Maternal Health Outcomes After Pregnancy-Associated Stroke: A Population-Based Study With 19 Years of Follow-Up.

BACKGROUND: Pregnancy-associated stroke carries high short-term morbidity and mortality, but data on subsequent maternal outcomes are limited. We evaluated long-term maternal health outcomes after pregnancy-associated stroke. METHODS: In this retrospective cohort study, we used administrative data to identify pregnant adults aged ≤49 years with stroke between 2002-2020 in Ontario, Canada and 2 comparison groups: (1) non-pregnant female patients with stroke and (2) pregnant patients without stroke. Patients who survived the index admission were followed until 2021. After propensity score matching, we used Cox regression with a robust variance estimator to compare pregnant patients with stroke and the 2 comparison groups for the composite outcome of death and all-cause non-pregnancy readmission. Where proportional hazard assumption was not met, we reported time-varying hazard ratios (HR) with 95% CIs by modeling the log-hazard ratio as a function of time using restricted cubic splines. RESULTS: We identified 217 pregnant patients with stroke, 7604 non-pregnant patients with stroke, and 1 496 256 pregnant patients without stroke. Of the 202 pregnant patients with stroke who survived the index stroke admission, 41.6% (6.8 per 100 person-years) subsequently died or were readmitted during follow-up. Median follow-up times were 5 years (pregnancy-associated stroke), 3 years (non-pregnant stroke), and 8 years (pregnant without stroke). Pregnant patients with stroke had a lower hazard of death and all-cause readmission compared with non-pregnant patients with stroke at 1-year follow-up (HR, 0.64 [95% CI, 0.44-0.94]), but this association did not persist during longer-term follow-up. Conversely, pregnant patients with stroke had higher hazard of death and readmission compared with pregnant patients without stroke at 1-year follow-up (HR, 5.70 [95% CI, 3.04-10.66]), and this association persisted for a decade. CONCLUSIONS: Stroke during pregnancy is associated with long-term health consequences. It is essential to transition care postpartum to primary or specialty care to optimize vascular health.

Quantifying COPD as a risk factor for cardiac disease in a primary prevention cohort.

BACKGROUND: Despite COPD being a risk factor for cardiovascular disease (CVD) and knowing that risk stratification for CVD primary prevention is important, little is known about the real-world risk of CVD among people with COPD with no history of CVD. This knowledge would inform CVD management for people with COPD. The current study aimed to examine the risk of major adverse cardiovascular events (MACE) (including acute myocardial infarction, stroke or cardiovascular death) in a large, complete real-world population with COPD without previous CVD. METHODS: We conducted a retrospective population cohort study using health administrative, medication, laboratory, electronic medical record and other data from Ontario, Canada. People without a history of CVD with and without physician-diagnosed COPD were followed between 2008 and 2016, and cardiac risk factors and comorbidities compared. Sequential cause-specific hazard models adjusting for these factors determined the risk of MACE in people with COPD. RESULTS: Among ∼5.8 million individuals in Ontario aged ≥40 years without CVD, 152 125 had COPD. After adjustment for cardiovascular risk factors, comorbidities and other variables, the rate of MACE was 25% higher in persons with COPD compared with those without COPD (hazard ratio 1.25, 95% CI 1.23-1.27). CONCLUSIONS: In a large real-world population without CVD, people with physician-diagnosed COPD were 25% more likely to have a major CVD event, after adjustment for CVD risk and other factors. This rate is comparable to the rate in people with diabetes and calls for more aggressive CVD primary prevention in the COPD population.

Association of prior outpatient diabetes screening with cardiovascular events and mortality among people with incident diabetes: a population-based cohort study.

