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Insertable Cardiac Monitor for Primary Atrial Fibrillation Detection in High-Risk Heart Failure Patients

Insertable Cardiac Monitor for Primary Atrial Fibrillation Detection in High-Risk Heart Failure Patients (ASSERT-AF)

Status
Active, not recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04818645
Acronym
ASSERT-AF
Enrollment
477
Registered
2021-03-26
Start date
2023-01-31
Completion date
2028-07-01
Last updated
2026-03-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Atrial Fibrillation, Heart Failure

Keywords

Implantable cardiac monitor, Atrial fibrillation, Heart failure, Remote monitoring, Stroke

Brief summary

Patients with heart failure (HF) represent a large population of patients who are at high risk for complications related to undiagnosed atrial fibrillation (AF). However, currently there are limited modalities for early AF detection and subsequent stroke prevention in this high-risk population. An implantable cardiac monitor (ICM) is inserted subcutaneously and can provide long term arrhythmia information via remote monitoring. The ASSERT-AF study seeks to accurately define the burden of AF and other arrhythmias in high-risk HF patients using an ASSERT ICM.

Detailed description

Over 6 million people in the United States suffer from heart failure (HF). By the year 2030 the prevalence of HF is expected to exceed 8 million people. Heart failure accounts for 1 million hospital admissions each year, costing our economy in excess of $30 billion dollars per year. Mortality in patients with HF remains high, and nearly half of all patients diagnosed with HF will die within 5 years. More than half of all patients admitted with HF decompensation have preserved left ventricular systolic function. Patients with HF and mildly reduced or preserved left ventricular systolic function are at high risk for developing atrial fibrillation (AF), the occurrence of which often contributes to HF decompensation and increases morbidity and all-cause mortality. Similarly, patients with AF are at high risk for developing HF due to loss of atrio-ventricular synchrony and rapid uncontrolled ventricular rates. Detection of AF can be challenging and may go undiagnosed in asymptomatic or minimally symptomatic patients through conventional monitoring methods. Patients with HF represent a large population who are at risk for complications related to undiagnosed AF. AF increases the risk of stroke five-fold and the risk of death nearly two-fold. Moreover, strokes related to AF are twice as likely to be fatal or severely disabling compared to strokes due to other causes, such as ischemic small vessel disease or atheromatous large vessel disease. Cardiac implantable electronic devices (CIEDs), can be used for the early detection of AF in asymptomatic or mildly symptomatic patients with HF. However, current guidelines provide an indication for prophylactic implantable cardioverter defibrillator (ICD) only in HF patients with left ventricular ejection fraction (LVEF) ≤ 35%, whereas there are limited data for device-based detection of AF in HF patients with more preserved LVEF. Implantable cardiac monitors (ICM) are devices that can be injected into the subcutaneous tissue and can provide automatic electrocardiographic recordings of asymptomatic arrhythmias as well as patient triggered electrocardiographic recordings of symptomatic episodes during long term follow-up. Implantable cardiac monitors are be paired with remote monitoring systems, capable of rapid remote review of electrograms. Accordingly, we hypothesize that a management strategy that incorporates ICM implantation in patients with HF and LVEF \>35% will result in a significantly higher rate of AF detection leading to arrhythmia related interventions compared to conventional monitoring and follow-up in patients with HF.

Interventions

DEVICEASSERT Insertable Cardiac Monitor

Subjects will be subcutaneously implanted with an Abbott ASSERT ICM with the device implant procedure per standard of care and current labelling. Data related to subjects' arrhythmias, via the Merlin.net Patient CareNetwork will be transmitted on a monthly basis to the treating physician and subsequently to the study coordination and database center (CCRC) at the University of Rochester. Data on the frequency/types of symptomatic (patient triggered) versus ICM detected (asymptomatic) arrhythmic events will be collected and adjudicated. Clinical data on medication, device interventions, cardiovascular events will be collected at follow-up visits.

