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Background: Hip fractures are costly and common in older adults, but there is limited understanding of how treatment patterns and outcomes might differ between countries. Methods: We performed a retrospective serial cross‐sectional cohort study of adults aged ≥66 years hospitalized with hip fracture between 2011 and 2018 in the US, Canada, England, the Netherlands, Taiwan, and Israel using population‐representative administrative data. We examined mortality, hip fracture treatment approaches (total hip arthroplasty [THA], hemiarthroplasty [HA], internal fixation [IF], and nonoperative), and health system performance measures, including hospital length of stay (LOS), 30‐day readmission rates, and time‐to‐surgery. Results: The total number of hip fracture admissions between 2011 and 2018 ranged from 23,941 in Israel to 1,219,696 in the US. In 2018, 30‐day mortality varied from 3% (16% at 1 year) in Taiwan to 10% (27%) in the Netherlands. With regards to processes of care, the proportion of hip fractures treated with HA (range 23%–45%) and THA (0.2%–10%) differed widely across countries. For example, in 2018, THA was used to treat approximately 9% of patients in England and Israel but less than 1% in Taiwan. Overall, IF was the most common surgery performed in all countries (40%–60% of patients). IF was used in approximately 60% of patients in the US and Israel, but only 40% in England. In 2018, rates of nonoperative management ranged from 5% of patients in Taiwan to nearly 10% in England. Mean hospital LOS in 2018 ranged from 6.4 days (US) to 18.7 days (England). The 30‐day readmission rate in 2018 ranged from 8% (in Canada and the Netherlands) to nearly 18% in England. The mean days to surgery in 2018 ranged from 0.5 days (Israel) to 1.6 days (Canada). Conclusions: We observed substantial between‐country variation in mortality, surgical approaches, and health system performance measures. These findings underscore the need for further research to inform evidence‐based surgical approaches. [ABSTRACT FROM AUTHOR]

We aimed to determine whether early public health interventions in 2020 mitigated the association of sociodemographic and clinical risk factors with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We conducted a population-based cohort study of all adults in Ontario, Canada who underwent testing for SARS-CoV-2 through December 31, 2020. The outcome was laboratory-confirmed SARS-CoV-2 infection, determined by reverse transcription polymerase chain reaction testing. Adjusted odds ratios (ORs) were determined for sociodemographic and clinical risk factors before and after the first-wave peak of the pandemic to assess for changes in effect sizes. Among 3,167,753 community-dwelling individuals, 142,814 (4.5%) tested positive. The association between age and SARS-CoV-2 infection risk varied over time (P-interaction < 0.0001). Prior to the first-wave peak, SARS-CoV-2 infection increased with age whereas this association reversed thereafter. Risk factors that persisted included male sex, residing in lower income neighborhoods, residing in more racially/ethnically diverse communities, immigration to Canada, hypertension, and diabetes. While there was a reduction in infection rates after mid-April 2020, there was less impact in regions with higher racial/ethnic diversity. Immediately following the initial peak, individuals living in the most racially/ethnically diverse communities with 2, 3, or ≥ 4 risk factors had ORs of 1.89, 3.07, and 4.73-fold higher for SARS-CoV-2 infection compared to lower risk individuals in their community (all P < 0.0001). In the latter half of 2020, this disparity persisted with corresponding ORs of 1.66, 2.48, and 3.70-fold higher, respectively. In the least racially/ethnically diverse communities, there was little/no gradient in infection rates across risk strata. Further efforts are necessary to reduce the risk of SARS-CoV-2 infection among the highest risk individuals residing in the most racially/ethnically diverse communities. [ABSTRACT FROM AUTHOR]

Aims: We assessed the effect of transitional care on patient‐reported outcomes (PROs) in women and men hospitalized for heart failure. Methods and results: In this sex‐specific analysis of a stepped wedge cluster randomized trial in Canada, the effect of a patient‐centered transitional care model was tested on pre‐specified PROs of discharge preparedness (B‐PREPARED score, range 0–22), quality of transition [Care Transitions Measure‐3 (CTM‐3) score, range 0–100], and health‐related quality of life (HRQOL) (EQ‐5D‐5L, range 0–1). Among 986 patients (47.4% women), B‐PREPARED at 6 weeks was greater with the intervention than usual care [mean difference (MD) 4.01 (95% confidence interval‐CI 2.90–5.12); P < 0.001], with no sex differences (P sex‐interaction = 0.24). CTM‐3 at 6 weeks was greater with the intervention than usual care [MD 10.52 (95% CI 6.00–15.04); P < 0.001], with no sex differences (P sex‐interaction = 0.69). EQ‐5D‐5L was greater with intervention than usual care at discharge [MD 0.17 (95% CI 0.12–0.22); P < 0.001], 6 weeks [MD 0.06 (95% CI 0.01–0.12); P = 0.02], and 6 months [MD 0.05 (95% CI −0.01 to 0.12); P = 0.09], although the 6‐month difference was not statistically significant. At discharge, women reported lower EQ‐5D‐5L but experienced significantly greater treatment benefit than men (P sex‐interaction = 0.02). Treatment effect on EQ‐5D‐5L was numerically greater in women than men at 6 weeks and 6 months, but there were no significant sex differences (P sex‐interaction 0.18 and 0.19, respectively). Conclusion: A patient‐centered transitional care model improved discharge preparedness, transition quality, and HRQOL in the weeks following heart failure hospitalization, with effects largely consistent in women and men. However, women reported lower HRQOL and experienced greater treatment benefit in this endpoint than men at hospital discharge. Clinical Trial Registration: ClinicalTrials.gov NCT02112227. [ABSTRACT FROM AUTHOR]

