Search

The ISCHEMIA trial showed similar cardiovascular outcomes of an initial conservative strategy as compared with invasive management in patients with stable ischemic heart disease without left main stenosis. We aim to assess the feasibility of predicting significant left main stenosis using extensive clinical, laboratory and non-invasive tests data.All adult patients who had stress testing prior to undergoing an elective coronary angiography for stable ischemic heart disease in Ontario, Canada, between April 2010 and March 2019, were included. Candidate predictors included comprehensive demographics, comorbidities, laboratory tests, and cardiac stress test data. The outcome was stenosis of 50% or greater in the left main coronary artery. A traditional model (logistic regression) and a machine learning algorithm (boosted trees) were used to build prediction models.Among 150,423 patients included (mean age: 64.2 ± 10.6 years; 64.1% males), there were 9,225 (6.1%) with left main stenosis. The final logistic regression model included 24 predictors and 3 interactions, had an optimism-adjusted c-statistic of 0.72 and adequate calibration (optimism-adjusted Integrated Calibration Index 0.0044). These results were consistent in subgroups of males and females, diabetes and non-diabetes, and extent of ischemia. The boosted tree algorithm had similar accuracy, also resulting in a c-statistic of 0.72 and adequate calibration (Integrated Calibration Index 0.0054).In this large population-based study of patients with stable ischemic heart disease using extensive clinical data, only modest prediction of left main coronary artery disease was possible with traditional and machine learning modelling techniques.

Amiodarone is a commonly used pharmacotherapy in patients with atrial fibrillation (AF), with a potential for drug-drug interactions with direct oral anticoagulants (DOACs). We aimed to assess the bleeding risk after co-prescription of amiodarone and DOACs among adults with AF. We conducted a population-based, nested case-control study in Ontario, Canada. The study population included all patients with AF aged66 years on a DOAC between April 1, 2011 and March 31, 2018. Cases were patients admitted with major bleeding (index date). Controls were matched in a 2:1 ratio to cases. We categorized exposure to amiodarone before the index date as: (1) current users (amiodarone within 60 days), (2) past users (amiodarone within 61 to 140 days), and (3) unexposed (no amiodarone prescription or amiodarone prescription140 days before index date). Conditional logistic regression models were used to examine the association between bleeding and amiodarone co-prescription. Among 86,679 patients with AF on a DOAC, we identified 2,766 cases (3.2%) admitted with major bleeding. The median age of patients with AF was 80 years (interquartile range 75 to 85); 48.3% were women. After multivariable adjustment, there was a significant association between major bleeding and current use of amiodarone (adjusted odds ratio 1.53; 95% confidence interval 1.24 to 1.89, p0.001) but no significant association between major bleeding and past use of amiodarone (adjusted odds ratio 1.13, 95% confidence interval 0.76 to 1.68, p = 0.545) compared with the unexposed group. In conclusion, among older patients with AF on a DOAC, there was 53% increased odds of major bleeding with the current use of amiodarone.

For younger women with acute myocardial infarction (AMI), little is known regarding their contemporary care pathways and clinical outcomes.We studied AMI patients aged 18-55 years, hospitalized from April 1, 2009, to March 31, 2019, in Ontario, Canada. We compared trends in comorbidities, angiographic findings, and revascularisation rates in men and women. The primary outcome was 1-year all-cause mortality or readmission for unstable angina, AMI, heart failure, or stroke. Inverse probability of treatment weighting was used to account for differences in baseline clinical characteristics between men and women.Among the 38,071 AMI patients included, 8,077 (21.2%) were women. Over the study period, women had increasing rates of diabetes (24.8% to 34.9%; PCoronary angiography is performed almost universally in younger women with AMI; however, coronary revascularisation is less frequent, perhaps reflecting less obstructive disease. Although mortality rates after AMI were similar between sexes, cardiovascular readmission rates and all-cause readmissions were significantly increased among women.

