Bystander cardiopulmonary resuscitation differences by sex - The role of arrest recognition.

PURPOSE: To assess whether bystander cardiopulmonary resuscitation (CPR) differed by patient sex among bystander-witnessed out-of-hospital cardiac arrests (OHCA). METHODS: This study is a retrospective analysis of paramedic-attended OHCA in New South Wales (NSW) between January 2017 to December 2019 (restricted to bystander-witnessed cases). Exclusions included OHCA in aged care, medical facilities, with advance care directives, from non-medical causes. Multivariate logistic regression examined the association of patient sex with bystander CPR. Secondary outcomes were OHCA recognition, bystander AED application, initial shockable rhythm, and survival outcomes. RESULTS: Of 4,491cases, females were less likely to receive bystander CPR in private residential (Adjusted Odds ratio [AOR]: 0.82, 95%CI: 0.70-0.95) and public locations (AOR: 0.58, 95%CI:0.39-0.88). OHCA recognition during the emergency call was lower for females arresting in public locations (84.6% vs 91.6%, p = 0.002) and this partially explained the association of sex with bystander CPR (∼44%). This difference in recognition was not observed in private residential locations (p = 0.2). Bystander AED use was lower for females (4.8% vs 9.6%, p < 0.001); however, after adjustment for location and other covariates, this relationship was no longer significant (AOR: 0.83, 95%CI: 0.60-1.12). Females were less likely to be in an initial shockable rhythm (AOR: 0.52, 95%CI: 0.44-0.61), but more likely to survive the event (AOR: 1.34, 95%CI: 1.15-1.56). There was no sex difference in survival to hospital discharge (AOR: 0.96, 95%CI: 0.77-1.19). CONCLUSION: OHCA recognition and bystander CPR differ by patient sex in NSW. Research is needed to understand why this difference occurs and to raise public awareness of this issue.

Long-Term Safety and Efficacy of Transcatheter Microwave and Radiofrequency Denervation in a Chronic Ovine Model.

BACKGROUND: Transcatheter renal denervation (RDN) has had inconsistent efficacy and concerns for durability of denervation. We aimed to investigate long-term safety and efficacy of transcatheter microwave RDN in vivo in normotensive sheep in comparison to conventional radiofrequency ablation. METHODS AND RESULTS: Sheep underwent bilateral RDN, receiving 1 to 2 microwave ablations (maximum power of 80-120 W for 240 s-480 s) and 12 to 16 radiofrequency ablations (180 s-240 s) in the main renal artery in a paired fashion, alternating the side of treatment, euthanized at 2 weeks (acute N=15) or 5.5 months (chronic N=15), and compared with undenervated controls (N=4). Microwave RDN produced substantial circumferential perivascular injury compared with radiofrequency at both 2 weeks [area 239.8 (interquartile range [IQR] 152.0-343.4) mm2 versus 50.1 (IQR, 32.0-74.6) mm2, P <0.001; depth 16.4 (IQR, 13.9-18.9) mm versus 7.5 (IQR, 6.0-8.9) mm P <0.001] and 5.5 months [area 20.0 (IQR, 3.4-31.8) mm2 versus 5.0 (IQR, 1.4-7.3) mm2, P=0.025; depth 5.9 (IQR, 1.9-8.8) mm versus 3.1 (IQR, 1.2-4.1) mm, P=0.005] using mixed models. Renal denervation resulted in significant long-term reductions in viability of renal sympathetic nerves [58.9% reduction with microwave (P=0.01) and 45% reduction with radiofrequency (P=0.017)] and median cortical norepinephrine levels [71% reduction with microwave (P <0.001) and 72.9% reduction with radiofrequency (P <0.001)] at 5.5 months compared with undenervated controls. CONCLUSIONS: Transcatheter microwave RDN produces deep circumferential perivascular ablations without significant arterial injury to provide effective and durable RDN at 5.5 months compared with radiofrequency RDN.

Intra-cardiac motion detection catheter for the early identification of acute pericardial tamponade during invasive cardiac procedures.