Background: High-quality ambulatory care can reduce cardiovascular disease risk, but important gaps exist in the provision of cardiovascular preventive care. We sought to develop a set of key performance indicators that can be used to measure and improve cardiovascular care in the primary care setting. Methods: As part of the Cardiovascular Health in Ambulatory Care Research Team initiative, we established a 14-member multidisciplinary expert panel to develop a set of indicators for measuring primary prevention performance in ambulatory cardiovascular care. We used a 2-stage modified Delphi panel process to rate potential indicators, which were identified from the literature and national cardiovascular organizations. The top-rated indicators were pilot tested to determine their measurement feasibility with the use of data routinely collected in the Canadian health care system. Results: A set of 28 indicators of primary prevention performance were identified, which were grouped into 5 domains: risk factor prevalence, screening, management, intermediate outcomes and long-term outcomes. The indicators reflect the major cardiovascular risk factors including smoking, obesity, hypertension, diabetes, dyslipidemia and atrial fibrillation. All indicators were determined to be amenable to measurement with the use of population-based administrative (physician claims, hospital admission, laboratory, medication), survey or electronic medical record databases. Interpretation: The Cardiovascular Health in Ambulatory Care Research Team indicators of primary prevention performance provide a framework for the measurement of cardiovascular primary prevention efforts in Canada. The indicators may be used by clinicians, researchers and policy-makers interested in measuring and improving the prevention of cardiovascular disease in ambulatory care settings. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular disease is costly, and annual expenditures are projected to increase. Our objective was to examine the variation in patient-level costs and identify drivers of cost in patients with stable coronary artery disease. Methods: In this retrospective cohort study using administrative databases in Ontario, Canada, we identified all patients with stable coronary artery disease after index angiography between Oct. 1, 2008, and Sept. 30, 2011. We excluded patients with a myocardial infarction within 90 days before the index, with normal coronaries, or with mild coronary disease. We categorized hospitals into low, medium or high revascularization ratio centres. The primary outcome was cumulative 1-year health care costs. A hierarchical generalized linear model identified patient, physician and hospital characteristics associated with patient costs, with 2 main covariates of interest: treatment allocation (medical v. percutaneous coronary intervention v. coronary artery bypass grafting) and hospital revascularization ratio. Results: A total of 183 630 angiography procedures were performed in Ontario during the study period. The final cohort included 39 126 patients with stable coronary artery disease, of which 15 138 received medical treatment and 23 988 received revascularization. The mean 1-year cost was $24 026 (interquartile range $8235–$30 511). The mean costs for medical management and revascularization were $18 069 and $27 786, respectively. The strongest predictor of costs was revascularization (percutaneous coronary intervention: cost ratio 1.27, 95% CI [confidence interval] 1.24–1.31; coronary artery bypass grafting: cost ratio 2.62, 95% CI 2.53–2.71). Hospital revascularization ratio did not significantly affect costs. There was no significant interaction between treatment and revascularization ratio. Interpretation: Most health care costs were due to acute care hospital admissions, and costs were higher for patients undergoing revascularization than medical therapy. This study suggests that treatment decision has a substantial impact on health care resources. [ABSTRACT FROM AUTHOR]

Background Canadians of Chinese descent, represent one of the fastest growing visible minority groups in Canada, (as well as the second largest), but relatively little is known about the clinical features of heart failure (HF) in Chinese-Canadian versus non-Chinese Canadian patients. Methods We conducted a population-based analysis of urban patients hospitalized in Ontario, Canada for the first time with a most responsible diagnosis of HF between April 1, 1995 and March 31, 2008. Among the 99,278 patients, 1,339 (1.3%) were classified as Chinese using a previously validated list of Chinese surnames. Through linkage to other administrative databases, we compared the clinical characteristics, pharmacological management, and outcomes of Chinese versus non-Chinese HF patients. Results Ischemic heart disease was identified as the possible etiology of HF in a greater proportion of non-Chinese patients (47.7% vs. 35.3%; p < 0.001) whereas hypertension (26.1% vs. 16.1%; p < 0.001) and valvular heart disease (11.6% vs. 7.2%; p < 0.001) were relatively more common in Chinese patients. Chinese patients were prescribed angiotensin-converting enzyme (ACE) inhibitors less frequently (57.5% vs. 66.4%, p < 0.001) and angiotensin receptor blockers (ARBs) more frequently (17.4% vs. 8.9%, p < 0.001) compared to non- Chinese patients. They were also less likely to be adherent to ACE inhibitors over a 1-year follow up period. However, the 1-year case-fatality rates were comparable between the Chinese (31.7%) and non-Chinese (30.2%) subjects (p = 0.24). Conclusion There are important differences in the causes and medical management of HF in Chinese and non-Chinese patients residing in Canada. Despite these differences, the long-term outcomes of HF patients were similar. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated trends in and economic implications of the use of fibrates in the U.S. and Canada. The researchers also examined the relationship between differences in the availability and use of brand-name versus generic formulations of fenofibrate in both countries. The population-level, observational cohort study utilized IMS Health data from both countries between January 2002 and December 2009. It was found that there has been an increase in prescriptions for fibrates in the U.S., while prescriptions in Canada remained stable.

