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Biomedical subjects

Koon Teo

Publications and source records attributed to Koon Teo.

15 recordsLinked to original sources
PubMed2007

Carbohydrate intake and HDL in a multiethnic population.

BACKGROUND: Ethnic differences in serum lipids are not explained by genetics, central adiposity, lifestyle, or diet, possibly because dietary carbohydrate has not been considered. OBJECTIVE: The aim was to evaluate the relation between carbohydrate intake and HDL and triacylglycerol concentrations in a multiethnic population. DESIGN: We conducted a population-based cross-sectional study of 619 Canadians of Aboriginal, South Asian, Chinese, and European origin with no previously diagnosed medical conditions. Energy-adjusted carbohydrate intake was measured by a validated food-frequency questionnaire. RESULTS: South Asians consumed the most carbohydrate, followed by European, Aboriginal, and Chinese persons. Mean (95% CI) HDL concentrations in the lowest and highest categories of carbohydrate intake after adjustment for age, sex, ethnicity, physical activity, smoking, the waist-to-hip ratio, body mass index, alcohol intake, and intakes of total energy, protein, and fiber were 1.21 mmol/L (1.16, 1.27 mmol/L) and 1.08 mmol/L (1.02, 1.13 mmol/L), respectively, and HDL cholesterol was significantly (P < 0.01) higher in the lowest tertile of carbohydrate intake than in the highest tertile. High carbohydrate intake was associated with higher fasting triacylglycerols (P = 0.04); the adjusted mean fasting triacylglycerol concentrations in the lowest and highest categories of carbohydrate intake were 1.43 mmol/L (1.28, 1.60 mmol/L) and 1.71 mmol/L (1.57, 1.87 mmol/L), respectively. Fewer servings of sugar-containing soft drinks, juices, and snacks were associated with higher HDL (P for trend = 0.02); the multivariate-adjusted mean HDL in the lowest and highest categories of carbohydrate intake was 1.22 mmol/L (1.17, 1.27 mmol/L) and 1.11 mmol/L (1.06, 1.26 mmol/L), respectively. CONCLUSIONS: Differences in HDL and triacylglycerols observed in different ethnic groups may be due in part to carbohydrate intake. Reducing the frequency of intake of sugar-containing soft drinks, juices, and snacks may be beneficial.

Beverages↗
PubMed2006

Social disadvantage and cardiovascular disease: development of an index and analysis of age, sex, and ethnicity effects.

BACKGROUND: Social disadvantage is defined by adverse socio-economic characteristics and is distributed unequally by age, sex, and ethnicity. We studied the relationship between social disadvantage, cardiovascular risk factors, and cardiovascular disease (CVD) among men and women from diverse ethno-racial backgrounds. METHODS: A total of 1227 men and women of South Asian, Chinese, Aboriginal, and European ancestry were randomly selected from four communities in Canada to undergo a health assessment. Socio-economic factors, conventional and novel CV risk factors, atherosclerosis, and CVD were measured. A social disadvantage index was generated and included employment status, income, and marital status. Social disadvantage was examined in relation to risk factors for CVD, atherosclerosis, and prevalent CVD. RESULTS: Social disadvantage was higher among older people, women, and non-white ethnic groups. Cigarette smoking, glucose, overweight, abdominal obesity, and CRP were higher among individuals with higher social disadvantage, whereas systolic blood pressure, lipids, norepinephrine, and atherosclerosis were not. Social disadvantage is an independent predictor of CVD after adjustment for conventional and novel risk markers for CVD (OR for 1 point increase = 1.25; 95% CI 1.06-1.47). CONCLUSION: The social disadvantage index combines social and economic exposures into a single continuous measure. Significant variation in social disadvantage by age, sex, and ethnic group exists. Increased social disadvantage is associated with an increased burden of some CV risk factors, and is an independently associated with CVD.

Adult↗
PubMed2006

Economics methods in the Clinical Outcomes Utilizing percutaneous coronary Revascularization and Aggressive Guideline-driven drug Evaluation (COURAGE) trial.

