Atrial Fibrillation

Atrial Fibrillation (AF) is the most common arrhythmia and is associated with significant healthcare-related expenses. With the aging population, the prevalence of AF is increasing. AF frequently co-exists with heart failure (HF) with reduced (HFrEF) or preserved (HFpEF) ejection fraction. The relationship between AF and HF is complex, and one condition constitutes a risk factor for the other. Myocardial interstitial fibrosis is a hallmark of myocardial remodeling occurring as a consequence of risk factor exposure leading to both AF and heart failure. However, the role of interstitial fibrosis in the prognosis of patients with atrial fibrillation with and without heart failure remains unknown. AF has a significant impact on patients' well-being and quality of life. In addition to coping with uncomfortable symptoms, individuals with this condition face an increased risk of future adverse events like frailty, stroke, dementia, and all-cause mortality. To address these concerns, many patients opt for procedures such as AF ablation, hoping for a cure. While the results of this procedure show promise, a small percentage of patients who undergo AF ablation may experience a recurrence of the arrhythmia or find that the participant's heart's systolic function does not fully recover. The investigators aim is to investigate whether there is a connection between myocardial fibrosis and poor outcomes following AF ablation. Cardiac MRI (CMR) has been the gold standard methodology of quantification of interstitial fibrosis. Diffuse interstitial fibrosis can be quantified by extracellular volume (ECV) imaging. CMR-based left ventricular ECV has been associated with adverse outcomes in multiple cardiovascular disease states. However, the availability of CMR is confined only to tertiary centers with expertise. Cardiac CT is an alternative way to detect and quantify interstitial fibrosis by quantification of ECV. CT-derived ECV has been shown in multiple studies to have an excellent correlation with CMR-derived ECV. Cardiac CT is widely available and has a higher spatial resolution. Since as part of the standard pre-ablation routine, patients will undergo a cardiac CT scan to accurately map the anatomy of the participant's heart, investigators ought to measure ECV parameters during this visit.

Background: One-in-four Canadians will develop atrial fibrillation (AF), increasing risk of heart failure and stroke. Obesity (i.e., BMI ≥30 kg/m2) represents a strong, independent risk factor for increased incidence and severity of AF. Weight loss reduces AF symptom burden, and patients with obesity who lose ≥10% of their body weight may achieve AF regression/remission. Cardiac rehabilitation (CR) improves AF risk factors including hypertension and cardiorespiratory fitness (CRF), yet the efficacy of CR for reducing AF symptom burden is not established. CR rarely includes targeted obesity management and, on average, has a negligible impact on BMI. Adding behavioural weight-loss treatment (BWLT) to traditional CR may therefore enhance weight loss and lead to improvements in AF prognosis, symptoms, and health-related quality-of-life (HRQOL) in patients with AF and obesity. Given the high prevalence of obesity among individuals with AF, and its detrimental effect on AF burden and outcomes, there is a critical need for interventions that can support weight-loss-promoting behaviours and can be integrated into routine clinical care for AF. CR programs are available in all major Canadian cities and have a proven track-record of achieving clinically-relevant improvements in important AF risk factors including hypertension, lipid profile, and exercise capacity. Therefore, CR represents an ideal setting to promote risk factor management for patients with AF. Yet, because traditional CR does not produce meaningful weight loss there is a clear gap in the ability of current CR programming to meet the needs of a growing population of individuals with AF and obesity. The addition of a novel BWLT component to CR is needed to bridge this gap and provide the appropriate treatment regimen of comprehensive risk factor management, exercise, and weight loss to achieve optimal AF outcomes. The primary aim is to: Assess whether the combination of an AF-specific 'small changes' BWLT and traditional CR results in a greater proportion of patients with AF and obesity achieving ≥ 10% body weight loss compared to patients who receive standard care (traditional CR alone). The secondary aims of the proposed study are to evaluate the impact of BWLT+CR on: 1) mean % weight loss of controls vs. intervention group; 2) AF burden; 3) self-reported AF symptom burden; 4) disease-specific and generic patient-reported outcome measures (e.g., AF- and health-related quality-of-life \[HRQoL\]; psychological distress); and 5) exercise volume measured in weekly steps. Hypotheses: The primary study hypothesis is that patients in the BWLT+CR group will be more likely to achieve ≥10% weight loss at 12 months post-randomization relative to the CR-only group. Secondary hypotheses are that: patients in the BWLT+CR group will experience greater improvements in AF burden, AF self-reported symptom burden, increased HRQoL, decreased psychological distress, and increased leisure-time exercise and CR exercise session attendance relative to the CR-only group. Study design: Design and Procedure. Patients will be assessed for eligibility at TotalCardiology Rehabilitation (TCR). Eligible patients who consent to participate will be enrolled into the CR program and randomized to either the BWLT+CR or CR-only group. Prior to randomization, patients will complete a questionnaire battery including socio-demographic variables (age, sex, ethnicity, income, education), self-reported weight and height to establish BMI, and validated questionnaires assessing AF symptom burden, AF-related quality-of-life, general HRQOL, and psychological distress at baseline (T1). Patients will be re-administered the test battery following the 12-week BWLT+CR program, or 12 weeks of the CR-only program (T2). (Note: T2 measures will be administered even if the patient is still completing their remaining CR exercise sessions. CR completion/adherence will be determined after patients have completed their 12-week exercise program). The test battery will be administered for a final time approximately 24 weeks post-randomization. Weight loss from baseline to 52-weeks will be calculated and converted to a percentage of initial body weight at baseline. Clinical variables (e.g., CRF from graded exercise tests; blood pressure, lipids) will be obtained by TCR chart review. Recruitment. Patients will be recruited in two ways: (1) directly from TotalCardiology Rehabilitation using referrals from Dr. Wilton and TCR clinic staff, and (2) from an existing database of patients who participated in the Part I qualitative study and Part II acceptability study that provided consent to be contacted about future studies. The recruitment period will be from October 2022 to April 2024. Equal numbers of men and women will be recruited. AF clinic patients who are both (a) eligible for the CR program and (b) eligible for the proposed study will be identified by Dr. Wilton and/or TCR clinic staff. Dr. Wilton/TCR clinic staff will inform patients who meet (a) and (b) criteria about the study and invite them to participate. Interested patients will receive a CR referral and their contact information will be provided to the research coordinator. The research coordinator (B. Valdarchi) will contact patients, provide additional information about the study, and obtain informed consent. The research coordinator will then send an email link to complete baseline questionnaires. Following the completion of the questionnaires, participants will be informed about the group they were randomized to, and scheduled for BWLT groups if needed. Concurrently, patients will be contacted by CR staff to schedule their orientation appointment, as per typical clinic procedures. This recruitment procedure will also apply to patients who previously participated in Part I and II (i.e the qualitative and acceptability studies, respectively). TCR patients who are currently enrolled in CR will also be recruited. A research team member will identify CR patients who have consented to be approached about research and who are eligible for inclusion by reviewing patient chart data. An RA will contact patients by telephone to review study procedures and obtain patients' informed consent. Sample Size/Analysis. Analysis will be by intention to treat. Conservatively assuming a 5% success rate in the control group and a 30% success rate in the intervention group, 78 patients (39 per group) will provide 80% power to detect a difference using a two-sided independent test of proportions with a 5% significance level. The investigators estimate loss to follow-up and drop-outs of 20% and 10% respectively, therefore 120 patients will be recruited in total (60 per group). The primary analysis will compare the proportion in each group achieving ≥10% weight loss between baseline and 52 weeks post-randomization. A secondary per-protocol analysis will be performed including only participants who complete at least the initial 12-weeks of the BWLT. AF burden will be calculated as a % of total ECG tracings and compared between treatment and controls. Self-reported secondary outcomes will be evaluated using linear mixed modelling.