Background: Although several Utstein variables are known to independently improve survival, how they moderate the effect of emergency medical service (EMS) response times on survival is unknown.Objectives: To quantify how public location, witnessed status, bystander CPR, and bystander AED shock individually and jointly moderate the effect of EMS response time delays on OHCA survival.Methods: This retrospective cohort study was a secondary analysis of the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest database (December 2005 to June 2015). We included all adult, non-traumatic, non-EMS witnessed, and EMS-treated OHCAs from eleven sites across the US and Canada. We trained a logistic regression model with standard Utstein control variables and interaction terms between EMS response time and the four aforementioned OHCA characteristics.Results: 102,216 patients were included. Three of the four characteristics - witnessed OHCAs (OR = 0.962), bystander CPR (OR = 0.968) and public location (OR = 0.980) - increased the negative effect of a one-minute delay on the odds of survival. In contrast, a bystander AED shock decreased the negative effect of a one-minute response time delay on the odds of survival (OR = 1.064). The magnitude of the effect of a one-minute delay in EMS response time on the odds of survival ranged from 1.3% to 9.8% (average: 5.3%), depending on the underlying OHCA characteristics.Conclusions: Delays in EMS response time had the largest reduction in survival odds for OHCAs that did not receive a bystander AED shock but were witnessed, occurred in public, and/or received bystander CPR. A bystander AED shock appears to be protective against a delay in EMS response time. [ABSTRACT FROM AUTHOR]

Introduction: Although out-of-hospital cardiac arrest (OHCA) is thought of as a sudden event, recent studies suggest that many patients have symptoms or have sought medical attention prior to their arrest. Our objective was to evaluate patterns of healthcare utilization before OHCA.Methods: We conducted a population-based cohort study in Ontario, Canada, which included all patients ≥20 years, who suffered out-of-hospital cardiac arrest and transferred to an emergency department (ED) from 2007 to 2018. Measurements included emergency room assessments, hospitalizations and physician visits prior to arrest.Results: The cohort comprised 38,906 patients, their mean age was 66.5 years, and 32.7% were women. Rates of ED assessments and hospital admissions were relatively constant until 90 days prior to arrest where they markedly increased to the time before arrest. Within 90 days, rates of ED assessment, hospitalization, and primary care physician visit were 29.5%, 16.4%, and 70.1%, respectively. Cardiovascular conditions were diagnosed in 14.4% of ED visits, and 33.7% of hospitalizations in this time period. The largest age-difference was the mental and behavioural disorders within 90 days of OHCA in the ED, where rates were 12.2% among patients <65 years vs. 1.9% for patients ≥65 years.Conclusions: In contrast to the conventional wisdom that OHCA occurs without prior contacts to the health care system, we found that more than 1 in 4 patients were assessed in the ED prior within 90 days of their arrest. Identification of warning signs of OHCA may allow future development of prevention strategies. [ABSTRACT FROM AUTHOR]

Although randomized studies have shown optimal medical therapy (OMT) to be as efficacious as revascularization in stable coronary heart disease (CHD), the application of OMT in routine practice is suboptimal. We sought to understand the predictors of receiving OMT in stable CHD and its impact on clinical outcomes. All patients with stable CHD based on coronary angiography from October 2008 to September 2011 were identified in Ontario, Canada. OMT was defined as concurrent use of β blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and statin. Aspirin use was not part of the OMT definition because of database limitations. Multivariable hierarchical logistic models identified predictors of OMT in the 12 months after angiography. Cox proportional hazard models with time-varying covariates for OMT and revascularization status examined differences in death and nonfatal myocardial infarction (MI). In these models, patients transitioned among 4 mutually exclusive treatment groups: no OMT and no revascularization, no OMT and revascularization, OMT and no revascularization, OMT and revascularization. Our cohort had 20,663 patients. Over a mean period of 2.5 years, 8.7% had died. Only 61% received OMT within 12 months. The strongest predictor of receiving OMT at 12 months was OMT before the angiogram (odds ratio 14.40, 95% confidence interval [CI] 13.17 to 15.75, p <0.001). Relative to no OMT and nonrevascularized patients, patients on OMT and revascularized had the greatest reduction in mortality (hazard ratio 0.52, 95% CI 0.45 to 0.60, p <0.001) and nonfatal MI (hazard ratio 0.74, 95% CI 0.64 to 0.84, p <0.001). In conclusion, our study highlights the low rate of OMT in stable CHD. Patients who received both OMT and revascularization achieved the greatest reduction in mortality and nonfatal MI. [ABSTRACT FROM AUTHOR]