Percutaneous coronary intervention (PCI) remains a major therapeutic option for the treatment of chronic coronary artery disease. In the COURAGE trial, 2287 patients with chronic coronary disease were randomized between PCI with medical management and medical management alone. Embedded within the COURAGE trial is a detailed economic analysis being conducted in three health care systems: the US Veterans Administration (VA), Canada, and the US non-VA. Resource use and costs are being collected for each system and overall. Survival is assessed internally in the trial with mean follow-up of 4.5 years. Long-term mean survival will be estimated by projecting survival beyond the trial period by extrapolating the in-trial hazard rates. Utility is being assessed at baseline and at 1, 3, and 6 months and annually thereafter, using a computer-administered standard gamble. Quality-adjusted life years are calculated by multiplying survival by utility. The incremental cost-effectiveness ratio of PCI will be defined as the additional cost of PCI divided by the gain in life years and quality-adjusted life years. The 95% confidence regions of efficacy and costs will be determined by bootstrap over a range of acceptability thresholds, which will then be displayed in the cost-effectiveness plane and as a cost-effectiveness acceptability curve. A multilevel regression model will assess cost-effectiveness from a net benefit perspective. These approaches should provide the most detailed assessment available of the cost-effectiveness of PCI for coronary artery disease.

Angioplasty, Balloon, Coronary↗
PubMed2006

Gated myocardial perfusion single photon emission computed tomography in the clinical outcomes utilizing revascularization and aggressive drug evaluation (COURAGE) trial, Veterans Administration Cooperative study no. 424.

BACKGROUND: Stress gated myocardial perfusion single photon emission computed tomography (gSPECT) is increasingly used before and after intercurrent therapeutic intervention and is the basis for ongoing evaluation in the Department of Veterans Affairs clinical outcomes utilizing revascularization and aggressive drug evaluation (COURAGE) trial. METHODS AND RESULTS: The COURAGE trial is a North American multicenter randomized clinical trial that enrolled 2287 patients to aggressive medical therapy vs percutaneous coronary intervention plus aggressive medical therapy. Three COURAGE nuclear substudies have been designed. The goals of substudy 0 are to examine the diagnostic accuracy of the extent and severity of inducible ischemia at baseline in COURAGE patients compared with patient symptoms and quantitative coronary angiography and to explore the relationship between inducible ischemia and the benefit from revascularization when added to medical therapy. Substudy 1 will correlate the extent and severity of provocative ischemia with the frequency, quality, and instability of recurrent symptoms in postcatheterization patients. Substudy 2 (n = 300) will examine the usefulness of sequential gSPECT monitoring 6 to 18 months after therapeutic intervention. Together, these nuclear substudies will evaluate the role of gSPECT to determine the effectiveness of aggressive risk-factor modifications, lifestyle interventions, and anti-ischemic medical therapies with or without revascularization in reducing patients' ischemic burdens. CONCLUSIONS: The unfolding of evidence on the application of gSPECT in trials such as COURAGE defines a new era for nuclear cardiology. We hope the evidence that emerges from the COURAGE trial will further establish the role of nuclear imaging in the evidence-based management of patients with stable coronary disease.

Algorithms↗
PubMed2006

Canadian Cardiovascular Society consensus conference recommendations on heart failure 2006: diagnosis and management.

Heart failure remains a common diagnosis, especially in older individuals. It continues to be associated with significant morbidity and mortality, but major advances in both diagnosis and management have occurred and will continue to improve symptoms and other outcomes in patients. The Canadian Cardiovascular Society published its first consensus conference recommendations on the diagnosis and management of heart failure in 1994, followed by two brief updates, and reconvened this consensus conference to provide a comprehensive review of current knowledge and management strategies. New clinical trial evidence and meta-analyses were critically reviewed by a multidisciplinary primary panel who developed both recommendations and practical tips, which were reviewed by a secondary panel. The resulting document is intended to provide practical advice for specialists, family physicians, nurses, pharmacists and others who are involved in the care of heart failure patients. Management of heart failure begins with an accurate diagnosis, and requires rational combination drug therapy, individualization of care for each patient (based on their symptoms, clinical presentation and disease severity), appropriate mechanical interventions including revascularization and devices, collaborative efforts among health care professionals, and education and cooperation of the patient and their immediate caregivers. The goal is to translate best evidence-based therapies into clinical practice with a measureable impact on the health of heart failure patients in Canada.

