Myocardial infarction (MI) contributes to significant morbidity and mortality globally. Platelet derived growth factor-AB (PDGF-AB) is potentially a novel translational therapeutic for improving cardiac function post-MI, which we assess here using a 60 day porcine left anterior descending artery occlusion ischemia-reperfusion model. MI was induced in 10 female Landrace swine, with 5 controls, 5 receiving PDGF-AB treatment and 2 additional shams. PDGF-AB improved left ventricular ejection fraction 58 days after MI, without affecting overall infarct scar size, as shown using serial cardiac magnetic resonance imaging. Preserved infarct zone microvascular function and increased vessel maturity was also observed. Multi-omic analyses showed that PDGF-AB treatment altered the expression of proteins, metabolites, and lipids that are known to be involved in myocardial energetics and redox balance. Novel therapeutics such as PDGF-AB may lead to more sustained salvage of cardiac function by modulating the post-MI microvasculature, myocardium and extracellular matrix.

Atrial fibrillation (AF) screening among people aged ≥75 years offers an opportunity to initiate management. Recruiting, onboarding (registering), monitoring and training this population for AF screening using digital technologies required strategic approaches. To describe the approaches to recruiting, onboarding, monitoring, and training community dwellers aged ≥75 years to use AliveCor handheld single-lead electrocardiogram (ECG) devices in a virtual clinical trial. We approached clinicians (general practitioners [GPs] and cardiologists), community organisations and social media to recruit participants. Flyers were disseminated at clinicians' practices and community avenues. Face-to-face community recruitment talks were conducted when COVID-19 restrictions were eased. Participant onboarding and step-by-step device training were conducted virtually (by telephone). Participants' ECGs were monitored by clinicians remotely. This trial was funded by the National Heart Foundation of Australia and registered (ACTRN12621000184875). 200 participants were enrolled over 13 months (average:15 participants per month): mean age 79.0 years (SD 3.4 years); 107 (54%) females; 131 (66%) from major cities and 69 (34%) from regional/rural areas; 52 (26%) were referred by GPs and 148 (74%) via other avenues (Table 1). Participants independently transmitted ECGs to the central monitoring system and responded to telephone communications. Approaching GPs and community avenues and conducting face-to-face community recruitment talks synergised recruitment. With a supportive team, virtual onboarding, monitoring, and training participants aged ≥75 years were feasible.Table 1The number of participants recruited by each recruitment avenue.Recruitment avenuesTotal=200; n (%)General practitioners52 (26) Peers and family:38 (19)Friends & participants in the study28Family/Partner10 Face-to-face community recruitment talks:33 (16)Bicycle club & various community clubs19Retirement residences (urban)14Flyers (self-referred)28 (14)Media (a rural newspaper)13 (7)Others36 (18) Country Women's Association10 Cardiologists7 "Meals on Wheels" organisation5 Older Women's Network4 Health Match/Join Us websites3 Miscellaneous7 Open table in a new tab

The effect of radiofrequency ablation for ventricular tachycardia (VT) on left ventricular (LV) parameters in patients with structural heart disease (SHD) has not been extensively studied. Patients with ischaemic cardiomyopathy (ICM) and non-ischaemic cardiomyopathy (NICM) have different pathophysiological substrates for VT, and it is unclear whether this translates into differences in LV parameters following ablation for VT. Clinical, demographical, and procedural data were collected on consecutive patients with SHD presenting for ablation of VT at Westmead Hospital between 2017 and 2020. Pre-ablation and post-ablation transthoracic echocardiograms (TTEs) were compared. A total of 142 patients were evaluated, comprising of 70 with ICM and 72 with NICM. Mean time to post-ablation TTE was 277 days. The NICM patients had higher pre-ablation left ventricular ejection fraction (LVEF) (p<0.001), lower pre-ablation left ventricular end-diastolic diameter (LVEDD( (p<0.001), lower pre-ablation left ventricular end-systolic diameter (p<0.001), higher post-ablation LVEF (p<0.001), and lower post-ablation LVEDD (p=0.03) than ICM patients. When analysed irrespective of pre-ablation LVEF, there was no significant post-ablation change in LVEF. However, patients with pre-ablation LVEF ≤20 had restoration of LVEF (mean 5.3; 95% CI 0.6–10.1; p=0.032), as did those with 20< LVEF ≤50 (mean 2.5; 95% CI 0.2–4.7; p=0.030). There was no significant difference in change in LVEF post-ablation between ICM and NICM patients. This remained true after excluding patients presenting with VT storm (p=0.685), patients who had cardiac resynchronisation therapy insertion post-ablation (p=0.425), and patients with VT recurrence prior to post-ablation TTE (p=0.988). Neither ICM nor NICM patients undergoing VT ablation experienced significant LVEF decline. Patients with severe LV dysfunction experienced some restoration following ablation.