Background--Guidelines recommend that noncardiac surgery be delayed until 30 to 45 days after bare-metal stent implantation and 1 year after drug-eluting stent implantation Methods and Results--We used linked registry data and population-based administrative health care databases to conduct a cohort study of 8116 patients (£40 years of age) who underwent major elective noncardiac surgery in Ontario, Canada between 2003 and 2009, and received coronary stents within 10 years before surgery. Approximately 34% (n=2725) underwent stent insertion within 2 years before surgery, of whom 905 (33%) received drug-eluting stents. For comparison, we assembled a separate cohort of 341 350 surgical patients who had not undergone coronary revascularization. The primary outcome was 30-day major adverse cardiac events (mortality, readmission for acute coronary syndrome, or repeat coronary revascularization). The overall rate of 30-day events in patients with coronary stents was 2.1% (n=170). When the interval between stent insertion and surgery was <45 days, event rates were high for bare-metal (6.7%) and drug-eluting (20.0%) stents. When the interval was 45 to 180 days, the event rate for bare-metal stents was 2.6%, approaching that of intermediate-risk nonrevascularized individuals. Adjusted analyses suggested that event rates were increased if this interval exceeded 180 days. For drug-eluting stents, the event rate was 1.2% once the interval exceeded 180 days, approaching that of intermediate-risk nonrevascularized individuals Conclusions--The earliest optimal time for elective surgery is 46 to 180 days after bare-metal stent implantation or >180 days after drug-eluting stent implantation [ABSTRACT FROM AUTHOR]

Immigration policies shape the composition, socioeconomic characteristics, and health of migrant populations. The health of migrants is also influenced by a confluence of social, economic, environmental, and political factors. Immigrants and refugees often face various barriers to accessing health care because of factors such as lack of familiarity with navigating the health care system, language barriers, systemic racism, and gaps in health insurance. Social determinants of health and access to primary care health services likely influence the burden of cardiovascular risk factors among immigrants. The relatively low burden of many cardiovascular risk factors in many immigrant populations likely contributes to the generally lower incidence rates of acute myocardial infarction, heart failure, and stroke in immigrants compared with nonimmigrants, although cardiovascular disease incidence rates vary substantially by country of origin. The "healthy immigrant effect" is the hypothesis that immigrants to high-income countries, such as Canada, are healthier than nonimmigrants in the host population. However, this effect may not apply universally across all immigrants, including recent refugees, immigrants without formal education, and unmarried immigrants. As unfolding sociopolitical events generate new waves of global migration, policymakers and health care providers need to focus on addressing social and structural determinants of health to better manage cardiovascular risk factors and prevent cardiovascular disease, especially among the most marginalized immigrants and refugees., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction (MI) in young to middle-aged women., Objectives: We aim to define the long-term natural history of SCAD., Methods: We performed a multicenter, prospective, observational study of patients with nonatherosclerotic SCAD presenting acutely from 22 North American centers. We recorded baseline demographics, in-hospital characteristics, precipitating and predisposing conditions, angiographic features (adjudicated), in-hospital and 3-year major adverse cardiovascular events (MACE). Cox regression multivariable analysis was performed., Results: We prospectively enrolled 750 consecutive patients with SCAD from June 2014 to June 2018. Mean age was 51.7 ± 10.5 years, 88.5% were women (55.0% postmenopausal); 31.3% presented with ST-segment elevation myocardial infarction, and 68.3% with non-ST-segment elevation myocardial infarction. Precipitating emotional stressor was reported in 50.3%, and physical stressor in 28.9%. Predisposing conditions included fibromuscular dysplasia in 42.9% (56.4% in those with complete screening), peripartum state 4.5%, and genetic disorders 1.6%. Most patients were treated conservatively (84.3%); 14.1% underwent percutaneous coronary intervention (PCI), 0.7% coronary artery bypass graft. At 3.0-year median follow-up, mortality was 0.8%, recurrent MI 9.9% (extension of previous SCAD 3.5%, de novo recurrent SCAD 2.4%, iatrogenic dissection 1.9%), with overall MACE 14.0%. Presence of genetic disorders, peripartum SCAD, and extracoronary fibromuscular dysplasia were independent predictors of 3-year MACE. Patients who underwent PCI at index hospitalization had similar postdischarge MACE compared with no PCI. At 3 years, 80.0% remained on aspirin and 73.5% on beta-blockade., Conclusions: Long-term mortality and de novo recurrent SCAD was low in our contemporary large SCAD cohort that included low revascularization rate and high use of beta-blockade and aspirin. Genetic disorders, extracoronary fibromuscular dysplasia, and peripartum SCAD were independent predictors of long-term MACE., Competing Interests: Funding Support and Author Disclosures This study was funded by the Canadian Institutes of Health Research, Abbott Vascular, AstraZeneca, St Jude Medical, and Servier. Dr Saw has received unrestricted research grant support from the Canadian Institutes of Health Research, Heart & Stroke Foundation of Canada, National Institutes of Health, University of British Columbia Division of Cardiology, AstraZeneca, Abbott, St Jude Medical, Boston Scientific, and Servier; has received salary support from Michael Smith Foundation of Health Research; has received speaker honoraria from AstraZeneca, Abbott, Boston Scientific, and Sunovion; has received consultancy and advisory board honoraria from AstraZeneca, St Jude Medical, Abbott, Boston Scientific, Baylis, Gore, and FEops; and has received proctorship honoraria from Abbott, St Jude Medical, and Boston Scientific. Dr So has received unrestricted research grant supports from the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, National Institutes of Health, Eli Lilly, Spartan Biosciences, Roche Diagnostics, and Aggredyne; and has received speaker honoraria and advisory board honoraria from AstraZeneca and Bayer. Dr Gornik has received research support from CVR Global; has received equity and intellectual property from Flexlife Health; and is on the advisory board of FMD Society of America. Dr Lavoie has received speaking honoraria from Boehringer Ingelheim, Pfizer, BMS Sanofi, Novartis, Servier, and Bayer. Dr Ganesh has received research grants from the National Heart, Lung, and Blood Institute (HL139672), NIH, Doris Duke Charitable Foundation, and the Frankel Cardiovascular Center at the University of Michigan; and is on advisory boards of FMD Society of America and SCAD Alliance. Dr Ko is supported by the Jack Tu Chair in Cardiovascular Outcomes, Sunnybrook Hospital, and University of Toronto. Dr Madan is supported by the Heart & Stroke Foundation Polo Chair in Cardiology at the University of Toronto; and has received advisory board honoraria from Medtronic Canada, HLS therapeutics, JAMP Pharma, Novartis Canada, and Pendopharm Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022. Published by Elsevier Inc.)

