Evaluating the Coronary Artery Disease Consortium Model and the Coronary Artery Calcium Score in Predicting Obstructive Coronary Artery Disease in a Symptomatic Mixed Asian Cohort.

Background The utility of a given pretest probability score in predicting obstructive coronary artery disease (CAD) is population dependent. Previous studies investigating the additive value of coronary artery calcium (CAC) on pretest probability scores were predominantly limited to Western populations. This retrospective study seeks to evaluate the CAD Consortium (CAD2) model in a mixed Asian cohort within Singapore with stable chest pain and to evaluate the incremental value of CAC in predicting obstructive CAD. Methods and Results Patients who underwent cardiac computed tomography and had chest pain were included. The CAD2 clinical model comprised of age, sex, symptom typicality, diabetes, hypertension, hyperlipidemia, and smoking status and was compared with the CAD2 extended model that added CAC to assess the incremental value of CAC scoring, as well as to the corresponding locally calibrated local assessment of the heart models. A total of 522 patients were analyzed (mean age 54±11 years, 43.1% female). The CAD2 clinical model obtained an area under the curve of 0.718 (95% CI, 0.668-0.767). The inclusion of CAC score improved the area under the curve to 0.896 (95% CI, 0.867-0.925) in the CAD2 models and from 0.767 (95% CI, 0.721-0.814) to 0.926 (95% CI, 0.900-0.951) in the local assessment of the heart models. The locally calibrated local assessment of the heart models showed better discriminative performance than the corresponding CAD2 models (P<0.05 for all). Conclusions The CAD2 model was validated in a symptomatic mixed Asian cohort and local calibration further improved performance. CAC scoring provided significant incremental value in predicting obstructive CAD.

Patterns of motivators and barriers to heart health behaviors among adults with behavior-modifiable cardiovascular risk factors: A population-based survey in Singapore.

OBJECTIVES: Motivators and barriers are pivotal factors in the adoption of health behaviors. This study aims to identify patterns of the motivators and barriers influencing heart health behaviors among multi-ethnic Asian adults with behavior-modifiable risk factors for heart disease, namely obesity, physical inactivity and smoking. METHODS: A population-based survey of 1,000 participants was conducted in Singapore. Participants were assessed for behavior-modifiable risk factors and asked about motivators and barriers to heart health behaviors. Exploratory and confirmatory factor analyses were conducted to identify factors underlying motivator and barrier question items. Logistic regression was conducted to examine the associations of motivator and barrier factors with sociodemographic characteristics. RESULTS: The twenty-five motivator and barrier items were classified into three (outcome expectations, external cues and significant others including family and friends) and four (external circumstances, limited self-efficacy and competence, lack of perceived susceptibility, benefits and intentions and perceived lack of physical capability) factors respectively. Among participants with behavior-modifiable risk factors, those with lower education were more likely to be low in motivation factor of "outcome expectations" and "external cues". The well-educated were more likely to be high in the barrier factor of "lack of perceived susceptibility, benefits and intention" and were less likely to have the motivation factor of "significant others (family or friends)". Those aged 60-75 years had low motivations and high barriers compared to their younger counterparts. Older age was more likely to be low in motivation factor of "outcome expectations" and "external cues" and high in barrier factor of "limited self-efficacy and competence" and "perceived lack of physical capability". CONCLUSIONS: Findings underscore the importance of a targeted intervention and communication strategy addressing specific motivation and barrier factors in different population segments with modifiable risk factors.

Public perceptions and knowledge of cholesterol management in a multi-ethnic Asian population: A population-based survey.

