Ablation of ventricular tachycardia after septal myectomy for hypertrophic cardiomyopathy.

Electrocardiography and 3D mapping images of the case.

Same-Day Discharge After Percutaneous Left Atrial Appendage Occlusion Procedures.

Information is evolving on the safety of same-day discharge (SDD) after left atrial appendage occlusion (LAAO) procedures. This single-centre retrospective study evaluated the feasibility of SDD and reported on the 30-day rehospitalization rate in patients discharged same-day compared with those admitted overnight after LAAO. Key findings of this study included more than 85% of patients with LAAO were safely discharged same-day; the rate of postdischarge rehospitalization was similar in SDD patients and those admitted overnight; and approximately 1 in 10 patients who had LAAO procedures were rehospitalized within 30 days postprocedure.

Les informations sur la sécurité de la sortie de l'hôpital le jour même (SHJM) après avoir subi une occlusion de l'appendice auriculaire gauche (OAAG) évoluent constamment. La présente étude rétrospective unicentrique a permis d'évaluer la faisabilité de la SHJM et de rendre compte du taux de réhospitalisation dans les 30 jours des patients SHJM par rapport aux patients hospitalisés jusqu'au lendemain après l'OAAG. Les principales conclusions de cette étude étaient les suivantes : 85 % des patients ayant eu une OAAG ont reçu leur congé de l'hôpital le jour même en toute sécurité; le taux de réhospitalisation après la sortie de l'hôpital étaient similaires entre les patients SHJM et les patients hospitalisés jusqu'au lendemain; environ 1/10 des patients qui avaient eu une OAAG étaient réhospitalisés dans les 30 jours après l'opération.

MRI Accurately Visualizes RF Ablation Delivery Targeted to MRI-Defined Arrhythmia Substrates in the Left Ventricle.

OBJECTIVE: Investigate the capacity of MRI to evaluate efficacy of radiofrequency (RF) ablations delivered to MRI-defined arrhythmogenic substrates. METHODS: Baseline MRI was performed at 3T including 3D LGE in a swine model of chronic myocardial infarct (N=8). MRI-derived maps of scar and heterogeneous tissue channels (HTCs) were generated using ADAS 3D. Animals underwent electroanatomic mapping and ablation of the left ventricle in CARTO3, guided by MRI-derived scar maps. Post-ablation MRI (in vivo at 3T in 5/8 animals; ex vivo at 1.5T in 3/8) included 3D native T1-weighted IR-SPGR (TI=700-800ms) to visualize RF lesions. T1-derived RF lesions were compared against excised tissue. The locations of T1-derived RF lesions were compared against CARTO ablation tags, and segment-wise sensitivity and specificity of lesion detection were calculated within the AHA 17-segment model. RESULTS: RF lesions were clearly visualized in HTCs, scar, and myocardium. Ablation patterns delivered in CARTO matched T1-derived RF lesion patterns with high sensitivity (88.9%) and specificity (94.7%), and were closely matched in registered MR-EP data sets, with a displacement of 5.4 ±3.8mm (N=152 ablation tags). CONCLUSION: Integrating MRI into ablative procedures for RF lesion assessment is feasible. Patterns of RF lesions created using a standard 3D EAM system are accurately reflected by MRI visualization in healthy myocardium, scar, and HTCs comprising the MRI-defined arrhythmia substrate. SIGNIFICANCE: MRI visualization of RF lesions can provide near-immediate (<24h) assessment of ablation, potentially indicating whether critical MRI-defined ventricular tachycardia substrates have been adequately ablated.

Rural-urban differences in out-of-network treatment initiation and engagement rates for substance use disorders.