Objectives: To develop and test an intra-cardiac catheter fitted with accelerometers to detect acute pericardial effusion prior to the onset of hemodynamic compromise. Background: Early detection of an evolving pericardial effusion is critical in ensuring timely treatment. We hypothesized that the reduction in movement of the lateral heart border present in developing pericardial effusions could be quantified by positioning an accelerometer in a lateral cardiac structure. Methods: A "motion detection" catheter was created by implanting a 3-axis accelerometer at the distal tip of a cardiac catheter. The pericardial space of 5 adult sheep was percutaneously accessed, and pericardial tamponade was created by infusion of normal saline. The motion detection catheter was positioned in the coronary sinus. Intracardiac echocardiography was used to confirm successful creation of pericardial effusion and hemodynamic parameters were collected. Results: Statistically significant reduction in acceleration from baseline was detected after infusion of only 40 ml of normal saline (p < 0.05, ANOVA). In comparison, clinically significant change in systolic blood pressure (defined as >10% drop in baseline systolic blood pressure) occurred after infusion of 80 ml of normal saline (107 ± 22 mmHg vs. 90 ± 12 mmHg p = 0.97, ANOVA), and statistically significant change was recorded only after infusion of 200 ml (107 ± 22 mmHg vs. 64 ± 5 mmHg, p < 0.05, ANOVA). Conclusions: An intra-cardiac motion detection catheter is highly sensitive in identifying acute cardiac tamponade prior to clinically and statistically significant changes in systolic blood pressure, allowing for early detection and treatment of this potentially life-threatening complication of all modern percutaneous cardiac interventions.

Pre-stroke anticoagulation for atrial fibrillation in primary English speakers and non-primary English speakers: a multicentre retrospective cohort study.

BACKGROUND: Anticoagulation can prevent most strokes in individuals with atrial fibrillation (AF); however, many people presenting with stroke and known AF are not anticoagulated. Language barriers and poor health literacy have previously been associated with decreased patient medication adherence. The association between language barriers and initiation of anticoagulation therapy for AF is uncertain. AIMS: The aims of this study were to determine whether demographic factors, including non-English primary language, were (1) associated with not being initiated on anticoagulation for known AF prior to admission with stroke, and (2) associated with non-adherence to anticoagulation in the setting of known AF prior to admission with stroke. METHODS: A multicentre retrospective cohort study was conducted for consecutive individuals admitted to the three South Australian tertiary hospitals with stroke units over a 5-year period. RESULTS: There were 6829 individuals admitted with stroke. These cases included 5835 ischaemic stroke patients, 1333 of whom had pre-existing AF. Only 40.0% presenting with ischaemic stroke in the setting of known pre-existing AF were anticoagulated. When controlling for demographics, socioeconomic status and past medical history (including the components of the CHADS2VASC score and anticoagulation contraindications), having a primary language other than English was associated with a lower likelihood of having been commenced on anticoagulant for known pre-stroke AF (odds ratio: 0.52, 95% confidence interval: 0.36-0.77, P = 0.001), but was not associated with a differing likelihood of anticoagulation adherence. CONCLUSIONS: A significant proportion of patients with stroke have pre-existing unanticoagulated AF; these rates are substantially higher if the primary language is other than English. Targeted research and interventions to minimise evidence-treatment gaps in this cohort may significantly reduce stroke burden.

Clinician-Created Video Education for Patients With AF: A Randomized Clinical Trial.

Importance: Patient education is a critical aspect of atrial fibrillation (AF) management. However, there is limited time to provide effective patient education during routine care, and resources available online are of variable quality. Objective: To determine whether clinician-led creation of video-based AF education is feasible and improves knowledge of AF. Design, Setting, and Participants: This single-center randomized clinical trial was conducted between 2020 and 2022. Outcomes were assessed prior to their clinic visit and 2 and 90 days after the visit by blinded assessors. Participants included adults with AF and congestive heart failure, hypertension, age at least 75 years (doubled), diabetes, prior stroke or transient ischemic attack or thromboembolism (doubled), vascular disease, age 65 to 74 years, and sex category scores of 1 or greater presenting for routine care at publicly funded outpatient cardiology clinics within a tertiary teaching hospital. Individuals too unwell to participate or with limited English were excluded. Data were assessed as intention to treat and analyzed from December 2022 to October 2023. Intervention: Intervention participants viewed a series of 4 videos designed and narrated by clinicians that aimed to improve understanding of AF pathophysiology, clinical presentation, diagnosis, and management. After viewing the videos, participants received weekly email links to review the videos. The control group received usual care. Main Outcomes and Measures: The prospectively selected primary outcome was AF knowledge at 90 days, measured by the validated Jessa Atrial Fibrillation Knowledge Questionnaire (JAFKQ). Results: Among 657 individuals screened, 208 adults with AF were randomized (mean [SD] age, 65.0 [12.2] years; 133 [65.2%] male) and included in analysis. Participants were randomized 1-to-1, with 104 participants in the control group and 104 participants in the video intervention group. At 90 days after the baseline clinic visit, intervention participants were more likely to correctly answer JAFKQ questions than control participants (odds ratio [OR], 1.23 [95% CI, 1.01-1.49]). The difference was greater in participants who remotely accessed videos on 3 or more occasions during the study (OR, 1.46 [95% CI, 1.14-1.88]). Conclusions and Relevance: In this randomized clinical trial of patients with AF, remotely delivered, clinician-created video education improved medium-term AF knowledge beyond usual care of standard in-clinic education. The improvement demonstrated in this study provides support for the implementation of clinician-created educational resources across the care continuum. Further work is needed to assess for impact on clinical outcomes. Trial Registration: anzctr.org.au Identifier: ANZCTRN12620000729921.