The study will evaluate the safety and 12-month effectiveness of the Pulmonary Vein Isolation plus Box Isolation of Fibrotic Areas (BIFA) ablation strategy with the Globe Pulsed Field System (Globe PF System) for the treatment of atrial fibrillation.

This trial is a pilot-scale, single institution randomized, placebo-controlled trial to assess the feasibility, acceptability, and efficacy of administering dapagliflozin for cardiovascular risk reduction in the postpartum period. The target population is patients at high risk of adverse cardiovascular outcomes within five years post-delivery. Eligible participants will be randomized to receive either: 1) dapagliflozin (10mg daily) for six months (DAPA group) or 2) an orally administered, daily placebo (Control group). The study hypothesizes: The dapagliflozin group will have higher cardiovascular risk reduction scores than the Control Group.

The study is designed to collect data on the acute and long-term (1 year) safety and effectiveness outcome when an ablation procedure is performed in a commercial and standard of care setting with the FARAPULSE™ Pulsed Field Ablation System, whereby the FARAWAVE NAV Ablation catheter is used in conjunction with the OPAL HDx Mapping System. In addition, the study intends to analyse the association between several workflow-related variables, inclusive of intracardiac electro-anatomical mapping and ablation strategy with procedure-related complications (safety parameters), and one-year effectiveness parameters.

A Safety, Tolerability, and Biomarker Trial of VS-041 in Participants with Heart Failure with Preserved Ejection Fraction (HFpEF)

The purpose of this study is to assess the safety and feasibility of the investigational catheter for mapping the atrial and ventricular regions of the heart.

The purpose of this study is to evaluate the long-term safety and effectiveness of the VARIPULSE catheter system for pulmonary vein isolation (PVI) in the treatment of participants with symptomatic paroxysmal atrial fibrillation (PAF).

The purpose of this study is to provide real-world data useful to address the factors associated to the administration of oral anticoagulants in the elderly population affected by non-valvular atrial fibrillation (NVAF), in Italy, and it's persistence rate after one year.

The purpose of this study is to demonstrate the safety and 12-month effectiveness of the BWI OMNYPULSE™ pulsed field ablation (PFA) platform for pulmonary vein isolation (PVI) in the treatment of participants with symptomatic paroxysmal atrial fibrillation (PAF), an irregular heart rate that causes abnormal blood flow.