Accurate electroanatomic mapping (EAM) via modern multi-electrode mapping (MEM) catheters are critical for identifying substrate relevant to the long-term success of ventricular tachycardia ablation. Five commercially available MEM catheters were compared in an ovine infarction model. In addition, whole heart histology was compared to sites of EAM discordance between rhythms, and cardiac magnetic resonance imaging (CMR) defined fibrosis and abnormal electrograms (LAVA) in scar regions. Six animals had an anteroseptal infarction created, and four controls (weight 52.1±5.4 kg, range 43–60 kg). In 5 animals, histology confirmed the presence of isolated regions of fibrosis remote (>10mm) from confluent scarring. All catheters showed a bipolar low-voltage (<1.5mV) scar accuracy of 56.5–84.1% to detect CMR-defined fibrosis in the endocardial to mid-myocardial layers. Sites with discordant voltages between rhythms were more likely to detect subendocardial (24.5±5.9% vs 13.0±5.9%, p<0.001), mid-wall (35.9±7.1% vs 19.4±8.5%, p<0.001), subepicardial (47.5±2.9% vs 25.4±8.8%, p<0.001) and transmural (13.1±3.1% vs 6.7±4.1%, p<0.001) fibrosis locations then concordant sites. Adiposity was detected more frequently at sites of voltage discordance than concordance (65.1±4.2% vs 32.6±10.5%, p<0.001). LAVA within confluent scar showed elevated fibrosis (32.5±2.0% vs 18.3%±2.4, p<0.001) and adiposity (12.6±0.8% vs 7.2%±0.9, p<0.001) levels compared with non-LAVA sites. All catheters showed reasonable accuracy of low-voltage bipolar to endocardial CMR fibrosis areas. Focal fibrosis, remote from confluent regions of scarring, was often present. Sites of voltage discordance showed the elevated presence of all fibrosis locations, compact fibrosis architecture and substantial adiposity. Areas of abnormal electrograms show elevated fibrosis and adiposity.

Cardiovascular disease (CVD) is a leading cause or mortality in Australia. Text message programs have shown to be an efficient modality to deliver information to improve patient CVD knowledge and improve CVD risk factor profiles. The Heart Health program was implemented as a post-discharge service, offered to all Westmead Hospital, Sydney CVD patients during the COVID-19 pandemic. An observational study using surveys following the completion of the Heart Health program was conducted. Patients ≥18 years old who recently attended cardiology clinics or discharged from the cardiology unit at Westmead Hospital, post April 2020 were able to opt into the program. Regular semi-personalised text messages providing CVD and COVID-19 information, advice and support to patients were sent for a six-month period. Patients were invited to complete a survey at program completion to determine user engagement, effectiveness, acceptance, and required program modifications. The survey was completed by 1,230 participants; male: 61.5%, mean age 60.5 (±13.4) years. • Effectiveness: 56.9%, 50.1%, 52.2% and 60.6% agreed–strongly agreed the program improved their diet, exercise levels, medication adherence and motivation to change their lifestyle, respectively. • Acceptability: 84.8% participants agreed–strongly agreed the messages were useful. • Engagement: 86.5% participants read 75%–100% of messages, 48.8% shared messages with friends/family. • Adaptions: Further message personalisation and links to resources would improve future use. The Heart Health program can improve healthy lifestyle activities, management adherence and motivation in community CVD patients, whilst being useful and engaging. Increasing personalisation and further access to resources are required for future improvements.

