The associations between direct and delayed critical care unit admission with mortality and readmissions among patients with heart failure.

BACKGROUND: Although greater than 20% of patients hospitalized with heart failure (HF) are admitted to a critical care unit, associated outcomes, and costs have not been delineated. We determined 30-day mortality, 30-day readmissions, and hospital costs associated with direct or delayed critical care unit admission. METHODS: In a population-based analysis, we compared HF patients who were admitted to critical care directly from the emergency department (direct), after initial ward admission (delayed), or never admitted to critical care during their hospital stay (ward-only). RESULTS: Among 178,997 HF patients (median age 80 [IQR 71-86] years, 49.6% men) 36,175 (20.2%) were admitted to critical care during their hospitalization (April 2003 to March 2018). Critical care patients were admitted directly from the emergency department (direct, 81.9%) or after initial ward admission (delayed, 18.1%). Multivariable-adjusted hazard ratios (HR) for all-cause 30-day mortality were: 1.69 for direct (95% confidence interval [CI]; 1.55, 1.84) and 4.92 for delayed (95% CI; 4.26, 5.68) critical care-admitted compared to ward-only patients. Multivariable-adjusted repeated events analysis demonstrated increased risk for all-cause 30-day readmission with both direct (HR 1.04, 95% CI; 1.01, 1.08, P = .013) and delayed critical care unit admissions (HR 1.20, 95% CI; 1.13, 1.28, P < .001). Median 30-day costs were $12,163 for direct admissions, $20,173 for delayed admissions, and $9,575 for ward-only patients (P < .001). CONCLUSIONS: While critical care unit admission indicates increased risk of mortality and readmission at 30 days, those who experienced delayed critical care unit admission exhibited the highest risk of death and highest costs of care.

Prospective Validation of the Emergency Heart Failure Mortality Risk Grade for Acute Heart Failure.

BACKGROUND: Improved risk stratification of acute heart failure in the emergency department may inform physicians' decisions regarding patient admission or early discharge disposition. We aimed to validate the previously-derived Emergency Heart failure Mortality Risk Grade for 7-day (EHMRG7) and 30-day (EHMRG30-ST) mortality. METHODS: We conducted a multicenter, prospective validation study of patients with acute heart failure at 9 hospitals. We surveyed physicians for their estimates of 7-day mortality risk, obtained for each patient before knowledge of the model predictions, and compared these with EHMRG7 for discrimination and net reclassification improvement. We also prospectively examined discrimination of the EHMRG30-ST model, which incorporates all components of EHMRG7 as well as the presence of ST-depression on the 12-lead ECG. RESULTS: We recruited 1983 patients seeking emergency department care for acute heart failure. Mortality rates at 7 days in the 5 risk groups (very low, low, intermediate, high, and very high risk) were 0%, 0%, 0.6%, 1.9%, and 3.9%, respectively. At 30 days, the corresponding mortality rates were 0%, 1.9%, 3.9%, 5.9%, and 14.3%. Compared with physician-estimated risk of 7-day mortality (PER7; c-statistic, 0.71; 95% CI, 0.64-0.78) there was improved discrimination with EHMRG7 (c-statistic, 0.81; 95% CI, 0.75-0.87; P=0.022 versus PER7) and with EHMRG7 combined with physicians' estimates (c-statistic, 0.82; 95% CI, 0.76-0.88; P=0.003 versus PER7). Model discrimination increased nonsignificantly by 0.014 (95% CI, -0.009-0.037) when physicians' estimates combined with EHMRG7 were compared with EHMRG7 alone ( P=0.242). The c-statistic for EHMRG30-ST alone was 0.77 (95% CI, 0.73-0.81) and 30-day model discrimination increased nonsignificantly by addition of physician-estimated risk to 0.78 (95% CI, 0.73-0.82; P=0.187). Net reclassification improvement with EHMRG7 was 0.763 (95% CI, 0.465-1.062) when assessed continuously and 0.820 (0.560-1.080) using risk categories compared with PER7. CONCLUSIONS: A clinical model allowing simultaneous prediction of mortality at both 7 and 30 days identified acute heart failure patients with a low risk of events. Compared with physicians' estimates, our multivariable model was better able to predict 7-day mortality and may guide clinical decisions. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02634762.

Development and validation of a multivariable prediction model for major adverse cardiovascular events after early stage breast cancer: a population-based cohort study.

