Ambulatory Care Research Team Research Articles

Assessing Cardiovascular Health in Paediatric Hypertrophic Cardiomyopathy Using the CANHEART Health Index

BackgroundPaediatric hypertrophic cardiomyopathy (HCM) is associated with sudden cardiac death, often resulting in restriction of strenuous physical activity. High levels of inactivity and a rise in youth obesity may increase risk of poor cardiovascular (CV) health in these patients. We aim to compare the CV disease risk profile of paediatric patients with HCM to Canadian youth. MethodsPatients with HCM (10-19 years) were recruited from 10 paediatric cardiac centres in Canada. The CV disease risk profile was determined using the Healthy Hearts School Program questionnaire and Cardiovascular Health in Ambulatory Care Research Team (CANHEART) health index. Poisson regressions were used to assess associations between the CV disease risk profile of paediatric patients with HCM and the overall CANHEART health score. ResultsA total of 56 subjects were enrolled (71% male, median age: 15.5 years [interquartile range: 13.8-16.8], median body mass index: 23.3 [interquartile range: 19.5-27.7]). Results of the CANHEART health index revealed that 89% of participants with HCM never tried smoking, 52% had a healthy body mass index, 39% consumed ≥5 fruits/vegetables per day, and 50% engaged in ≥60 minutes of walking or 20 minutes of running/jogging per day. When CANHEART intermediate and poor health index scores were combined, similar proportions were obtained for each group (HCM 82.1% vs Canadian youth 83.4%; P = 0.724). ConclusionsMany paediatric patients with HCM in Canada have intermediate or poor CV health as determined by the CANHEART health score, with high rates of obesity and low physical activity levels driving these trends. Interventions should be developed to promote positive CV health behaviours among patients with HCM.

Development and Validation of the CANHEART Population-Based Laboratory Prediction Models for Atherosclerotic Cardiovascular Disease.

Prediction of atherosclerotic cardiovascular disease (ASCVD) in primary prevention assessments exclusively with laboratory results may facilitate automated risk reporting and improve uptake of preventive therapies. To develop and validate sex-specific prediction models for ASCVD using age and routine laboratory tests and compare their performance with that of the pooled cohort equations (PCEs). Derivation and validation of the CANHEART (Cardiovascular Health in Ambulatory Care Research Team) Lab Models. Population-based cohort study in Ontario, Canada. A derivation and internal validation cohort of adults aged 40 to 75 years without cardiovascular disease from April 2009 to December 2015; an external validation cohort of primary care patients from January 2010 to December 2014. Age and laboratory predictors measured in the outpatient setting included serum total cholesterol, high-density lipoprotein cholesterol, triglycerides, hemoglobin, mean corpuscular volume, platelets, leukocytes, estimated glomerular filtration rate, and glucose. The ASCVD outcomes were defined as myocardial infarction, stroke, and death from ischemic heart or cerebrovascular disease within 5 years. Sex-specific models were developed and internally validated in 2 160 497 women and 1 833 147 men. They were well calibrated, with relative differences less than 1% between mean predicted and observed risk for both sexes. The c-statistic was 0.77 in women and 0.71 in men. External validation in 31 697 primary care patients showed a relative difference less than 14% and an absolute difference less than 0.3 percentage points in mean predicted and observed risks for both sexes. The c-statistics for the laboratory models were 0.72 for both sexes and were not statistically significantly different from those for the PCEs in women (change in c-statistic, -0.01 [95% CI, -0.03 to 0.01]) or men (change in c-statistic, -0.01 [CI, -0.04 to 0.02]). Medication use was not available at the population level. The CANHEART Lab Models predict ASCVD with similar accuracy to more complex models, such as the PCEs. Canadian Institutes of Health Research.

Primary Care Clinical Volumes, Cholesterol Testing, and Cardiovascular Outcomes.

It is unknown whether the annual number of primary care physician (PCP) unique outpatient assessments, which we refer to as clinical volume, translates into better cardiovascular preventive care. We examined the relationship between PCP outpatient clinical volumes and cholesterol testing and major adverse cardiovascular event rates among guideline-recommended eligible patients. This was a retrospective cohort study conducted as part of the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) cohort, a population-based cohort of almost all adult residents of Ontario, Canada, followed from 2008 to 2012. For each clinical volume quintile, we compared cholesterol testing and major adverse cardiovascular events, defined as time to first event of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. The 10,037 PCPs evaluated had an annualized median volume of 2303 clinical encounters (IQR 1292-3680). Among 4,740,380 patients, 84% underwent guideline-concordant cholesterol testing at least once over 5 years, ranging from 73% with the lowest clinical volume quintile physicians to 86% with the highest. After multivariable adjustment, there was a 10.5% relative increase in the probability of cholesterol testing for every doubling of clinical volumes (95% CI 9.7-11.4; P < 0.001). Patients treated by the lowest volume quintile physicians had the highest rate of major adverse cardiovascular outcomes (compared with the highest volume quintile physicians: adjusted HR 1.15, 95% CI 1.10-1.21; P < 0.001). Patients of physicians with the lowest clinical volumes received less frequent cholesterol testing and had the highest rate of incident cardiovascular events. Further research investigating the drivers of this relationship is warranted.

