Reversal of Atrial Substrate to Prevent Atrial Fibrillation Cohort Study (RASTA-Cohort)

Atrial fibrillation (AF) is a major health problem, with a prevalence of 0.4-1% of the population. It results in high healthcare costs and significant morbidity, especially for patients with severe symptoms. The RASTA-AF randomized control trial (RCT) is designed to answer the following question: does vigorous treatment of AF with aggressive risk factor management plus catheter ablation reduce AF-related outcomes as compared to catheter ablation plus usual care in patients with symptomatic AF and risk factors that promote AF.

This study is a multicenter, prospective cohort study that will enrol patients who decline participation in the RASTA-AF RCT but agree to be followed in a registry. The objective of RASTA-Cohort is to determine whether patients who decline participation in the RASTA-AF RCT have different clinical characteristics and quality of life than patients who accept participation in the study, and whether they suffer from worse AF-related outcomes than patients in the RCT.

Study Overview

• Status: Recruiting
• Conditions: Atrial Fibrillation, Paroxysmal or Persistent

Detailed Description

Randomized clinical trials remain the gold standard for determining the efficacy of an intervention, however, it is well known that patients will decline participation in clinical trials for various reasons. It is critical to understand outcomes of patients who are eligible for a clinical trial, but decline participation, as it may affect the magnitude of an intervention, and ultimately its clinical meaningfulness. The RASTA cohort study will address this issue in patients with AF. Atrial fibrillation has become a significant burden globally, and is more often present in older individuals. This is particularly important in Nova Scotia where our healthcare system is especially burdened as the population ages, 20% of the current population is >65 years. Improved understanding of the AF patient population in Nova Scotia, and beyond, will permit further understanding of how best to treat this increasingly common chronic illness.

The RASTA-Cohort study is designed to answer the following questions:

1. Do patients who decline participation in the RASTA AF RCT have different clinical characteristics and quality of life than patients who accept participation in the study.
2. Do patients who do not participate in the RASTA AF RCT suffer from worse AF-related outcomes than patients in the study, as compared to the control arm and intervention arm.

This is a multicenter, prospective cohort study that will enrol patients who are eligible for, but do not participate in the RASTA-AF study, but agree to be followed in this registry. Once the patient has consented to participate in RASTA Cohort, they will be scheduled for their AF ablation at the next available timeframe (2-4 months from entry into the study). All patients will continue to receive care as per current guidelines; this will be managed at the discretion of their treating physician.

Clinical characteristics collected at baseline include quality of life (CCS-SAF, AFEQT, EQ-5D), physical activity measures: IPAQ and stress test results (where available), blood pressure, weight, hemoglobin A1C, alcohol use and smoking cessation. The measures of risk factors will be performed in a similar fashion as the main study to ensure that these can be compared.

The conservative estimated event rate for the cohort is 20% greater than that of the control population of the RASTA AF study. Given the control population having an event rate of 30%, and the cohort group being 43.5%, a sample size of 313 patients is required in the control population of RASTA and 185 patients in the cohort group with a minimum 2 year follow up. Using a 7% loss to follow up rate, the sample size required in the cohort group is 198 patients. This sample size will provide 90% power with a type I error of 0.05 to detect a difference in survival between the cohort and the control group in the study. There is >99% power to detect a difference between the intervention group and the cohort group based on the sample of 198 patients.

• Study Type: Observational
• Enrollment (Estimated): 198

Contacts and Locations

• Study Contact: Name: Laura Hamilton, BSC, MAHSR; Phone Number: 902 473-7226; Email: laura.hamilton@nshealth.ca
• Study Contact Backup: Name: Karen Giddens; Phone Number: 902 237-5551; Email: karen.giddens@nshealth.ca

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada
      • Recruiting
      • Foothills Hospital
      • Contact: Jennifer McKeage
      • Principal Investigator: Stephen Wilton, MD, FRCPC
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3H 3A7
      • Recruiting
      • QEIIHSC
      • Contact: Laura Hamilton; Phone Number: 902-473-7226; Email: laura.hamiton@nshealth.ca
      • Principal Investigator: Ratika Parkash, MD, FRCPC
  • Ontario
    • London, Ontario, Canada
      • Recruiting
      • London Health Sciences Centre
      • Contact: Keza Motlana
      • Principal Investigator: Allan Skanes, MD, FRCP(C)
    • Ottawa, Ontario, Canada
      • Recruiting
      • University of Ottawa Heart Institute
      • Contact: Tammy Knight
      • Principal Investigator: David Birnie, MD, FRCP(C)
    • Toronto, Ontario, Canada
      • Recruiting
      • Sunnybrook Hospital
      • Contact: Ambreen Syeda
      • Principal Investigator: Eugene Crystal, MD, FRCP(C)
  • Quebec
    • Montreal, Quebec, Canada
      • Recruiting
      • Montreal Heart Institute
      • Contact: Caroline Girard
      • Principal Investigator: Lena Rivard, MD, FRCP (C)
  • Saskatchewan
    • Regina, Saskatchewan, Canada
      • Recruiting
      • Regina General Hospital
      • Contact: Maria Gagarinova
      • Principal Investigator: Omar Sultan, MD, FRCP(C)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Probability Sample

Study Population

Patients with persistent or paroxysmal AF requiring catheter ablation and meet the inclusion/exclusion criteria for RASTA-AF, but decline or are not approached for participation in the Randomized Clinical Trial will be asked to participate in RASTA Cohort.

