Incidence of Long-TeRm Atrial Fibrillation After Acute Illness (ILR-AF)

Incidence of Long-TeRm Atrial Fibrillation After Acute Illness (ILR-AF)

The investigators seek to conduct a prospective study to assess the recurrence of AF in patients with acute AF using a long-term ECG monitoring strategy with an insertable cardiac monitor (ICM), which is clinically indicated in this scenario as part of the standard of care. The investigators hypothesize that patients diagnosed with acute AF in the setting of cardiac surgery will have higher rates of AF recurrence than acute AF diagnosed in the setting of non-cardiac surgery or medical illness.

Study Overview

• Status: Recruiting
• Conditions: Atrial Fibrillation (AF)

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Benjamin U Hoffman, MD, PhD; Phone Number: 858-246-2016; Email: b2hoffman@health.ucsd.edu

Study Locations

• United States
  • California
    • La Jolla, California, United States, 92037
      • Recruiting
      • Sulpizio Cardiovascular Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The selection of participants for this study will be equitable, and no specific populations will be excluded without a clear and compelling rationale related to the health of the participants or the purpose of the research. Limited English proficiency will not be an exclusion criterion.

Description

Inclusion Criteria:

1. Patient has an existing clinical indication for implantation of an insertable cardiac monitor (ICM) and will undergo ICM implantation as part of their standard medical care.
2. Patient is scheduled to receive or has received a Boston Scientific LUX-DX™ insertable cardiac monitor.

3. Episode of acute AF. Acute AF is defined as AF detected in an acute care setting or during an acute illness. Before enrollment, the following tests are minimally required as standard tests to establish the diagnosis of acute AF:

   • 12-lead ECG for AF detection
   • 24-h ECG or telemetry monitoring for AF detection and PAC analysis
4. Patient or legally authorized representative signs and dates the patient consent form.
5. Patient is ≥18 years old.
6. Patient is willing and able to comply with all study procedures and attend the required follow-up visits for the duration of the study.

Exclusion Criteria:

1. Patient has a known history of AF or atrial flutter prior to the index acute AF episode.
2. Patient has another indication for antiarrhythmic medications according to AHA/ACC/HRS guidelines, independent of the acute AF episode.
3. Patient has a permanent contraindication to oral anticoagulation (OAC) that, in the opinion of the treating physician, would preclude any future consideration of OAC for AF management.
4. Patient is currently enrolled in another clinical trial that will affect the objectives or endpoints of this study.
5. Patient's life expectancy is less than one year, as determined by the treating physician.
6. Patient is pregnant.
7. Patient has a current indication for implant with a cardiac implantable electronic device (CIED) such as a pacemaker or defibrillator, or an implantable hemodynamic monitoring system, as the study intervention would be redundant or potentially interfere with the clinical indication.
8. Patient is not fit, able, or willing to follow the required procedures of the Clinical Investigation Plan.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
ILR

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to first documented event of AF by 12 months	The primary objective is to determine the time to first documented event of AF by 12 months of continuous rhythm monitoring, stratified by the setting of acute AF diagnosis (cardiac surgery, non-cardiac surgery, and medical illness).	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of hospitalization		12 months
Incidence of death		12 months
Time to first documented AF by 6 months		6 months
Time to first documented AF episode lasting ≥ 5 minutes		12 months
Mean AF burden		12 months
Mean AF episode length		12 months
Change in use of oral anticoagulation and antiarrhythmic drugs		12 months
Quality of life scores (SF-36)	Change in Quality of Life scores as assessed by the Short Form 36 Health Survey (SF-36). The SF-36 is a 36-item, patient-reported survey assessing patient health across eight domains. The scores are weighted and summed to produce a value ranging from 0 to 100, where higher scores indicate a better quality of life (better health outcome).	12 months
Change in medication use		12 months
Incidence of stroke		12 months

Collaborators and Investigators

• Sponsor: University of California, San Diego
• Collaborators: Boston Scientific Corporation

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2025
• Primary Completion (Estimated): November 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: December 21, 2025
• First Submitted That Met QC Criteria: February 19, 2026
• First Posted (Actual): February 25, 2026

Study Record Updates

• Last Update Posted (Actual): February 25, 2026
• Last Update Submitted That Met QC Criteria: February 19, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: AF; ILR; AFIB; Paroxysmal AF; Lone AF
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation
• Other Study ID Numbers: 812338

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: In general, de-identified data may be shared with other researchers for scientific purposes, subject to IRB approval and any data sharing agreements. Any such sharing will not include information that could reasonably identify individual participants. No plans to publish participant family pedigrees are anticipated for this study.

Drug and device information, study documents

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