Screening atrial fibrillation (AF) using handheld electrocardiogram (ECG) devices in older people offers treatment initiation opportunities. The "Mass AF study" is a patient-led randomised controlled trial to explore the feasibility of community AF screening. To investigate feasibility of the "Mass AF study" using a process evaluation framework to examine participant experiences. This study involved 200 community dwellers aged ≥75 years. Participants were trained to self-record ECGs using AliveCor handheld single-lead ECG devices. After using the devices for ≥3 months, some participants were invited to a semi-structured interview. The Medical Council Guidelines on Process Evaluation Framework was adopted to outline three domains: implementation, mechanism of impact, and context. Interview transcripts were inductively coded into the domains. Two researchers independently coded the same eight initial transcripts and achieved consensus by discussion. This trial was funded by the Heart Foundation Australia and registered (ACTRN12621000184875). 48 participants were interviewed: 27 (56%) males, 34 (71%): major cities, 14 (29%): regional/rural areas. Median interview duration: 21.9 mins. Figure 1 outlines the main codes within the three domains. Participants integrated self-screening into their daily routines. They appreciated the team for diagnosing AF, which would otherwise be missed. However, some participants reported frustrations recording ECGs because of interferences (noises). They were anxious about potential abnormal ECGs reported by the device's automatic algorithm. Participants described their perceptions and experiences of the screening program and enablers and barriers when using the devices. These findings will inform the scaling up of the program in the future.

Patients with idiopathic ventricular tachycardia (VT) have structurally normal hearts. It is unknown whether radiofrequency ablation (RFA) of VT in these patients can adversely affect left ventricular (LV) function. A retrospective analysis was undertaken of consecutive patients presenting for VT ablation between 2017 and 2020 at Westmead Hospital. Clinical and demographical data were collected, and pre-ablation and post-ablation transthoracic echocardiograms (TTEs) were analysed. Seventeen patients with idiopathic VT and 142 patients with structural heart disease (SHD) were identified. The TTEs were performed a mean of 269 days following ablation for VT. Patients with idiopathic VT were younger (p<0.001) and more likely to be female (p<0.001) than those with SHD. On TTE, patients with idiopathic VT had higher LV ejection fraction (LVEF) (p<0.001), lower left ventricular end-diastolic diameter (p<0.001), and lower left ventricular end-systolic diameter (p<0.001) prior to ablation. There was no statistically significant change in LVEF following ablation in patients with idiopathic VT, including in the subset of patients (n=5) with follow-up TTEs <10 days after ablation. Thirty-two patients with SHD post-ablation had an LVEF increase >5%, 28 had a decline >5%, and 82 had no significant change; this was distinct from patients with idiopathic VT, where no patients had a change in LVEF >5% (p=0.002). Radiofrequency ablation for patients with idiopathic VT is safe and well-tolerated, without short-term or long-term risk of LV dysfunction.