OTHERConventional Management and monitoring

Subjects randomized to the conventional management arm of the trial will undergo arrhythmia monitoring based on clinical indications and per standard available modalities including periodic electrocardiograms (ECG), Holter and/or event monitoring.

Sponsors

University of Rochester
Lead SponsorOTHER
Abbott
CollaboratorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)

Masking description

Events Review Committee: A blinded three-member Events Review Committee will review de-identified source documents obtained from each of the enrolling sites that will only be labelled with a subject ID. No data will be provided indicating the randomized treatment arm to the study and appropriately redacted with no ICM data provided. The information will be used to determine the nature of any clinical and adverse events. Available medical records and source documents will be used to determine cause-specific mortality.

Intervention model description

Subjects will be randomized in a 2:1 fashion to undergo implant of an ASSERT ICM implant with remote monitoring and symptom-triggered mobile app transmissions versus conventional follow-up without an ICM. Randomization will be stratified by the degree of LV dysfunction to ensure balanced enrollment of HF subjects with mild LV dysfunction (LVEF = 36%-49%) and those with preserved LVEF (≥ 50% \[i.e. heart failure with preserved ejection fraction - HFpEF\]).

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Male and female patients more than 18 years of age (no upper age limit) * HF exacerbation requiring initiation or augmentation of decongestive therapy in a hospital setting (hospitalization or emergency department visit) during the past 24 calendar months prior to consent date OR current treatment with loop-diuretics (furosemide, bumetanide, or torsemide). * LVEF \> 35% on a cardiac imaging study (echocardiogram, nuclear imaging, cardiac magnetic resonance imaging) performed during the past 24 calendar months prior to consent date * One or more FDA-approved indications for an Abbott ICM (unexplained symptoms such as: dizziness, palpitations, chest pain, syncope, and shortness of breath, as well as patients who are at risk for cardiac arrhythmias). * Willing to undergo an Abbott ICM implant and agree to remote ICM monitoring.

Exclusion criteria

* Existing implantable cardioverter defibrillator (ICD), biventricular ICD, implantable cardiac monitor or pacemaker. * Known or documented history AF or atrial flutter any time in past. * Has had a heart transplant * Participation in other clinical trials (observational registries are allowed with approval from the Coordination Center) * Unable or unwilling to cooperate with the protocol * Unable or unwilling to sign the consent for participation

Design outcomes

Primary

MeasureTime frameDescription
Median Time to first detection of AF lasting > 5 minutes24 monthsDefined as ICM detected AF in the intervention (implantable cardiac monitor) arm or captured by clinical symptoms and documented by ECG or Holter in the conventional arm.

Secondary

MeasureTime frameDescription
Time to initiation of guideline directed anti-arrhythmic and HF interventions24 monthsInterventions such AF ablation, initiation of antiarrhythmic, anticoagulation, beta-blocker therapy and others.
Number cardiovascular hospitalizations or death24 monthsTotal number of cardiovascular hospitalizations or death in each arm.
Compare healthcare utilization using Abbott ICM vs. non-ICM monitoring.24 monthsIncluding emergency department visits, unplanned office visits, cardiovascular hospitalization or death
Mean quality of life measured using the Kansas City Cardiomyopathy Questionnaire (KCCQ)24 monthsAll KCCQ scores are scaled from 0 to 100 and frequently summarized in 25-point ranges, where scores represent health status as follows: 0 to 24: very poor to poor; 25 to 49: poor to fair; 50 to 74: fair to good; and 75 to 100: good to excellent.
Mean percentage of time spent in atrial fibrillation (AF Burden)24 monthsAF burden, defined as average percentage of time spent in AF (i.e. amount of time spent in AF divided by the total amount of time a patient was monitored). AF burden will be quantified only in the intervention arm.
Time to detection of composite of arrhythmic events endpoint24 monthsArrhythmic events consisting of AF, sustained ventricular tachycardia, and high-risk bradyarrhythmias (high degree AV block or sinus pause \> 5 seconds), whichever occurs first.

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORIlan Goldenberg, MD

University of Rochester

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 24, 2026