Background: It is uncertain whether beta-blockers (BBs) are beneficial in contemporary stable patients with prior myocardial infarction (MI). Therefore, we sought to examine the effectiveness of BB use in this population., Methods: We conducted a cohort study with the use of administrative databases of patients ≥ 65 years of age, alive on April 1, 2012 (index date) with a hospital discharge diagnosis of MI within the previous 3 years. The primary outcome was time to death or hospitalization for MI or angina 1 year after the index date, with inverse probability of treatment weighting., Results: We included 33,811 patients with prior MI, of whom 21,440 (63.4%) were dispensed a BB. The median age was 78 years, and 56% were male. There was no difference in the 1-year hazard of death/hospitalization for MI or angina (14.8% vs 14.7%, hazard ratio 1.00, 95% confidence interval 0.94-1.07; P = 0.90) in those receiving vs not receiving BB. Similarly, there was no difference in the individual end points in composite nor in 3-year outcomes. Subgroup analysis by age, sex, MI timing, MI type, heart failure, and atrial fibrillation found no benefit. Patients with a history of revascularisation treated with BBs had a lower rate of the composite outcome compared with those without such history (P = 0.006 for interaction) at 1 year but not at 3 years., Conclusions: In this large contemporary population-based observational study of older stable patients with prior MI, BBs were not associated with a reduction in major cardiovascular events or mortality in those with MI within the previous 3 years. This study supports the need to conduct contemporary clinical trials evaluating the use of BBs after MI., (Copyright © 2020 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: There has been an exponential increase in the demand for transcatheter aortic valve replacement (TAVR). Our goal was to examine trends in TAVR capacity and wait-times across Canada., Methods: All TAVR cases were identified from April 1, 2014, to March 31, 2017. Wait-time was defined as the duration in days from the initial referral to the TAVR procedure. TAVR capacity was defined as the number of TAVR procedures per million population/province/fiscal year. We performed multivariable multilevel Cox proportional hazards modelling of the time to TAVR as the dependant variable and the effect of provinces as random effects. We quantified the variation in wait-times among provinces using the median hazard ratio., Results: We identified a total of 4906 TAVR procedures across 9 provinces. Despite a year over year increase in overall capacity, there was a greater than 3-fold difference in capacity between provinces. Crude median wait-times increased over time in all provinces, with marked variation from 71.5 days in Newfoundland to 190.5 and 203 days in Manitoba and Alberta, respectively. This suggests increasing demand outpaced the growth in capacity. We found a median hazard ratio of 1.62, indicating that in half of the possible pairwise comparisons, the time to TAVR for identical patients was at least 62% longer between different provinces., Conclusion: We found substantial geographic inequity in TAVR access. This calls for policy makers, clinicians, and administrators across Canada to address this inequity through revaluation of provincial funding mechanisms, as well as implementation of efficient care pathways., (Copyright © 2019 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Background: The ability to predict readmission accurately after hospitalization for acute myocardial infarction (AMI) is limited in current statistical models. Machine-learning (ML) methods have shown improved predictive ability in various clinical contexts, but their utility in predicting readmission after hospitalization for AMI is unknown., Methods: Using detailed clinical information collected from patients hospitalized with AMI, we evaluated 6 ML algorithms (logistic regression, naïve Bayes, support vector machines, random forest, gradient boosting, and deep neural networks) to predict readmission within 30 days and 1 year of discharge. A nested cross-validation approach was used to develop and test models. We used C-statistics to compare discriminatory capacity, whereas the Brier score was used to indicate overall model performance. Model calibration was assessed using calibration plots., Results: The 30-day readmission rate was 16.3%, whereas the 1-year readmission rate was 45.1%. For 30-day readmission, the discriminative ability for the ML models was modest (C-statistic 0.641; 95% confidence interval (CI), 0.621-0.662 for gradient boosting) and did not outperform previously reported methods. For 1-year readmission, different ML models showed moderate performance, with C-statistics around 0.72. Despite modest discriminatory capabilities, the observed readmission rates were markedly higher in the tenth decile of predicted risk compared with the first decile of predicted risk for both 30-day and 1-year readmission., Conclusions: Despite including detailed clinical information and evaluating various ML methods, these models did not have better discriminatory ability to predict readmission outcomes compared with previously reported methods., (Copyright © 2019 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Objectives: Vitamin K antagonists (VKAs) remain one of the most commonly used anticoagulation therapies. The potential anticancer effect of long-term use of VKAs has been a matter of debate with conflicting results. Our goal was to perform a systematic review and meta-analysis examining the association between long-term VKAs use and cancer risk., Methods: Systematic searches of multiple major databases were performed from inception until January 2018. We included studies of adults that compared incidence of any cancer between ≥6 months use of VKAs (long-term group) and <6 months use of VKAs or nonuse (control group). Primary outcome was all-cancer incidence and secondary outcomes were cancer-specific incidence, all-cause death and cancer-specific mortality. Hazard ratios (HRs) were pooled using a random-effects model, and individual studies were weighted using inverse variance., Results: We identified 9 observational studies that included 1,521,408 patients. No randomized trials were identified. In comparison to control, long-term use of VKAs was associated with a significant reduction in incidence of all cancers (HR, 0.84; 95% confidence interval [CI], 0.81-0.88; P<0.001). In a prespecified subgroup analysis, long-term use of VKAs demonstrated a significant reduction in all-cancer incidence when compared with control in individuals whose indication for VKAs were venous thromboembolism (HR, 0.69; 95% CI, 0.52-0.90; P=0.007)., Conclusions: The use of long-term VKAs, for any indication, is associated with lower cancer incidence. This finding could have important clinical implications for the choice of oral anticoagulation therapies among specific patients with a higher baseline risk of cancer.