Canada↗
PubMed2005

Protein intake is inversely associated with abdominal obesity in a multi-ethnic population.

Abdominal obesity is related to significant morbidity and mortality and differs by ethnicity; however, the relation between diet and abdominal obesity has not been extensively studied. The aim of this study was to evaluate the dietary and lifestyle determinants of abdominal obesity in a multi-ethnic population. We conducted a cross-sectional study among 617 Canadians of Aboriginal, South Asian, Chinese, and European origins, with diet evaluated using validated, culture specific, interviewer-administered FFQs, and abdominal obesity measured as waist-hip ratio (WHR). The mean proportion of energy intake from protein in the diet was 17.4 vs. 15.8% comparing the lowest and highest tertiles of WHR. Energy-adjusted protein substituted for an equivalent amount of carbohydrate was associated with a reduction in WHR (difference in WHR for every g/d increase in protein intake = -0.0005, P = 0.01) after accounting for age, sex, ethnicity, smoking status, BMI, alcohol intake, height, physical activity, and total energy. Fat or total energy were not related to WHR in the same linear regression model. Smoking was positively and physical activity inversely related to WHR in the multivariate model independent of BMI and other potential confounders. Substituting a modest amount of protein for carbohydrate may reduce abdominal obesity in a diverse multi-ethnic population. Smoking was positively related to abdominal obesity after accounting for BMI.

Abdomen↗
PubMed2005

Concordance, compliance and adherence in healthcare: closing gaps and improving outcomes.

The gap between best care and usual care is large for many important diseases. In particular, poor adherence remains a significant, inadequately addressed, cause of the care gap. About half of all patients with chronic diseases stop refilling prescriptions by one year. Several effective interventions are available and adaptations of clinical trials practices offer promise for further improvement. Poor adherence is a remedial problem in healthcare quality and its improvement and accountability offer shared opportunities for providers and patients. There is a large gap between best care, defined as the optimal use of proven efficacious therapies in whole populations at risk from any disease, and usual care, the actual level of efficacious care being provided (Montague et al. 1997). This gap in patient care has four main causes: diseases may not be diagnosed, efficacious therapies may not be prescribed, access to therapy may be restricted or patients may not adhere to prescriptions. Irrespective of causation, the ultimate result of care gaps is the same--less than optimal clinical outcomes and associated lost opportunities for improved quality of life and productivity. Systematic approaches to improving prescribing practices are increasing, and there is much debate around improving patients' access to care. Poor diagnosis is judged to be relatively uncommon, leaving decayed adherence as the major under-addressed cause of care gaps and a major opportunity for improvement. This paper reviews the scope and causation of sub-optimal adherence, evaluates improvement strategies and explores a best-practice benchmark.

Chronic Disease↗
PubMed2004

C-reactive protein as a screening test for cardiovascular risk in a multiethnic population.