INTRODUCTION: Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. Hyperlipidemia is one of the important modifiable risk factors for CVDs. Raising public awareness of CVD risks is an important step in reducing CVD burdens. In this study, we aimed to assess public awareness and knowledge of cholesterol and its management in a multiethnic Asian population. METHODS: We recruited 1000 participants from three major ethnic groups for this nationwide population-based survey. A structured questionnaire was used to collect socio-demographics, knowledge of cholesterol and cholesterol-lowering medications. Univariate and multivariate analyses were conducted to identify factors associated with good knowledge on cholesterol and its management. RESULTS: Of the participants, 65% thought that high cholesterol produces symptoms and that lifestyle modification would be as effective as medication at lowering cholesterol. Nearly 70% believed that long term statin could lead to kidney or liver damage, and 56% thought that statin was associated with higher risk of cancer. A third saw herbal medicine or supplements as healthier and safer. About 45% believed that statin therapy should not be taken long term and that one could stop taking cholesterol medication when cholesterol is under control. Malays were more likely to have poor knowledge (adjusted OR 0.68; 95% CI 0.47-0.98; P = 0.039) compared to Chinese. Participants with intermediate education were more likely to have good knowledge of cholesterol and its management (adjusted OR 1.67; 95% CI 1.11-2.51; P = 0.013) compared to those with primary education. CONCLUSION: Public knowledge and awareness of high cholesterol and its management remains poor in Asian multi-ethnic population. Understanding gaps in public knowledge can inform the implementation of health promotion programs to effectively raise awareness of cholesterol and its management.

Adding Coronary Calcium Score to Exercise Treadmill Test: An Alternative to Refine Coronary Artery Disease Risk Stratification in Patients with Intermediate Risk Chest Pain.

Introduction: Chest pain is a common symptom for cardiology referrals. The ACC-AHA guidelines recommend exercise stress electrocardiography (TMX) as the initial diagnostic test. However, the TMX only has moderate sensitivity and non-diagnostic cases may require further stress imaging studies. In this study we aimed to look at the feasibility of combining coronary artery calcium (CAC) score with TMX to refine risk stratification. This may be an alternative to stress imaging in cases of non low-risk TMX, with the added advantage of short time turnaround time and low radiation dose. Methods: A total of 145 patients who presented consecutively to the National Heart Centre Singapore with chest pain were included in this study. These were intermediate risk patients with an average Duke Clinical Score of 38.8%. All patients underwent both TMX and computed tomography scan of the coronary arteries (CTCA) which also includes CAC. The primary outcome was defined as obstructive coronary artery disease i.e. >50% left main artery stenosis and/or >70% stenosis in other epicardial arteries. Results: The combination of TMX and CAC was comparable to stress imaging in detecting obstructive coronary artery disease. When added to TMX, CAC has an integrated discriminative improvement of 74.1%, achieved an area under the curve of 0.974 and adjusted R2 of 0.670 in detecting the primary outcome. Conclusion: The strategy of combining TMX and CAC is feasible in clinical practice to refine risk stratification in outpatients with intermediate risk chest pain. The calcium score readout also further guides therapy for primary prevention. Highlights: Treadmill exercise is one of the first line tests for cardiac chest pain work up.Non diagnostic test treadmill results requires further adjunctive tests.Downstream stress imaging causes delay in time to diagnosis.Coronary artery calcium scoring needs minimal preparation with fast turnaround time.Addition of coronary artery calcium to treadmill performs comparably to stress imaging.This is a feasible alternative to risk stratify non diagnostic treadmill tests and guide therapy for primary prevention.

Harnessing technology and molecular analysis to understand the development of cardiovascular diseases in Asia: a prospective cohort study (SingHEART).

BACKGROUND: Cardiovascular disease (CVD) imposes much mortality and morbidity worldwide. The use of "deep learning", advancements in genomics, metabolomics, proteomics and devices like wearables have the potential to unearth new insights in the field of cardiology. Currently, in Asia, there are no studies that combine the use of conventional clinical information with these advanced technologies. We aim to harness these new technologies to understand the development of cardiovascular disease in Asia. METHODS: Singapore is a multi-ethnic country in Asia with well-represented diverse ethnicities including Chinese, Malays and Indians. The SingHEART study is the first technology driven multi-ethnic prospective population-based study of healthy Asians. Healthy male and female subjects aged 21-69 years old without any prior cardiovascular disease or diabetes mellitus will be recruited from the general population. All subjects are consented to undergo a detailed on-line questionnaire, basic blood investigations, resting and continuous electrocardiogram and blood pressure monitoring, activity and sleep tracking, calcium score, cardiac magnetic resonance imaging, whole genome sequencing and lipidomic analysis. Outcomes studied will include mortality and cause of mortality, myocardial infarction, stroke, malignancy, heart failure, and the development of co-morbidities. DISCUSSION: An initial target of 2500 patients has been set. From October 2015 to May 2017, an initial 683 subjects have been recruited and have completed the initial work-up the SingHEART project is the first contemporary population-based study in Asia that will include whole genome sequencing and deep phenotyping: including advanced imaging and wearable data, to better understand the development of cardiovascular disease across different ethnic groups in Asia.