Eligibility and Implementation of Rivaroxaban for Secondary Prevention of Atherothrombosis in Clinical Practice-Insights From the CANHEART Study.

Background The COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) trial decreased major adverse cardiovascular events with very low-dose rivaroxaban and aspirin in patients with coronary artery disease and peripheral artery disease. We examined the eligibility and potential real-world impact of this strategy on the COMPASS-eligible population. Methods and Results COMPASS eligibility criteria were applied to the CANHEART (Cardiovascular Health in Ambulatory Care Research Team) registry, a population-based cohort of Ontario adults. We compared 5-year major adverse cardiovascular eventsand major bleeding rates stratified by COMPASS eligibility and by clinical risk factors. We applied COMPASS trial rivaroxaban/aspirin arm hazard ratios to estimate the potential impact on the COMPASS-eligible cohort. Among 362 797 patients with coronary artery disease or peripheral artery disease, 38% were deemed eligible, 47% ineligible, and 15% indeterminate. Among eligible patients, a greater number of risk factors was associated with higher rates of cardiovascular outcomes, whereas bleeding rates increased minimally. Over 5 years, applying COMPASS treatment effects to eligible patients resulted in a 2.4% absolute risk reduction of major adverse cardiovascular events and a number needed to treat of 42, and a 1.3% absolute risk increase of major bleeding and number needed to harm (NNH) of 77. Those with at least 2 risk factors had a 3.0% absolute risk reduction of major adverse cardiovascular events (number needed to treat =34) and a 1.6% absolute risk increase of major bleeding (number needed to harm =61). Conclusions Implementation of very-low-dose rivaroxaban therapy would potentially impact 2 in 5 patients with atherosclerotic disease in Ontario. Eligible individuals with 2 comorbidities represent a high-risk subgroup that may derive the greatest benefit-to-risk ratio. Selection of patients with high-risk predisposing factors appears appropriate in routine practice.

IMPACT OF OUTCOME DEFINITIONS ON CARDIOVASCULAR RISK PREDICTION IN A CONTEMPORARY PRIMARY PREVENTION POPULATION

IMPACT OF OUTCOME DEFINITIONS ON CARDIOVASCULAR RISK PREDICTION IN A CONTEMPORARY PRIMARY PREVENTION POPULATION

Impact of outcome definitions on cardiovascular risk prediction in a contemporary primary prevention population.

Estimation of an individual's cardiovascular disease (CVD) risk may enhance risk discussion and treatment decisions. Yet, common cardiovascular outcomes such as heart failure (HF) or coronary revascularization are not included in the estimation of atherosclerotic cardiovascular disease (ASCVD) risk. Our objective was to determine the incidence of ASCVD in a contemporary primary prevention population with >10 years of follow-up and how incidence estimates change when incorporating additional cardiovascular endpoints. We used the population-level Cardiovascular Health in Ambulatory Care Research Team database of all Ontario residents alive 1 January 2008, aged 30-99 years, and with no prior history of CVD. Individuals were followed to 31 December 2018 for incident first and recurrent cardiovascular events. ASCVD outcomes were defined by hospitalizations for myocardial infarction, stroke, and circulatory death, while global CVD outcomes also included hospitalizations for unstable angina, transient ischemic attacks, peripheral arterial disease, out-of-hospital cardiac arrests, HF, and coronary revascularization. Among 7496165 individuals free of CVD, their mean age was 50 years (SD: 13.9 years) and 52.3% were women. After 11 years of follow-up, the rate of an incident ASCVD event was 3.95 per 1000 person-years, while the rate of a global CVD event was almost doubled at 6.67 per 1000 person-years. The most common additional first manifestations of CVD were HF, which accounted for 12.0% of additional events and coronary revascularization, which accounted for 12.7%. When considering first and recurrent events, the rate of ASCVD was 5.20 per 1000 person-years, while the rate of all global CVD events was more than double at 10.90 per 1000 person-years. This was mainly due to a higher proportion of recurrent HF (13.8%) and coronary revascularization (23.2%) events. ASCVD accounts for just over half of all preventable first cardiovascular events and even fewer first and recurrent cardiovascular events in contemporary practice. Estimating broader CVD endpoints may enhance risk-discussions with patients and improve informed decision-making.