Ventricular tachycardia (VT) is common in patients with heart failure with reduced ejection fraction (HFrEF). In patients with HFrEF and VT, optimisation of HFrEF therapy is necessary alongside management of VT. This study assessed utilisation of guideline-directed medical therapy (GDMT) in patients with HFrEF and VT. Consecutive patients undergoing radiofrequency ablation (RFA) for VT at Westmead Hospital between 2017 and 2020 with comorbid HFrEF were identified. Clinical data and utilisation of GDMT for HFrEF were compared between patients with ischaemic cardiomyopathy (ICM) and non-ischaemic cardiomyopathy (NICM). Eighty-two patients met criteria, of whom 56 had ICM and 26 had NICM. Utilisation of GDMT was suboptimal both pre-ablation and post-ablation for administration of angiotensin-converting enzymes/angiotensin receptor blockers/angiotensin receptor-neprilysin inhibitors (62.2% and 62.2%, respectively), beta blockers (68.3% and 73.2%, respectively), and mineralocorticoid-receptor antagonists (32.9% and 40.2%, respectively). Use of "triple therapy" for HFrEF (the standard of care during the study period) was also poor pre-ablation (17.1%) and post-ablation (22.0%). There were no significant differences in utilisation between ICM and NICM patients of "triple therapy" or any of its individual components. However, GDMT administration was significantly lower in women compared with men, especially in use of "triple therapy" pre-ablation (8.3% vs 18.6%) and post-ablation (8.3% vs 24.3%). Guideline-directed medical therapy is underutilised in patients with HFrEF and VT requiring RFA, especially in women. Strategies to increase real-world administration of these medications are needed in this subgroup of patients, to promote recovery of left ventricular function and decrease risk of ventricular arrhythmias.

Bystander response, (including cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use), is essential to survival in OHCA. Studies from other countries have reported differences in bystander response by patients’ sex. This study aimed to examine whether such disparities exist in NSW. Three-year (January 2017–December 2019) paramedic-attended OHCA data were obtained from the NSW Public Health Risks and Outcomes Registry. Logistic regression analysis was used to examine adjusted (for patients’ age, urban/nonurban setting) associations between patients’ sex with bystander response and with survival, in non-traumatic bystander-witnessed arrests. Models were stratified by arrest location. The bystander-witnessed analytic group included 25% of all OHCA cases (5,507/21,698); 33% of these were female and 69% occurred in a private residential location. In non-residential locations, females were significantly less likely to receive bystander CPR (63% vs 81%; AdjOR 0.51, 95%CI: 0.40-0.65); have an AED applied (14% vs 26%; AdjOR 0.58, 95%CI: 0.43-0.78) and survive to hospital discharge (12% vs 25%; AdjOR 0.53, 95%CI: 0.38-0.73) compared with males. In arrests occurring in private residences, bystander CPR was also lower in females (56% vs 63%; AdjOR 0.78, 95%CI: 0.68-0.89). Bystanders used an AED in 1% of all residential arrests and survival to hospital discharge was 8%, with no significant difference by patients’ sex. Among bystander-witnessed arrests, bystander CPR provision was lower for females. Bystander AED-use and survival outcomes were significantly worse for females that arrested in non-residential locations. Further research is urgently needed to understand and address this sex-based disparity.

Abnormal strain using speckle tracking echocardiography is presumed to non-invasively identify scar. However, whether strain correlates with multi-modality scar assessments is unknown.

Abstract Background Early atrial fibrillation (AF) diagnosis offers an opportunity to initiate management to reduce stroke risk. Hand-held single-lead electrocardiograph (ECG) devices are widely available, yet there is little data on the implementation of AF screening using the devices in high-AF-risk communities and examining the accuracy of the devices over time. Such data may provide insights into the possibility of using artificial intelligence to scale up screening. Purpose To examine the accuracy of AliveCor ECG devices’ automated interpretation against clinicians’ diagnoses and explore the characteristics of the ECGs of older community-dwelling people in a real-world setting. Methods This is an analysis of ECGs received from people aged ≥75 years participating in an implementation trial of a community AF screening program over 12 months. Clinicians reviewed all ECGs transmitted to a central portal. Clinicians’ interpretations were taken as diagnostically accurate. Participants and their general practitioners (GPs) were notified of AF. The devices’ automatic ECG interpretations, including the participants’ pulse rates automatically recorded by the devices, were extracted from the central portal and analysed using R v3.6.0. Results 200 participants were enrolled. From May 2021 to Feb 2023, 30,040 ECGs were received; of these traces, clinicians confirmed AF in 479 traces and no AF in 29,561 traces. The devices’ automatic algorithm had a sensitivity of 91.4 % (i.e., detected AF in 438 of these 479 traces) and specificity of 96.6% (no AF: 28,546 / 29,561 traces). In total, the devices’ automated interpretation identified 1,453 ECGs with "Possible AF", of which clinicians confirmed 911 (62.7%) were in sinus rhythm and 438 (30.1%) had AF (Table 1). Breaking down the statistics for various rhythms and comparing the devices’ automatic algorithms with the clinicians’ diagnoses, discrepancies were found in 5296 ECG traces (Kappa = 0.33). Of these, 4277 (80.8%) were interpreted by the device automated algorithm as "Unreadable" (interferences), "Unclassified" (the device was unable to determine a result), and "Too short" (< 30 seconds of recording). Excluding the 3799 "Unclassified’ traces, the level of agreement between the ECG devices and clinicians improved (Kappa 0.63). The device automatically reported "Unclassified" and "Possible AF" rhythm traces had wide dispersion of the participants’ pulse rates (Figure 1). Conclusions The ECG devices had high sensitivity to detect AF but a low level of agreement in differentiating various rhythms. The characteristics of the longitudinal ECG rhythm traces, including the participants’ pulse rates over time coupled with the clinicians’ diagnoses of this large dataset, could be used to improve the devices’ automated algorithm and inform artificial intelligence strategies for large-scale community AF screening programs.Table 1Figure 1

