0.10 per SD increase in log-transformed hsTnI). There is a potential role for the prognostic use of high-sensitivity troponin assays, particularly hsTnT, in men and women with HFpEF. The predictive association of hsTnI with outcome appears strongest in men with HFpEF.

Exploring Product-Specific Attributes of a Community Cardiac Rehabilitation Program in an Asian Urban City

BackgroundCardiac rehabilitation (CR) has been proven to improve long-term outcomes for patients. Despite its benefits, its uptake throughout the world is poor. Factors affecting the motivation and barriers impeding an individual from participating in a CR program have been extensively studied. Nevertheless, knowledge of product-specific factors in affecting participation is lacking. ObjectivesTo find out cultural-specific product attributes that are important to those contemplating participation in a community-based CR program using Consolidated criteria for Reporting Qualitative research (COREQ) as an anchor. MethodsParticipants were recruited from attendees of the CR program at the Singapore Heart Foundation. A literature review was done to identify product-specific attributes that affected participation in CR programs. An interview guide was developed on the basis of the list of product attributes. The analysis was done by two independent analysts using NVivo version 11 (QSR International, Melbourne, Australia) via an inductive approach. Data analysis was carried out with recruitment and interviews ongoing until thematic saturation was reached. ResultsIn total, 13 male and 9 female participants (16 Chinese, 4 Indian, 1 Malay, and 1 Eurasian) aged between 47 and 89 years were interviewed. A total of 8 categories (System, Infrastructure, Environment, Monitoring, Activity, Program, Staff, and Companionship) with 30 subcategories were identified. New themes that have not been explored by previous studies were discovered under five different categories: System, Infrastructure, Environment, Program, and Companionship. ConclusionsThis study allows a better understanding of product-specific factors affecting participation in CR programs and serves as a springboard for further research to improve participation in community-based CR programs.

Effect of Catchment-Scale Green Roof Deployment on Stormwater Generation and Reuse in a Tropical City

Low-impact development (LID) comprises a broad spectrum of stormwater management technologies for mitigating the impacts of urbanization on hydrological processes. Among these technologies, green roofs are one of the most adopted solutions, especially in densely populated metropolitan areas, where roofs take up a significant portion of the impervious surfaces and land areas are scarce. While the in situ hydrological performance of green roofs—i.e., reduction of runoff volume and peak discharge—is well addressed in literature, less is known about their impact on stormwater management and reuse activities at a catchment or city scale. This study developed an integrated urban water cycle model (IUWCM) to quantitatively assess the effect of uniform green roof deployment (i.e., 25, 50, and 100% conversion of traditional roofs) over the period 2009–2011 in the Marina Reservoir catchment, a 100-km2, highly urbanized area located in the heart of Singapore. The IUWCM consists of two components: (1) a physically based model for extensive green roofs integrated within a one-dimensional numerical hydrological-hydraulic catchment model linked with (2) an optimization-based model describing the operation of the downstream, stormwater-fed reservoir. The event-based hydrological performance of green roofs varied significantly throughout the simulation period with a median of about 5% and 12% for the catchment scale reduction of runoff volume and peak discharge (100% conversion of traditional roofs). The high variability and lower performance (with respect to temperate climates) are strongly related to the tropical weather and climatic conditions—e.g., antecedent dry weather period and maximum rainfall intensity. Average annual volume reductions were 0.6, 1.2, and 2.4% for the 25, 50, and 100% green roof scenarios, respectively. The reduction of the stormwater generated at the catchment level through green roof implementation had a positive impact on flood protection along Marina Reservoir shores and the energy costs encountered when operating the reservoir. Vice versa, the drinking water supply, which depends on the amount of available stormwater, decreased due to the evapotranspiration losses from green roofs. Better performance in terms of stormwater reuse could only be obtained by increasing the time of concentration of the catchment. This may be achieved through the combination of green roofs with other LID structures.

The Singapore Heart Failure Outcomes and Phenotypes (SHOP) Study and Prospective Evaluation of Outcome in Patients With Heart Failure With Preserved Left Ventricular Ejection Fraction (PEOPLE) Study: Rationale and Design

BackgroundHeart failure (HF) with preserved ejection fraction (EF) accounts for a substantial proportion of cases of HF, and to date no treatments have clearly improved outcome. There are also little data comparing HF cohorts of differing ethnicity within the Asia-Pacific region. MethodsThe Singapore Heart Failure Outcomes and Phenotypes (SHOP) study and Prospective Evaluation of Outcome in Patients with Heart Failure with Preserved Left Ventricular Ejection Fraction (PEOPLE) study are parallel prospective studies using identical protocols to enroll patients with HF across 6 centers in Singapore and 4 in New Zealand. The objectives are to determine the relative prevalence, characteristics, and outcomes of patients with HF and preserved EF (EF ≥50%) compared with those with HF and reduced EF, and to determine initial data on ethnic differences within and between New Zealand and Singapore. Case subjects (n = 2,500) are patients hospitalized with a primary diagnosis of HF or attending outpatient clinics for management of HF within 6 months of HF decompensation. Control subjects are age- and gender-matched community-based adults without HF from Singapore (n = 1,250) and New Zealand (n = 1,073). All participants undergo detailed clinical assessment, echocardiography, and blood biomarker measurements at baseline, 6 weeks, and 6 months, and are followed over 2 years for death or hospitalization. Substudies include vascular assessment, cardiopulmonary exercise testing, retinal imaging, and cardiac magnetic resonance imaging. ConclusionsThe SHOP and PEOPLE studies are the first prospective multicenter studies defining the epidemiology and interethnic differences among patients with HF in the Asia-Oceanic region, and will provide unique insights into the pathophysiology and outcomes for these patients.