BACKGROUND: Small increases in the inflammatory marker C-reactive protein (CRP) are predictive of vascular events among asymptomatic individuals. There are few data supporting the use of CRP as a risk marker among nonwhite individuals. METHODS AND RESULTS: 1250 adults of South Asian, Chinese, European, and Aboriginal ancestry were randomly sampled from 4 communities in Canada. Participants provided fasting blood samples for CRP, glucose, lipids, and coagulation factors, and they had undergone a carotid B-mode ultrasound. Cardiovascular disease was determined by history and electrocardiogram. The age- and sex-adjusted mean CRP was 3.74 mg/L (standard error, 0.14) among Aboriginals, 2.59 mg/L (0.12) among South Asians, and 1.18 mg/L (0.13) among Chinese compared with 2.06 mg/L (0.12) among Europeans (overall P<0.0001). Differences in the CRP concentration between ethnic groups were substantially diminished, but not abolished, after adjustment for metabolic factors. CRP was independently associated with CVD after adjusting for the Framingham risk factors, atherosclerosis, anthropometric measurements, and ethnicity (OR=1.03 for a 0.1-increase in CRP; P=0.02). CONCLUSIONS: CRP varies substantially between people of different ethnic origin and is influenced by their differences in metabolic factors. Prospective validation of CRP as a risk predictor for cardiovascular disease among nonwhite ethnic groups is required.

Adult↗
PubMed2004

Rationale, design, and baseline characteristics of 2 large, simple, randomized trials evaluating telmisartan, ramipril, and their combination in high-risk patients: the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial/Telmisartan Randomized Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease (ONTARGET/TRANSCEND) trials.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors reduce mortality, myocardial infarction, stroke, heart failure, need for revascularization, nephropathy, and diabetes and its complications. Although angiotensin-II receptor blockers (ARBs) have been less extensively evaluated, theoretically they may have "protective" effects similar to those of ACE inhibitors, but with better tolerability. Currently, there is uncertainty about the role of ARBs when used alone or in combination with an ACE inhibitor in high-risk populations with controlled hypertension. OBJECTIVES: Primary objectives of the ONgoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) are to determine if the combination of the ARB telmisartan and the ACE inhibitor ramipril is more effective than ramipril alone, and if telmisartan is at least as effective as ramipril. The Telmisartan Randomized AssessmeNt Study in aCE iNtolerant subjects with cardiovascular Disease (TRANSCEND) will determine if telmisartan is superior to placebo in patients who are intolerant of ACE inhibitors. The primary outcome for both trials is the composite of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure. METHOD: High-risk patients with coronary, peripheral, or cerebrovascular disease or diabetes with end-organ damage are being recruited and followed for 3.5 to 5.5 years in 2 parallel, randomized, double-blind clinical trials. PROGRESS: Recruitment from 730 centers in 40 countries for ONTARGET (n = 25,620) was completed in July 2003. For TRANSCEND, 5776 patients (out of a projected total of 6000) have been recruited (by May 10, 2004). Baseline patient characteristics are comparable to the Heart Outcomes Prevention Evaluation (HOPE) trial, the basis of the design of the current study, confirming that patients are at high-risk.

Aged↗
PubMed2004

The Warfarin and Antiplatelet Therapy in Heart Failure trial (WATCH): rationale, design, and baseline patient characteristics.

BACKGROUND: The role of anticoagulation in patients with chronic heart failure has long been an area of interest and controversy. Traditionally the goal of anticoagulation has been to prevent embolic events, but recent trials also demonstrated that oral anticoagulation also prevents vascular events in patients with prior myocardial infarction, who constitute the majority of heart failure patients. Although antiplatelet agents also reduce postinfarction vascular events, few data are available in heart failure patients, and some evidence suggests that aspirin may also have the potential to worsen heart failure morbidity and mortality, possibly by interfering with the effects of angiotensin-converting enzyme inhibitors. Methods and results The Warfarin and Antiplatelet Therapy in Chronic Heart Failure (WATCH) trial was undertaken to determine the optimal antithrombotic agent for heart failure patients. WATCH was a prospective-randomized trial in which symptomatic heart failure patients in sinus rhythm with ejection fractions < or =35% taking angiotensin-converting enzyme inhibitors (unless not tolerated) and diuretics were randomized to open-label warfarin (target International Normalized Ratio 2.5-3.0) or double-blind antiplatelet therapy with aspirin 162 mg or clopidogrel 75 mg. Two primary comparisons were specified: anticoagulation with warfarin versus antiplatelet therapy with aspirin and antiplatelet therapy with clopidogrel versus antiplatelet therapy with aspirin. The primary outcome is the composite of death from all causes, nonfatal myocardial infarction, and nonfatal stroke analyzed as time to first event using the intent-to-treat approach. The secondary endpoint was the broader composite of death from all causes, nonfatal myocardial infarction, non-fatal stroke, and hospitalizations for worsening heart failure, unstable angina pectoris, and systemic or pulmonary artery embolic events. Additional prespecified analyses include heart failure events, coronary events, and resource utilization. CONCLUSIONS: Although the trial was designed to enter 4500 patients, it was terminated 18 months prematurely in June 2003 by the VA Cooperative Study Program because of poor enrollment with a resulting reduction of its power to achieve its original objective. This manuscript describes the study rationale, protocol design, and the baseline characteristics of the 1587 patients who were entered into the study. The WATCH trial will help define the optimal approach to antithrombotic therapy in the contemporary management of patients with chronic heart failure resulting from left ventricular systolic dysfunction.