NSW HEARTS aims to recruit a large, well-characterised and inclusive cohort of patients with inherited cardiomyopathies living in New South Wales (NSW), Australia, for cross-sectional and longitudinal analysis. Specifically, we seek to: (1) Understand the underlying genetic basis of disease; (2) Characterise disease expression, natural history and clinical course of inherited cardiomyopathies; (3) Investigate the clinical utility of polygenic risk scores and understand how these can inform family screening recommendations; and (4) Describe patterns of care and burden of disease for patients with inherited cardiomyopathies using NSW Health linked datasets. We will recruit patients with a clinical diagnosis of hypertrophic (HCM), dilated (DCM), arrhythmogenic (ACM), restrictive (RCM), left ventricular non-compaction (LVNC) cardiomyopathies, as well as those with clinically unclassified heritable cardiomyopathies. Patients will be >18 years of age and reside in NSW. Recruitment will occur from clinical sites (e.g., Royal Prince Alfred Hospital, St Vincent’s Hospital and Westmead Hospital in Sydney), from existing studies such as the Australian Genetic Heart Disease Registry, and via self-referral. We will support the recruitment of individuals from diverse ancestry groups. We will collect detailed clinical, environmental and health status information at baseline and in follow-up. A blood sample will be collected for whole-genome sequencing and stored at the NSW Health Statewide Biobank. A sub-group will undergo cardiac magnetic resonance imaging at two sites in Sydney. Participants will be engaged to participate now and into the future. NSW HEARTS will be an important resource for studying inherited cardiomyopathies. By better defining these diseases, we will be able to provide tailored advice regarding personalised therapeutic options, risk stratification, overall prognosis, and optimised family screening.

Only small numbers of studies explored quality of life (QoL) after ablation for arrhythmias other than atrial fibrillation (AF). We aim to review studies on QoL after catheter ablations (CA) on all non-AF arrhythmias.

Atrial fibrillation (AF) results in significant morbidity and mortality. Pulmonary vein isolation (PVI) is an effective therapy for AF; however, AF recurrence post-PVI remains relatively high.

Worldwide, there are 60 million people living with atrial fibrillation (AF). Early AF detection and anticoagulation reduce risk of stroke. However, an AF screening program that facilitates AF diagnosis and management has not been established. The contexts of patients (e.g., frailty and social circumstances) and general practitioners' (GPs) (e.g., time pressure in clinical practice) affect AF screening and access to therapy.

Cardiac implantable electronic devices (CIEDs) include PPMs, ICDs and CRT devices. Few studies have compared implant rates in men versus women adequately controlling for comorbidities.