OBJECTIVE: To examine rural-urban disparities in substance use disorder treatment access and continuation. DATA SOURCES AND STUDY SETTING: We analyzed a 2016-2018 U.S. national secondary dataset of commercial insurance claims. STUDY DESIGN: This cross-sectional study examined individuals with a new episode of opioid, alcohol, or other drug use disorders. Treatment initiation and engagement rates, and rates of using out-of-network providers for these services, were compared between rural and urban patients. DATA COLLECTION: We included individuals 18-64 years old with continuous employer-sponsored insurance. PRINCIPAL FINDINGS: Patients in rural settings experienced lower treatment initiation rates for alcohol (36.6% vs. 38.0%, p < 0.001), opioid (41.2% vs. 44.2%, p < 0.001), and other drug (37.7% vs. 40.1%, p < 0.001) use disorders, relative to those in urban areas. Similarly, rural patients had lower treatment engagement rates for alcohol (15.1% vs. 17.3%, p < 0.001), opioid (21.0% vs. 22.6%, p < 0.001), and other drug (15.5% vs. 17.5%, p < 0.001) use disorders. Rural patients had higher out-of-network rates for treatment initiation for other drug use disorders (20.4% vs. 17.2%, p < 0.001), and for treatment engagement for alcohol (27.6% vs. 25.2%, p = 0.006) and other drug (36.1% vs. 31.1%, p < 0.001) use disorders. CONCLUSIONS: These findings indicate that individuals with substance use disorders in rural areas have lower rates of initial and ongoing treatment, and are more likely to seek care out-of-network.

Physical Activity, Heart Rate Variability, and Ventricular Arrhythmia During the COVID-19 Lockdown: Retrospective Cohort Study.

BACKGROUND: Ventricular arrhythmias (VAs) increase with stress and national disasters. Prior research has reported that VA did not increase during the onset of the COVID-19 lockdown in March 2020, and the mechanism for this is unknown. OBJECTIVE: This study aimed to report the presence of VA and changes in 2 factors associated with VA (physical activity and heart rate variability [HRV]) at the onset of COVID-19 lockdown measures in Ontario, Canada. METHODS: Patients with implantable cardioverter defibrillator (ICD) followed at a regional cardiac center in Ontario, Canada with data available for both HRV and physical activity between March 1 and 31, 2020, were included. HRV, physical activity, and the presence of VA were determined during the pre- (March 1-10, 2020) and immediate postlockdown (March 11-31) period. When available, these data were determined for the same period in 2019. RESULTS: In total, 68 patients had complete data for 2020, and 40 patients had complete data for 2019. Three (7.5%) patients had VA in March 2019, whereas none had VA in March 2020 (P=.048). Physical activity was reduced during the postlockdown period (mean 2.3, SD 1.6 hours vs mean 2.1, SD 1.6 hours; P=.003). HRV was unchanged during the pre- and postlockdown period (mean 91, SD 30 ms vs mean 92, SD 28 ms; P=.84). CONCLUSIONS: VA was infrequent during the COVID-19 pandemic. A reduction in physical activity with lockdown maneuvers may explain this observation.

Stroke risk in women with atrial fibrillation.

BACKGROUND AND AIMS: Female sex is associated with higher rates of stroke in atrial fibrillation (AF) after adjustment for other CHA2DS2-VASc factors. This study aimed to describe sex differences in age and cardiovascular care to examine their relationship with stroke hazard in AF. METHODS: Population-based cohort study using administrative datasets of people aged ≥66 years diagnosed with AF in Ontario between 2007 and 2019. Cause-specific hazard regression was used to estimate the adjusted hazard ratio (HR) for stroke associated with female sex over a 2-year follow-up. Model 1 included CHA2DS2-VASc factors, with age modelled as 66-74 vs. ≥ 75 years. Model 2 treated age as a continuous variable and included an age-sex interaction term. Model 3 further accounted for multimorbidity and markers of cardiovascular care. RESULTS: The cohort consisted of 354 254 individuals with AF (median age 78 years, 49.2% female). Females were more likely to be diagnosed in emergency departments and less likely to receive cardiologist assessments, statins, or LDL-C testing, with higher LDL-C levels among females than males. In Model 1, the adjusted HR for stroke associated with female sex was 1.27 (95% confidence interval 1.21-1.32). Model 2 revealed a significant age-sex interaction, such that female sex was only associated with increased stroke hazard at age >70 years. Adjusting for markers of cardiovascular care and multimorbidity further decreased the HR, so that female sex was not associated with increased stroke hazard at age ≤80 years. CONCLUSION: Older age and inequities in cardiovascular care may partly explain higher stroke rates in females with AF.

Long-term Clinical Outcomes in Contemporary Patients Undergoing Left Atrial Appendage Occlusion Procedures in Ontario, Canada.

