Background:Although education and income are established determinants of atherosclerotic cardiovascular disease (ASCVD), whether sex differences in ASCVD risk are associated with these factors within a universal public healthcare system is unclear. We examined the independent associations of income and educational attainment with incident ASCVD and their potential variations by sex in Quebec, Canada. Methods:CARTaGENE is an ongoing prospective cohort study. We completed Cox models to estimate hazard ratios (HRs) for incident ASCVD, stratified by annual household income and educational attainment, among female and male participants without prior ASCVD. The primary endpoint was time to first ASCVD event. Results:There were 17,626 participants with a mean age of 54 ± 8 years (52% female), followed for a median of 6.6 years (2009-2016). Females with the lowest level of education, without collegiate education, had a 61% increase in the hazard of incident ASCVD compared to females with the highest level of education, with university studies (hazard ratio [HR]: 1.61; 95% confidence interval [CI]: 1.15, 2.26). Compared to those with an annual household income of ≥ $CAD100,000, males with an annual household income of < $CAD50,000 had a 61% increase in the hazard of incident ASCVD (HR:1.61; 95% CI: 1.23, 2.11). Conclusions:Within a public healthcare system and with relatively affordable medication coverage, we still observed inequalities in ASCVD risk associated with educational attainment and household income. Future research is needed to confirm the potential sex differences in the impacts of educational attainment and income on the risk of ASCVD.

BACKGROUND:Atrial fibrillation (AF) that is first diagnosed during hospitalization for other causes can subside with resolution of the inciting stressor. OBJECTIVE:To describe the risk for stroke after newly diagnosed AF during hospitalization for other causes. DESIGN:Population-based retrospective cohort study. SETTING:Ontario, Canada. PARTICIPANTS:Patients aged 66 years or older discharged alive from the hospital between April 2013 and March 2023 with a first diagnosis of AF. INTERVENTION:Newly diagnosed AF during hospitalization for other causes, categorized into cardiac medical, noncardiac medical, cardiac surgical, and noncardiac surgical. MEASUREMENTS:The primary outcome was hospitalization for stroke. The cumulative incidence function was used to estimate crude incidence, censoring on anticoagulant dispensation. Inverse probability of censoring weights were used to account for informative censoring. RESULTS:Atrial fibrillation was diagnosed in 20 639 patients (mean age, 77.1 years; 58.1% male) while hospitalized for other causes: 8340 (40.4%) for noncardiac medical, 7097 (34.4%) for cardiac surgical, 3553 (17.2%) for noncardiac surgical, and 1649 (8.0%) for cardiac medical diagnoses. At 1 year, anticoagulants were being dispensed to 26.4% of patients with CHA2DS2-VA scores of 1 to 4 and 35.2% of those with CHA2DS2-VA scores of 5 to 8. The 1-year risk for stroke without anticoagulation was 1.3% (95% CI, 0.7% to 2.3%) for cardiac medical, 1.2% (CI, 0.9% to 1.5%) for noncardiac medical, 1.1% (CI, 0.8% to 1.7%) for noncardiac surgical, and 1.0% (CI, 0.7% to 1.3%) for cardiac surgical patients. Patients with CHA2DS2-VA scores of 1 to 4 had a 1-year stroke risk of 0.7% (CI, 0.6% to 1.0%) without anticoagulation, compared with 1.8% (CI, 1.4% to 2.2%) at CHA2DS2-VA scores of 5 to 8. LIMITATION:Long-standing AF may have been misclassified as newly diagnosed, leading to overestimation of stroke risk. CONCLUSION:Among patients with newly diagnosed AF during hospitalization for other causes, a substantial proportion with low CHA2DS2-VA scores receive anticoagulation, with modest increases in this proportion at higher scores. The stroke risk in patients with CHA2DS2-VA scores greater than 4 approximated the 2% threshold commonly used to initiate anticoagulation in AF. PRIMARY FUNDING SOURCE:Canadian Cardiovascular Society.

