Temporary Nontherapeutic Ambulatory Cardiac Monitoring Devices

CMS Publication 100-03, National Coverage Determinations, Part 1:

20.15 Coverage for electrocardiographic services under Medicare Part B.

CMS Manual System Pub. 100-03 National Coverage Determinations Transmittal 26: Electrocardiographic Services

CMS Publication 100-02, Medicare Benefit Policy, Chapter 1: Inpatient Hospital Services, §50.

CMS Publication 100-02, Medicare Benefit Policy, Chapter 6: Hospital Services Covered Under Part B, §10 and §20.3.

CMS Publication 100-02, Medicare Benefit Policy, Chapter 15:

80 Coverage of diagnostic x-ray, diagnostic laboratory and other diagnostic tests.

CMS Publication 100-02, Medicare Benefit Policy, Chapter 15: Covered Medical and Other Health Services, §§60.1 and 250.

CMS IOM Pub 100-02, Ch 16, §10 General Exclusions from Coverage

Background

Ambulatory electrocardiography provides a record of a patient’s heart rhythm and rate during a specific time frame. The recording could lead to the diagnosis of underlying and undetectable abnormalities. Monitoring allows for the detection of irregular heart rhythms or arrhythmias. These rate disturbances including waveform abnormalities can be missed on a standard electrocardiogram (ECG). The prevalence of cardiac arrythmias in the general population is 1.5% to 5%.¹ However, with advancing age and increased incidence of structural heart disease, the frequency, complexity and the prognostic significance of the arrythmias worsens.² Cardiac arrhythmias are the presenting event in approximately 50% of deaths from cardiovascular disease.¹

Temporary nontherapeutic ambulatory cardiac monitoring devices (TNACMD) provide invaluable data regarding arrhythmias, palpitations, syncope and other cardiac monitoring needs. The devices include Holter monitors, event recorders/monitors, patch recorders, external loop recorders (ELR), mobile cardiovascular telemetry (MCT) and mobile cardiovascular outpatient telemetry (MCOT). These distinct devices have different capabilities, varying from intermittent to continuous recordings, and are either patient activated, or rhythm activated recordings. They range in terms of number of leads, time frame length, whether the recordings are being monitored in real time, or if the information recorded needs to be transferred from the device for further interpretation. These devices are not to be utilized in patients at risk for immediate, life-threatening arrythmias (Class I) which require inpatient care.³

The purpose of the LCD is to provide the scope of indications that are supported as reasonable and necessary for the usage of temporary ambulatory nontherapeutic monitoring devices in the appropriate patients.

Coverage

All utilization of electrocardiographic services must align with requirements in NCD 20.15.

Cardiac monitoring is reasonable and necessary when the following criteria are met:

1. Temporary (not implanted), AND
2. Presence of symptoms suggestive of cardiac arrythmia with symptoms (such as palpitations, presyncope, syncope, chest pain or shortness of breath) occurring infrequently (>24 hours between symptomatic episodes),^{31-33,39,41,42,47} OR
3. Monitoring is necessary to regulate medication management such as antiarrhythmic drug dosage^22,41 OR
4. Patient with non-lacunar cryptogenic stroke or stroke or TIA of undetermined origin to monitor undiagnosed atrial fibrillation or anticoagulation management,^{28-30,36,37,43,44,46} OR
5. To monitor patients who have had surgical or ablative procedures for arrhythmia,^26,40 OR
6. To assess for asymptomatic ventricular premature beats or non-sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, long QT syndrome, dilated or restrictive cardiomyopathy, congenital heart disease, or Brugada syndrome^35,38,41 OR
7. Embolic-appearing pattern of myocardial infarction.³⁴

Device Requirements:

1. FDA cleared, AND
2. Device is patient or event activated with intermittent or continuous cardiac arrhythmic events monitoring capacity, AND
3. Monitored by 24-hour monitoring stations to receive transmissions, AND
4. A system is in place to notify patients or emergency services for potentially life-threatening arrhythmias.