Description

Inclusion Criteria:

• symptomatic AF (CCS-SAF ≥2),
• paroxysmal or persistent atrial fibrillation despite rate control, desiring catheter ablation and either: i) BMI ≥ 30 or, ii) at least two of the following: BMI>27, BP>140/90 mmHg or history of hypertension, Diabetes, Heart failure (prior heart failure admission or LVEF<40%), Age ≥ 65 years, Prior stroke/TIA, Current smoker, Excessive alcohol use {For women: 10 or more drinks/week, more than 2 drinks a day (most days). For men: 15 or more drinks/week, more than 3 drinks a day (most days)}, and iii) declined or were not approached for participation in the main study. Eligible patients must have received catheter ablation for AF during the same timeline of the RASTA-AF Mian Study (November 1st, 2019 to December 31st, 2025).

Exclusion Criteria:

• permanent AF (AF lasting > 3 years),
• prior catheter ablation for AF
• New York Heart Association Class IV heart failure
• participation in a cardiac rehabilitation program within the last year,
• currently performing exercise training >150 minutes/week of moderate to vigorous physical activity,
• unable to exercise,
• unable to give informed consent,
• other noncardiovascular medical condition making 1 year survival unlikely
• less than 18 years of age

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
RASTA AF Cohort; Patients who meet the inclusion criteria for RASTA-AF, and do not meet any of the exclusion criteria but decline or are not approached for participation in the RCT will be asked to participate.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of patients with atrial fibrillation (AF) related hospitalizations	Defined as any hospitalization (greater than 24 hours) from 2 months post ablation to end of follow up due to: atrial fibrillation/atrial flutter, stroke/transient ischemic attack/systemic embolism, heart failure, syncope or bradycardia requiring pacing.	Up to 60 months
Number of patients with atrial fibrillation (AF) related ED visits	Defined as any presentation to the emergency department (less than 24 hours) due to: atrial fibrillation/atrial flutter, stroke/transient ischemic attack/systemic embolism, heart failure, syncope or bradycardia requiring pacing.	Up to 60 months
Number of patients with clinically significant atrial fibrillation post ablation	Clinically significant AF events lasting greater or equal to 24 hours within 26 hours (either an irregular R-R interval or atrial cycle length less than 280 ms, as obtained from an insertable cardiac monitor) from 2 months post ablation to end of follow-up.	Up to 60 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of Life Health Outcomes using EuroQol-5D-5L	The EQ-5D-5L quality of life questionnaire will be used to assess health related outcomes. The scale measures quality of life on a 5-component scale including mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension in the EQ-5D-5L has five response levels: no problems (Level 1); slight; moderate; severe; and extreme problems (Level 5). The lower the number, the better the impact on quality of life.	Up to 24 months
Number of patients with gender association, Atrial fibrillation risk factors and risk factor management	GENESIS PRAXY Gender Questionnaire	Up to 24 months
Number of patients with a composite of AF-related hospitalizations and ED visits or clinically significant AF	Defined as any hospitalization or presentation to the emergency department due to: atrial fibrillation/atrial flutter, stroke/transient ischemic attack/systemic embolism, heart failure, syncope or bradycardia requiring pacing and/or clinically significant atrial fibrillation (greater than or equal to 24 hours with symptoms) from randomization to end of follow up.	Up to 60 months
Number of patients with stroke or systemic embolism	Hospitalization or treatment for a stroke or systemic embolism	Up to 60 months
Quality of Life - CCS SAF scale	Symptom burden as measured by the Canadian Cardiovascular Society (CCS) Severity of Atrial Fibrillation (SAF) Scale. CCS-SAF scores range from 0 to 4, with higher values representing more severe impact of AF-related symptoms on quality of life and activities of daily living.	Up to 60 months
Quality of Life - AFEQT	Quality of life scale as measured by the Atrial Fibrillation Effect on QualiTy-of-life (AFEQT) scale. The scale consists of 21 questions with 7-point Likert scale responses. Questions 1-18 are grouped into three subscales (symptoms, daily activities and treatment concern). Questions 19-21 capture satisfaction with treatment and are not included in the HRQoL score of the questionnaire. Overall and subscale scores range from 0 to 100. Lower cores correspond to higher levels of disability (e.g., 0 corresponds to complete disability or responding "extremely" limited, difficult or bothersome to all questions answered), withe a score of 100 corresponds to no disability (e.g., responding "not at all" limited, difficult or bothersome to all questions answered). For Satisfaction questions, a score of 100 corresponds to extreme satisfaction with current treatment.	Up to 60 months
Number of patients with recurrent AF Catheter ablations	Any subsequent catheter ablations after the initial procedure	Up to 60 months
Number of patients with recurrent cardioversions for atrial fibrillation	Electrical or chemical cardioversions	Up to 60 months
Number of patients with Major bleeding	Fall in Hgb of ≥2 g/dL, transfusion of ≥2 units packed red blood cells (PRBC) or whole blood, in a critical location (e.g., intracranial, intraspinal, intraocular, retroperitoneal, intraarticular or pericardial	Up to 60 months
Number of Deaths	Study Exit due to death from time of inclusion	Up to 60 months

Collaborators and Investigators

• Sponsor: Ratika Parkash
• Collaborators: Nova Scotia Health Research Fund
• Investigators: Principal Investigator: Ratika Parkash, MD, FRCPC, Nova Scotia Health

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): March 1, 2027

Study Registration Dates

• First Submitted: January 3, 2024
• First Submitted That Met QC Criteria: February 6, 2024
• First Posted (Actual): February 8, 2024

Study Record Updates

• Last Update Posted (Actual): December 2, 2025
• Last Update Submitted That Met QC Criteria: November 25, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation
• Other Study ID Numbers: RP-08

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No