Background: Percutaneous left atrial appendage occlusion (LAAO) is an alternative for stroke prevention in patients with atrial fibrillation with contraindications to oral anticoagulation. Population-level real-world data describing the use and outcomes of LAAO procedures are evolving, with a paucity of longer-term follow-up data. We report on the patient characteristics, procedure complications, and longer-term clinical outcomes in all patients undergoing LAAO procedures in Ontario, Canada. Methods: All patients undergoing LAAO procedure between April 1, 2013 and March 31, 2022 were identified. Linked administrative databases were utilized to determine patient clinical and procedural characteristics. Outcomes of interest included procedural complications at 7 and 30 days, and longer-term rates of stroke, bleeding, all-cause rehospitalization, and mortality. Results: A total of 549 individuals were included in the study cohort. The average age was 75 ± 8 years, with 66% being of male sex, with a mean CHA2DS2VASc score of 4.4 ± 1.6, and with 68% not receiving oral anticoagulation. Follow-up for 2.6 ± 2.0 patient-years was available. Stroke occurred in 2.8% during the follow-up period (1.1 per 100 patient-years), bleeding in 10% (4.0 per 100 patient-years), and any hospital readmission in 63% (43 per 100 patient-years). A total of 29% of the cohort died during the follow-up period (11 per 100 patient-years), with 1.8% of the cohort dying during the procedural hospitalization. The mortality rate was unchanged during the study period (P for trend = 0.72). Conclusions: Long-term stroke and bleeding rates are low in patients undergoing LAAO procedures in Ontario, Canada. All-cause mortality in this population is high and remained unchanged during the study period.

Contexte: La fermeture percutanée de l'appendice auriculaire gauche (FPAAG) est une intervention possible pour prévenir les accidents vasculaires cérébraux (AVC) chez les patients atteints de fibrillation auriculaire chez qui les anticoagulants oraux sont contre-indiqués. Les données populationnelles en contexte réel décrivant l'utilisation de la FPAAG et les résultats cliniques qui y sont associés sont de plus en plus nombreuses, mais il y a toujours peu de données sur le suivi à long terme. Nous présentons ici les caractéristiques des patients, les complications liées à l'intervention et les résultats cliniques à long terme pour l'ensemble des patients ayant subi une FPAAG en Ontario (Canada). Méthodologie: Tous les patients ayant subi une FPAAG entre le 1er avril 2013 et le 31 mars 2022 ont été recensés. Des bases de données administratives liées ont été utilisées pour relever les caractéristiques des patients et des interventions. Les résultats cliniques d'intérêt incluaient les complications liées à l'intervention à 7 et à 30 jours ainsi que les taux de divers événements à long terme : AVC, hémorragie, réadmission à l'hôpital toutes causes confondues et mortalité. Résultats: Au total, 549 personnes faisaient partie de la cohorte à l'étude. L'âge moyen des patients était de 75 ± 8 ans, et 66 % étaient des hommes. La moyenne du score CHA2DS2VASc s'élevait à 4,4 ± 1,6, et 68 % des patients ne prenaient pas d'anticoagulants par voie orale. En moyenne, les données de suivi portaient sur 2,6 ± 2,0 patients-années. Un AVC est survenu chez 2,8 % des patients au cours du suivi (1,1 pour 100 patients-années), une hémorragie est survenue chez 10 % des patients (4,0 pour 100 patients-années) et le taux de réadmission hospitalière toutes causes confondues s'élevait à 63 % (43 pour 100 patients-années). Au total, 29 % des patients de la cohorte sont morts au cours de la période de suivi (11 pour 100 patients-années), et 1,8 % des patients de la cohorte sont morts au cours de l'hospitalisation liée à l'intervention. Le taux de mortalité est demeuré le même au cours de la période à l'étude (valeur p de 0,72 pour la tendance). Conclusions: Les taux de survenue d'AVC et d'hémorragie à long terme sont faibles chez les patients ayant subi une FPAAG en Ontario (Canada), mais leur taux de mortalité toutes causes confondues est élevé et est demeuré le même au cours de la période à l'étude.

Prognostic Value of Different Thresholds for Myocardial Scar Quantification on Cardiac MRI Late Gadolinium Enhancement Images in Patients Receiving Implantable Cardioverter Defibrillators.