Limitations:

1. TNACMD service is medically unnecessary if it offers little or no potential for new clinical data beyond that which has been obtained from a previous test, (e.g., a standard ECG has already established a diagnosis), or if other tests are better suited to obtain clinical data relevant to the patient's condition. The TNACMD should be coordinated with results from standard ECGs, Holter monitor tests, and stress tests.
2. The purpose of TNACMD is the long-term monitoring of patients to document suspected or paroxysmal dysrhythmia. Therefore, it is considered medically unnecessary to utilize a TNACMD service when only a standard ECG is required (even if it is used to transmit that ECG to another location).
3. The receiving station must be staffed on a 24-hour basis with personnel trained to read ECGs (e.g., critical care nurses or paramedics), who should be able to direct the patient for the management of all emergencies. An answering service/answering machine would not fulfill this requirement. Systems utilizing computers to dial the physician's office, so the physician receives transmission by way of a relay are not covered since there is no 24-hour personnel attendance.
4. A test not ordered by a physician or qualified non physician practitioner treating the beneficiary will be denied as not medically necessary.
5. It is expected that TNACMD will not be used for the routine daily transmission of ECG rhythm strips, or monitoring, in the absence of identified symptoms necessitating diagnosis as stated in this LCD.
6. TNACMD are covered only as diagnostic tests or for evaluating a patient being actively managed on arrhythmic medication.
7. TNACMD are not covered for patients in hospitals, emergency rooms, skilled nursing facilities or other specialized facilities, including outpatient or facility-based cardiac monitoring.
8. Testing for more than 30 consecutive days is only rarely medically necessary, and the need for the continued testing must be justified by the treating physician. Failure to document arrhythmia during a 30-day test period is not sufficient justification to reimburse a second or subsequent test. It is unlikely to be medically necessary to repeat a second test within a year in the absence of new or recurrent undiagnosed symptoms.
9. Event recorders may be patient activated and may not use time-sampling technology. Accordingly, this test will be considered medically unnecessary for any patient who is unresponsive, comatose, severely confused or otherwise unable to recognize symptoms, or activate the recorder (patient activated devices) or unable to participate in the use of the device.
10. "Routine" continued monitoring in the absence of treatable symptoms is considered screening and is not medically necessary.
11. Because the cardiac event detection service requires the diagnosis and evaluation of intermittent arrhythmias, and patients must be continuously attached to pre-symptom loop recorders or be able to be attached at the start of symptoms to post-symptom loop recorders, each patient is required to have a recorder for his/her own exclusive use throughout the duration of the monitoring period. Recorders may not be "shared" amongst two or more patients, regardless of the environment or site of the service. Claims for TNACMD will be denied as not medically necessary when patients do not have exclusive use of a recorder for the entire service period (30 days).
12. Cardiac event detection is a 30-day packaged service. Tests may not be billed within 30 days of each other, even if the earlier of the tests were discontinued when arrhythmias were documented and the patient is now reconnected for follow-up of therapy or intervention.

Definitions

Temporary Nontherapeutic Ambulatory Cardiac Devices (TNACMD): A portable device which can be attached to the skin to temporarily record the electrical activity of the heart. This allows healthcare providers to monitor the patient over a period of up to 30 days.

Atrial Fibrillation (AF): Supraventricular tachyarrhythmia with uncoordinated atrial electrical activation and ineffectual atrial contraction.

Clinical AF: Symptomatic or asymptomatic AF documented on surface electrocardiogram (ECG).

Subclinical AF or Atrial high-rate episode (AHRE): Asymptomatic AF without previous clinical diagnosis of AF.

Cryptogenic Stroke: Subtype of Ischemic stroke without a determined cause or more than one competing cause (30-40% of all ischemic strokes).

Embolic Stroke of Undetermined Source (ESUS): Non-lacunar cryptogenic stroke subtype without identifiable cause despite extensive investigation, including more than 24 hours of cardiac monitoring.

Heart Block: The partial or complete interruption of electrical impulses from the atria to the ventricles (Atrioventricular (AV) block), where the rate is slower, or the rhythm is abnormal.

Intraventricular conduction delay (IVCD): Prolongation of the QRS exceeding the typical upper limit of normal but does not meet criteria for a specific conduction block.