BACKGROUND: Outcomes of diabetes screening in contemporary, multi-ethnic populations are unknown. We examined the association of prior outpatient diabetes screening with the risks of cardiovascular events and mortality in Ontario, Canada. METHODS: We conducted a population-based cohort study using administrative databases among adults aged ≥ 20 years with incident diabetes diagnosed during 2014-2016. The exposure was outpatient diabetes screening performed within 3 years prior to diabetes diagnosis. The co-primary outcomes were (1) a composite of all-cause mortality and hospitalization for myocardial infarction, stroke, coronary revascularization, and (2) all-cause mortality (followed up until 2018). We calculated standardized rates of each outcome and conducted cause-specific hazard modelling to determine the adjusted hazard ratio (HR) of the outcomes, adjusting for prespecified confounders and accounting for the competing risk of death. RESULTS: We included 178,753 Ontarians with incident diabetes (70.2% previously screened). Individuals receiving prior screening were older (58.3 versus 53.4 years) and more likely to be women (49.6% versus 40.0%) than previously unscreened individuals. Individuals receiving prior screening had relatively lower standardized event rates than those without prior screening across all outcomes (composite: 12.8 versus 18.1, mortality: 8.2 versus 11.1 per 1000 patient-years). After multivariable adjustment, prior screening was associated with 34% and 32% lower risks of the composite (HR 0.66, 0.63-0.69) and mortality (0.68, 0.64-0.72) outcomes. Among those receiving prior screening, a result in the prediabetes range was associated with lower risks of the composite (0.82, 0.77-0.88) and mortality (0.71, 0.66-0.78) outcomes than a result in the normoglycemic range. CONCLUSIONS: Previously screened individuals with diabetes had lower risks of cardiovascular events and mortality versus previously unscreened individuals. Better risk assessment tools are needed to support wider and more appropriate uptake of diabetes screening, especially among young adults.

Comorbidity-stratified estimates of 30-day mortality risk by age for unvaccinated men and women with COVID-19: a population-based cohort study.

BACKGROUND: The mortality risk following COVID-19 diagnosis in men and women with common comorbidities at different ages has been difficult to communicate to the general public. The purpose of this study was to determine the age at which unvaccinated men and women with common comorbidities have a mortality risk which exceeds that of 75- and 65-year-old individuals in the general population (Phases 1b/1c thresholds of the Centre for Disease Control Vaccine Rollout Recommendations) following COVID-19 infection during the first wave. METHODS: We conducted a population-based retrospective cohort study using linked administrative datasets in Ontario, Canada. We identified all community-dwelling adults diagnosed with COVID-19 between January 1 and October 31st, 2020. Exposures of interest were age (modelled using restricted cubic splines) and the following conditions: major cardiovascular disease (recent myocardial infarction or lifetime history of heart failure); 2) diabetes; 3) hypertension; 4) recent cancer; 5) chronic obstructive pulmonary disease; 6) Stages 4/5 chronic kidney disease (CKD); 7) frailty. Logistic regression in the full cohort was used to estimate the risk of 30-day mortality for 75- and 65-year-old individuals. Analyses were repeated after stratifying by sex and medical condition to determine the age at which 30-day morality risk in strata exceed that of the general population at ages 65 and 75 years. RESULTS: We studied 52,429 individuals (median age 42 years; 52.5% women) of whom 417 (0.8%) died within 30 days. The 30-day mortality risk increased with age, male sex, and comorbidities. The 65- and 75-year-old mortality risks in the general population were exceeded at the youngest age by people with CKD, cancer, and frailty. Conversely, women aged < 65 years who had diabetes or hypertension did not have higher mortality than 65-year-olds in the general population. Most people with medical conditions (except for Stage 4-5 CKD) aged < 45 years had lower predicted mortality than the general population at age 65 years. CONCLUSION: The mortality risk in COVID-19 increases with age and comorbidity but the prognostic implications varied by sex and condition. These observations can support communication efforts and inform vaccine rollout in jurisdictions with limited vaccine supplies.

The risk of death or unplanned readmission after discharge from a COVID-19 hospitalization in Alberta and Ontario.