AIMS:Patients with cardiac disease living in rural areas may face significant challenges in accessing care, and studies suggest that living in rural areas may be associated with worse outcomes. However, it is unclear whether rural-urban disparities have an impact on mortality in patients presenting with acute myocardial infarction (AMI) and heart failure (HF). This meta-analysis aimed to assess differences in mortality between rural and urban patients presenting with AMI and HF. METHODS AND RESULTS:A systematic search of the literature was performed using PubMed, Embase, MEDLINE, and CENTRAL for all studies published until 16 January 2024. A grey literature search was also performed using a manual web search. The following inclusion criteria were applied: (i) studies must compare rural patients to urban patients presenting to hospital with AMI or HF, and (ii) studies must report on mortality. The primary outcome was all-cause mortality. Comprehensive data were extracted including study design, patient characteristics (sex, age, and comorbidities), sample size, follow-up period, and outcomes. Odds ratios (ORs) were pooled with fixed-effects model. A subgroup analysis was performed to investigate causes for heterogeneity in which studies were separated based on in-hospital mortality, post-discharge mortality, and region of origin including North America, Europe, Asia, and Australia. In total, 37 studies were included (29 retrospective studies, 4 cross-sectional studies, and 4 prospective cohort studies) in our meta-analysis: 24 studies for AMI, 11 studies for HF, and 2 studies for both AMI and HF. This included a total of 21 107 886 patients with AMI (2 230 264 of which were in rural regions) and 18 434 270 patients with HF (2 655 469 of which were in rural regions). Rural patients with AMI had similar age (mean age 69.8 ± 5.7; vs. 67.5 ± 5.1) and were more likely to be female (43.2% vs. 38.5%) compared to urban patients. Rural patients with HF had similar age (mean age 77.1 ± 4.4 vs. 76.5 ± 4.2) and were more likely to be female (56.4% vs. 49.5%) compared to urban patients. The range of follow-up for the AMI cohort was 0 days to 24 months, and the range of follow-up for the HF cohort was 0 days to 24 months. Compared with urban patients, rural patients with AMI had higher mortality rate at follow-up [15.5% vs. 13.4%; OR 1.18, 95% confidence interval (CI), 1.13-1.24; I2 = 97%]. Compared with urban patients, rural patients with HF had higher mortality rate at follow-up (12.3% vs. 11.6%; OR 1.11, 95% CI, 1.11-1.12; I2 = 98%). CONCLUSION:To our knowledge, this is the first systematic review and meta-analysis assessing mortality differences between rural and urban patients presenting with AMI and HF. We found that patients living in rural areas had an increased risk of mortality when compared to patients in urban areas. Clinical and policy efforts are required to reduce these disparities. LAY SUMMARY:A total of 37 studies were included in our meta-analysis, involving over 39.5 million patients, and found higher mortality rates in rural patients with AMI and HF compared to those in urban areas. Clinical and policy efforts should focus on improving access to care and outcomes to reduce disparities between rural and urban areas.

BACKGROUND:The authorization process and coverage/reimbursement mechanisms for medical devices play critical roles in device adoption and usage. However, international variation in these processes remains poorly characterized, especially with regard to data transparency and the effects of reimbursement on usage.METHODS:This study examined publicly available databases, governmental agency recommendations and policies, and press releases from the United States, Canada, the United Kingdom, and the Netherlands to compare the regulatory approval processes and coverage/reimbursement mechanisms for 2 novel cardiovascular devices introduced in the early and late 2000's: the Watchman left atrial appendage occlusion device and the Impella percutaneous ventricular assist device. In addition to qualitative comparisons for each country, this study compared the date of the first regulatory review, time from submission to review completion, device approval date, agency approval requirements, number of review cycles, and necessity of postapproval studies as determined by the regulator, date of funding decision, final funding decision, and requirements for device reimbursement by relevant government payors.RESULTS:Authorization data were easily accessible for the United States and Canada but extremely limited for the United Kingdom and the Netherlands. Chronologically, authorization occurred approximate to 10 years earlier in Europe (United Kingdom and the Netherlands) than in North America (United States and Canada) for both devices. The United States was the only country where the principal public payor (Medicare) explicitly reimbursed both procedures. The United States was similarly notable for more rapid adoption and higher utilization of both devices than the other countries, with the Watchman implanted at 3.4 devices per 100 000 adults annually and Impella used in 7 to 8 procedures per 100 000 people annually. In contrast, uptake was far lower in Canada and Europe.CONCLUSIONS:This research provides insights into how differences among countries in authorization and reimbursement mechanisms may impact the adoption and usage of medical devices, and may inform future policies on these processes.