Based on current studies, the incidence of Ewing sarcoma (ES) varies significantly by race and ethnicity, with the disease being most common in patients of European ancestry. However, race/ethnicity has generally been self-reported rather than formally evaluated at a population level using DNA evidence. Additionally, mitochondrial dysfunction is a hallmark of ES, yet there have been no reported studies of mitochondrial genetics in ES. Thus, we evaluated both the mitochondrial and nuclear ancestries of 420 pediatric ES patients in the United States using whole-genome sequencing. We found that the mitochondrial DNA (mtDNA) genomes of only six (1.4 %) patients belonged to African L haplogroups, while those of 90 % of the patients belonged to macrohaplogroup R, which includes haplogroup H, the most common maternal lineage in Europe. Compared to the general US population, European haplogroups were significantly enriched in ES patients (p 2.2e-16) and the African haplogroups are significantly impoverished (p 4.6e-16). Using the ancestry informative markers defined in a National Genographic study, the vast majority of patients exhibited significant nuclear ancestry originating from the Mediterranean, Northern Europe, and Southwest Asia, including all six patients with African L mtDNAs. Very few had primarily African nuclear ancestry. This is the first genomic epidemiology study to simultaneously interrogate the mitochondrial and nuclear ancestries of ES patients. While supporting previous findings of enriched European ancestry in ES patients, these results also suggest alternative hypotheses for the significant contribution of mitochondrial ancestry in ES patients, as well as the protective role of African ancestry.

Although we had previously reported the cardiac and neurologic outcomes of Chinese and South Asian Ontarians in wave 1 of COVID-19, data on subsequent waves of COVID-19 remain unexamined. This is an extension study of this cohort in waves 2 and 3.We identified adult Ontarians with a positive COVID-19 polymerase chain reaction test from January 1, 2020 to June 30, 2021, and they were classified as being Chinese or South Asian using a validated surname algorithm; we compared their outcomes of mortality, and cardiac and neurologic complications with those of the general population using multivariable logistic regression models.Compared to the general population (n = 439,977), the Chinese population (n = 15,208) was older (mean age 44.2 vs 40.6 years,Ethnicity continues to be an important determinant of mortality, cardiac and neurologic outcomes, and healthcare use among patients with COVID-19, requiring further studies to understand factors driving these differences.Nous avons déjà présenté les issues cliniques cardiaques et neurologiques chez les Ontariens de descendance chinoise ou sud-asiatique pour la première vague de la pandémie de COVID-19, mais les données au sujet des vagues ultérieures n’avaient pas encore été analysées. Nous présentons ici une prolongation de cette étude de cohortes pour la seconde et la troisième vague de COVID-19.Notre analyse porte sur des adultes ontariens ayant obtenu un résultat positif à un test de COVID-19 par réaction en chaîne de la polymérase entre le 1En comparaison de la population générale (n = 439 977), les personnes de descendance chinoise (n = 15 208) se sont révélées plus âgées (âge moyen de 44,2 ans contre 40,6 ans,L’origine ethnique demeure un déterminant important de la mortalité, des issues cliniques cardiaques et neurologiques ainsi que de l’utilisation des ressources en santé chez les patients atteints de la COVID-19. D’autres études sont toutefois nécessaires pour mieux comprendre les facteurs qui expliquent ces différences.