Adult↗
PubMed2003

Relationship of metabolic syndrome and fibrinolytic dysfunction to cardiovascular disease.

BACKGROUND: The clustering of impaired glucose metabolism, elevated triglycerides, low HDL cholesterol, and abdominal obesity is known as the metabolic syndrome. Individuals with this syndrome suffer an excess of cardiovascular disease (CVD) for reasons that are unclear. METHODS AND RESULTS: We randomly sampled 1276 adults of South Asian, Chinese, European, and Native Indian ancestry from 4 communities in Canada. Participants provided fasting blood samples for glucose, lipids, and fibrinolytic measurements; had an oral glucose tolerance test; and underwent a B-mode carotid ultrasound examination. CVD was determined by history and ECG. The prevalence of the metabolic syndrome was 25.8% (95% CI, 23.5 to 28.2) and varied substantially by ethnic group: 41.6% among Native Indians, 25.9% among South Asians, and 22.0% among Europeans, compared with 11.0% among the Chinese (overall, P=0.0001). People with the metabolic syndrome had more atherosclerosis (maximum intimal medial thickness, 0.78+/-0.18 versus 0.74+/-0.18 mm; P=0.0005), CVD (17.2% versus 7.0%; P=0.0001), and elevated plasminogen activator inhibitor-1 (24.2 versus 14.6 U/mL; P=0.001) compared with levels among people without the metabolic syndrome. For the same amount of atherosclerosis, people with the metabolic syndrome had a greater prevalence of CVD, even among nondiabetic individuals. This difference in CVD prevalence among the groups was attenuated after adjustment for plasminogen activator inhibitor-1 levels, suggesting that fibrinolytic dysfunction mediates the increased risk of CVD in individuals with the metabolic syndrome. CONCLUSIONS: CVD among people with the metabolic syndrome is explained by their excess of atherosclerosis and impaired fibrinolysis. Interventions to prevent atherosclerosis progression and improve fibrinolytic function require evaluation in this high-risk group.

Adult↗
PubMed2003

The relationship between dysglycemia and atherosclerosis in South Asian, Chinese, and European individuals in Canada: a randomly sampled cross-sectional study.

OBJECTIVE: Raised glucose levels extending from normal into the diabetic range (dysglycemia) are an emerging risk factor for clinical cardiovascular events. The relationship between dysglycemia and atherosclerosis (AS) in the general population and in different ethnic groups remains controversial. RESEARCH DESIGN AND METHODS: Glucose tolerance, HbA1c, other metabolic risk factors for AS, and carotid mean maximal intimal media thickness were assessed in a random sample of 979 Canadians of South Asian, Chinese, and European descent. RESULTS: The age and sex-adjusted intimal medial thickness increased 0.026 mm for every 0.9% increase in HbA1c in all participants (P < 0.0001) and in those of South Asian (P = 0.018), Chinese (P = 0.002), and European (P < 0.0001) descent. This progressive curvilinear relationship was most apparent at HbA1c levels >5.7%. The HbA1c-AS relationship persisted after adjustment for ethnicity, age, sex, diabetes status, abdominal obesity, insulin resistance, insulin secretion, fasting free fatty acids, blood pressure, and/or dyslipidemia (P < 0.004). Both diabetes (P = 0.002) and HbA1c (P < 0.0001) were determinants of the intimal medial thickness when included in separate statistical models. When included together in a single model, HbA1c (P < 0.0001) but not diabetes (P = 0.6) was a significant determinant. CONCLUSIONS: The degree of AS is related to the level of HbA1c irrespective of diabetes status and independent of abdominal obesity and other markers of the metabolic syndrome. This progressive relationship between HbA1c and AS was observed within different ethnic groups.