Relationship of frailty with excess mortality during the COVID-19 pandemic: a population-level study in Ontario, Canada.

There is a paucity of the literature on the relationship between frailty and excess mortality due to the COVID-19 pandemic. The entire community-dwelling adult population of Ontario, Canada, as of January 1st, 2018, was identified using the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) cohort. Residents of long-term care facilities were excluded. Frailty was categorized through the Johns Hopkins Adjusted Clinical Groups (ACG® System) frailty indicator. Follow-up was until December 31st, 2020, with March 11th, 2020, indicating the beginning of the COVID-19 pandemic. Using multivariable Cox models with patient age as the timescale, we determined the relationship between frailty status and pandemic period on all-cause mortality. We evaluated the modifier effect of frailty using both stratified models as well as incorporating an interaction between frailty and the pandemic period. We identified 11,481,391 persons in our cohort, of whom 3.2% were frail based on the ACG indicator. Crude mortality increased from 0.75 to 0.87% per 100 person years from the pre- to post-pandemic period, translating to ~ 13,800 excess deaths among the community-dwelling adult population of Ontario (HR 1.11 95% CI 1.09-1.11). Frailty was associated with a statistically significant increase in all-cause mortality (HR 3.02, 95% CI 2.99-3.06). However, all-cause mortality increased similarly during the pandemic in frail (aHR 1.13, 95% CI 1.09-1.16) and non-frail (aHR 1.15, 95% CI 1.13-1.17) persons. Although frailty was associated with greater mortality, frailty did not modify the excess mortality associated with the pandemic.

Prevalence and Treatment of Familial Hypercholesterolemia and Severe Hypercholesterolemia in Older Adults in Ontario, Canada

BackgroundA simplified Canadian definition was recently developed to enable identification of individuals with familial hypercholesterolemia (FH) and severe hypercholesterolemia in the general population. Our objective was to use a modified version of this new definition to assess contemporary disease prevalence, treatment patterns, and low-density lipoprotein cholesterol (LDL-C) control in Ontario, Canada. MethodsWe identified individuals aged 66 to 105 years who were alive as of January 1, 2011, using the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) database, which was created by linking 19 population-based health databases in Ontario. Hypercholesterolemia was identified using LDL-C values. Cholesterol reduction and lipid-lowering treatment were assessed at time of diagnosis and after at least 2 and 5 years’ follow-up. ResultsAmong 922,464 individuals, 2440 (0.26%) met criteria for definite or probable FH, and 72,893 (7.90%) for severe hypercholesterolemia. At diagnosis, mean LDL-C concentration was 9.52 mmol/L for those with definite FH, 5.83 mmol/L for those with probable FH, 5.73 mmol/L for those with severe hypercholesterolemia, and 3.33 mmol/L for all other individuals. After > 5 years, LDL-C concentration remained elevated at 3.58 mmol/L for those with definite FH, 2.72 mmol/L for those with probable FH, and 2.93 mmol/L for those with severe hypercholesteremia. Use of statin therapy was initially high (83% of those with definite FH, 78% of those with probable FH, 62% of those with severe hypercholesterolemia); however, fewer patients remained on statins at follow-up at > 5 years (62% of those with definite FH, 67% of those with probable FH, 58% of those with severe hypercholesterolemia). ConclusionsAmong older Ontarians, we estimated that 1 in 378 individuals had FH, and 1 in 13 had severe hypercholesterolemia. Despite being at substantially increased cardiovascular risk, these patients acheived suboptimal LDL-C level control and fewer were on medical therapy at follow-up.

Abstract 9297: Assessing Cardiovascular Health in Pediatric Hypertrophic Cardiomyopathy Using the CANHEART Index

Introduction: Pediatric hypertrophic cardiomyopathy (HCM) is associated with sudden death often resulting in restriction from strenuous physical activity and competitive sports. Restrictions may increase the risk of poor cardiovascular (CV) health. Hypothesis: CV health, as measured by the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) health index (https://www.cmaj.ca/content/cmaj/186/3/180.full.pdf) are lower in pediatric HCM compared to other Canadian children. Methods: Pediatric HCM patients between age 10 and 18 years were prospectively recruited at 5 Canadian sites and assessed using the CANHEART health index. The index uses four factors for the definition of ideal CV health: never smoked, body mass index (BMI), fruit and vegetable (veg) consumption &gt; 5 times/day and walking &gt;60 minutes walking or 20 mins of running/jogging per day. Ideal health is defined by the presence of all four factors and poor health 0-2 factors. Results: There were 36 subjects enrolled in the study [27 males; median age 14.8 years (10-18); median BMI 24 (17-37)]. With regards to CANHEART health index results, 50% (n=18) were overweight/obese, 56% (n= 20) walked &lt;60 minutes or ran/jogged &lt;20 min per day, 70% consumed fruits/veg &lt; 5 times/day and 94.4% had never smoked. The mean CANHEART index score was 2.19 (95 th CI 1.87-2.52) compared to the previously reported for Canadian youths without HCM (2.49 95% CI 2.47-2.52). Ideal CV health was seen in 11.1% (n=5) of HCM patients with poor health in 66.7% (n=24) [See Table 1]. Conclusions: A small percentage of pediatric HCM patients had ideal CV health as defined by the CANHEART index and the mean score was lower than previous reported in the CANHEART population study. These finding are predominantly driven by a lack of fruit/veg consumption, poor physical activity and BMI. CV profiling for pediatric HCM patients should be considered as part of the longitudinal care to help decrease the risk of premature CV disease in adulthood.