BACKGROUND:The possibility of myocardial involvement is well recognised with Covid-19 infection but less so with influenza. We designed this study to explore the frequency of elevated biomarkers and new clinical cardiac diagnoses in patients hospitalised with influenza or Covid-19. METHODS:This was a retrospective cohort study of all adults hospitalised from April 2015 to March 2023 with either influenza or Covid-19 in 29 hospitals in Ontario. We used multivariable regression with generalised estimating equations to compare troponin and natriuretic peptide levels and new cardiac diagnoses during the index hospitalisations. RESULTS:The 25,200 patients with Covid-19 were younger (67 vs 72 years) and more likely to be men (56% vs 47%), and fewer had prior cardiovascular disease (7% vs 13%) than the 8569 patients with influenza (all P < 0.001). Although more likely to have their troponin (84.2% vs 78.7%; P < 0.001) or natriuretic peptides (21.6% vs 12.7%; P < 0.001) measured, patients with Covid-19 were not more likely to have elevated levels compared with influenza patients: 42.7% vs 39.8% for troponin (adjusted risk ratio [aRR] 1.07, 95% CI 0.99-1.15), and 72.3% vs 81.7% for natriuretic peptides (aRR 0.93, 95% CI 0.87-0.99). The frequency of new clinical diagnoses of heart failure (2.4% vs, 2.6%, aRR 1.18, 95% CI 0.79-1.77) or new atrial fibrillation (3.4% vs 5.2%, aRR 0.89, 95% CI 0.79-1.77) did not differ between those with Covid-19 or influenza. CONCLUSIONS:The frequencies of elevated troponins (two-fifths) and natriuretic peptides (three-fourths) were similar in patients hospitalised with influenza and Covid-19 who had biomarkers measured, but the frequencies of clinically recognised diagnoses were low.

AIMS:Persistent atrial fibrillation (AF) patients undergoing a catheter ablation are at risk for adverse outcomes, due to comorbidities and a more advanced arrhythmia substrate. There may be barriers to catheter ablation in patients with persistent AF, compared to those with paroxysmal AF. We compared long-term outcomes after ablation in patients with paroxysmal and persistent AF. METHODS AND RESULTS:Patients undergoing de novo AF catheter ablation from April 2012 to March 2022 in Ontario, Canada, were included. The primary outcome was a composite of all-cause mortality and all-cause hospitalization. Inverse probability of treatment weighting created balanced cohorts of paroxysmal and persistent AF patients. Cox proportional hazards models estimated the effect on persistent vs. paroxysmal AF. There were 10 788 patients who underwent an ablation. Persistent AF patients accounted for 25% of the population. In our weighted cohort, patients had similar age (standardized difference 0.027), female sex [standardized difference (SD) 0.018], and medical comorbidities (Charlson comorbidity score; 0.5% in both, SD 0.018). In the weighted cohort, the primary composite outcome occurred in 5.5% in paroxysmal AF and 6.3% in persistent AF at 30 days (HR 1.15, 95% CI 0.94-1.40, P = 0.168), 19.8% vs. 19.7% at 1 year (HR 1.00, 95% CI 0.90-1.11, P = 0.971), and 34.1% vs. 35.4% at 3 years (HR 1.05, 95% CI 0.97-1.13, P = 0.269). There was no increased risk of the individual components at 30 days, 1 year, or 3 years. CONCLUSION:The risk of all-cause mortality and hospitalization outcomes in persistent and paroxysmal AF patients undergoing ablation was similar at 30 days, 1 year, and 3 years post-ablation. The impact of persistent AF on long-term outcomes (i.e. all-cause mortality) is primarily attributable to comorbid conditions.