A simplified Canadian definition was recently developed to enable identification of individuals with familial hypercholesterolemia (FH) and severe hypercholesterolemia in the general population. Our objective was to use a modified version of this new definition to assess contemporary disease prevalence, treatment patterns, and low-density lipoprotein cholesterol (LDL-C) control in Ontario, Canada.We identified individuals aged 66 to 105 years who were alive as of January 1, 2011, using theAmong 922,464 individuals, 2440 (0.26%) met criteria for definite or probable FH, and 72,893 (7.90%) for severe hypercholesterolemia. At diagnosis, mean LDL-C concentration was 9.52 mmol/L for those with definite FH, 5.83 mmol/L for those with probable FH, 5.73 mmol/L for those with severe hypercholesterolemia, and 3.33 mmol/L for all other individuals. After5 years, LDL-C concentration remained elevated at 3.58 mmol/L for those with definite FH, 2.72 mmol/L for those with probable FH, and 2.93 mmol/L for those with severe hypercholesteremia. Use of statin therapy was initially high (83% of those with definite FH, 78% of those with probable FH, 62% of those with severe hypercholesterolemia); however, fewer patients remained on statins at follow-up at5 years (62% of those with definite FH, 67% of those with probable FH, 58% of those with severe hypercholesterolemia).Among older Ontarians, we estimated that 1 in 378 individuals had FH, and 1 in 13 had severe hypercholesterolemia. Despite being at substantially increased cardiovascular risk, these patients acheived suboptimal LDL-C level control and fewer were on medical therapy at follow-up.Une définition canadienne simplifiée a récemment été élaborée pour permettre la détection des personnes atteintes d’hypercholestérolémie familiale (HF) et d'hypercholestérolémie grave au sein de la population générale. Notre objectif était d’utiliser la version modifiée de cette nouvelle définition pour évaluer la prévalence contemporaine de la maladie, les schémas de traitement et la maîtrise du cholestérol à lipoprotéines de faible densité (cholestérol LDL) en Ontario, au Canada.Nous avons recensé les individus âgés de 66 à 105 ans qui étaient en vie au 1Parmi les 922 464 personnes, 2 440 (0,26 %) répondaient aux critères de diagnostic définitif ou de diagnostic probable d’HF, et 72 893 (7,90 %), aux critères d’hypocholestérolémie grave. Au diagnostic, les concentrations moyennes de cholestérol LDL étaient de 9,52 mmol/l chez ceux qui avaient un diagnostic définitif d’HF, de 5,83 mmol/l chez ceux qui avaient un diagnostic probable d’HF, de 5,73 mmol/l chez ceux qui avaient un diagnostic d’hypercholestérolémie grave et de 3,33 mmol/l chez toutes les autres personnes. Après5 ans, les concentrations de cholestérol LDL étaient demeurées élevées : 3,58 mmol/l chez ceux qui avaient un diagnostic définitif d’HF, 2,72 mmol/l chez ceux qui avaient un diagnostic probable d’HF et 2,93 mmol/l chez ceux qui avaient un diagnostic d’hypercholestérolémie grave. L’utilisation du traitement par statines était initialement élevée (83 % de ceux qui avaient un diagnostic définitif d’HF, 78 % de ceux qui avaient un diagnostic probable d’HF, 62 % de ceux qui avaient un diagnostic d’hypercholestérolémie grave). Toutefois, moins de patients avaient conservé les statines au suivi5 ans (62 % de ceux qui avaient un diagnostic définitif d’HF, 67 % de ceux qui avaient un diagnostic probable d’HF, 58 % de ceux qui avaient un diagnostic d’hypercholestérolémie grave).Parmi les Ontariens âgés, nous avons estimé que 1 sur 378 personnes avaient une HF, et que 1 sur 13 avaient une hypercholestérolémie grave. Malgré le fait qu’ils sont exposés à un risque cardiovasculaire substantiellement élevé, ces patients ont atteint une maîtrise sous-optimale du taux de cholestérol LDL et moins d'entre eux étaient sous traitement médical au suivi.

Atherosclerotic plaque quantification from coronary CT angiography (CCTA) enables accurate assessment of coronary artery disease burden and prognosis. We sought to develop and validate a deep learning system for CCTA-derived measures of plaque volume and stenosis severity.This international, multicentre study included nine cohorts of patients undergoing CCTA at 11 sites, who were assigned into training and test sets. Data were retrospectively collected on patients with a wide range of clinical presentations of coronary artery disease who underwent CCTA between Nov 18, 2010, and Jan 25, 2019. A novel deep learning convolutional neural network was trained to segment coronary plaque in 921 patients (5045 lesions). The deep learning network was then applied to an independent test set, which included an external validation cohort of 175 patients (1081 lesions) and 50 patients (84 lesions) assessed by intravascular ultrasound within 1 month of CCTA. We evaluated the prognostic value of deep learning-based plaque measurements for fatal or non-fatal myocardial infarction (our primary outcome) in 1611 patients from the prospective SCOT-HEART trial, assessed as dichotomous variables using multivariable Cox regression analysis, with adjustment for the ASSIGN clinical risk score.In the overall test set, there was excellent or good agreement, respectively, between deep learning and expert reader measurements of total plaque volume (intraclass correlation coefficient [ICC] 0·964) and percent diameter stenosis (ICC 0·879; both p0·0001). When compared with intravascular ultrasound, there was excellent agreement for deep learning total plaque volume (ICC 0·949) and minimal luminal area (ICC 0·904). The mean per-patient deep learning plaque analysis time was 5·65 s (SD 1·87) versus 25·66 min (6·79) taken by experts. Over a median follow-up of 4·7 years (IQR 4·0-5·7), myocardial infarction occurred in 41 (2·5%) of 1611 patients from the SCOT-HEART trial. A deep learning-based total plaque volume of 238·5 mmOur novel, externally validated deep learning system provides rapid measurements of plaque volume and stenosis severity from CCTA that agree closely with expert readers and intravascular ultrasound, and could have prognostic value for future myocardial infarction.National Heart, Lung, and Blood Institute and the MiriamSheldon G Adelson Medical Research Foundation.

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.