Background: Ezetimibe use has steadily increased in Canada during the past decade even in the absence of evidence demonstrating a beneficial effect on clinical outcomes. Among the 4 most populated provinces in Canada, there is a gradient in the restrictiveness of ezetimibe in public-funded formularies (most to least strict: British Columbia, Alberta, Quebec, and Ontario). The effect of formulary policy on the use of ezetimibe over time is unknown., Methods and Results: We conducted a population-level cohort study using Intercontinental Marketing Services Health Canada's data from June 2003 to December 2012 to examine ezetimibe use in these 4 provinces to better understand the association between use and formulary restrictiveness. We found regional variations in the patterns of ezetimibe use. From June 2003 to December 2012, British Columbia (most restrictive) had the lowest monthly increasing rate from $261 to $21 926 ($190/100 000 population/mo), whereas Ontario (least restrictive) had the most rapid monthly increase from $223 to $74 030 ($ 647/100 000 population/mo), and Quebec from $130 to $59 690 ($522/100 000 population/mo) and Alberta from $356 to $ 37 604 ($327/100 000 population/mo) were intermediate (P<0.001)., Conclusions: Ezetimibe use remains common, increasing during the past decade. Use steadily increased in provinces with the most lenient formularies. In contrast, use was lower, plateauing since 2008 in British Columbia and Alberta, which have more restrictive formularies. The gradient in ezetimibe use was related to variability in restrictiveness of the provincial formularies, illustrating the potential of a policy response gradient that may be used to more effectively manage medication use., (© 2014 American Heart Association, Inc.)

Background: We previously found that the use of ezetimibe increased rapidly with different patterns between the United States (US) and Canada prior to the landmark Ezetimibe and Simvastatin in Hypercholesterolemia Enhance Atherosclerosis Regression (ENHANCE) trial, which was reported in January 2008, and failed to show that the drug slowed the progression of atherosclerosis. What is not known is how practice in the 2 countries changed after the ENHANCE trial. We examined ezetimibe use trends in the US and Canada before and after the reporting of the ENHANCE trial., Methods: We conducted a population-based, retrospective, time-series analysis using the data collected by IMS Health in the US and CompuScript in Canada from January 1, 2002, to December 31, 2009. The main outcome measure was monthly number of prescriptions for ezetimibe-containing products., Results: The monthly number of ezetimibe prescriptions/100,000 population rose from 6 to 1,082 in the US from November 2002 to January 2008, then significantly declined to 572/100,000 population by December 2009 after the release of the ENHANCE trial, a decrease of 47.1% (P < .001). In contrast, in Canada, use continuously rose from 2 to 495/100,000 population from June 2003 to December 2009 (P = .2). United States expenditures totaled $2.24 billion in 2009., Conclusions: Ezetimibe remains commonly used in both the US and Canada. Ezetimibe use has decreased in the US post-ENHANCE, whereas use has gradually but steadily increased in Canada. The diverging patterns of ezetimibe use in the US and Canada require further investigation, as they reveal that a common evidence base is eliciting very different utilization patterns in neighboring countries., (Copyright © 2014 Mosby, Inc. All rights reserved.)