This cohort study assesses utilization rates of microaxial flow pumps and intra-aortic balloon pumps among older adults who underwent percutaneous coronary interventions in the US, UK, and Canada.

OBJECTIVE:To describe differences in regionalization of hip fracture care and the volume-outcome relationship in five countries. STUDY SETTING AND DESIGN:We conducted a population-based cross-sectional cohort study in Canada, Israel, the Netherlands, Taiwan, and the United States. Within each country, we stratified patients into quintiles based upon the volume of hip fractures in the hospital where they were treated. We measured regionalization by the proportion of acute-care hospitals that treated patients with hip fractures and summarized the hospital volume distribution by the ratio of hip fracture volumes for high-volume hospitals versus low-volume hospitals. We then examined age- and sex-standardized outcomes and treatment for patients treated at high-volume and low-volume hospitals. DATA SOURCES AND ANALYTIC SAMPLE:We used nationally representative administrative data on adults aged ≥ 66 years hospitalized with hip fracture from 2011 to 2019. We followed them until death or 365 days after the discharge date. PRINCIPAL FINDINGS:Across countries, the percentage of all acute-care hospitals that treated hip fractures differed widely (from 37.0% in Canada to 82.8% in Israel), with high-volume hospitals treating 4-14 times as many hip fractures as low-volume hospitals. The absolute risk-adjusted difference in 30-day mortality for high-volume compared to low-volume hospitals ranged between (-1.9% [95% CI, -2.2 to -1.7] in Canada and +1.1% [95% CI, 0.4-1.8] in the Netherlands). The proportion of patients receiving non-operative fracture treatment was lower in high-volume hospitals than low-volume hospitals in all countries (-5.4% [95% CI, -6.5 to -4.3] in Israel to -0.1% [95% CI, -0.5 to 0.3] in the Netherlands). CONCLUSIONS:Hip fracture regionalization differed substantially across countries. The direction and the magnitude of association between greater regionalization and improved patient outcomes were inconsistent across countries.

BACKGROUND: Bleeding after starting anticoagulation for atrial fibrillation (AF) may be the first sign of malignancy, especially in elderly individuals. There are no recommendations to guide investigations for malignancy after new-onset bleeding after anticoagulation for AF. Our objective was to determine the association of bleeding after starting oral anticoagulation for AF with new diagnoses of malignancy in a population-wide sample. METHODS: We conducted a population-based cohort study using linked administrative data sets of people ≥66 years of age who newly initiated warfarin or direct oral anticoagulants after diagnosis with AF between 2008 and 2022. Follow-up was 2 years after starting anticoagulation. We excluded patients with valvular disease, chronic dialysis, venous thromboembolism, previous cancer, or previously documented bleeding. Bleeding was identified from hospital/emergency department discharge records and physician billings, then handled as a time-varying covariate in cause-specific regression models while adjusting for baseline characteristics. The primary outcome was incident malignancy. We also determined the site of origin of the malignancy and the stage at diagnosis if indicated in the Ontario Cancer Registry. Analyses were repeated while limiting the exposure to specific bleeding sites. RESULTS: Among 119 480 people (mean age, 77.4 years; 52% male) who started anticoagulants, 26 037 (21.8%) had documented bleeding, and 5800 (4.9%) were diagnosed with malignancy within the next 2 years. Bleeding was associated with a higher hazard of cancer diagnosis with a hazard ratio (HR) of 4.0 (95% CI, 3.8–4.3). The HRs for any malignancy were 5.0 (95% CI, 4.6–5.5) for gastrointestinal, 5.0 (95% CI, 4.4–5.7) for genitourinary, 4.0 (95% CI, 3.5–4.6) for respiratory, 1.8 (95% CI, 1.4–2.2) for intracranial, and 1.5 (95% CI, 1.2–2.0) for nasopharyngeal bleeds. The HRs were substantially higher for cancers concordant with the bleeding site (gastrointestinal, 15.4; genitourinary, 11.8; respiratory, 10.1). Cancers were diagnosed at an earlier stage after bleeding (27.6% stage 4 after bleeding versus 31.3% without bleeding; P =0.029). CONCLUSIONS: In anticoagulated patients with AF, bleeding was strongly associated with new cancer diagnoses. Antecedent bleeding was associated with cancer diagnosis at an earlier stage. This highlights the importance of timely investigations in patients with bleeding after anticoagulation for AF, rather than attributing bleeding as an expected adverse effect.