BACKGROUND: The frequency of readmissions after COVID-19 hospitalizations is uncertain, as is whether current readmission prediction equations are useful for discharge risk stratification of COVID-19 survivors or for comparing among hospitals. We sought to determine the frequency and predictors of death or unplanned readmission after a COVID-19 hospital discharge. METHODS: We conducted a retrospective cohort study of all adults (≥ 18 yr) who were discharged alive from hospital after a nonpsychiatric, nonobstetric, acute care admission for COVID-19 between Jan. 1, 2020, and Sept. 30, 2021, in Alberta and Ontario. RESULTS: Of 843 737 individuals who tested positive for SARS-CoV-2 by reverse transcription polymerase chain reaction during the study period, 46 412 (5.5%) were adults admitted to hospital within 14 days of their positive test. Of these, 8496 died in hospital and 34 846 were discharged alive (30 336 discharged after an index admission of ≤ 30 d and 4510 discharged after an admission > 30 d). One in 9 discharged patients died or were readmitted within 30 days after discharge (3173 [10.5%] of those with stay ≤ 30 d and 579 [12.8%] of those with stay > 30 d). The LACE score (length of stay, acuity, Charlson Comorbidity Index and number of emergency visits in previous 6 months) for predicting urgent readmission or death within 30 days had a c-statistic of 0.60 in Alberta and 0.61 in Ontario; inclusion of sex, discharge locale, deprivation index and teaching hospital status in the model improved the c-statistic to 0.73. INTERPRETATION: Death or readmission after discharge from a COVID-19 hospitalization is common and had a similar frequency in Alberta and Ontario. Risk stratification and interinstitutional comparisons of outcomes after hospital admission for COVID-19 should include sex, discharge locale and socioeconomic measures, in addition to the LACE variables.

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

BACKGROUND: There is a paucity of the literature on the relationship between frailty and excess mortality due to the COVID-19 pandemic. METHODS: 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. RESULTS: 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. CONCLUSION: Although frailty was associated with greater mortality, frailty did not modify the excess mortality associated with the pandemic.

Patient clustering in primary care settings: Outcomes and quality of care.

OBJECTIVE: To determine whether neighbours who share the same family physicians have better cardiovascular and health care outcomes. DESIGN: Retrospective cohort study using administrative health databases. SETTING: Ontario. PARTICIPANTS: The study population included 2,690,482 adult patients cared for by 1710 family physicians. INTERVENTIONS: Adult residents of Ontario were linked to their family physicians and the geographic distance between patients in the same panel or list was calculated. Using distance between patients within a panel to stratify physicians into quintiles of panel proximity, physicians and patients from close-proximity practices were compared with those from more-distant-proximity practices. Age- and sex-standardized incidence rates and hazard ratios from cause-specific hazards regression models were determined. MAIN OUTCOME MEASURES: The occurrence of a major cardiovascular event during a 5-year follow-up period (2008 to 2012). RESULTS: Patients of panels in the closest-proximity quintile lived an average of 3.9 km from the 10 closest patients in their panel compared with 12.4 km for the 10 closest patients of panels in the distant-proximity quintile. After adjusting for various patient and physician characteristics, patients in the most-distant-proximity practices had a 24% higher rate of cardiovascular events (adjusted hazard ratio=1.24 [95% CI 1.20 to 1.28], P<.001) than patients in the closest-proximity practices. Age- and sex-standardized all-cause mortality and total per patient health care costs were also lowest in the closest-proximity quintile. In sensitivity analyses restricted to large urban communities and to White long-term residents, results were similar. CONCLUSION: The better cardiovascular outcomes observed in close-proximity panels may be related to a previously unrecognized mechanism of social connectedness that extends the effectiveness of primary care practitioners.

A feasibility study for CODE-MI: High-sensitivity cardiac troponin-Optimizing the diagnosis of acute myocardial infarction/injury in women.

BACKGROUND: CODE-MI is a pan-Canadian, multicentre, stepped-wedge, cluster randomized trial that evaluates the impact of using the female-specific 99th percentile threshold for high-sensitivity cardiac troponin (hs-cTn) on the diagnosis, treatment and outcomes of women presenting to the emergency department (ED) with symptoms suggestive for myocardial ischemia. A feasibility study was conducted to estimate the number of eligible patients, the rate of the study's primary outcome under control conditions, and the statistical power to detect a clinically important difference in the primary outcome. METHODS: Using linked administrative data from 11 hospitals in Ontario, Canada, from October 2014 to September 2017, the following estimates were obtained: number of women presenting to the ED with symptoms suggestive of myocardial ischemia and a 24-hour peak hs-cTn value within the female-specific and overall thresholds (ie, primary cohort); the rate of the 1-year composite outcome of all-cause mortality, re-admission for nonfatal myocardial infarction, incident heart failure, or emergent/urgent coronary revascularization. Study power was evaluated via simulations. RESULTS: Overall, 2,073,849 ED visits were assessed. Among women, chest pain (with or without cardiac features) and shortness of breath were the most common complaints associated with a diagnosis of acute coronary syndrome. An estimated 7.7% of women with these complaints are eligible for inclusion in the primary cohort. The rate of the 1-year outcome in the primary cohort varied significantly across hospitals with a median rate of 12.2% (95%CI: 7.9%-17.7%). With 30 hospitals, randomized at 5-month intervals in 5 steps, approximately 19,600 women are expected to be included in CODE-MI, resulting in >82% power to detect a 20% decrease in the odds of the primary outcome at a 0.05 significance level. CONCLUSIONS: This feasibility study greatly enhanced the design of CODE-MI, allowed accurate evaluation of the study power, and demonstrated the strength of using linked administrative health data to guide the design of pragmatic clinical trials.