Junctional Rhythm: Abnormal rhythm originating from the AV node or the Bundle of HIS (HB).

Non-lacunar Stroke: Cerebrovascular accident presumed to be caused by a thromboembolic event from the heart or the large extracranial arteries.

Acute Coronary syndrome (ACS): Acute myocardial infarction or ischemia.

Silent Myocardial Ischemia: Asymptomatic cardiac ischemia on testing without angina or an anginal equivalent.

Device Types

Holter Monitor – A portable device which continuously records the electrical activity of the heart (an electrocardiogram (ECG)) over a period, typically 24 hours.

Event recorders/monitors – A portable device, either carried or worn, to record the beneficiary’s cardiac activity (ECG) as they go about their normal activities. It only records when symptoms are experienced.

Patch recorders – An adhesive patch, worn on the chest wall that continuously records cardiac activity (ECG).

External loop recorders (ELR) – A portable device worn on the anterior chest wall, attached via electrodes to continuously record cardiac activity (ECG).

Mobile cardiovascular telemetry (MCT) – A portable device which continuously monitors the electrical activity of the heart and transmits the data to healthcare providers in real-time.

Mobile cardiovascular outpatient telemetry (MCOT) – Monitors a beneficiary’s heart rate, cardiac activity and cardiac rhythm over time. Data is transmitted to a remote 24-hour, certified technician monitored, monitoring center in real time.

Literature Analysis

This summary of the evidence has been formatted by the type of comparator, outcome category, (e.g., diagnostic yield, undesirable effects), and study design. The literature analysis emphasizes the research designs representative of the body of evidence (systematic reviews, meta-analyses) and the primary studies most applicable to specific outcomes e.g., RCTs for diagnostic yield. Multiple publications from the same dataset were grouped together in the analysis regardless of study design. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach domains of study limitations (risk of bias), indirectness (applicability), imprecision, inconsistency, and publication bias formed the basis of appraisal of the certainty of evidence [see Appendix].

Description of Studies

This evidentiary review included 12 systematic reviews, most with meta-analysis [Table 1]. These reviews synthesized studies for all types of TNACMD. Only two reviews were limited to the analysis of RCTs. The number of primary studies and participants in the reviews ranged from 3 to 50 and 1149 to 135,300, respectively. The patient populations varied from asymptomatic older adults to individuals diagnosed with stroke or transient ischemic attack (TIA). The detection of AF was a common primary outcome [Table 2]. Implantable cardiac monitors were the most frequently employed comparator. Five systematic reviews assessed clinical outcomes. Three syntheses reported on undesirable effects. Two reviews described the effect of TNACMD on clinical management. Five of the systematic reviews provided data about potential effect modifiers, patient selection, or the timing of TNACMD.

A total of 9 randomized controlled trials (RCTs) were included in the evidence review [Table 3]. Most trials were multi-centered and took place in North America. The number of participants varied widely from 21 to 11,931. The mean/median ages of participants ranged from 64.1 to 75 years. These studies included multi-morbid patients without known AF who had cryptogenic ischemic stroke, transient ischemic attack (TIA), risk factors for stroke following cardiac surgery, or received opportunistic screening. Five trials assessed long-term cardiac monitors (LTCM) i.e., patch devices. Three randomized controlled trials (RCTs) evaluated Holter type monitoring devices. Four studies investigated event monitors e.g., external loop monitor (ELR). There were no RCTs concerning mobile cardiovascular telemetry (MCT) or mobile cardiac outpatient telemetry (MCOT) devices that met eligibility criteria. Comparator interventions included usual care, implantable cardiac monitors, and between different types of TNACMD. Most studies reported diagnostic yield (detection of atrial fibrillation) as a primary endpoint [Table 4]. Primary and secondary outcomes were assessed at follow-up time points between 14 days and 15 months. A single large retrospective cohort study of Medicare beneficiaries (N = 287,789) was also included in the analysis.