Introduction: Although sodium-glucose cotransporter 2 inhibitors (SGLT2i) are guideline-directed medical therapy for heart failure, their safety in patients with acute decompensated heart failure (ADHF) remains uncertain. This study compared the risk of adverse events between early versus late initiation of SGLT2is following ADHF hospitalization. Methods: We conducted a retrospective cohort study emulating a target trial using linked administrative data from Ontario, Canada. Adults aged ≥66 years discharged after hospitalization for ADHF between April 1, 2016, and March 31, 2021 were included. Patients with prior SGLT2i use or with prior heart failure hospitalizations were excluded. We compared two strategies for initiating SGLT2is: early initiation (within 30 days post-discharge), and late initiation (between days 31 and 365 after discharge). The primary outcome was a composite of eight prespecified adverse events requiring hospitalization or emergency department visit within one year of discharge (diabetic ketoacidosis, genitourinary infections, hypotension/syncope, dehydration, acute kidney injury, and falls/fractures). We applied a clone-censor-weight approach, using inverse probability weighted Cox regression models to estimate cause-specific hazard ratios (csHR) and cumulative incidence functions to account for the competing risk of death. Multiple imputation was used to deal with missing values of serum creatinine. Results: The mean number of included patients across 32 imputed datasets was 58,744 (median age, 83 years [IQR 77–89]; 53.4% women). In the overall cohort, during the 1-year follow-up, 18.2% experienced at least one adverse event, most commonly genitourinary infections (5.9%) and acute kidney injury (4.9%). At one year, no difference in the risk of adverse events was observed between the early and late initiation strategies (cumulative incidence at 1 year was 14.5% in the early and 18.7% in the late initiation strategies; absolute risk difference: 4.1%; csHR: 0.96; 95% CI 0.90 to 1.01; p=0.13). Sensitivity analyses using alternative definitions of early and late initiation yielded similar results. Conclusions: In this population-based target trial emulation study, there was no difference in the risk of one-year adverse events with early initiation of SGLT2i within 30 days post-discharge for ADHF compared with delayed initiation. These findings support the safety of early SGLT2i initiation in patients recently hospitalized for ADHF.

BACKGROUND:A lack of consensus exists across guidelines as to which risk model should be used for the primary prevention of cardiovascular disease (CVD). Our objective was to determine potential improvements in the number needed to treat (NNT) and number of events prevented (NEP) using different risk models in patients eligible for risk stratification. METHODS AND RESULTS:A retrospective observational cohort was assembled from primary care patients in Ontario, Canada, between 1 January 2010 and 31 December 2014 and followed for up to 5 years. Risk estimation was undertaken in patients 40-75 years of age, without CVD, diabetes, or chronic kidney disease using the Framingham Risk Score (FRS), the Pooled Cohort Equations (PCEs), a recalibrated FRS (R-FRS), the Systematic Coronary Risk Evaluation 2 (SCORE2), and the low-risk region recalibrated SCORE2 (LR-SCORE2). The cohort consisted of 47 399 patients (59% women, mean age 54 years). The NNT with statins was lowest for the SCORE2 at 40, followed by the LR-SCORE2 at 41, the R-FRS at 43, the PCEs at 55, and the FRS at 65. Models that selected for individuals with a lower NNT recommended statins to fewer, but higher-risk patients. For instance, the SCORE2 recommended statins to 7.9% of patients (5-year CVD incidence 5.92%). The FRS, however, recommended statins to 34.6% of patients (5-year CVD incidence 4.01%). Accordingly, the NEP was highest for the FRS at 406 and lowest for the SCORE2 at 156. CONCLUSIONS:Newer models such as the SCORE2 may improve statin allocation to higher-risk groups with a lower NNT but prevent fewer events at the population level.