AIMS: Develop a score to predict the risk of major adverse cardiovascular events (MACE) after early stage breast cancer (EBC) to facilitate personalized decision-making about potentially cardiotoxic treatments and interventions to reduce cardiovascular risk. METHODS AND RESULTS: Using administrative databases, we assembled a cohort of women diagnosed with EBC in Ontario between 2003 and 2014, with follow-up through 2015. Two-thirds of the cohort were used for risk score derivation; the remainder were reserved for its validation. The outcome was a composite of hospitalizations for acute myocardial infarction, unstable angina, transient ischaemic attack, stroke, peripheral vascular disease, heart failure (HF), or cardiovascular death. We developed the score by regressing MACE incidence against candidate predictors in the derivation sample using a Fine-Gray model. Discrimination was assessed in the validation sample using Wolber's c-index for prognostic models with competing risks, while calibration was assessed by comparing predicted and observed MACE incidence. The risk score was derived in 60 294 women and validated in 29 810 women. Age, hypertension, diabetes, ischaemic heart disease, atrial fibrillation, HF, cerebrovascular disease, peripheral vascular disease, chronic obstructive pulmonary disease, and chronic kidney disease were significantly associated with MACE incidence and incorporated into the score. Ten-year MACE incidence was >40-fold higher for patients in the highest score decile compared to the lowest. The c-index was 81.9% (95% confidence interval 80.9-82.9%) at 5 years and 79.8% (78.8-80.8%) at 10 years in the validation cohort, with good agreement between predicted and observed MACE incidence. CONCLUSION: Cardiovascular prognosis after EBC can be estimated using patients' pre-treatment characteristics.

International population-based health surveys linked to outcome data: A new resource for public health and epidemiology.

BACKGROUND: National health surveys linked to vital statistics and health care information provide a growing source of individual-level population health data. Pooling linked surveys across jurisdictions would create comprehensive datasets that are larger than most existing cohort studies, and that have a unique international and population perspective. This paper's objectives are to examine the feasibility of pooling linked population health surveys from three countries, facilitate the examination of health behaviours, and present useful information to assist in the planning of international population health surveillance and research studies. DATA AND METHODS: The design, methodologies and content of the Canadian Community Health Survey (2003 to 2008), the United States National Health Interview Survey (2000, 2005) and the Scottish Health Survey (SHeS) (2003, 2008 to 2010) were examined for comparability and consistency. The feasibility of creating common variables for measuring smoking, alcohol consumption, physical activity and diet was assessed. Sample size and estimated mortality events were collected. RESULTS: The surveys have comparable purposes, designs, sampling and administration methodologies, target populations, exclusions, and content. Similar health behaviour questions allow for comparable variables to be created across the surveys. However, the SHeS uses a more detailed risk factor evaluation for alcohol consumption and diet data. Therefore, comparisons of alcohol consumption and diet data between the SHeS and the other two surveys should be performed with caution. Pooling these linked surveys would create a dataset with over 350,000 participants, 28,424 deaths and over 2.4 million person-years of follow-up. DISCUSSION: Pooling linked national population health surveys could improve population health research and surveillance. Innovative methodologies must be used to account for survey dissimilarities, and further discussion is needed on how to best access and analyze data across jurisdictions.

Multiple Arterial Grafting Is Associated With Better Outcomes for Coronary Artery Bypass Grafting Patients.

BACKGROUND: Observational studies have shown better survival in patients undergoing coronary artery bypass grafting (CABG) with 2 arterial grafts compared with 1. However, whether a third arterial graft is associated with incremental benefit remains uncertain. We sought to analyze the outcomes of 3 versus 2 arterial grafts during CABG. As a secondary objective, we compared CABG with 2 or 3 arterial grafts (multiple arterial grafts [MAG]) with CABG using a single arterial graft (SAG). METHODS: Retrospective cohort analyses of all patients undergoing primary isolated CABG in Ontario, Canada, from October 2008 to March 2016. Propensity score matching was performed between patients with 3 arterial grafts (3Art group) versus 2 (2Art group). The primary outcome was time to first event of a composite of death, myocardial infarction, stroke, and repeat revascularization (major adverse cardiac and cerebrovascular events). Additional analyses were performed to evaluate the association between MAG versus SAG and long-term outcomes using propensity score matching. RESULTS: Fifty thousand, two hundred thirty patients underwent isolated CABG during our study period; 3044 (6.1%) and 8253 (16.4%) patients had 3 and 2 arterial grafts, respectively, resulting in 2789 propensity score matching pairs for the primary analyses. Mean and maximum follow-up was 4.2 and 8.5 years, respectively. Radial artery grafting was more common in the 3Art versus 2Art group (79.3% versus 65.6%, P<0.01). In-hospital outcomes were not significantly different, including death (3Art 0.8% versus 2Art 0.5%, P=0.26). Up to 8 years, there were no differences in major adverse cardiac and cerebrovascular events (3Art 27%, 95% confidence interval [CI], 24% to 30% versus 2Art 25%, 95% CI, 22% to 28%; hazard ratio [HR], 1.08, 95% CI, 0.94-1.25), death (HR, 1.08; 95% CI, 0.90-1.29), myocardial infarction (HR, 1.15; 95% CI, 0.87-1.51), stroke (HR, 1.39; 95% CI, 0.95-2.06), or repeat revascularization (HR, 1.04; 95% CI, 0.82-1.32). When evaluating MAG versus SAG, 8629 patient pairs were formed using propensity score matching. At 8 years, cumulative incidences of major adverse cardiac and cerebrovascular events (HR, 0.82, 95% CI, 0.77-0.88), survival (HR, 0.80; 95% CI, 0.73-0.88), repeat revascularization (HR, 0.79; 95% CI, 0.69-0.90), and myocardial infarction (HR, 0.83; 95% CI, 0.72-0.97) were superior in the MAG group. CONCLUSIONS: CABG with 3 arterial grafts was not associated with increased in-hospital death nor with better clinical outcomes at 8-year follow-up, compared with CABG with 2 arterial grafts. MAG was associated with superior outcomes compared with SAG.