Public perceptions, knowledge and awareness of cholesterol management in Singapore: a prospective pilot study

Hyperlipidaemia is a major risk factor for coronary artery disease (CAD). Its effective treatment has been shown to reduce the incidence of cardiovascular events, both in secondary and primary prevention. An essential component of risk factor management at the community level is public awareness and knowledge of treatment benefits. However, this data is limited in Singapore. A cross-sectional survey questionnaire of public perception and knowledge on cholesterol treatment among adult Singaporeans aged 30-69 years was commissioned by the Singapore Heart Foundation and conducted by a professional market survey company. Regional quota sampling was performed to ensure that the sample was representative of the Singapore population. This was followed by random sampling of households and respondents. Of the 365 respondents, 40.9% were male, 70.3% were Chinese, 18.8% Malay and 10.9% Indian. The mean age was 47.5 years. Although 81.9% of respondents had medical check-ups involving blood tests, only 11.0% knew their actual cholesterol levels. A third of the respondents saw herbal medicine as healthier and safer than Western medication. More than 80% of respondents believed that diet and exercise were equally effective at lowering cholesterol as medication. About half of the respondents associated long-term use of statins with damage to the liver and kidney, while a third associated chronic statin use with the development of cancer. There are gaps in the level of public awareness and understanding of cholesterol treatment in Singapore. Common misconceptions should be addressed, as they could potentially impair effective management or treatment compliance.

Managing Water Quality in Gardens by the Bay

The Gardens by the Bay, a visionary cluster of three distinctive waterfront gardens in the heart of the city of Singapore, epitomizes the nation’s vision of ultimately being a city in a garden. Covering 101 hectares (249.57 acres) of land at Marina Bay, the site is comprised of the Gardens at Marina South (Bay South), Gardens at Marina East (Bay East) and Gardens at Marina Centre (Bay Central). When complete, the gardens will capture the essence of Singapore as a premier tropical garden city with an ideal environment in which to live and work, showcasing the application of cutting-edge innovations in environmentally friendly technology, sustainable natural resource management internationally. Bay South is located in the heart of Singapore’s new downtown. With an area of 54 hectares (133.43 acres), it incorporates two conservatories covering around 2.5 hectares (6.17 acres); steel ’SuperTree‘ structures that are 30 to 50 meters (98.42 to 164.04 feet) tall and clad with vertical green and floral displays; a series of theme gardens; open green spaces; a network of paved areas and a lake system. The lake system is about five hectares

Capital and the Transfiguring Monumentality of Raffles Hotel

Celebrated as a leading luxury hotel in the world, the Raffles Hotel stands as a monument to Singapore’s status as a global city of commerce. The century‐old Hotel also represents successful postcolonial heritage conservation. Drawing from archival and published sources, I analyze the Hotel as a changing cultural form in the historical transformation of Singapore by the circuits of global capital, from imperial capitalism, through the postcolonial development of national capitalism, to the current phase of neoliberal globalization. Together with developments in the surrounding urban heart of Singapore, Raffles Hotel is a space of cultural disjuncture transfiguring through the three ages of capital. I argue that the Hotel took the dominant form of white male domesticity in British Singapore, nostalgic authenticity in the postcolonial period and cosmopolitan hybridity in the current global phase. In each phase, the form elided the racial, class, gender and sexual contradictions of transnational capital and produced social relations of relative mobility. It shows that the global city is not made by transnational capital but by the developmental state harnessing economic flows for global city‐making with the ensuing spatial‐cultural politics in tow.

Gardens by the Bay – Designing A Nation's Garden in the Heart of Singapore's Downtown

Gardens by the Bay – Designing A Nation's Garden in the Heart of Singapore's Downtown

Research Findings

Singapore Heart, Stroke and Cancer Center Conducts Research on CT Coronary Angiogram.