Purpose: To compare the predictive value of different myocardial scar quantification thresholds using cardiac MRI for appropriate implantable cardioverter defibrillator (ICD) shock and mortality. Materials and Methods: In this retrospective, two-center observational cohort study, patients with ischemic or nonischemic cardiomyopathy underwent cardiac MRI prior to ICD implantation. Late gadolinium enhancement (LGE) was first determined visually and then quantified by blinded cardiac MRI readers using different SDs above the mean signal of normal myocardium, full-width half-maximum, and manual thresholding. The intermediate signal "gray zone" was calculated as the differences between different SDs. Results: Among 374 consecutive eligible patients (mean age, 61 years ± 13 [SD]; mean left ventricular ejection fraction, 32% ± 14; secondary prevention, 62.7%), those with LGE had a higher rate of appropriate ICD shock or death than those without (37.5% vs 26.6%, log-rank P = .04) over a median follow-up of 61 months. In multivariable analysis, none of the thresholds for quantifying scar was a significant predictor of mortality or appropriate ICD shock, while the extent of gray zone was an independent predictor (adjusted hazard ratio per 1 g = 1.025; 95% CI: 1.008, 1.043; P = .005) regardless of the presence or absence of ischemic heart disease (P interaction = .57). Model discrimination was highest for the model incorporating the gray zone (between 2 SD and 4 SD). Conclusion: Presence of LGE was associated with a higher rate of appropriate ICD shock or death. Although none of the scar quantification techniques predicted outcomes, the gray zone both in infarct and nonischemic scar was an independent predictor and may refine risk stratification.Keywords: MRI, Scar Quantification, Implantable Cardioverter Defibrillator, Sudden Cardiac Death Supplemental material is available for this article. © RSNA, 2023.

Statin Use and Stroke Rate in Older Adults With Atrial Fibrillation: A Population-Based Cohort Study.

Background Atherosclerotic disease is an important contributor to adverse outcomes in patients with atrial fibrillation (AF). There is limited recognition of the association between statin use and stroke rates in AF. We aimed to quantify the association between statin use and stroke rate in AF. Methods and Results Using linked administrative databases in Ontario, Canada, we conducted a population-based retrospective cohort study of patients, aged ≥66 years, diagnosed with AF between 2009 and 2019. We used cause-specific hazard regression to determine the association of statin use with stroke rate. We developed a second model to further adjust for lipid levels in the subset of patients with available measurements in the year before AF diagnosis. Both models adjusted for age, sex, heart failure, hypertension, diabetes, stroke/transient ischemic attack, vascular disease, and P2Y12 inhibitors at baseline, plus anticoagulation as a time-varying covariate. We studied 261 659 qualifying patients (median age, 78 years; 49% women). Statins were used in 142 834 (54.6%) patients, and 145 673 (55.7%) had lipid measurement(s) in the preceding year. Statin use was associated with lower stroke rates, with adjusted hazard ratios of 0.83 (95% CI, 0.77-0.88; P<0.001) in the full cohort and 0.87 (95% CI, 0.78-0.97; P=0.01) when adjusting for lipid data. Stroke rates increased in a near-linear manner as low-density lipoprotein values increased >1.5 mmol/L. Conclusions Statins were associated with lower stroke rates in patients with AF, whereas higher low-density lipoprotein levels were associated with higher stroke rates, highlighting the importance of vascular risk factor treatment in AF.

PROSER: A Web-Based Peripheral Blood Smear Interpretation Support Tool Utilizing Electronic Health Record Data.

OBJECTIVES: Peripheral blood smear (PBS) interpretation represents a cornerstone of pathology practice and resident training but has remained largely static for decades. Here, we describe a novel PBS interpretation support tool. METHODS: In a mixed-methods quality improvement study, a web-based clinical decision support (CDS) tool to assist pathologists in PBS interpretation, PROSER, was deployed in an academic hospital over a 2-month period in 2022. PROSER interfaced with the hospital system's electronic health record and data warehouse to obtain and display relevant demographic, laboratory, and medication information for patients with pending PBS consults. PROSER used these data along with morphologic findings entered by the pathologist to draft a PBS interpretation using rule-based logic. We evaluated users' perceptions of PROSER with a Likert-type survey. RESULTS: PROSER displayed 46 laboratory values with corresponding reference ranges and abnormal flags, allowed for entry of 14 microscopy findings, and computed 2 calculations based on laboratory values; it composed automated PBS reports using a library of 92 prewritten phrases. Overall, PROSER was well received by residents. CONCLUSIONS: In this quality improvement study, we successfully deployed a web-based CDS tool for PBS interpretation. Future work is needed to quantitatively evaluate this intervention's effects on clinical outcomes and resident training.