Incidence of Heart Failure Among Immigrants to Ontario, Canada: A CANHEART Immigrant Study.

BACKGROUND: Several known traditional cardiovascular risk factors contribute to the development of heart failure (HF); however, whether ethnicity is also an important predictor is not well established. We determined the incidence of hospitalization for HF among ethnic groups in Ontario, Canada, and examined differences in risk factor prevalence that may contribute to disparities in HF hospitalization incidence between groups. METHODS AND RESULTS: We conducted a retrospective observational study from 2008 to 2012 with the use of a linked cohort derived from population-based health administrative, clinical, and survey datasets. We followed 895,823 recent immigrants from 8 ethnic groups and 5.3 million long-term residents aged 40-105 years for incident HF hospitalization. Sex-stratified age-standardized HF incidence was lower among all immigrant groups than long-term residents. Among immigrants, Black men and West Asian women had the highest incidence of hospitalizations for HF (1.19 and 1.60 per 1000 person-years, respectively), and East Asians of both sexes had the lowest incidence. After adjusting for sociodemographic characteristics, comorbidities, and other risk factors, the association between ethnicity and HF hospitalization risk remained significant. CONCLUSIONS: HF hospitalization incidence varies widely among ethnic immigrant groups, highlighting the importance of ethnicity as a potential independent risk factor for HF development.

Trends in cardiovascular care and event rates among First Nations and other people with diabetes in Ontario, Canada, 1996-2015.

BACKGROUND: Rates of cardiovascular disease among people with diabetes have declined over the last 20-30 years. To determine whether First Nations people have experienced similar declines, we compared time trends in rates of cardiac event and disease management among First Nations people with diabetes and other people with diabetes in Ontario, Canada. METHODS: We conducted a retrospective cohort study of patients aged 20 to 105 years with diabetes between 1996 and 2015, using linked health administrative databases. Outcomes compared were the annual incidence of each admission to hospital for myocardial infarction and heart failure, and death owing to ischemic heart disease. Management indicators were coronary revascularization and prescription rates for cardioprotective medications. Overall rates and annual percent changes were compared using Poisson regression. RESULTS: Incidence rates for all cardiac outcomes decreased over the study period. The greatest relative annual decline among First Nations men and women were observed in ischemic heart disease death (4.4%, 95% confidence interval [CI] 3.0 to 5.9) and heart failure (5.4%, 95% CI 4.5 to 6.4), respectively. Among other men and women, the greatest annual declines were seen in ischemic heart disease death (6.3%, 95% CI 6.1 to 6.5 and 7.3%, 95% CI 7.1 to 7.6, respectively). However, all absolute cardiac event rates were higher among First Nations people (p < 0.001). Coronary artery revascularization procedures and prescriptions for cardioprotective medications increased among First Nations people, while only prescriptions increased among other people. INTERPRETATION: Over the last 20 years, the incidence of cardiac events has declined among First Nations people with diabetes, but remains higher than other people with diabetes in Ontario. For continued reductions in incidence, future efforts need to recognize First Nations people's unique social and cultural determinants of health.

Association between transitional care factors and hospital readmission after transcatheter aortic valve replacement: a retrospective observational cohort study.