Adult↗
PubMed2002

The risks of waiting for cardiac catheterization: a prospective study.

BACKGROUND: Few large, systematic, prospective studies have documented the characteristics and clinical outcomes of patients awaiting cardiac catheterization and the delays that they experience. The primary objective of this study was to quantify the waiting times, morbidity and mortality of patients waiting for catheterization. A secondary objective was to identify predictors of cardiac events that occur while patients are waiting. METHODS: A computerized, prospective, central waiting list registry was developed at a regional centre in Hamilton, Ont., serving 2.2 million people in southern Ontario. Between Apr. 1, 1998, and Mar. 31, 2000, 8030 consecutive patients (4725 outpatients and 3305 inpatients) were referred for cardiac catheterization. Major cardiac outcomes while on the waiting list (death, myocardial infarction and congestive heart failure) were documented prospectively and related to requested versus actual waiting time. RESULTS: Most of the referrals (7345 [91.5%]) were for a primary diagnosis of suspected coronary artery disease. The median waiting time was 6 (interquartile range [IQR] 4) days for inpatients and 60 (IQR 68) days for outpatients. Actual waiting times correlated with the waiting times requested by the referring physicians. However, only 37% of the procedures overall were completed within the requested waiting time. Of the 8030 patients, 50 (0.6%) died, 32 (0.4%) had a myocardial infarction and 41 (0.5%) experienced congestive heart failure. Overall, 109 patients (1.4%) had a major cardiac event, namely, death, myocardial infarction or congestive heart failure. These events occurred over a median wait of 27 days (2 days for inpatients and 35 days for outpatients), and over half (57%) occurred within the waiting time requested by the referring physician. In the multivariate analysis, predictors of the composite of death, myocardial infarction or congestive heart failure were increasing age (relative risk [RR] 2.39, 95% confidence interval [CI] 1.52-3.75) and New York Heart Association class III/IV symptoms (RR 2.86, 95% CI 1.11-7.33) in inpatients, and increasing age (RR 1.36, 95% CI 1.12-1.66), aortic stenosis (RR 3.70, 95% CI 1.93-7.08) and left ventricular ejection fraction less than 35% (RR 4.35, 95% CI 2.48-7.61) in outpatients. INTERPRETATION: Patients awaiting cardiac catheterization may experience major adverse events, such as death, myocardial infarction and congestive heart failure, which may be preventable. Our findings provide a benchmark by which to measure the effect of increased capacity and prioritization schemes that allow earlier access for patients at higher risk, such as those with aortic stenosis and reduced left ventricular function.

Aged↗
PubMedDate not supplied

Cardiac plasmacytoma.

A 69-year-old white woman presented with a 3-month history of progressive dyspnea, orthopnea, fatigue and weakness. Clinical, diagnostic imaging and echocardiographic investigations suggested an occult primary cancer with metastasis to the heart. The patient's condition deteriorated gradually, and she died 2 months later. At autopsy, a malignant tumor encasing the heart and a 1-cm solitary tumor nodule in the lower lobe of the left lung were found. Histologic and electron microscopic studies revealed a plasmacytoma predominantly involving the epicardium and a small solitary plasmacytoma located in the left lung. The two tumors were further confirmed by immunohistochemical studies that showed monoclonal IgG expression and kappa light chain restriction.

Aged↗