Singapore's focus on applications

The Institute of Bioengineering and Nanotechnology (IBN) is one of five nationally funded biomedical research institutes in Singapore. The institute's remit is to exploit opportunities presented by bioengineering and nanotechnology, and generate research breakthroughs that will impact positively on healthcare and quality of life. Research projects are consequently chosen for their commercial potential as much as their fundamental scientific interest. IBN is located in the heart of Singapore's new $300 million biomedical R&D complex known as the Biopolis. The Biopolis houses key government agencies, numerous R&D laboratories belonging to pharmaceutical and biotechnological companies, and public research institutes. This mix of public and private research has been designed to encourage greater collaboration between Singapore's knowledge-creators and entrepreneurs, fostering an environment conducive to technology transfer.

ω-3 fatty acids and selenium as coronary heart disease risk modifying factors in Asian Indian and Chinese males

Objective Asian Indian men are reported to have a higher incidence of coronary heart disease than men of other ethnic groups worldwide. Among the many hypotheses, one possible risk factor may be related to their dietary habits. This study estimated the plasma concentrations of fatty acids, antioxidant vitamins, and selenium in Indians and Chinese of Singapore. Methods The study population consisted of 145 Indian men and 147 Chinese men ages 26 to 79 y from a cross-sectional survey, the National University of Singapore Heart Study. Results Our findings indicated that Indians had lower plasma concentrations of docosahexanoic acid (3.07% versus 3.54%, P < 0.001), α-linolenic acid (0.48% versus 0.57%, P < 0.001), and total ω-3 fatty acids (4.71% versus 5.27%, P < 0.001) than did the Chinese. Arachidonic acid was higher in Indians (4.83%) than in the Chinese (4.51%, P = 0.007). The ratio of ω-3 acid to ω-6 fatty acid was also lower in Indians (0.15) than in the Chinese (0.16, P = 0.007). There were no significant differences in the concentrations of monounsaturated fatty acids, but saturated fatty acids were higher in Indians (39.17%) than in the Chinese (38.28%, P < 0.001). Analysis of vitamins A, C, and E showed no significant differences between Indians (0.67, 5.72, and 13.04 mg/L, respectively) and Chinese (0.68, 6.48, and 12.71 mg/L, respectively); however, serum concentration of selenium in Indians (117.49 μg/L) was significantly lower than in the Chinese (126.72 μg/L, P < 0.001). Conclusion The results suggest that lower plasma concentrations of ω-3 fatty acids and selenium and higher concentrations of arachidonic acid and saturated fatty acids in Indians may reflect lower intakes of marine foods and, as a consequence, higher susceptibility to coronary heart disease.

Wessex Estate: Recollections of British Military and Imperial History in the Heart of Singapore

Although the island Republic of Singapore has been submitted to a systematic territorial revolution since the 1960s, some of its urban heritage has been preserved. This is the case with Wessex Estate, a quiet residential neighbourhood located in the low hills extending on the western flank of the central urban area. Made up of less than a dozen bungalows and 26 small blocks of flats, Wessex Estate is of no particular architectural interest, but it does represent a heritage through the names borne by the blocks of flats. Clearly printed on the façades of the 26 blocks of flats, these names all refer to military feats of British history. The study locates and briefly describes these events, several of which took place on European fronts, as far back as the early 18th century (such as Ramilies, Blenheim), others throughout the British Empire, starting from the middle of the same century (such as Plassey, Quebec, Khartoum, Pegu). Built just prior to or just following WWII, it seems that the flats housed non-commissioned British officers during the Malayan Emergency (1948–1960). Their names refer to battles or theatres of war in all of which a given British regiment, the 67th or South Hampshire Regiment, might have been involved. Whatever the case, it remains somewhat remarkable that so many reminders of the colonial past, even a good number with "no natural connection" to Singapore, have remained prominent in this city-state otherwise apparently prone to sever "colonial apron strings".

A case study of two tunnels driven in the Singapore ‘Boulder Bed’ and in grouted coral sands

Abstract As part of the construction of the Singapore Mass Rapid Transit, two tunnels had to be driven from a shaft to Raffles Place Station. Each drive was approximately 170 m long and was mostly in the Singapore ‘Boulder Bed’. This formation underlies much of the Central Business District of Singapore, and is thought to be a colluvial deposit comprising sandstone boulders in a stiff clay matrix The first 60 m of the upper tunnel had a mixed face with an old coral reef above axis and the Boulder Bed below it. The corals and sands of the reef were highly permeable and had to be injected with chemical grout before tunnelling commenced. The Raffles Place area is in the commercial heart of Singapore and the tunnels passed close to two high-rise buildings. One of these buildings had an underground car park within 5 m of the upper tunnel. Shield drives in the Boulder Bed had recorded high surface settlements, and there was concern about the underground car park which was known to be sensitive to settlement. It was proposed to drive the tunnels using the New Austrian Tunnelling Method, and one of the justifications for choosing the technique was that the resulting soil movements could be minimized. In order to check this claim surface settlement arrays, inclinometers and extensometers were installed to monitor movements caused by the tunnelling. Records of ground movements measured are presented, and compared with the movements recorded above shield driven tunnels in the same deposit. Methods of grouting and testing used in the coral and sands are also reported.