Influence of standard modifiable risk factors on ventricular tachycardia after myocardial infarction.

Background: Inducible ventricular tachycardia (VT) at electrophysiology study (EPS) predicts sudden cardiac death because of ventricular tachyarrhythmia, the single greatest cause of death within 2 years after myocardial infarction (MI). Objectives: We aimed to assess the association between standard modifiable risk factors (SMuRFs) and inducible VT at EPS early after MI. Methods: Consecutive patients with left ventricle ejection fraction ≤40% on days 3-5 after ST elevation MI (STEMI) who underwent EPS were prospectively recruited. Positive EPS was defined as induced sustained monomorphic VT cycle length ≥200 ms for ≥10 s or shorter if hemodynamically compromised. The primary outcome was inducibility of VT at EPS, and the secondary outcome was all-cause mortality on follow-up. Results: In 410 eligible patients undergoing EPS soon (median of 9 days) after STEMI, 126 had inducible VT. Ex-smokers experienced an increased risk of inducible VT [multivariable logistic regression adjusted odds ratio (OR) 2.0, p = 0.033] compared with current or never-smokers, with comparable risk. The presence of any SMuRFs apart from being a current smoker conferred an increased risk of inducible VT (adjusted OR 1.9, p = 0.043). Neither the number of SMuRFs nor the presence of any SMuRFs was associated with mortality at a median follow-up of 5.4 years. Conclusions: In patients with recent STEMI and impaired left ventricular function, the presence of any SMuRFs, apart from being a current smoker, conferred an increased risk of inducible VT at EPS. These results highlight the need to modify SMuRFs in this high-risk subset of patients.

Optimizing electrophysiology studies to prevent sudden cardiac death after myocardial infarction.

AIMS: This study assessed associations of minimum final extrastimulus coupling interval utilized within electrophysiology study (EPS) after myocardial infarction (MI) and possible site of origin of induced ventricular tachycardia (VT) with long-term occurrence of spontaneous ventricular tachyarrhythmia and long-term survival. METHODS AND RESULTS: This prospective study recruited consecutive patients with left ventricular ejection fraction (LVEF) ≤ 40% who underwent EPS days 3-5 after MI between 2004 and 2017. Positive EPS was defined as sustained monomorphic VT cycle length ≥200 ms for ≥10 s or shorter duration if haemodynamic compromise occurred. Each of the four extrastimuli was shortened by 10 ms at a time, until it failed to capture the ventricle (ventricular refractoriness) or induced ventricular tachyarrhythmia. Outcomes included spontaneous ventricular tachyarrhythmia occurrence and all-cause mortality. Shorter coupling interval length of final extrastimulus that induced VT was associated with higher risk of spontaneous ventricular tachyarrhythmia (P < 0.001). Significantly higher rates of spontaneous ventricular tachyarrhythmia (65.2% vs. 23.2%; P < 0.001) were observed for final coupling interval at EPS <200 ms vs. >200 ms. Right bundle branch block (RBBB) morphology of induced VT, with possible site of origin from the left ventricle, was associated with all-cause mortality [hazard ratio (HR) 3.2, P = 0.044] and a composite of spontaneous ventricular tachyarrhythmia recurrence or mortality (HR 1.8, P = 0.043). CONCLUSION: Ventricular tachycardia induced with shorter coupling intervals was associated with higher risk of spontaneous ventricular tachyarrhythymia on follow-up, indicating that the final extrastimulus coupling interval at EPS early after MI should be determined by ventricular refractoriness. Induced VT with possible origin from left ventricle was associated with increased risk of spontaneous ventricular tachyarrhythmia recurrence or death.

Examining training and attitudes to basic life support in multi-ethnic communities residing in New South Wales, Australia: A mixed-methods investigation.