Derivation and validation of predictive indices for 30-day mortality after coronary and valvular surgery in Ontario, Canada.

BACKGROUND: Coronary artery bypass grafting (CABG) and surgical aortic valve replacement (AVR) are the 2 most common cardiac surgery procedures in North America. We derived and externally validated clinical models to estimate the likelihood of death within 30 days of CABG, AVR or combined CABG + AVR. METHODS: We obtained data from the CorHealth Ontario Cardiac Registry and several linked population health administrative databases from Ontario, Canada. We derived multiple logistic regression models from all adult patients who underwent CABG, AVR or combined CABG + AVR from April 2017 to March 2019, and validated them in 2 temporally distinct cohorts (April 2015 to March 2017 and April 2019 to March 2020). RESULTS: The derivation cohorts included 13 435 patients who underwent CABG (30-d mortality 1.73%), 1970 patients who underwent AVR (30-d mortality 1.68%) and 1510 patients who underwent combined CABG + AVR (30-d mortality 3.05%). The final models for predicting 30-day mortality included 15 variables for patients undergoing CABG, 5 variables for patients undergoing AVR and 5 variables for patients undergoing combined CABG + AVR. Model discrimination was excellent for the CABG (c-statistic 0.888, optimism-corrected 0.866) AVR (c-statistic 0.850, optimism-corrected 0.762) and CABG + AVR (c-statistic 0.844, optimism-corrected 0.776) models, with similar results in the validation cohorts. INTERPRETATION: Our models, leveraging readily available, multidimensional data sources, computed accurate risk-adjusted 30-day mortality rates for CABG, AVR and combined CABG + AVR, with discrimination comparable to more complex American and European models. The ability to accurately predict perioperative mortality rates for these procedures will be valuable for quality improvement initiatives across institutions.

Making Informed CHOICES: The Launch of a "Big Data" Pragmatic Trial to Improve Cholesterol Management and Prevent Heart Disease in Ontario.

Cholesterol-lowering statin medications are a safe and effective therapy to lower cholesterol and reduce the risk of cardiovascular events. Yet physician prescribing patterns and patient adherence remain suboptimal in Canada and the United States, often due to pervasive misconceptions. The Community Heart Outcomes Improvement and Cholesterol Education Study (CHOICES) is a pragmatic, registry-based, cluster randomized controlled trial that aims to improve cholesterol management through appropriate statin use in adults and to ultimately reduce cardiovascular events in high-risk communities across Ontario. The trial uses an innovative, multicomponent intervention and implementation approach that includes audit and feedback reports for family physicians and educational materials and tools for patients.

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.

Impact of Pneumococcal Vaccination on Pneumonia Hospitalizations and Related Costs in Ontario: A Population-Based Ecological Study.

Background: In Ontario, Canada, pneumococcal conjugate vaccine (PCV) was approved for infants in 2001 and became part of the publicly funded routine immunization schedule in 2005. We assessed the population-level impact of PCV on pneumonia hospitalizations and related costs. Methods: We used the difference-in-differences approach to evaluate the impact of pneumococcal vaccination on pneumonia hospitalizations and related costs, using nonpneumonia hospitalization as the control condition. We extracted monthly hospitalization costs, stratified by age group, from population-based health administrative data between April 1992 and March 2014. The study period was divided into 5 intervals: prevaccine period, availability of 7-valent PCV (PCV7) for private purchase, public funding for PCV7, replacement of PCV7 with 10-valent PCV (PCV10), and replacement of PCV10 with 13-valent PCV (PCV13). Results: A total of 1063700 pneumonia hospitalizations were recorded during the study period. In the vaccine-eligible age group, pneumonia hospitalizations declined by 34% (95% confidence interval, 32%-37%), 38% (32%-43%), and 45% (40%-51%) and hospitalization-related costs declined by 38% (25%-51%), 39% (33%-45%), and 46% (41%-52%) after public funding for PCV7, PCV10, and PCV13, respectively. Pneumonia hospitalizations and related costs also declined substantially for PCV-ineligible older children and elderly persons (aged >65 years). Conclusions: Our results suggest that the publicly funded PCV immunization program is responsible for substantial reductions in pneumonia hospitalizations and related healthcare costs, among both young children eligible for publicly funded vaccination and other age groups not included in the publicly funded program.