BACKGROUND: Studies have shown that patients who undergo trans-catheter aortic valve replacement (TAVR) have high rates of hospital readmission. Our objectives were to identify the causes of readmission after TAVR, determine whether transitional care factors were associated with a reduction in readmission and to identify other predictors that could be used to target quality improvement efforts. METHODS: We conducted a chart abstraction study that included all patients who underwent TAVR in Ontario, Canada between 2007 and 2013 and survived to hospital discharge. These data were linked to provincial administrative databases. The association between transitional care factors (home care, rehabilitation, family physician and cardiologist follow-up) and 1-year hospital readmission was examined using a time-to-event analysis. Cause-specific hazards models were used to account for the competing risk of death. RESULTS: There were 937 patients in the cohort and the rate of readmission at 1-year was 49%. The most common causes of readmission were heart failure and bleeding. Rehabilitation (HR 1.34, 95% CI 1.11-1.62; p = 0.002) and cardiologist follow-up (HR 1.41, 95% CI 1.14-1.75; p = 0.002) were both associated with higher readmission rates. While, home care (HR 1.18, 95% CI 0.96-1.44; p = 0.12) and family physician follow-up (HR 1.04, 95% CI 0.85-1.28; p = 0.71) were not associated with readmission. CONCLUSION: Readmission post TAVR is common; however, we did not identify any transitional care factors associated with reductions in hospital readmission. This suggests ongoing research is required to identify targets for improvement in post-procedural care.

Long-term Outcomes of Carotid Endarterectomy Versus Stenting in a Multicenter Population-based Canadian Study.

OBJECTIVE: To compare the long-term outcomes of patients treated with carotid endarterectomy and carotid-artery stenting. BACKGROUND: Evidence for the long-term safety and efficacy of carotid-artery stenting compared with endarterectomy is accumulating from randomized trials. However, comparative data on the long-term outcomes of carotid revascularization strategies in real world practice are lacking. METHODS: We conducted a population-based, multicenter, observational cohort study using validated linked databases from Ontario, Canada. We identified all individuals treated with carotid endarterectomy and stenting (2002-2014), and followed them up to 2015. We compared long-term (up to 13 years) and 30-day outcomes of each strategy using multilevel multivariable Cox proportional-hazards models, and conducted confirmatory analyses using propensity-score matching methods. RESULTS: In all, 15,525 patients received carotid-artery revascularization. Rate of the primary composite outcome of 30-day death, stroke, or myocardial infarction plus any stroke during 13-year follow-up was higher with stenting (16.3%) compared with endarterectomy (9.7%) [adjusted hazard ratio (HR) 1.57, 95% confidence interval (CI) 1.43-1.73, P < 0.001). The increased risk with stenting was observed regardless of age, sex, intervention year, carotid-artery symptoms, or diabetes. The primary outcome was driven by higher rates of 30-day stroke (adjusted HR 1.59, 95% CI 1.29-1.95), 30-day death (adjusted HR 2.62, 95% CI 2.20-3.13), and long-term stroke >30 days after the procedure (adjusted HR 1.47, 95% CI 1.36-1.59) with stenting; 30-day myocardial infarction was lower with stenting (adjusted HR 0.70, 95% CI 0.57-0.86). These results were confirmed with 1:2 propensity-score matching (HR for primary composite outcome with stenting 1.55, 95% CI 1.31-1.83, P < 0.001). CONCLUSIONS: Compared with carotid endarterectomy, stenting was associated with an early and sustained approximately 55% increased hazard for major adverse events over long-term follow-up. Although nonrandomized, these results raise potential concerns about the interchangeability of carotid endarterectomy and stenting in the context of actual clinical practice.

A clinical decision instrument to predict 30-day death and cardiovascular hospitalizations after an emergency department visit for atrial fibrillation: The Atrial Fibrillation in the Emergency Room, Part 2 (AFTER2) study.

BACKGROUND: In previous work, we derived and validated a tool that predicts 30-day mortality in emergency department atrial fibrillation (AF) patients. The objective of this study was to derive and validate a tool that predicts a composite of 30-day mortality and return cardiovascular hospitalizations. METHODS: This retrospective cohort study at 24 emergency departments in Ontario, Canada, included patients with a primary diagnosis of AF who were seen between April 2008 and March 2009. We assessed a composite outcome of 30-day mortality and subsequent hospitalizations for a cardiovascular reason, including stroke. RESULTS: Of 3,510 patients, 2,343 were randomly selected for the derivation cohort, leaving 1,167 in the validation cohort. The composite outcome occurred in 227 (9.7%) and 125 (10.7%) patients in the derivation and validation cohorts, respectively. Eleven variables were independently associated with the outcome: older age, not taking anticoagulation, HAS-BLED score of ≥3, 3 laboratory results (positive troponin, supratherapeutic international normalized ratio, and elevated creatinine), emergency department administration of furosemide, and 4 patient comorbidities (heart failure, chronic obstructive lung disease, cancer, dementia). In the validation cohort, the observed 30-day outcomes in the 5 risk strata that were defined using the derivation cohort were 2.0%, 6.6%, 10.7%, 12.5%, and 20.0%. The c statistic was 0.73 and 0.69 in the derivation and validation cohort, respectively. CONCLUSIONS: Using a population-based sample, we derived and validated a tool that predicts the risk of early death and rehospitalization for a cardiovascular reason in emergency department AF patients. The tool can offer information to managing physicians about the risk of death and rehospitalization for AF patients seen in the in emergency department, as well as identify patient groups for future targeted interventions aimed at preventing these outcomes.