SUBOPTIMAL CONTROL OF CHOLESTEROL LEVELS AMONG INDIVIDUALS WITH FAMILIAL HYPERCHOLESTEROLEMIA AND SEVERE HYPERCHOLESTEROLEMIA IN ONTARIO, CANADA

SUBOPTIMAL CONTROL OF CHOLESTEROL LEVELS AMONG INDIVIDUALS WITH FAMILIAL HYPERCHOLESTEROLEMIA AND SEVERE HYPERCHOLESTEROLEMIA IN ONTARIO, CANADA

CARDIOVASCULAR RISK AND UPTAKE OF EVIDENCE-BASED THERAPIES IN PATIENTS WITH TYPE 2 DIABETES AFTER AN ACUTE CARDIOVASCULAR EVENT: INSIGHTS FROM THE CANHEART REGISTRY

BACKGROUND Numerous type 2 diabetes (T2DM) therapies that improve cardiovascular (CV) outcomes are now available; however, there is limited data on their utilization following an acute CV event. This study characterized the association between T2DM and adverse CV events following a hospital admission for a major CV event and identified high-risk patient subgroups who could benefit from further CV risk reduction with such therapies. METHODS AND RESULTS We conducted a population-based retrospective study using the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) registry of health services databases in the province of Ontario, Canada. These datasets were linked using unique encoded identifiers and analyzed at ICES. Patients were eligible if they were ≥18 years of age and discharged alive from hospital between June 1, 2015 and March 31, 2019 with a diagnosis of a major adverse CV event (defined as acute myocardial infarction [AMI], hospitalization for heart failure [HHF], ischemic stroke, or peripheral arterial disease [PAD]). The main exposure was the presence of T2DM at the time of index hospitalization. Multivariate Cox models were adjusted for baseline sociodemographic and clinical comorbidities to estimate hazard ratios (HR) associated between T2DM and the primary outcome (a composite of all-cause death or recurrent AMI, HHF, ischemic stroke, or PAD). Among the subset of patients ≥66 years of age who were eligible for universal drug coverage, prescription patterns were determined following discharge. The cohort comprised 157,640 patients (T2DM: N=67,083; 42.6%; median age 72 years). After a median of 2 years of follow up, the primary outcome occurred in 30,939 (46.1%) patients with T2DM compared to 29,097 (32.1%) patients without T2DM (adjusted HR 1.28, 95% CI, 1.26-1.30, p < 0.0001). The presence of T2DM accounted for the greatest increase in risk in the primary endpoint in patients admitted for PAD, followed by AMI, ischemic stroke, and HHF respectively (Figure). In T2DM patients ≥66 years of age, uptake of guideline-directed medical therapy increased from 100 days prior to hospitalization to 2 years of follow-up: ACEi/ARB (66.0% to 75.6%), statin (64.8% to 82.7%), SGLT2i (4.7% to 15.3%), GLP1-RA (previously not covered to 2.3%). CONCLUSION Patients with T2DM admitted for a major CV event have an adjusted 28% higher risk of all-cause death or recurrent CV event compared with patients without diabetes. This population is at high risk for recurrent events and would benefit from higher implementation of evidence-based diabetes therapies with demonstrated CV protection. Numerous type 2 diabetes (T2DM) therapies that improve cardiovascular (CV) outcomes are now available; however, there is limited data on their utilization following an acute CV event. This study characterized the association between T2DM and adverse CV events following a hospital admission for a major CV event and identified high-risk patient subgroups who could benefit from further CV risk reduction with such therapies. We conducted a population-based retrospective study using the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) registry of health services databases in the province of Ontario, Canada. These datasets were linked using unique encoded identifiers and analyzed at ICES. Patients were eligible if they were ≥18 years of age and discharged alive from hospital between June 1, 2015 and March 31, 2019 with a diagnosis of a major adverse CV event (defined as acute myocardial infarction [AMI], hospitalization for heart failure [HHF], ischemic stroke, or peripheral arterial disease [PAD]). The main exposure was the presence of T2DM at the time of index hospitalization. Multivariate Cox models were adjusted for baseline sociodemographic and clinical comorbidities to estimate hazard ratios (HR) associated between T2DM and the primary outcome (a composite of all-cause death or recurrent AMI, HHF, ischemic stroke, or PAD). Among the subset of patients ≥66 years of age who were eligible for universal drug coverage, prescription patterns were determined following discharge. The cohort comprised 157,640 patients (T2DM: N=67,083; 42.6%; median age 72 years). After a median of 2 years of follow up, the primary outcome occurred in 30,939 (46.1%) patients with T2DM compared to 29,097 (32.1%) patients without T2DM (adjusted HR 1.28, 95% CI, 1.26-1.30, p < 0.0001). The presence of T2DM accounted for the greatest increase in risk in the primary endpoint in patients admitted for PAD, followed by AMI, ischemic stroke, and HHF respectively (Figure). In T2DM patients ≥66 years of age, uptake of guideline-directed medical therapy increased from 100 days prior to hospitalization to 2 years of follow-up: ACEi/ARB (66.0% to 75.6%), statin (64.8% to 82.7%), SGLT2i (4.7% to 15.3%), GLP1-RA (previously not covered to 2.3%). Patients with T2DM admitted for a major CV event have an adjusted 28% higher risk of all-cause death or recurrent CV event compared with patients without diabetes. This population is at high risk for recurrent events and would benefit from higher implementation of evidence-based diabetes therapies with demonstrated CV protection.