Abstract Background Idiopathic ventricular arrhythmias (IVA) occurs in patients without overt heart disease. 2D speckle tracking strain echocardiography parameters, including global longitudinal strain (GLS) and mechanical dispersion (MD), have been shown to predict ventricular arrhythmias. It is unclear if the abnormalities are due to structural substrate abnormality, or substrate abnormality consequent to electrical alterations. Aim: We sought to assess whether patients with IVA have impaired left ventricular (LV) strain indices, and if so, whether these persist following successful treatment with radiofrequency ablation (i.e. correction of electrical alteration). Methods: 2D strain analysis was performed (in sinus rhythm) in 23 consecutive patients with IVA (no structural heart disease by cardiac magnetic resonance imaging (MRI); Group A) prior to electrophysiological mapping/ablation, and compared to 23 age and gender matched healthy controls (Group B). Follow up echocardiography and multiday Holter monitoring was performed 12 months post ablation. Results: Baseline characteristics were similar for indexed LV end diastolic volume (EDV) and ejection fraction (EF) (p = 0.1 for both) (Table 1). LV GLS was lower (p = 0.03) and LV MD was increased (p = 0.002) in the IVA group prior to treatment. At follow up, 18 patients (78%) (Group C) remained free of ventricular arrhythmias – in these patients, LV GLS improved and was similar to controls (p = 0.217); however, LV MD remained significantly increased at 12 months compared to controls (p = 0.009). In the 5 patients (22%) (Group D) that continued to have ventricular arrhythmias at follow up, both LV GLS (p = 0.04) and LV MD (p = 0.008) remained significantly impaired compared to controls. Conclusion: Despite demonstrable absence of structural abnormalities with cardiac MRI, 2D strain can detect subtle alterations in myocardial contraction heterogeneity. Furthermore, 12 months post successful ablation treatment, the increase in MD persists. This suggest the presence of subtle substrate abnormality that results in IVA. In uncured patients, both myocardial deformation parameters remain impaired, suggesting the need for close future surveillance of these patients. Long term follow up with greater number of patients is required to further validate these findings. Table 1. Echocardiographic parameters Group Indexed LVEDV (ml/m2) LVEF (%) LV GLS (%) LV MD (ms) IVA (Group A) 55 ± 15 61 ± 5 -19.9 ± 3* 44 ± 12* Controls (Group B) 54 ± 14 64 ± 7 -21.2 ± 2 33 ± 9 Group C 12 months follow up -21.7 ± 3 42 ± 11* Group D 12 month follow up -19.8 ± 2* 43 ± 11* * denotes p < 0.05

Premature ventricular complex (PVC) burden as detected by holter monitoring forms the basis of diagnosis and informs therapeutic decisions. Holter monitors can be cumbersome and uncomfortable for patients often leading to poor compliance. We hypothesize that PVC burden on a patient’s 12-lead ECG correlates with PVC burden ascertained on multi-day holter monitoring. Data was extracted from a centralised multi-day Holter database at Westmead Hospital. 41 consecutive patients undergoing multi-day Holter (48hours – 6 days) from 2017-18, had daily assessment of PVC burden as a percentage of total beats. For this same group of patients, retrospective analysis of all 12-lead ECGs and transthoracic echocardiograms (TTE) was performed. Only the ECG showing the greatest burden of ventricular ectopy was recorded, with burden measured as the number of ventricular ectopic beats as a percentage of total beats on a single 12 lead ECG. Left ventricular ejection fraction (LVEF) was reviewed on TTE to assess for underlying structural heart disease. Mean age of patients was 59±17yrs (44% female); mean LVEF 58.2±0.1%. There was a linear correlation between ventricular ectopy burden on 12-lead ECG and PVC burden as recorded on Holter monitor (R2=0.41, p<0.001). Ventricular ectopy burden on a 12-lead ECG correlates with ectopy burden on multi-day Holter monitor in patients with preserved LVEF. The bedside 12-lead ECG could therefore be used as a marker to inform diagnosis and therapeutic decisions in patients with palpitations attributed to ventricular ectopy.