Trends in the incidence and outcomes of patients with aortic stenosis hospitalization.

BACKGROUND: Although the burden of aortic stenosis (AS) on our health care system is expected to rise, little is known regarding its epidemiology at the population level. Our primary objective was to evaluate trends in AS hospitalization, treatment and outcomes. METHODS: We performed a population-based observational study including 37,970 patients newly hospitalized with AS from 2004 and 2013 in Ontario, Canada. We calculated age- and sex-standardized rate of AS hospitalization through direct standardization. The independent association between year of the hospitalization, and 30-day and 1-year mortality rate was evaluated using logistic regression models to account for temporal changes in patient characteristics. RESULTS: The overall age- and sex-standardized AS hospitalization rate increased slightly from 36 per 100,000 in 2004 to 39 per 100,000 in 2013. A substantial increase was seen in patients ≥85years, where hospitalization rates increased 29% from 400 to 516 per 100,000 from 2004 to 2013 (P<.001). In this study period, 36.2% of patients received aortic valve interventions within 30days of hospitalization. Among treated patients, an improving mortality trend was observed in which the adjusted odds ratio (OR) was significantly lower in 2013 as compared to 2004 (OR 0.55 for 30-day mortality, 0.74 for 1-year morality). In contrast, no significant temporal change in mortality was seen among patients without aortic valve intervention. CONCLUSION: AS hospitalizations in the elderly increased significantly beyond that was expected from population growth. Many AS patients did not receive aortic valve intervention after hospitalization. Mortality among the treated patients improved significantly over time.

Sex-Specific Trends in Incidence and Mortality for Urban and Rural Ambulatory Patients with Heart Failure in Eastern Ontario from 1994 to 2013.

BACKGROUND: Differences in outcomes have previously been reported between urban and rural settings across a multitude of chronic diseases. Whether these discrepancies have changed over time, and how sex may influence these findings is unknown for patients with ambulatory heart failure (HF). We examined the temporal incidence and mortality trends by geography in these patients. METHODS AND RESULTS: We conducted a retrospective cohort study of 36,175 eastern Ontario residents who were diagnosed with HF in an outpatient setting from 1994 to 2013. The primary outcome was 1-year mortality. We examined temporal changes in mortality risk factors with the use of multivariable Cox proportional hazard models. The incidence of HF decreased in women and men across both rural and urban settings. Age-standardized mortality rates also decreased over time in both sexes but remained greater in rural men compared with rural women. CONCLUSIONS: The incidence of HF in the ambulatory setting was greater for men than women and greater in rural than urban areas, but mortality rates remained higher in rural men compared with rural women. Further research should focus on ways to reduce this gap in the outcomes of men and women with HF.

Association between operator specialty and outcomes after carotid artery revascularization.