Exploring the associations between cardiovascular health measured with the CANHEART model and early cognitive impairment in a middle-aged population in Korea.

OBJECTIVESBoth cardiovascular health (CVH) and inflammation are associated with cognition, and inflammation is also associated with CVH. However, limited information has been reported on these factors in the Korean population. The objective of our study was to investigate the influence of inflammation on the association between CVH and cognition using a cross-sectional design.METHODSData were obtained from the Cardiovascular and Metabolic Diseases Etiology Research Center baseline study. Participants who completed fasting serum analysis, questionnaires, and cognitive function tests were included in the analysis, whereas those with a history of autoimmune disease were excluded. The CVH in Ambulatory Care Research Team health index metrics, including smoking, physical activity, healthy diet, obesity, history of hypertension, and diabetes, were used to assess CVH. Cognitive function was evaluated with the Korean version of the Mini-Mental State Estimation for Dementia Screening. Inflammatory status was assessed based on a high-sensitivity C-reactive protein (hs-CRP) test.RESULTSAmong 2,622 total participants (mean age, 57.2 years; 1,792 women), 13%, 58%, and 29% had poor, intermediate, and ideal CVH, respectively. Logistic regression analysis demonstrated that CVH was significantly associated with cognitive function only in women. A stratified analysis showed that cognitive impairment due to CVH was not associated with hs-CRP levels. When the same analyses were conducted for each CVH component, the only component affecting the association was hypertension history in men.CONCLUSIONSCVH is not significantly associated with cognitive decline in the middle-aged Korean population. Inflammation did not play a significant modifying role in this relationship.

Association Between Neighborhood Walkability and Predicted 10-Year Cardiovascular Disease Risk: The CANHEART (Cardiovascular Health in Ambulatory Care Research Team) Cohort.

BackgroundIndividuals living in unwalkable neighborhoods appear to be less physically active and more likely to develop obesity, diabetes mellitus, and hypertension. It is unclear whether neighborhood walkability is a risk factor for future cardiovascular disease.Methods and ResultsWe studied residents living in major urban centers in Ontario, Canada on January 1, 2008, using linked electronic medical record and administrative health data from the CANHEART (Cardiovascular Health in Ambulatory Care Research Team) cohort. Walkability was assessed using a validated index based on population and residential density, street connectivity, and the number of walkable destinations in each neighborhood, divided into quintiles (Q). The primary outcome was a predicted 10‐year cardiovascular disease risk of ≥7.5% (recommended threshold for statin use) assessed by the American College of Cardiology/American Heart Association Pooled Cohort Equation. Adjusted associations were estimated using logistic regression models. Secondary outcomes included measured systolic blood pressure, total and high‐density lipoprotein cholesterol levels, prior diabetes mellitus diagnosis, and current smoking status. In total, 44 448 individuals were included in our analyses. Fully adjusted analyses found a nonlinear relationship between walkability and predicted 10‐year cardiovascular disease risk (least [Q1] versus most [Q5] walkable neighborhood: odds ratio =1.09, 95% CI: 0.98, 1.22), with the greatest difference between Q3 and Q5 (odds ratio=1.33, 95% CI: 1.23, 1.45). Dose–response associations were observed for systolic blood pressure, high‐density lipoprotein cholesterol, and diabetes mellitus risk, while an inverse association was observed with smoking status.ConclusionsIn our setting, adults living in less walkable neighborhoods had a higher predicted 10‐year cardiovascular disease risk than those living in highly walkable areas.