BACKGROUND: Bystander response, including cardiopulmonary resuscitation (CPR), is critical to out-of-hospital cardiac arrest (OHCA) survival. Nearly 30% of Australian residents were born overseas, and little is known about their preparedness to perform CPR. In this mixed-methods study, we examined rates of training and willingness and barriers to performing CPR among immigrants in Australia. METHODS: First, we surveyed residents in New South Wales, Australia, using purposeful sampling to enrich immigrant populations. Multivariate logistic regression was used to examine the association between place of birth and willingness to perform CPR. Next, we conducted focus-group discussions with members of the region's largest migrant groups to explore barriers and relevant societal or cultural factors. RESULTS: Of the 1267 survey participants (average age 49.6 years, 52% female), 60% were born outside Australia, most in Asia and 73% had lived in Australia for more than 10 years. Higher rates of previous CPR training were reported among Australian-born participants compared with South Asian-born and East Asian-born (77%, 35%, 48%, respectively, p <0.001). In adjusted models, the odds of willingness to perform CPR on a stranger were significantly lower among migrants than Australian-born (adjusted OR: 0.64; 95% CI 0.49 to 0.83); however, this association was mediated by history of training. Themes emerging from the focus-group discussions included concerns about causing harm, fear of liability, and birthplace-specific social and cultural barriers. CONCLUSIONS: Targeted awareness and training interventions, which address common and culture-specific barriers to response and improved access to training, may improve confidence and willingness to respond to OHCA in multi-ethnic communities.

Public attitudes towards automated external defibrillators: results of a survey in the Australian general population.

Background: Swift defibrillation by lay responders using automated external defibrillators (AEDs) increases survival in out-of-hospital cardiac arrest (OHCA). This study evaluated newly designed yellow-red vs. commonly used green-white signage for AEDs and cabinets and assessed public attitudes to using AEDs during OHCA. Methods: New yellow-red signage was designed to enable easy identification of AEDs and cabinets. A prospective, cross-sectional study of the Australian public was conducted using an electronic, anonymised questionnaire between November 2021 and June 2022. The validated net promoter score investigated public engagement with the signage. Likert scales and binary comparisons evaluated preference, comfort and likelihood of using AEDs for OHCA. Results: The yellow-red signage for AED and cabinet was preferred by 73.0% and 88%, respectively, over the green-white counterparts. Only 32% were uncomfortable with using AEDs, and only 19% indicated a low likelihood of using AEDs in OHCA. Conclusion: The majority of the Australian public surveyed preferred yellow-red over green-white signage for AED and cabinet and indicated comfort and likelihood of using AEDs in OHCA. Steps are necessary to standardise yellow-red signage of AED and cabinet and enable widespread availability of AEDs for public access defibrillation.

A Prospective, Multicentre Randomised Controlled Trial Comparing Catheter Ablation Versus Antiarrhythmic Drugs in Patients With Structural Heart Disease Related Ventricular Tachycardia: The CAAD-VT Trial Protocol.

IMPORTANCE: Randomised trials have shown that catheter ablation (CA) is superior to medical therapy for ventricular tachycardia (VT) largely in patients with ischaemic heart disease. Whether this translates to patients with all forms and stages of structural heart disease (SHD-e.g., non-ischaemic heart disease) is unclear. This trial will help clarify whether catheter ablation offers superior outcomes compared to medical therapy for VT in all patients with SHD. OBJECTIVE: To determine in patients with SHD and spontaneous or inducible VT, if catheter ablation is more efficacious than medical therapy in control of VT during follow-up. DESIGN: Randomised controlled trial including 162 patients, with an allocation ratio of 1:1, stratified by left ventricular ejection fraction (LVEF) and geographical region of site, with a median follow-up of 18-months and a minimum follow-up of 1 year. SETTING: Multicentre study performed in centres across Australia. PARTICIPANTS: Structural heart disease patients with sustained VT or inducible VT (n=162). INTERVENTION: Early treatment, within 30 days of randomisation, with catheter ablation (intervention) or initial treatment with antiarrhythmic drugs only (control). MAIN OUTCOMES, MEASURES, AND RESULTS: Primary endpoint will be a composite of recurrent VT, VT storm (≥3 VT episodes in 24 hrs or incessant VT), or death. Secondary outcomes will include each of the individual primary endpoints, VT burden (number of VT episodes in the 6 months preceding intervention compared to the 6 months after intervention), cardiovascular hospitalisation, mortality (including all-cause mortality, cardiac death, and non-cardiac death) and LVEF (assessed by transthoracic echocardiography from baseline to 6-, 12-, 24- and 36-months post intervention). CONCLUSIONS AND RELEVANCE: The Catheter Ablation versus Anti-arrhythmic Drugs for Ventricular Tachycardia (CAAD-VT) trial will help determine whether catheter ablation is superior to antiarrhythmic drug therapy alone, in patients with SHD-related VT. TRIAL REGISTRY: Australian New Zealand Clinical Trials Registry (ANZCTR) TRIAL REGISTRATION ID: ACTRN12620000045910 TRIAL REGISTRATION URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377617&isReview=true.