Percutaneous Decommissioning of Left Ventricular Assist Device.

BACKGROUND: The left ventricular assist device (LVAD) has revolutionised our treatment of advanced stage heart failure, giving debilitated patients a new lease on life. A small proportion of these LVAD patients can be bridged-to-recovery. The identification of these patients and decision to wean, however, can be challenging. METHODS: The need to fully explant the device upon recovery has evolved to a minimalist approach aiming to avoid injury to the 'recovered' heart. A review of the evolution of explant strategies was performed to guide our decision to wean the LVAD in our early experience. RESULTS: Between 2009 and 2014, two patients in our series of 69 LVAD implants (2.9%) were successfully weaned off their LVADs. The second patient had a minimal access implantation of his HeartWare Ventricular Assist Device (HVAD, Medtronic Inc, Framingham, MA, USA). His clinical variables and minimalist weaning strategy are described. CONCLUSIONS: A case of LVAD decommissioning by thrombosis of the outflow graft, using percutaneous Amplatzer Vascular Plug II (St. Jude Medical, St. Paul, MN, USA) without surgery is reported.

Abnormal origin of right coronary artery from left ventricle with bicuspid aortic stenosis.

Anomalous coronary arteries are rare but can lead to serious complications during cardiac operations if not recognized. We report a 55-year-old woman with anomalous origin of the right coronary artery from the left ventricle, and bicuspid aortic valve stenosis. Coronary angiography and computerized tomographic angiography indicated the diagnosis preoperatively. She underwent aortic valve replacement and coronary artery bypass grafting subsequently, with good recovery. One adult and two children with the same right coronary artery anomaly have been reported in the literature. Preoperative diagnosis is essential in these cases, and long-term follow-up is warranted.

Iliofemoral anatomy among Asians: implications for transcatheter aortic valve implantation.

BACKGROUND/OBJECTIVES: This study aims to examine iliofemoral anatomy and predictors of vessel size and tortuosity in Asian patients as transfemoral transcatheter aortic valve implantation (TAVI) may be limited by the smaller Asian physique. METHODS: Characteristics and vessel dimensions of 549 patients undergoing ultrasonography were reviewed. The minimal luminal diameter (MLD) along the iliofemoral vasculature of each side was identified and the larger of the two sides was used to determine suitability for transfemoral TAVI. RESULTS: The mean age was 66 ± 11 years (68% males). Mean iliac MLD was 7.6 ± 1.7 mm, females smaller than males (7.2 ± 1.7 vs 7.8 ± 1.7, p<0.001). Mean iliac MLD decreased with age: 7.9 ± 1.7 mm, 7.4 ± 1.9 mm and 7.3 ± 1.6mm for ages <70 years, 70-79 years and ≥ 80 years respectively (p=0.038). Mean femoral MLD was 7.0 ± 1.7 mm, females smaller than males (6.3 ± 1.5mm vs 7.3 ± 1.8mm, p<0.001). Females were more likely than males to have iliac and femoral MLD <6mm (20% vs 12%, p=0.019 and 34% vs 21%, p=0.001). Independent predictors of smaller iliofemoral dimensions were female gender, lower body surface area, diabetes mellitus, dyslipidemia and smoking history. Significant iliac tortuosity was present in 11.8%, more frequent in males than females (15% vs 6%, p=0.005), and in those with logistic EuroSCORE ≥ 15 than <15 (27% vs 10%, p=0.001). CONCLUSIONS: This study establishes the mean iliac and femoral artery diameters in a cohort of relatively young Asian patients. Age and female gender were associated with smaller vessel dimension and several independent predictors of smaller vasculature and tortuosity were identified. These results have implications for TF TAVI in Asia.