DERIVATION OF A MODEL THAT ACCURATELY PREDICTS CARDIOVASCULAR FROM NON-CARDIOVASCULAR CAUSE OF DEATH USING ADMINISTRATIVE HEALTH DATA SOURCES

Cardiovascular (CV) mortality remains an important endpoint in CV outcome studies. Traditionally, cause of death (COD) is determined with expert adjudication following clinical notes and attestations from study investigators; however, this approach is cumbersome and expensive. Alternatively, COD is available within routinely collected administrative healthcare data, but there is typically a prolonged latency in the collecting and reporting of this information which may be ineffective for prospective research studies. An innovative and cost-effective method to supplant the delay is to derive and validate an accurate prediction model of COD analyzing routine healthcare data leading up to a fatal event. Predicting CV mortality in this manner provides a real-time practical solution for pragmatic CV clinical trials studying this outcome. The model was developed using all deaths that occurred between 2008-2012 in the CArdiovascular HEalth in Ambulatory Care Research Team (CANHEART) cohort of almost the entire Ontario adult population in 2008 created using linkage of 17+ health-related databases. Patients 40 years and older at the time of death with COD information available in the Ontario Vital Statistics Database were included (n = 362,778); COD was categorized into CV (n = 104, 590) or non-CV (n = 258,188) causes according to standard ICD-10 diagnostic codes. Candidate sociodemographic factors, past medical history and healthcare utilization variables that could be ascertained from health administrative data sources were considered as potential predictors. A backwards elimination model building strategy using logistic regression was used to ascertain the final set of predictors in the model. Model diagnostics including discrimination and calibration were computed to assess model performance. A single model for males and females combined was determined to be most appropriate. The model contained 34 predictors and had good discrimination (c-statistic = 0.831) and calibration (HL χ2 = 1394.6, p < 0.0001). Estimated differences between observed versus predicted probabilities of CV death was < 10% across all risk decile groups (Figure). Strong predictors for CV death included recent stroke (OR, 2.16; 95% CI, 2.11-2.21), heart failure (OR, 1.44; 95% CI 1.41-1.47), and any cardiovascular (OR, 3.94; 95% CI 3.83-4.04) or ophthalmologic (OR, 1.43; 95% CI 1.14-1.79) related hospitalization 1 month before death. The model will be validated in independent primary and secondary prevention cohorts. An administrative healthcare data model had good discrimination and calibration in determining whether a death was attributed to CV or non-CV causes suggesting potential use in pragmatic clinical trials.

Associations between Traffic-Related Air Pollution and Cardiovascular Disease Risk Factors Were Stronger in More Walkable Neighborhoods: The Cardiovascular Health in Ambulatory Care Research Team (CANHEART) Cohort

Introduction Studies suggest living in a more walkable neighborhood may protect against cardiovascular disease risk factors such as hypertension (HTN) and diabetes mellitus (DM) by encouraging physical activity. Walkable neighborhoods, however, often carry higher levels of traffic-related air pollution. Little is known regarding whether synergistic effects may exist between walkability and air pollution on these risk factors.Hypothesis We hypothesized that the association between traffic-related air pollution, hypertension, and diabetes mellitus would be stronger in more walkable areas.Methods We drew a cross-sectional sample of individuals ages 40-74 on January 1, 2008 from the CANHEART cohort. HTN and DM were ascertained using validated algorithms. Walkability (quintiles, Q5 highest, Q1 lowest) was measured using a validated index which has previously been shown to be inversely associated with obesity and diabetes. Exposure to nitrogen dioxide, a valid marker for traffic-related air pollution, was assessed using a land use regression models. The associations were tested using logistic regression with cluster-robust standard errors, adjusting for age, sex, area-level income, ethnicity, and comorbidities.Results 2,618,584 individuals were included in the analysis. Walkability was inversely associated with odds for HTN (Q5 vs. Q1 OR &amp;#61; 0.80, 95% CI: 0.79, 0.82) and DM (Q5 vs. Q1 OR &amp;#61; 0.89, 95% CI: 0.87, 0.91), while NO2 was positively associated with each (HTN: OR &amp;#61; 1.02 per 10 ppb (1.01, 1.03); DM: OR &amp;#61; 1.11 per 10 ppb (1.09, 1.13)). We observed significant interactions between walkability and NO2 on odds for HTN and DM, with stronger NO2 associations in the most walkable neighborhoods.Conclusions We observed significant interactions between traffic-related air pollution and walkability on odds for HTN and DM. This finding suggests that benefits from living in more walkable neighborhoods may be partially offset by stronger negative associations with air pollution.