OBJECTIVE: To examine the association between operator specialty and 30-day outcomes among patients undergoing carotid endarterectomy and carotid artery stenting. METHODS: We conducted a population-based, observational cohort study of all individuals who underwent carotid endarterectomy or stenting in Ontario, Canada (population, 13.6 million) between April 1, 2002, and March 1, 2015, using administrative claims databases. We stratified endarterectomy and stenting patients according to operator specialty, and followed them for 30 days after the procedure. For carotid endarterectomy, we compared outcomes between vascular surgeons and nonvascular surgeons. For carotid artery stenting, we compared outcomes between radiologists and neurosurgeons. We built multilevel multivariable logistic regression models adjusted for patient demographics, comorbidities, carotid artery symptom status, and annual institutional and operator volume to examine rates of 30-day stroke or death. RESULTS: A total of 16,544 patients were studied (n = 14,301 endarterectomy and n = 2243 stenting). Vascular surgeons performed the majority (55.7%) of carotid endarterectomy procedures, followed by neurosurgeons (21.0%), general surgeons (15.3%), and cardiac surgeons (7.9%). Radiologists (82.5%) and neurosurgeons (17.5%) performed carotid artery stenting. In the endarterectomy group, the risk of stroke or death was higher among patients treated by nonvascular surgeons (4.0%) compared with vascular surgeons (2.9%; adjusted odds ratio [OR], 1.32; 95% confidence interval [CI], 1.08-1.62; P = .008). This difference was driven by a higher rate of stroke among nonvascular surgery-treated patients (3.6%) compared with vascular surgery-treated patients (2.5%; adjusted OR, 1.38; 95% CI, 1.11-1.71). The risk of death was similar between the two groups. With respect to specific nonvascular surgery specialties, the rate of 30-day stroke or death was higher in endarterectomy patients treated by neurosurgeons (4.1%; adjusted OR, 1.27; 95% CI, 1.00-1.61) and cardiac surgeons (4.4%; adjusted OR, 1.54; 95% CI, 1.04-2.30) compared with vascular surgeons (2.9%). Patients who underwent carotid artery stenting by radiologists vs neurosurgeons experienced 30-day stroke or death at similar rates (8.0% vs 7.9%, respectively; adjusted OR, 1.07; 95% CI, 0.66-1.74; P = .79). CONCLUSIONS: The risk for periprocedural stroke or death was significantly higher among carotid endarterectomy patients treated by nonvascular surgeons (neurosurgeons and cardiac surgeons) compared with vascular surgeons. Operator specialty did not seem to have a significant effect on periprocedural outcomes among patients who underwent carotid artery stenting. These results can have implications for physician referral practices and local policies.

Development and validation of a cardiovascular disease risk-prediction model using population health surveys: the Cardiovascular Disease Population Risk Tool (CVDPoRT).

BACKGROUND: Routinely collected data from large population health surveys linked to chronic disease outcomes create an opportunity to develop more complex risk-prediction algorithms. We developed a predictive algorithm to estimate 5-year risk of incident cardiovascular disease in the community setting. METHODS: We derived the Cardiovascular Disease Population Risk Tool (CVDPoRT) using prospectively collected data from Ontario respondents of the Canadian Community Health Surveys, representing 98% of the Ontario population (survey years 2001 to 2007; follow-up from 2001 to 2012) linked to hospital admission and vital statistics databases. Predictors included body mass index, hypertension, diabetes, and multiple behavioural, demographic and general health risk factors. The primary outcome was the first major cardiovascular event resulting in hospital admission or death. Death from a noncardiovascular cause was considered a competing risk. RESULTS: We included 104 219 respondents aged 20 to 105 years. There were 3709 cardiovascular events and 818 478 person-years follow-up in the combined derivation and validation cohorts (5-year cumulative incidence function, men: 0.026, 95% confidence interval [CI] 0.025-0.028; women: 0.018, 95% 0.017-0.019). The final CVDPoRT algorithm contained 12 variables, was discriminating (men: C statistic 0.82, 95% CI 0.81-0.83; women: 0.86, 95% CI 0.85-0.87) and was well-calibrated in the overall population (5-year observed cumulative incidence function v. predicted risk, men: 0.28%; women: 0.38%) and in nearly all predefined policy-relevant subgroups (206 of 208 groups). INTERPRETATION: The CVDPoRT algorithm can accurately discriminate cardiovascular disease risk for a wide range of health profiles without the aid of clinical measures. Such algorithms hold potential to support precision medicine for individual or population uses. Study registration: ClinicalTrials.gov, no. NCT02267447.

Sex differences in outcomes of heart failure in an ambulatory, population-based cohort from 2009 to 2013.

BACKGROUND: Heart failure remains a substantial cause of morbidity and mortality in women. We examined the sex differences in heart failure incidence, mortality and hospital admission in a population-based cohort. METHODS: All Ontario residents who were diagnosed with heart failure in an ambulatory setting between Apr. 1, 2009, and Mar. 31, 2014, were included in this study. Incident cases of heart failure were captured through physician billing using a validated algorithm. Outcomes were mortality and hospital admission for heart failure within 1 year of the diagnosis. Probability of death and hospital admission were calculated using the Kaplan-Meier method. The hazard of death was assessed using a multivariable Cox proportional hazard model. RESULTS: A total of 90 707 diagnoses of heart failure were made in an ambulatory setting during the study period (47% women). Women were more likely to be older and more frail, and had different comorbidities than men. The incidence of heart failure decreased during the study period in both sexes. The mortality rate decreased in both sexes, but remained higher in women than men. The female age-standardized mortality rate was 89 (95% confidence interval [CI] 80-100) per 1000 in 2009 and 85 (95% CI 75-95) in 2013, versus male age-standardized mortality rates of 88 (95% CI 80-97) in 2009 and 83 (95% CI 75-91) in 2013. Conversely, the rates of incident heart failure hospital admissions after heart failure diagnosis decreased in men and increased in women. INTERPRETATION: Despite decreases in overall heart failure incidence and mortality in ambulatory patients, mortality rates remain higher in women than in men, and rates of hospital admission for heart failure increased in women and declined in men. Further studies should focus on sex differences in health-seeking behaviour, medical therapy and response to therapy to provide guidance for personalized care.