Association between dietary zinc intake and mortality among Chinese adults: findings from 10-year follow-up in the Jiangsu Nutrition Study.

PURPOSE: Population studies of the association between zinc intake and mortality yield inconsistent findings. Using data from Jiangsu Nutrition Study, we aimed to assess the association between zinc intake and mortality among Chinese adults. METHODS: We prospectively studied 2832 adults aged 20 years and older with a mean follow-up of 9.8 years. At baseline, food intake was measured by 3-day weighed food record (WFR) between September and December in 2002. Death occurrence was assessed in 2012 during a household visit as well as by data linkage with the regional death registry. Hazard ratios (HRs) and 95% CI were calculated using competing risks regression (CVD and cancer mortality) and Cox proportional hazards analysis (all-cause mortality). RESULTS: During 27,742 person-years of follow-up, there were 184 deaths [63 cancer deaths and 70 cardiovascular disease (CVD) deaths]. Dietary zinc to energy ratio was positively associated with cancer and all-cause mortality. Across quartiles of the zinc to energy ratio from low to high, the HR (95% CI) for all-cause mortality was 1.00, 1.80 (95% CI 1.10-2.95), 1.55 (95% CI 0.96-2.50), and 1.85 (95% CI 1.11-3.07), respectively. Comparing the extreme quartiles of the zinc to energy ratio, the HR for cancer mortality was 2.28 (95% CI 1.03-5.04). CONCLUSION: Zinc intake was positively related to all-cause mortality and cancer mortality.

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.

Comparing Costs of Noninvasive Cardiac Diagnostic Tests-a Population-Based Study.

INTRODUCTION: Noninvasive cardiac diagnostic tests (NITs) for the diagnosis of coronary artery disease have been estimated to cost >$3 billion annually in the United States alone and have recently undergone scrutiny over concerns of overuse. Consequently, comparing costs of different NIT testing strategies is of urgent importance to health care planning. METHODS: We utilized population-based administrative and clinical data from Ontario, Canada, to compare downstream costs between 4 available NIT testing strategies (graded exercise stress testing [GXT], stress echocardiography, cardiac computed tomography angiography [CCTA], and myocardial perfusion imaging [MPI] as well as no testing), among patients evaluated for chest pain. To compare costs among the tested (overall and by testing strategy) and nontested groups, we used a log-gamma generalized linear model to account for the skewed distribution of health care cost data, adjusting for relevant clinical covariates. RESULTS: A total of 2,340,699 patients were included in our cohort, of whom 481,170 (21%) patients received 1 of the 4 NITs. Among patients who received a NIT, 254,492 (53%) received a GXT as their initial test, 154,137 (32%) received MPI, 69,160 (14%) received a stress echo, and 3,381 (<1%) received a CCTA. After adjustment for differences in baseline patient characteristics, receipt of any NIT was associated with an approximate 12% reduction in downstream 1-year mean costs (cost ratio = 0.88; 95% CI, 0.87, 0.89) compared with those without any testing. Comparing the different testing strategies with no testing, both GXT (cost ratio = 0.80; 95% CI, 0.79-0.81) and stress echocardiography (cost ratio = 0.82; 95% CI, 0.81-0.83) were associated with the lower downstream costs, while both MPI (cost ratio = 1.26; 95% CI, 1.25, 1.27) and CCTA (cost ratio = 1.29; 95% CI, 1.23, 1.35) were associated with higher downstream costs. CONCLUSIONS: In a large population-based cohort consisting of >2 million people evaluated for chest pain, we report that receipt of noninvasive testing was associated with a 12% reduction in downstream costs when compared with no testing. Graded exercise stress testing and stress echocardiography were associated with the least downstream costs, whereas CCTA and MPI were associated with higher costs when compared with no testing. These findings may help inform testing decisions in chest pain patients.