Linking big data for cardiovascular health surveillance – opportunities and challenges using the CANHEART cohort

IntroductionOur increasing ability to link large population-based health administrative datasets to create ‘big data’ cohorts offers unique opportunities to conduct health and health services surveillance at lower costs than traditional methods using surveys or primary data collection. However, comparability of findings from big data with traditional methods is unknown.&#x0D; Objectives and ApproachIn the CArdiovascular HEalth in Ambulatory Care Research Team (CANHEART) ‘big data’ initiative, we linked 19 population-based health databases to obtain baseline and 5-year follow-up health information on a cohort of 9.8 million adult residents of Ontario, Canada as of January 2008. We compared cardiovascular risk factor prevalence with results from 3500 participants in the 2007-09 Canadian Health Measures Survey (CHMS), a traditional population health surveillance survey. Additionally, we determined cardiovascular preventative care use and clinical event rates by sex and age. Planned linkages to new data sources will enable continued cohort surveillance of population health-related and care indicators.&#x0D; ResultsCholesterol and glucose levels determined from the CANHEART cohort were comparable to the CHMS, whereas blood pressure values and obesity rates were substantially higher. Overall, receipt of cardiovascular preventive care in the CANHEART cohort was high, with 85.7% of males and 91.8% of females having blood pressure assessments, and 67.8% of males and 79.4% of females having weight assessments. Cholesterol and diabetes screening rates among those recommended for screening were over 75%. Incidence of myocardial infarction, stroke or cardiovascular death was 51% higher among males than females (3.8 and 2.5 events per 1000 person-years, respectively). Challenges encountered in analyzing data included treatment of repeated and time-varying measures, selection of valid diagnostic and physician billing codes, changing coding practices and handling of missing and outlying data.&#x0D; Conclusion/ImplicationsComparability of cardiovascular risk factor prevalence using linked administrative data with survey methods varies by indicator. Selection biases amongst survey participants and different measurement methods could explain discrepancies. The added ability to examine health care indicators longitudinally and by subgroup supports use of linked population-based data to enhance health surveillance.

Modifiable cardiovascular risk factors in adolescents and adults with congenital heart disease.

Individuals with congenital heart disease (CHD) may be at higher risk of acquired cardiovascular disease than the general population due to their underlying physiology and/or surgical sequelae. We sought to assess the prevalence of cardiovascular disease risk factors in youth and adults with CHD. We assessed cardiovascular health as per the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) health index in patients with CHD aged 15+ years who attended cardiology outpatient clinics. Participants self-reported smoking behavior, fruit and vegetable consumption, physical activity, and whether they had diabetes and hypertension. Individual health indices were categorized into ideal/not ideal, and sum of individual health indices was categorized as poor, intermediate or ideal cardiovascular health as per CANHEART criteria. We included n = 102 adults (35.4 ± 12.9 years, 46% female) and n = 88 youth (17.2 ±1.1 years, 41% female). Most individuals reported to be nonsmokers (88% youth vs 86% adults) and to consume ≥5 servings of fruit and vegetables per day (83% vs 85%, respectively). More adults than youth were overweight/obese (52% vs 22%, p < 0.001) though more adults than youth reported meeting age-specific physical activity guidelines (84% vs 55%, p < 0.001). According to CANHEART health index criteria, 32% of youth and 27% of adults were in ideal cardiovascular health. A low proportion of individuals with CHD are in ideal cardiovascular health, suggesting a need to promote healthy lifestyles during adolescence and throughout adulthood in these individuals.

The Cardiovascular Health in Ambulatory Care Research Team (CANHEART) Initiative: Using Implementation science to improve dyslipidemia management in Ontario

We previously reported that HOXB9 is overexpressed in colon cancer and predicts a favourable patient outcome, which is opposite to the tumour-promoting role of HOXB9 in other cancers. We hypothesized that HOXB9 acetylation may account for its inhibitory role in colon cancer. We aim to examine the role of acetylated HOXB9 in colon cancer cells and patients. The AcK27-HOXB9 levels in colon cancer cells and patients were analysed by Western blot analysis and immunohistochemistry separately. Correlation between AcK27-HOXB9 expression and patient survival was assessed by Kaplan–Meier analysis. HOXB9 target gene EZH2 was determined by luciferase assay in HOXB9-transfected colon cancer cells. Nucleocytoplasmic translocation of HOXB9 was detected by subcellular fractionation and immunofluorescence. The AcK27-HOXB9 level was decreased in colon cancer patients and predicted better outcome. HOXB9 upregulated oncogenic EZH2 expression, whereas AcK27-HOXB9 suppressed it by translocating HOXB9 from nuclei into cytoplasm. We demonstrated that AcK27-HOXB9 inhibits while non-acetylated HOXB9 promotes EZH2 expression and colon cancer progression. Thus, AcK27-HOXB9 underlies the tumour suppressive role of HOXB9. Detection of the ratio between AcK27-HOXB9 and HOXB9 is of differential diagnostic value for colon cancer patients.