BACKGROUND:Some East Asian (EA) guidelines recommend lower doses of direct oral anticoagulants (DOACs) for atrial fibrillation (AF) than in North America and Europe. OBJECTIVE:The study aimed to investigate the association of immigration from EA with DOAC dosing and outcomes in AF. METHODS:This was a population-based cohort study using administrative databases of Ontario immigrants with AF aged ≥ 66 years who were dispensed DOAC prescriptions from 2012 to 2019. Birth country was classified as EA or not. We used multivariable logistic regression to assess the association of EA birth with DOAC dose and cause-specific hazards regression for the association of EA birth and DOAC dose with stroke or bleeding or death. The interaction between EA birth and DOAC dosing was studied for each outcome. RESULTS:Among 14,421 immigrants, 3958 (27.4%) were born in EA. EA immigrants had lower odds of receiving full-dose DOACs vs non-EA immigrants (odds ratio 0.64, 95% confidence interval [CI] 0.58-0.69, P < .001). EA birth was not associated with a composite of hospitalization for stroke or bleeding (hazard ratio [HR] 0.97, 95% CI 0.84-1.12, P = .67) or hospitalization for stroke (HR 0.86, 95% CI 0.71-1.04, P = .13), but was associated with higher bleeding hazard (HR 1.15, 95% CI 1.02-1.30, P = .02) and lower mortality (HR 0.91, 95% CI 0.84-0.99, P = .04). There was no significant interaction between EA birth and DOAC dosing for stroke (P = .41), bleeding (P = .27), or death (P = .33). CONCLUSIONS:EA immigrants were less likely to receive full-dose DOACs and had a higher bleeding hazard, similar stroke hazard, and lower mortality risk than non-EA immigrants. There was no evidence that DOAC dosing had a differential treatment effect in EA immigrants.

BACKGROUND:Albuminuria is associated with increased stroke risk in atrial fibrillation (AF), but its relationship with heart failure (HF) and other adverse outcomes in AF is less well understood. METHODS:Using linked administrative databases, we conducted a retrospective cohort study of individuals aged ≥66 years who were newly diagnosed with AF between April 2009 and March 2019 in Ontario, Canada. Albuminuria was assessed using (1) urine albumin-to-creatinine ratio (UACR, mg/g) and (2) dipstick proteinuria (negative, trace, 1+, 2+, ≥3+). Cause-specific hazards regression estimated adjusted hazard ratios (HRs) for HF hospitalizations or emergency department visits, stroke hospitalizations, bleeding hospitalizations, and death over 1 year. RESULTS:We included 64 717 individuals with UACR data and 110 430 with dipstick proteinuria data. Relative to UACR 5 mg/g, the HRs for UACR 30 mg/g (below the microalbuminuria threshold) were 1.39 (95% CI, 1.28-1.50) for HF, 1.22 (95% CI, 1.07-1.40) for bleeding, and 1.35 (95% CI, 1.27-1.42) for death. A UACR of 30 mg/g versus 5 mg/g was associated with an HR of 1.16 (95% CI, 0.99-1.36) for stroke but the HR was significantly elevated at UACR values ≥65 mg/g. Increasing dipstick proteinuria was also associated with increases in the HR for adverse outcomes. A UACR of 30 mg/g was associated with greater HF risk (versus 5 mg/g) than all CHA₂DS₂VASc components except age >75 years and prior HF. CONCLUSIONS:Albuminuria is associated with increased hazards of HF, stroke, bleeding, and death in patients with AF even at low UACR levels. Albuminuria may enhance risk stratification in AF beyond traditional scores.