Do nonfatal events during the first 5 years after coronary artery bypass surgery influence 10 year outcomes?

OBJECTIVE: Few have examined the influence of early adverse events after coronary artery bypass grafting (CABG) on long-term survival. We sought to determine if the occurrence of nonfatal major adverse cardiac and cerebrovascular events (MACCE) during the first 5 years after CABG influences survival and adverse events at 10 years. METHODS: All patients who underwent isolated CABG from 1990 to 2014 at a single center in Ontario, Canada, were included. Primary end point was all-cause mortality. The secondary end point of interest was MACCE, a composite of mortality, nonfatal myocardial infarction, stroke, and repeat revascularization. RESULTS: A total of 20,444 cases of elective primary isolated CABG were identified as being alive at 5 years, with 11% of patients developing nonfatal MACCE within the first 5 years after CABG (MACCE group) and the remaining 89% were alive without a MACCE event at 5 years (non-MACCE group). Following propensity score matching, 2167 patient-pairs were formed. Among the MACCE group, 972 out of 2167 (44.9%) developed a myocardial infarction, 519 out of 2167 (24.0%) had a stroke, and 946 out of 2167 (43.7%) required a repeat revascularization within the first 5 years after CABG. Non-MACCE was associated with better overall survival (hazard ratio, 1.42; 95% CI, 1.25-1.63; P < .01) and freedom from MACCE (hazard ratio, 1.61; 95% CI, 1.45-1.79; P < .01) up to 10 years after CABG compared with MACCE cases. CONCLUSIONS: Patients who experienced nonfatal MACCE during the first 5 years after CABG experienced worse survival and more MACCE at 10 years. Prevention of major adverse events during the first 5 years after surgical revascularization may be an important strategy to improve late outcomes.

An Interrupted Time-Series Analysis of the Impact of COVID-19 on Hospitalizations for Vascular Events in 3 Canadian Provinces.

Background: COVID-19 infection is associated with a pro-coagulable state, thrombosis, and cardiovascular events. However, its impact on population-based rates of vascular events is less well understood. We studied temporal trends in hospitalizations for stroke and myocardial infarction in 3 Canadian provinces (Alberta, Ontario, and Nova Scotia) between 2014 and 2022. Methods: Linked administrative data from each province were used to identify admissions for ischemic stroke, intracerebral hemorrhage, cerebral venous thrombosis, and myocardial infarction. Event rates per 100,000/quarter, standardized to the 2016 Canadian population, were calculated. We assessed changes from quarterly rates pre-pandemic (2014-2020), compared to rates in the pandemic period (2020-2022), using interrupted time-series analysis with a jump discontinuity at pandemic onset. Age group- and sex-stratified analyses also were performed. Results: We identified 162,497 strokes and 243,182 myocardial infarctions. At pandemic onset, no significant step change in strokesper 100,000/quarter was observed in any of the 3 provinces. During the pandemic, stroke rates were stable in Alberta and Ontario, but they increased in Nova Scotia (0.44 per 100,000/quarter, P = 0.004). At pandemic onset, a significant step decrease occurred in myocardial infarctions per 100,000/quarter in Alberta (4.72, P < 0.001) and Ontario (4.84, P < 0.001), but not in Nova Scotia. During the pandemic, myocardial infarctions per 100,000/quarter decreased in Alberta (-0.34, P = 0.01), but they remained stable in Ontario and Nova Scotia. No consistent patterns by age group or sex were noted. Conclusions: Hospitalization rates for stroke or myocardial infarction across 3 Canadian provinces did not increase substantially during the first 2 years of the pandemic. Continued surveillance is warranted as the virus becomes endemic.