Abstract MP55: Associations Between Traffic-Related Air Pollution and Cardiovascular Disease Risk Factors Were Stronger in More Walkable Neighborhoods: The Cardiovascular Health in Ambulatory Care Research Team Cohort

Introduction: Studies suggest living in a more walkable neighborhood may protect against cardiovascular disease risk factors such as hypertension (HTN) and diabetes mellitus (DM) by encouraging physical activity. Walkable neighborhoods, however, often carry higher levels of traffic-related air pollution. Little is known regarding whether synergistic effects may exist between walkability and air pollution on these risk factors. Hypothesis: We hypothesized that the association between traffic-related air pollution, hypertension, and diabetes mellitus would be stronger in more walkable areas. Methods: We drew a cross-sectional sample of individuals ages 40-74 on January 1, 2008 from the CANHEART cohort. HTN and DM were ascertained using validated algorithms. Walkability (quintiles, Q5 highest, Q1 lowest) was measured using a validated index which has previously been shown to be inversely associated with obesity and diabetes. Exposure to nitrogen dioxide, a valid marker for traffic-related air pollution, was assessed using a land use regression models. The associations were tested using logistic regression with cluster-robust standard errors, adjusting for age, sex, area-level income, ethnicity, and comorbidities. Results: In total, 2,618,584 individuals were included in the analysis (mean (SD) age = 53.2 (9.2), 52% female). Walkability was inversely associated with odds for HTN (Q5 vs. Q1 OR = 0.80, 95% CI: 0.79, 0.82) and DM (Q5 vs. Q1 OR = 0.89, 95% CI: 0.87, 0.91), while NO 2 was positively associated with each (HTN: OR = 1.02 per 10 ppb (1.01, 1.03); DM: OR = 1.11 per 10 ppb (1.09, 1.13)). We observed significant interactions between walkability and NO 2 on odds for HTN and DM, with stronger NO 2 associations in the most walkable neighborhoods (Fig. 1). Conclusions: We observed significant interactions between traffic-related air pollution and walkability on odds for HTN and DM. This finding suggests that benefits from living in more walkable neighborhoods may be offset by stronger negative associations with air pollution.

Abstract WMP58: Ambulatory Care for Secondary Prevention of Stroke in Rural versus Urban Areas in Ontario, Canada

Introduction: Residents of rural areas may have limited access to certain health care services. However, little is known about rural-urban differences in stroke secondary prevention care, or in the risk of recurrent stroke and death. We used linked population-based administrative databases from the province of Ontario, Canada, to assess the association between rural residence and ambulatory processes of care for secondary stroke prevention, as well as the incidence of recurrent stroke. Methods: We studied a sub-population of the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) cohort, comprised of individuals between ages 40 to 105 years with a history of stroke prior to January 1, 2008. We defined rural communities as those with a population size of ≤ 10, 000, and compared screening and treatment for hypertension, hyperlipidemia, diabetes mellitus and smoking in rural and urban areas, as well as the incidence of recurrent stroke, adjusting for age, sex and baseline risk factors. Results: In our study sample of 86,811 individuals with prior stroke, the prevalence of vascular risk factors was similar in both rural and urban residents. Rural residents (n=10,988) had fewer mean annual visits to family physicians (5.2 vs. 6.7; p&lt;0.001) and specialist physicians (2.5 vs. 3.5; p&lt;0.001) and were less likely to be screened for hyperlipidemia (67.9% vs. 81.5%; p &lt;0.05) compared to their urban counterparts. There were no rural-urban differences in prescription of medications for hypertension, diabetes and hyperlipidemia, and no differences in control of diabetes. The incidence of recurrent stroke was slightly higher in rural compared to urban areas (12.0 vs. 11.5 per 1000 person years, adjusted hazard ratio 1.09; 95% confidence interval 1.01 to 1.18). Conclusions: Rural and urban residents with prior stroke had similar prevalence and treatment of vascular risk factors, however, rural residence was associated with fewer physician visits, less screening for hyperlipidemia, and a slight increase in the risk of recurrent stroke. Ongoing efforts are needed to maintain equitable access to recommended ambulatory care services for secondary stroke prevention, and to address other social determinants of health in rural communities.