While prior studies have shown regional disparities in patients with myocardial infarction and heart failure within a universal health care, there are limited data on the association between different regions within a universal health care system and outcomes after an atrial fibrillation (AF) diagnosis. In this context, we aimed to assess variations in processes of care and outcomes among patients with the diagnosis of AF presenting to the emergency department (ED). We conducted a population-based retrospective cohort study of all adult patients (≥ 18 years) with their first presentation to the ED with AF between April 1, 2012, and March 31, 2022 in Ontario, Canada. We divided the analyses into five major Ontario Health Regions (North, East, Central, Toronto, and West). North was used as the reference group. The primary outcome was all-cause mortality or admission. Secondary outcomes included all-cause mortality, all-cause admission, and all-cause ED visit. We examined outcomes up to 1 year from index AF diagnosis. Cox proportional hazards regression analysis was used to study the association of different regions and outcomes. Among 104,383 patients with the diagnosis of AF in the ED (mean age 69.4 years, 47.1

BACKGROUND:Current pathways using high-sensitivity cardiac troponin (hs-cTn) to rule in and rule out myocardial infarction (MI) are assay specific. This requires clinicians and laboratories to use the correct assay-specific cutoffs, deltas, and time between measurements for optimal decision making. To overcome these challenges, we developed a new common laboratory pathway (i.e., ALARRM: a laboratory approach for rapid risk-assessment for MI) to aid in early risk stratification for MI in the emergency department (ED) using the combined validated clinical chemistry score (CCS) and common change criteria (3C) algorithm. The objective of our study was to assess the diagnostic performance (sensitivity and specificity) and effectiveness (combination of rule out/low risk and rule in/high risk) of ALARRM. METHODS:The study cohort (n = 855) consisted of patients presenting to the ED with acute coronary syndrome symptoms and had two blood samples collected three hours apart for measurement of Abbott hs-cTnI, Ortho hs-cTnI, Roche hs-cTnT, glucose, and creatinine (for the estimated glomerular filtration rate (eGFR) calculation). We also assessed the European society of cardiology (ESC) single sample assay-specific cutoffs with both ALARRM and ESC criteria being assessed for index MI in the cohort. RESULTS:The sensitivity for MI using ALARRM was 100 % for all three assays, however this was not the case for the ESC single cutoffs where the Ortho hs-cTnI assay missed 4 MIs. The specificities in patients with serial measurements with ALARRM were > 90 %, with the overall effectiveness for ALARRM being 61 % (95 %CI: 58 to 64) for Roche, 80 % (95 %CI: 77 to 82) for Abbott, and 89 % (95 %CI: 86 to 91) for Ortho. CONCLUSION:The ALARRM pathway represents a highly efficacious and common approach using hs-cTn for early risk stratification for MI.

Background:Variation exists in the practice of same-day discharge (SDD) after supraventricular tachycardia (SVT) catheter-ablation procedures. The aim of this study was to evaluate factors associated with SDD after SVT catheter-ablation procedures. Methods:All Ontario residents aged > 18 years undergoing a first-ever SVT ablation procedure between April 1, 2011 and May 31, 2020 were included. The rate of SDD at each hospital and the annual rate within Ontario were determined. A series of logistic regression models were created to determine the influence of clinical and procedural characteristics, and of the hospital performing the procedure, on the probability of SDD occurring. The median odds ratio was calculated to estimate the variation in the odds of similar patients receiving SDD at different hospitals. Results:The cohort included 16,044 individuals (aged 55.9 ± 16.5 years; female: 45.9%). Transseptal catheterization was performed in 7.8% of the cohort. The rate of SDD increased from 61% in 2011 to 91% in 2020. Hospital rates of SDD ranged from 41% to 95%. The discrimination ability (measured by C-statistics) in predicting SDD was high, at 0.84, in the model that included the hospital, as opposed to 0.58 in the model that did not include the hospital. After adjusting for age, sex, patient comorbidities, the arrhythmia diagnosis, and procedural details, the median odds ratio attributed to the hospital performing the procedure was 3.82. Conclusions:Variation in SDD after SVT ablation procedures is primarily related to hospital factors. Policymakers are encouraged to explore hospital-level barriers to adopting this approach.