Background: Despite the availability of several acute coronary syndrome (ACS) prognostic risk scores, there is no appropriate score for early-risk stratification at the time of the first medical contact with patients with ACS. The primary objective of this study is to develop a simple risk score that can be used for early-risk stratification of patients with ACS., Methods: We derived the risk score from the Acute Myocardial Infarction in Quebec and Canada ACS-1 registries and validated the risk score in 4 other large data sets of patients with ACS (Canada ACS-2 registry, Canada-GRACE, EFFECT-1, and the FAST-MI registries). The final risk score is named the Canada Acute Coronary Syndrome Risk Score (C-ACS) and ranged from 0 to 4, with 1 point assigned for the presence of each of these variables: age ≥75 years, Killip >1, systolic blood pressure <100 mm Hg, and heart rate >100 beats/min. The primary end points were short-term (inhospital or 30-day) and long-term (1- or 5-year) all-cause mortality., Results: The C-ACS has good predictive values for short- and long-term mortality of patients with ST-segment elevation myocardial infarction and non-ST-segment elevation ACS. The negative predictive value of a C-ACS score ≥1 is excellent at ≥98% (95% CI 0.97-0.99) for short-term mortality and ≥93% (95% CI 0.91-0.96) for long-term mortality. In other words, a C-ACS score of 0 can potentially identify correctly ≥97% short-term survivors and ≥91% long-term survivors., Conclusion: The C-ACS risk score permits rapid stratification of patients with ACS. Because this risk score is simple and easy to memorize and calculate, it can be rapidly applied by health care professionals without advanced medical training., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Background: Acute coronary syndrome (ACS) is one of the most frequent reasons for hospitalization worldwide. Although substantial advances have been made in the prevention and treatment of coronary artery disease, their impact on the rates of ACS hospitalization is unclear., Methods: Data from the Canadian Institute for Health Information Discharge Abstract Database were used to estimate secular trends in ACS hospitalization. A total of 1.3 million ACS hospitalizations in Canada from April 1, 1994, to March 31, 2006, were examined. Overall hospitalization rates were standardized for age and sex using 1991 Canadian census data, and hospitalization rates were also stratified by age group, sex and Canadian province to assess trends in each subgroup., Results: The Canadian age- and sex-standardized ACS hospitalization rate was 508 per 100,000 persons in 1994, and 317 per 100,000 persons in 2005 - a relative reduction of 37.8% and an average annual relative reduction of 3.9% per year. Declines in ACS hospitalization rates were observed among men (annual relative reduction 3.9%, relative reduction 39.0%) and women (annual relative reduction 3.8%, relative reduction 35.8%). Declining trends were also observed among patients of different age groups and among patients hospitalized across all Canadian provinces., Interpretation: Over the past decade, a substantial decline in ACS hospitalization rates occurred, which has not been previously observed. This finding is likely due to improvements in primary and secondary prevention of coronary artery disease. The present study's data should provide important insights and guidance for future health care planning in Canada.

Background: Quantifying adherence to quality indicators can serve as a direct measure of quality of care and provide the foundation for quality improvement. However, quality indicators for percutaneous coronary intervention (PCI) have not been developed in Canada., Objective: To develop a set of quality and outcome indicators for PCI that can be used across Canada., Methods: A 12-member national expert panel was selected to represent practice in different regions of Canada. Potential quality indicators were identified by a detailed search of published guidelines, randomized trials and outcomes studies. A two-step modified Delphi process was employed with an initial screening round of indicator ratings, followed by a national quality indicator panel meeting, and follow-up discussions to obtain consensus., Results: A total of 26 indicators including six structure indicators, nine process indicators, and 11 outcomes indicators were identified by the national expert panel to be representative of high quality of care for PCI. Pharmacological indicators included prescription of acetylsalicylic acid, clopidogrel and statin therapy as adjunctive therapy for PCI. Nonpharmacological process indicators included minimal procedure volumes, door-to-balloon time in primary PCI, prevention of contrast-induced nephropathy and selected patient education counselling instructions. Outcome indicators included death, myocardial infarction, target vessel revascularization and vascular access complications after PCI., Conclusions: A new set of PCI quality indicators for use in the Canadian health care system was developed. The widespread adoption and implementation of PCI quality indicators in clinical practice will facilitate the identification of practice gaps to enable quality improvement efforts and to optimize the outcomes of patients undergoing PCI throughout Canada.

Background: Historically, access to primary percutaneous coronary intervention (PCI) for the treatment of patients with ST segment elevation myocardial infarction (STEMI) has been limited in Canada. Recent studies have identified innovative strategies to improve timely access and reduce reperfusion time. Accordingly, the contemporary use of primary PCI treatment in Canada was ascertained., Methods: A cross-sectional survey of all 38 Canadian hospitals that were capable of performing PCI procedures was conducted from June 2007 to November 2007. The survey focused on the practice of primary PCI for patients with STEMI and whether the hospitals had implemented internal strategies to reduce 'door-to-balloon' times. Analyses were performed at the level of geographical regions., Results: Overall, 71% of PCI hospitals (27 of 38) provided around-the-clock primary PCI for patients with STEMI, but the proportion of PCI hospitals offering this service varied widely, from 33% to 100% across regions. All Canadian PCI hospitals provided around-the-clock rescue PCI treatment to STEMI patients who had failed fibrinolytic therapy. In terms of strategies that are associated with reduced reperfusion time, it was observed that only 42% of PCI hospitals (16 of 38) provided feedback on door-to-balloon time to the emergency department and to the cardiac catheterization laboratories within one week of the primary PCI procedure. Overall, 24% of the hospitals had not adopted any of the four identified strategies to improve door-to-balloon time., Conclusion: Although the majority of Canadian hospitals with PCI capability provide around-the-clock primary PCI for patients with STEMI, significant variations in this practice exist across the country. Canadian PCI hospitals have not consistently adopted strategies that are associated with improved door-to-balloon time.