The dopamine transporter (DAT) is targeted in substance use disorders (SUDs), and "non-classical”" DAT inhibitors with low abuse potential are therapeutic candidates. Lobinaline, from Lobelia cardinalis, is an atypical DAT inhibitor lead. Chemical synthesis of lobinaline is challenging; thus, "target-directed evolution" was used for lead optimization. A target protein is expressed in plant cells, and a mutant cell population is selected under conditions where target protein functional inhibition confers a survival advantage. Surviving mutants are "mined" for the targeted activity. Applied to a mutant L. cardinalis cell population expressing the human DAT, we identified 20 mutants overproducing DAT inhibitors. Microanalysis prioritized novel lobinaline derivatives, and we first investigated the more water-soluble lobinaline N-oxide. It inhibited rat synaptosomal [3H]DA uptake with an IC50 similar to lobinaline. Against repeated DA microinjections into the rat striatum, lobinaline produced transient DA clearance reductions. In contrast, lobinaline N-oxide prolongingly increased DA peak amplitudes, particularly in the ventral striatum. Lobinaline N-oxide also produced complex changes in post-peak DA clearance inconsistent with simple DAT inhibition. This unusual DAT interaction may prove therapeutically useful for treating SUDs. This study demonstrates the value of target-directed evolution of plant cells for optimizing lead compounds difficult to synthesize chemically.

The objective of this study was to determine the effect of transcatheter mitral valve repair (TMVr) on hospitalization rates by assessing pre- and postprocedural hospitalization patterns.TMVr has emerged as the treatment of choice for selected patients with mitral regurgitation, but the impact of these procedures on hospital utilization remains unclear.All patients who underwent TMVr in Ontario, Canada, between 2011 and 2017 were included in this observational study using population-based data. Hospitalization person-year rates were assessed in the years before and after TMVr and 4 predefined intervals: 1 to 30, 31 to 90, 91 to 182, and 183 to 365 days. Main outcomes of interest were all-cause and heart failure (HF) hospitalizations. Poisson regression models were used to compare incidence rates across all time periods.The study cohort included 523 patients. In the year preceding TMVr, 66.2% of patients were hospitalized compared with 47.4% in the year following. There were stepwise increases in both all-cause and HF hospitalization rates in the periods preceding the index procedure, and all postprocedural periods had significantly lower hospitalization rates. The adjusted rate ratios for all-cause and HF-related hospitalization in the year after TMVr were 0.65 (95% CI: 0.56-0.76) and 0.38 (95% CI: 0.29-0.51), respectively. All time periods had significant reductions in all-cause and HF hospitalization in the adjusted analysis.In this population-based study, significant reductions were observed in both all-cause and HF-related hospitalizations in all time periods after TMVr compared with the year prior. This suggests that TMVr has a sustained effect on hospitalization rates despite a high-risk population.

Background The novel SARS-CoV-2 (COVID-19) pandemic has dramatically altered the delivery of healthcare services, resulting in significant referral pattern changes, delayed presentations, and procedural delays. Our objective was to determine the effect of the COVID-19 pandemic on all-cause mortality in patients awaiting commonly performed cardiac procedures. Methods Clinical and administrative data sets were linked to identify all adults referred for: (1) percutaneous coronary intervention; (2) coronary artery bypass grafting; (3) valve surgery; and (4) transcatheter aortic valve implantation, from January 2014 to September 2020 in Ontario, Canada. Piece-wise regression models were used to determine the effect of the COVID-19 pandemic on referrals and procedural volume. Multivariable Cox proportional hazards models were used to determine the effect of the pandemic on waitlist mortality for the 4 procedures. Results We included 584,341 patients who were first-time referrals for 1 of the 4 procedures, of whom 37,718 (6.4%) were referred during the pandemic. The pandemic period was associated with a significant decline in the number of referrals and procedures completed compared with the prepandemic period. Referral during the pandemic period was a significant predictor for increased all-cause mortality for the percutaneous coronary intervention (hazard ratio, 1.83; 95% confidence interval, 1.47-2.27) and coronary artery bypass grafting (hazard ratio, 1.96; 95% confidence interval, 1.28-3.01), but not for surgical valve or transcatheter aortic valve implantation referrals. Procedural wait times were shorter during the pandemic period compared with the prepandemic period. Conclusions There was a significant decrease in referrals and procedures completed for cardiac procedures during the pandemic period. Referral during the pandemic was associated with increased all-cause mortality while awaiting coronary revascularization.