P-Wave Duration/Amplitude Ratio Quantifies Atrial Low-Voltage Area and Predicts Atrial Arrhythmia Recurrence After Pulmonary Vein Isolation.

BACKGROUND: Atrial low-voltage areas (LVAs) in patients with atrial fibrillation increase the risk of atrial arrhythmia (AA) recurrence after pulmonary vein isolation (PVI). Contemporary LVA prediction scores (DR-FLASH, APPLE) do not include P-wave metrics. We aimed to evaluate the utility of P-wave duration/amplitude ratio (PWR) in quantifying LVA and predicting AA recurrence after PVI. METHODS: In 65 patients undergoing first-time PVI, 12-lead ECGs were recorded during sinus rhythm. PWR was calculated as the ratio between the longest P-wave duration and P-wave amplitude in lead I. High-resolution biatrial voltage maps were collected and LVAs included bipolar electrogram amplitudes < 0.5 mV or < 1.0 mV. An LVA quantification model was created with the use of clinical variables and PWR, and then validated in a separate cohort of 24 patients. Seventy-eight patients were followed for 12 months to evaluate AA recurrence. RESULTS: PWR strongly correlated with left atrial (LA) (< 0.5 mV: r = 0.60; < 1.0 mV: r = 0.68; P < 0.001) and biatrial LVA (< 0.5 mV: r = 0.63; < 1.0 mV: r = 0.70; P < 0.001). Addition of PWR to clinical variables improved model quantification of LA LVA at the < 0.5 mV (adjusted R2 = 0.59 to 0.68) and < 1.0 mV (adjusted R2 = 0.59 to 0.74) cutoffs. In the validation cohort, PWR model-predicted LVA correlated strongly with measured LVA (< 0.5 mV: r = 0.78; < 1.0 mV: r = 0.81; P < 0.001). PWR model was superior to DR-FLASH (area under the receiver operating characteristic curve [AUC] 0.90 vs 0.78; P = 0.030) and APPLE (AUC 0.90 vs 0.67; P = 0.003) at detecting LA LVA and similar at predicting AA recurrence after PVI (AUC 0.67 vs 0.65 and 0.60). CONCLUSION: Our novel PWR model accurately quantifies LVA and predicts AA recurrence after PVI. PWR model-predicted LVA may help guide patient selection for PVI.

Variation and clinical consequences of wait-times for atrial fibrillation ablation: population level study in Ontario, Canada.

AIMS: Atrial fibrillation (AF) is the most common cardiac rhythm disorder. Emerging evidence supporting the efficacy of catheter ablation in managing AF has led to increased demand for this therapy, potentially outpacing the capacity to perform this procedure. Mismatch between demand and capacity for AF ablation results in wait-times which have not been comprehensively evaluated at a population level. Additionally, the consequences of such delays in AF ablation, namely the risk of hospitalization or adverse events, have not been studied. METHODS AND RESULTS: This observational cohort study included adults referred for catheter ablation to treat AF in Ontario, Canada, between 1 April 2016 and 31 March 2020. Wait-time was defined from referral to the earliest of ablation, death, off-list, or the study endpoint of 31 March 2022. The outcomes of interest included a composite of death, hospitalization for AF/heart failure, and emergency department visit for AF/heart failure. Our study cohort included 6253 patients referred for de novo AF ablation. The median wait-time for patients who received and who did not receive ablation was 218 days (IQR: 112-363) and 520 days (IQR: 270-763), respectively. Wait-time increased consistently for patients referred between October 2017 and March 2020. Mortality was rare, but significant morbidity was observed, affecting 19.2% of patients on the waitlist for AF ablation. Paroxysmal AF was associated with a statistically significant greater risk for adverse outcomes on the waitlist (HR 1.51, 95% CI 1.18-1.93). CONCLUSION: Wait-times for AF ablation are increasing and are associated with significant morbidity.