Background: Ezetimibe lowers low-density lipoprotein cholesterol, but current lipid-lowering guidelines in the United States and Canada do not recommend it as a first option for either primary or secondary prevention. We sought to describe the adoption of ezetimibe relative to that of other lipid-lowering agents and compare its use in the two countries., Methods: We conducted a population-level, cohort study using data from January 2002 to December 2006, provided by IMS Health, to describe prescribing practices and expenditures for lipid-lowering agents and ezetimibe in the United States and Canada., Results: From 2002 to 2006, the monthly number of prescriptions for lipid-lowering agents rose from 3719 to 7401 per 100,000 population in Canada and from 3927 to 6827 per 100,000 population in the United States. Of these prescriptions, the proportion for ezetimibe rose from 0.2% in 2003 to 3.4% in 2006 in Canada and from 0.1% in 2002 to 15.2% in 2006 in the United States. Statin use was relatively constant between 2002 and 2006 in Canada, whereas the proportion of statin prescriptions decreased from 86.5 to 80.8% in the United States. In 2006, the ratio of prescriptions for statins to those for ezetimibe was 26:1 in Canada and 5:1 in the United States. In 2006, expenditures for ezetimibe per 100,000 population were higher in the United States than in Canada by a factor of more than 4., Conclusions: Distinct patterns of use of ezetimibe emerged in the United States and Canada from 2002 to 2006, a difference that markedly altered the approach to the treatment of hyperlipidemia in the United States. The U.S. pattern increased overall costs, but the effect on clinical outcomes is uncertain., (Copyright 2008 Massachusetts Medical Society.)

Background: Previous comparisons of acute myocardial infarction (AMI) treatment between the United States and Canada are limited because they compared selected patients from randomized trials, used administrative data that lacked clinical detail, or did not consider regional differences in AMI treatment., Methods and Results: We compared medication use, invasive cardiac procedure use, and 30-day risk-standardized mortality rates of 38,886 fee-for-service Medicare beneficiaries hospitalized with AMI in the United States and 5634 similarly aged patients in Ontario, Canada, from 1998 and 2001. Baseline characteristics and illness severity across the US regions and Ontario were not substantially different. Cardiac catheterization use in AMI patients was significantly higher in the United States compared with Ontario (38.7% versus 16.8%, P<0.001), but significant regional variations existed, in which the northeastern United States had significantly lower utilization rates (25.6%) compared with other US regions. Beta-blocker use among ideal candidates was highest in the northeastern United States (77.6% versus 69.7% in the United States as a whole, P<0.001) and angiotensin-converting enzyme inhibitor use was highest in Ontario (69.1% versus 58.2% in the United States, P<0.001). Risk-standardized mortality rates at 30 days were not substantially different across the regions., Conclusions: Previous studies have suggested a clear divergence in invasive cardiac therapy for AMI patients between the United States and Canada on the basis of health care financing and structural differences. Our findings of similar treatment patterns in the northeastern United States and Ontario suggest that regional practices may have a greater impact on treatment patterns than the respective health care delivery systems.

Background: Health care expenditure per person is significantly higher in the United States compared with Canada, but whether there are differences in quality of care of many conditions is unknown. We compared the process of care and outcomes of patients with heart failure, the most common cause of hospitalization for individuals 65 years and older in both countries., Methods: We compared processes of care and 30-day and 1-year risk-standardized mortality rates among 28,521 US Medicare beneficiaries and 8180 similarly aged patients in Ontario, Canada, hospitalized with heart failure from 1998 to 2001., Results: More US patients underwent left ventricular ejection fraction assessment during hospitalization compared with Canadian patients (61.2% vs 41.7%, P<.001). At discharge, patients in the United States were prescribed beta-blockers more frequently (28.7% vs 25.4%, P<.001) but angiotensin-converting enzyme inhibitors less frequently (54.3% vs 63.4%, P<.001). Among ideal candidates, prescription of beta-blockers (32.5% vs 29.7%, P = .08) or angiotensin-converting enzyme inhibitors (78.3% vs 77.6%, P = .68) was not significantly different between the 2 countries. The US patients had lower risk characteristics on admission and lower crude mortality rates at 30 days and 1 year. Thirty-day risk-standardized mortality was significantly lower for the US patients (8.9% vs 10.7%, P<.001), but 1-year risk-standardized mortality was no longer significantly different (32.2% vs 32.3%, P = .98)., Conclusion: Patients with heart failure who are hospitalized in the United States had lower short-term mortality at 30 days, but 1-year mortality rates were not significantly different between the United States and Canada.