Factors associated with door-in to door-out delays among ST-segment elevation myocardial infarction (STEMI) patients transferred for primary percutaneous coronary intervention: a population-based cohort study in Ontario, Canada.

BACKGROUND: Compared to ST-segment elevation myocardial infarction (STEMI) patients who present at centres with catheterization facilities, those transferred for primary percutaneous coronary intervention (PCI) have substantially longer door-in to door-out (DIDO) times, where DIDO is defined as the time interval from arrival at a non-PCI hospital, to transfer to a PCI hospital. We aimed to identify potentially modifiable factors to improve DIDO times in Ontario, Canada and to assess the impact of DIDO times on 30-day mortality. METHODS: A population-based, retrospective cohort study of 966 STEMI patients transferred for primary PCI in Ontario in 2012 was conducted. Baseline factors were examined across timely DIDO status. Multivariate logistic regression was used to examine independent predictors of timely DIDO as well as the association between DIDO times and 30-day mortality. RESULTS: The median DIDO time was 55 min, with 20.1% of patients achieving the recommended DIDO benchmark of ≤30 min. Age (OR> 75 vs 18-55 0.30, 95% CI: 0.16-0.56), symptom-to-first medical contact (FMC) time (OR61-120mins vs < 60mins 0.60, 95% CI: 0.39-0.90; OR>120mins vs < 60mins 0.53, 95% CI:0.35-0.81) and emergency medical services transport with a pre-hospital electrocardiogram (ECG) (OREMS transport + ECG vs self-transport 2.63, 95% CI:1.59-4.35) were the strongest predictors of timely DIDO. Patients with timely ECG were more likely to have recommended DIDO times (33.0% vs 12.3%; P < 0.001). A significantly higher proportion of those who met the DIDO benchmark had timely FMC-to-balloon times (78.7% vs 27.4%; P < 0.001). Compared to patients with DIDO time ≤ 30 min, those with DIDO times > 90 min had significantly higher adjusted 30-day mortality rates (OR 2.82, 95% CI:1.10-7.19). CONCLUSIONS: While benchmark DIDO times were still rarely achieved in the province, we identified several potentially modifiable factors in the STEMI system that might be targeted to improve DIDO times. Our findings that patients who received a pre-hospital ECG were still being transferred to non-PCI capable centres suggest strategies addressing this gap may improve patient outcomes.

Validation of abdominal aortic aneurysm repair codes in Ontario administrative data.

PURPOSE: To determine the positive predictive values (PPV) of Ontario administrative data codes for the identification of open (OSR) and endovascular (EVAR) repairs of elective (eAAA) and ruptured (rAAA) abdominal aortic aneurysms. METHODS: We randomly identified 319 eAAA and rAAA repairs at two Toronto hospitals between April 2003 and March 2015, using administrative health data in Ontario, Canada. International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) codes I71.3 and I71.4, were used to identify rAAA and eAAA patients, respectively. A blinded retrospective chart review was conducted and served as the gold standard comparator. Re-abstracted records were compared to Canadian Classification of Health Interventions (CCI) and Ontario Health Insurance Plan (OHIP) codes in the Canadian Institute for Health Information Discharge Abstract Database (CIHI-DAD) and OHIP databases. We calculated the PPV and 95% confidence intervals (95% CI) of individual and combined procedure and billing codes for elective and ruptured OSR and EVAR (eOSR, eEVAR, rOSR, and rEVAR). RESULTS: Permutation of codes allowed identification of eOSR with 95% PPV (95% CI 88, 98), eEVAR with 96% PPV (95% CI 90, 99), rOSR with 87% PPV (95% CI 79, 93) and rEVAR with 91% PPV (95% CI 59, 100). CONCLUSIONS: Diagnostic, procedure and billing code combinations allow identification of eOSR, eEVAR, rOSR and rEVAR patients in Ontario administrative data with a high degree of certainty.

Interventions Supporting Long-term Adherence aNd Decreasing cardiovascular events (ISLAND): Pragmatic randomized trial protocol.