Standard vs Augmented Ablation of Paroxysmal Atrial Fibrillation for Reduction of Atrial Fibrillation Recurrence: The AWARE Randomized Clinical Trial.

Importance: Recurrent atrial fibrillation (AF) commonly occurs after catheter ablation and is associated with patient morbidity and health care costs. Objective: To evaluate the superiority of an augmented double wide-area circumferential ablation (WACA) compared with a standard single WACA in preventing recurrent atrial arrhythmias (AA) (atrial tachycardia, atrial flutter, or atrial fibrillation [AF]) in patients with paroxysmal AF. Design, Setting, and Participants: This was a pragmatic, multicenter, prospective, randomized, open, blinded end point superiority clinical trial conducted at 10 university-affiliated centers in Canada. The trial enrolled patients 18 years and older with symptomatic paroxysmal AF from March 2015 to May 2017. Analysis took place between January and April 2022. Analyses were intention to treat. Interventions: Patients were randomized (1:1) to receive radiofrequency catheter ablation for pulmonary vein isolation with either a standard single WACA or an augmented double WACA. Main Outcomes and Measures: The primary outcome was AA recurrence between 91 and 365 days postablation. Patients underwent 42 days of ambulatory electrocardiography monitoring after ablation. Secondary outcomes included need for repeated catheter ablation and procedural and safety variables. Results: Of 398 patients, 195 were randomized to the single WACA (control) arm (mean [SD] age, 60.6 [9.3] years; 65 [33.3%] female) and 203 to the double WACA (experimental) arm (mean [SD] age, 61.5 [9.3] years; 66 [32.5%] female). Overall, 52 patients (26.7%) in the single WACA arm and 50 patients (24.6%) in the double WACA arm had recurrent AA at 1 year (relative risk, 0.92; 95% CI, 0.66-1.29; P = .64). Twenty patients (10.3%) in the single WACA arm and 15 patients (7.4%) in the double WACA arm underwent repeated catheter ablation (relative risk, 0.72; 95% CI, 0.38-1.36). Adjudicated serious adverse events occurred in 13 patients (6.7%) in the single WACA arm and 14 patients (6.9%) in the double WACA arm. Conclusions and Relevance: In this randomized clinical trial of patients with paroxysmal AF, additional ablation by performing a double ablation lesion set did not result in improved freedom from recurrent AA compared with a standard single ablation set. Trial Registration: ClinicalTrials.gov Identifier: NCT02150902.

Use of Sacubitril/Valsartan Prior to Primary Prevention Implantable Cardioverter Defibrillator Implantation.

Background: Implantable cardioverter defibrillators (ICDs) are an adjunct to guideline-directed medical therapy for heart failure with reduced ejection fraction. The uptake of sacubitril/valsartan in this population is not well described. We report the uptake and factors associated with sacubitril/valsartan use in patients with left ventricular dysfunction undergoing ICD implantation. Methods: A retrospective chart review was performed on all patients with left ventricular dysfunction who underwent de novo primary prevention ICD implantation between October 2015 and December 2021 (n = 422) at Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada. Pre-procedure sacubitril/valsartan use was determined. Logistic regression analysis was performed to examine factors associated with sacubitril/valsartan use. A Bayesian estimator of abrupt change was employed to determine a time period in which a change in the rate of sacubitril/valsartan use occurred. Results: Loop diuretic use (odds ratio [OR] = 2.20) and higher severity of New York Heart Association class symptoms (OR = 1.62) were associated with sacubitril/valsartan use. Sacubitril/valsartan use increased during the study period, to 59% in December 2021. This increase was larger among those aged ≥ 65 years (OR = 1.09). A change in the rate of sacubitril/valsartan use occurred 3 years after drug approval, 1 year after provincial drug coverage became available, and 6 months after being strongly recommended in clinical guidelines. Conclusions: In a contemporary cohort of ICD patients, sacubitril/valsartan use increased between 2015 and 2021, notably in those aged ≥ 65 years and after government drug coverage became available. Understanding barriers to sacubitril/valsartan use in ICD patients is recommended to improve clinical outcomes and survival in this population.