Contexte: L'infection par la COVID-19 est associée à un état procoagulant, à la thrombose et à des événements cardiovasculaires. Son incidence sur les taux d'événements vasculaires dans la population est cependant moins bien comprise. Nous avons étudié les tendances temporelles des hospitalisations pour un accident vasculaire cérébral (AVC) et un infarctus du myocarde dans trois provinces canadiennes (Alberta, Ontario et Nouvelle-Écosse) entre 2014 et 2022. Méthodologie: Des données administratives couplées provenant de chaque province ont été utilisées pour recenser les hospitalisations pour un AVC ischémique, une hémorragie intracérébrale, une thrombose veineuse cérébrale et un infarctus du myocarde. Nous avons calculé les taux d'événements pour 100 000 admissions/trimestre, uniformisés pour correspondre à la population canadienne de 2016. Nous avons évalué les variations par rapport aux taux trimestriels d'avant la pandémie (2014-2020), comparativement aux taux pendant la pandémie (2020-2022), à l'aide d'une analyse de séries chronologiques interrompues avec discontinuité à saut fini au début de la pandémie. Des analyses stratifiées selon le groupe d'âge et le sexe ont également été réalisées. Résultats: Nous avons recensé 162 497 AVC et 243 182 infarctus du myocarde. Au début de la pandémie, aucune variation progressive significative au niveau des AVC pour 100 000 admissions/trimestre n'a été observée dans aucune des trois provinces. Pendant la pandémie, les taux d'AVC sont demeurés stables en Alberta et en Ontario, mais ont augmenté en Nouvelle-Écosse (0,44 pour 100 000 admissions/trimestre; p = 0,004). Au début de la pandémie, une diminution graduelle significative du taux d'infarctus du myocarde pour 100 000 admissions/trimestre a été observée en Alberta (4,72; p < 0,001) et en Ontario (4,84; p < 0,001), mais pas en Nouvelle-Écosse. Durant la pandémie, le taux d'infarctus du myocarde pour 100 000 admissions/trimestre a diminué en Alberta (­0,34; p = 0,01), mais est demeuré stable en Ontario et en Nouvelle-Écosse. Aucune tendance constante n'a été observée selon le groupe d'âge ou le sexe. Conclusions: Les taux d'hospitalisation pour un AVC ou un infarctus du myocarde n'ont pas augmenté de manière substantielle dans les trois provinces canadiennes durant les deux premières années de la pandémie. Une surveillance continue s'impose alors que le virus devient endémique.

Association Between Immigration Status and Ambulatory Secondary Stroke Preventive Care in Ontario, Canada.

BACKGROUND AND OBJECTIVES: Secondary stroke preventive care includes evaluation and control of vascular risk factors to prevent stroke recurrence. Our objective was to evaluate the quality of ambulatory stroke preventive care and its variation by immigration status in adult stroke survivors in Ontario, Canada. METHODS: We conducted a population-based administrative database-derived retrospective cohort study in Ontario, Canada. Using immigration records, we defined immigrants as those immigrating after 1985 and long-term residents as those arriving before 1985 or those born in Canada. We included community-dwelling stroke survivors 40 years and older with a first-ever stroke between 2011 and 2017. In the year following their stroke, we evaluated the following metrics of stroke prevention: testing for hyperlipidemia and diabetes; among those with the condition, control of diabetes (hemoglobin A1c ≤7%) and hyperlipidemia (low-density lipoprotein <2 mmol/L); medication use to control hypertension, diabetes, and atrial fibrillation; and visit to a family physician and a specialist (neurologist, cardiologist, or geriatrician). We determined age and sex-adjusted absolute prevalence difference (APD) between immigrants and long-term residents for each metric using generalized linear models with binomial distribution and an identity link function. RESULTS: We included 34,947 stroke survivors (median age 70 years, 46.9% women) of whom 12.4% were immigrants. The receipt of each metric ranged from 68% to 90%. Compared with long-term residents, after adjusting for age and sex, immigrants were slightly more likely to receive screening for hyperlipidemia (APD 5.58%; 95% CI 4.18-6.96) and diabetes (5.49%; 3.76-7.23), have visits to family physicians (1.19%; 0.49-1.90), receive a prescription for antihypertensive (3.12%; 1.76-4.49) and antihyperglycemic medications (9.51%; 6.46-12.57), and achieve control of hyperlipidemia (3.82%; 1.01-6.63). By contrast, they were less likely to achieve diabetes control (-4.79%; -7.86 to -1.72) or have visits to a specialist (-1.68%; -3.12 to -0.24). There was minimal variation by region of origin or time since immigration in immigrants. DISCUSSION: Compared with long-term residents, many metrics of secondary stroke preventive care were better in immigrants, albeit with small absolute differences. However, future work is needed to identify and mitigate the factors associated with the suboptimal quality of stroke preventive care for all stroke survivors.