Waiting on Atrial Fibrillation Intervention Therapy (WAIT) Study

Atrial fibrillation burden measured using continuous monitoring from an implantable loop recorder (ILR). AF burden is defined as the percentage of total monitored time spent in atrial fibrillation during each predefined assessment window.

Assessment of arrhythmia-free survival at 12 months post-ablation in participants who completed the study without major protocol deviations. Recurrence is defined identically to the primary ITT analysis (ILR-detected AF, atrial flutter, or atrial tachycardia ≥30 seconds after the blanking period). This analysis evaluates the treatment effect under optimal adherence.

Time from the end of the 3-month post-ablation blanking period to the first ILR-detected episode of atrial fibrillation, atrial flutter, or atrial tachycardia lasting ≥30 seconds. This endpoint evaluates the durability of rhythm control beyond the blanking period.

Total number of additional catheter ablation procedures performed per participant after the index ablation in order to restore or maintain sinus rhythm. This endpoint compares the need for redo ablations between the intervention and standard-of-care groups.

Proportion of participants who remain free from symptomatic atrial fibrillation, atrial flutter, or atrial tachycardia without requiring a repeat ablation procedure. Symptomatic episodes are defined by patient-reported symptoms corroborated by rhythm documentation. This endpoint evaluates clinically meaningful rhythm control without the need for additional invasive therapy.

Assessment of atrial fibrillation-related symptom burden and functional impact using the AFEQT and AFSS validated questionnaires. Changes in symptom and quality-of-life scores will be compared between groups to evaluate improvement over time. Each questionnaire will be reported as a separate score.

Assessment of changes in health-related quality of life using the RAND-36 questionnaire. A clinically meaningful change is defined as an improvement of approximately 3-5 points in any RAND-36 domain. This endpoint evaluates the impact of the intervention on physical, emotional, and functional well-being over time.

Body weight (kg) and height (cm) will be measured using standard clinical equipment. Height and weight will be combined to calculate Body Mass Index (BMI) in kg/m², which will be the single reported value for this outcome. The endpoint is the proportion of participants who meet either of the following criteria: ≥10% reduction in baseline body weight (kg) BMI \<27 kg/m² (kg/m²) Only the derived values (weight change % and BMI) are reported for this outcome; height and weight are not reported as separate outcome measures

Change in systolic blood pressure in mmHg compared with baseline, and diastolic blood pressure in mmHg. The secondary outcome will focus on the proportion of participants achieving \>10% blood pressure reduction in either systolic or diastolic blood pressure. Systolic and diastolic blood pressure will be reported separately in mmHg. Measurements are performed using standardized clinical procedures to evaluate the intervention's impact on blood pressure control.

Changes in individual blood biomarkers measured as part of routine clinical care, including: Fasting glucose (mmol/L; standard chemistry assay) HbA1c (mmol/mol; HPLC/immunoassay) Serum creatinine (µmol/L; enzymatic/Jaffe assay) NT-proBNP (ng/L; immunoassay) Each biomarker will be analysed separately using its native unit of measure. Descriptive only. No study-specific blood sampling is performed.

Incidence of procedure-related complications occurring during the catheter ablation or within the post-procedural follow-up period. Events may include vascular complications, pericardial effusion, tamponade, stroke/TIA, transient arrhythmias, anesthesia-related events, or other clinically relevant adverse outcomes, as documented in medical records. This endpoint compares procedural safety between study groups.

Assessment of changes in left ventricular ejection fraction from before to after the ablation procedure, based solely on echocardiograms performed as part of routine clinical care. No study-specific imaging is required; data will be included only for participants who undergo a post-ablation echocardiogram in standard practice. This endpoint evaluates whether the intervention influences cardiac function over time.

Assessment of the proportion of participants with diabetes, renal failure, or heart failure using information from routine clinical care, medical records, and linked registry data. No study-specific testing is performed. This endpoint describes baseline comorbidity burden and identifies new or worsening diagnoses captured through standard care or registries.

Incidence of hospitalizations due to cardiovascular causes, identified through routine clinical records and national or regional registry data. Events may include admissions for arrhythmias, heart failure, acute coronary syndromes, or other cardiovascular conditions. No study-specific assessments are required.

Incidence of hospital admissions for any cause, identified through routine clinical records and national or regional registry data. This endpoint evaluates the broader healthcare impact of the intervention beyond cardiovascular events. No study-specific assessments are required.

Assessment of initiation, discontinuation, or dose changes in antiarrhythmic medications (e.g., class I or III agents, beta-blockers) based on routine clinical records. This endpoint evaluates differences in pharmacologic rhythm control requirements between groups.

Total duration of the catheter ablation procedure, extracted from routine procedural reports. This endpoint evaluates whether pre-ablation metabolic optimization influences procedural complexity.

Total fluoroscopy exposure time and radiation dose recorded during the index ablation procedure, as documented in routine procedural logs. This endpoint assesses potential differences in radiation exposure related to patient characteristics or weight loss. Fluoroscopy time (minutes) and radiation dose (mGy or mGy·cm²) will be reported as separate values.

Assessment of overall healthcare use, including outpatient cardiology visits, emergency department visits, and telephone/remote consultations. Data will be obtained from routine clinical records and linked regional or national healthcare registries. This endpoint evaluates whether the intervention affects healthcare demand and resource use. No study-specific visits or assessments are required.