Contexte: Les défibrillateurs cardioverteurs implantables (DCI) sont un complément au traitement médical fondé sur les lignes directrices chez les patients atteints d'insuffisance cardiaque à fraction d'éjection réduite. L'adoption de l'association sacubitril-valsartan chez ces derniers n'est pas bien caractérisée. Nous abordons l'adoption de cette association médicamenteuse ainsi que les facteurs associés à son utilisation parmi les patients présentant une dysfonction ventriculaire gauche chez qui un DCI est implanté. Méthodologie: Nous avons effectué un examen rétrospectif des dossiers médicaux de tous les patients atteints d'une dysfonction ventriculaire gauche chez qui un DCI a été implanté de novo en prévention primaire entre octobre 2015 et décembre 2021 (n = 422) au Sunnybrook Health Sciences Centre, situé à Toronto (Ontario), au Canada. Nous avons recensé les cas où l'association sacubitril-valsartan avait été utilisée avant l'intervention, et une analyse de régression logistique a été réalisée pour mettre en lumière les facteurs associés à l'utilisation de l'association sacubitril-valsartan. Un estimateur bayésien de changement soudain a servi à déterminer si le taux d'utilisation de l'association sacubitril-valsartan avait changé au cours de cette période. Résultats: L'utilisation de diurétiques de l'anse (rapport de cotes [RC] = 2,20) et une plus grande intensité des symptômes selon la classification de la New York Heart Association (RC = 1,62) se trouvaient associées à l'utilisation de l'association sacubitril-valsartan. Au cours de la période à l'étude, le taux d'utilisation de l'association sacubitril-valsartan s'est accru, atteignant 59 % en décembre 2021. Cette augmentation était plus marquée parmi les patients de 65 ans ou plus (RC = 1,09). L'association sacubitril-valsartan a vu son taux d'utilisation changer trois ans après avoir été homologuée, un an après avoir été inscrite sur la liste des médicaments remboursés par le régime d'assurance médicaments provincial et six mois après avoir été fortement recommandée dans les lignes directrices cliniques. Conclusions: Au sein d'une cohorte contemporaine de patients ayant reçu un DCI, l'association sacubitril-valsartan a connu une hausse d'utilisation entre 2015 et 2021, notamment chez les patients âgés de 65 ans ou plus et à la suite de son inscription sur la liste des médicaments remboursés par le régime public d'assurance médicament. Il serait souhaitable de cerner les obstacles à l'utilisation de l'association sacubitril-valsartan chez les patients qui reçoivent un DCI afin d'améliorer les résultats cliniques et la survie au sein de cette population.

Association Between Concurrent Use of Amiodarone and DOACs and Risk of Bleeding in Patients With Atrial Fibrillation.

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 aged >66 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 prescription >140 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, p <0.001) 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.

Insulin resistance and racial disparities in breast cancer prognosis: a multi-center cohort study.

The survival for breast cancer (BC) is improving but remains lower in Black women than White women. A number of factors potentially drive the racial differences in BC outcomes. The aim of our study was to determine if insulin resistance (defined as homeostatic model assessment for insulin resistance (HOMA-IR)), mediated part of the relationship between race and BC prognosis (defined by the improved Nottingham prognostic index (iNPI)). We performed a cross-sectional study, recruiting self-identified Black and White women with newly diagnosed primary invasive BC from 10 US hospitals between March 2013 and February 2020. Survey, anthropometric, laboratory, and tumor pathology data were gathered, and we compared the results between Black and White women. We calculated HOMA-IR as well as iNPI scores and examined the associations between HOMA-IR and iNPI. After exclusions, the final cohort was 1206: 911 (76%) White and 295 (24%) Black women. Metabolic syndrome and insulin resistance were more common in Black than White women. Black women had less lobular BC, three times more triple-negative BC, and BCs with higher stage and iNPI scores than White women (P < 0.001 for all comparisons). Fewer Black women had BC genetic testing performed. HOMA-IR mediated part of the association between race and iNPI, particularly in BCs that carried a good prognosis and were hormone receptor (HR)-positive. Higher HOMA-IR scores were associated with progesterone receptor-negative BC in White women but not Black women. Overall, our results suggest that HOMA-IR contributes to the racial disparities in BC outcomes, particularly for women with HR-positive BCs.