BACKGROUND: Guidelines recommend cardiac rehabilitation and long-term use of cardiac medications for most patients who have had a myocardial infarction (MI), but adherence to these secondary prevention treatments is suboptimal. METHODS: This is a multicenter, pragmatic, 3-arm randomized trial. Eligible patients (n = 2,742) with obstructive coronary artery disease are randomized post-MI to usual care or 1 of 2 intervention arms. Patients in the first intervention arm receive mail-outs sent on behalf of their cardiologist at 4, 8, 20, 32, and 44 weeks post-MI; content is designed to address determinants of adherence and facilitate discussion between the patient and their health care team. Patients in the second intervention arm receive mail-outs plus automated interactive voice response system telephone calls 2 weeks after each letter, as well as a telephone call by trained lay health workers if the interactive voice response system identifies challenges with adherence. Outcomes are assessed 12 months post-MI via patient self-report and administrative data sources. Co-primary outcomes are adherence to cardiac medications and completion of cardiac rehabilitation. Secondary outcomes include cardiovascular events and mortality. An embedded, theory-informed process evaluation will explore the mechanism of action; an economic evaluation is also planned. CONCLUSIONS: We describe a complete program evaluation of a highly pragmatic, health-system intervention to support adherence to recommended treatments. Research ethics boards approved waiver of consent for patients enrolled in the trial with provision of multiple opportunities to opt out and a debrief at the time of outcome assessment. The methods used here may provide a model for similar interventions.

Regional variations in ambulatory care and incidence of cardiovascular events.

BACKGROUND: Variations in the prevalence of traditional cardiac risk factors only partially account for geographic variations in the incidence of cardiovascular disease. We examined the extent to which preventive ambulatory health care services contribute to geographic variations in cardiovascular event rates. METHODS: We conducted a cohort study involving 5.5 million patients aged 40 to 79 years in Ontario, Canada, with no hospital stays for cardiovascular disease as of January 2008, through linkage of multiple population-based health databases. The primary outcome was the occurrence of a major cardiovascular event (myocardial infarction, stroke or cardiovascular-related death) over the following 5 years. We compared patient demographics, cardiac risk factors and ambulatory health care services across the province's 14 health service regions, known as Local Health Integration Networks (LHINs), and evaluated the contribution of these variables to regional variations in cardiovascular event rates. RESULTS: Cardiovascular event rates across LHINs varied from 3.2 to 5.7 events per 1000 person-years. Compared with residents of high-rate LHINs, those of low-rate health regions received physician services more often (e.g., 4.2 v. 3.5 mean annual family physician visits, p value for LHIN-level trend = 0.01) and were screened for risk factors more often. Low-rate LHINs were also more likely to achieve treatment targets for hypercholes-terolemia (51.8% v. 49.6% of patients, p = 0.03) and controlled hypertension (67.4% v. 53.3%, p = 0.04). Differences in patient and health system factors accounted for 74.5% of the variation in events between LHINs, of which 15.5% was attributable to health system factors alone. INTERPRETATION: Preventive ambulatory health care services were provided more frequently in health regions with lower cardiovascular event rates. Health system interventions to improve equitable access to preventive care might improve cardiovascular outcomes.

The Incidence of Major Cardiovascular Events in Immigrants to Ontario, Canada: The CANHEART Immigrant Study.

BACKGROUND: Immigrants from ethnic minority groups represent an increasing proportion of the population in many high-income countries but little is known about the causes and amount of variation between various immigrant groups in the incidence of major cardiovascular events. METHODS AND RESULTS: We conducted the Cardiovascular Health in Ambulatory Care Research Team (CANHEART) Immigrant study, a big data initiative, linking information from Citizenship and Immigration Canada's Permanent Resident database to nine population-based health databases. A cohort of 824 662 first-generation immigrants aged 30 to 74 as of January 2002 from eight major ethnic groups and 201 countries of birth who immigrated to Ontario, Canada between 1985 and 2000 were compared to a reference group of 5.2 million long-term residents. The overall 10-year age-standardized incidence of major cardiovascular events was 30% lower among immigrants compared with long-term residents. East Asian immigrants (predominantly ethnic Chinese) had the lowest incidence overall (2.4 in males, 1.1 in females per 1000 person-years) but this increased with greater duration of stay in Canada. South Asian immigrants, including those born in Guyana had the highest event rates (8.9 in males, 3.6 in females per 1000 person-years), along with immigrants born in Iraq and Afghanistan. Adjustment for traditional risk factors reduced but did not eliminate differences in cardiovascular risk between various ethnic groups and long-term residents. CONCLUSIONS: Striking differences in the incidence of cardiovascular events exist among immigrants to Canada from different ethnic backgrounds. Traditional risk factors explain part but not all of these differences.