Effects of TNACMD

TNACMD compared to SOC

Diagnostic Yield

Two evidence syntheses analyzed data from primary studies that compared various TNACMD with SOC including short-term cardiac monitoring.^4,5 Dahal et al.⁴ performed a meta-analysis of 4 RCTs (N = 1149) that evaluated the prolonged monitoring (LTCM, MCOT, ELR) ≥7 days in patients with cryptogenic stroke or TIA. The reviewers found prolonged cardiac monitoring of ≥7 days compared to shorter cardiac monitoring of ≤48 hours duration increased the detection of AF (≥30 seconds duration) in patients after cryptogenic stroke or TIA (13.8% vs. 2.5%; odds ratio [OR] 6.4; 95% confidence interval [CI], 3.50, 11.73; P < 0.00001; I² = 0%]. It also increased the odds of AF detection of any duration (22.6% vs. 5.2%; 5.68 [3.3, 9.77]; P < 0.00001; I² = 0%). This meta-analysis has several limitations including lack of patient-level data, different duration of follow-up among studies, and variations in type of device. It was not possible to ascertain which device and follow-up duration worked better compared to the others.

A health technology assessment (HTA) employed a network meta-analysis, with SOC (short-term Holter monitoring) as the common comparator, in assessing the relative effectiveness of LTCM compared with ELRs.⁵ This HTA included 12 non-randomized studies of interventions (NRSI) that reported on patients with palpitations, syncope, dizziness, stable chronic heart failure, ischemic and non-ischemic stroke, cryptogenic stroke, TIA, or known/suspected dysrhythmias. Both types of devices were more effective than SOC. There was no substantial difference between them in their ability to detect symptoms (risk difference 0.01; 95% CI: –0.18, 0.20). Using GRADE for network meta-analysis, the quality of the evidence was evaluated as low. Additional constraints were that all primary studies were observational designs, and only indirect comparisons could be obtained.

Six RCTs reported on the detection of AF by different TNACMD as compared to SOC that included 24-hour Holter monitoring.^6-11 These studies included patients without known AF who had cryptogenic ischemic stroke, TIA, risk factors for stroke following cardiac surgery, or received asymptomatic screenings. Monitoring periods ranged from 14 to 90 days, with detection endpoints extending as much as 15.3 months. The TNACMD strategies were superior in detecting AF versus short-term monitoring at all follow-up periods (TNACMD = median 16.3% [14-19.6], SOC = 2.1% [1.7-5]) except for opportunistic screening (TNACMD = 0.7%, SOC = 0.6%).

Cumulative AF or atrial flutter (AFL) was calculated in 3 RCTs. Within the first 30 days of monitoring, AF/AFL of >6 and >24 hours durations were detected in 8.6% and 3.1% of the TNACMD group versus 0% in the SOC group, respectively.⁷ Paroxysmal atrial fibrillation (PAF) of any duration was identified in one RCT at 28 days (14% in the TNACMD group and 2.1% in the SOC group)⁹ and through 90 days (44% in the TNACMD group and 4% in the SOC group).⁸

Clinical Management

Dahal et al.⁴ meta-analyzed data from 4 RCTs (N = 1149). Patients diagnosed with cryptogenic stroke or TIA who underwent prolonged monitoring (LTCM, ELR, MCOT) were more likely to be on anticoagulation at follow-up than those receiving SOC (2.21[1.52, 3.21]; P < 0.0001; I², 0%).

There were four RCTs that explored the impact of TNACMD on the initiation of oral anti-coagulant (OAC) therapy.^6,8-10 Higgins et al.⁸ found absolute differences favoring the TNACMD group of 16% at 14- and 90-day time points. Another RCT reported an absolute difference of 7.5% in favor of TNACMD compare to SOC at 90 days.d⁶ Two RCTs provided insufficient details (uncertainties about the absolute effects and time frame) to permit conclusions about the effects of TNACMD on clinical management.^9,10

Mortality, Stroke, Major Adverse Cardiac Events

A single systematic review and meta-analysis of 4 RCTs involving 1149 patients with cryptogenic stroke or TIA who underwent prolonged monitoring (LTCM, ELR, MCOT) or SOC (short-term Holter monitoring) found no differences in mortality (1.33 [0.29, 6.00]; P = 0.71; I² = 0%] or recurrent stroke or TIA (0.78 [0.40, 1.55]; P = 0.48; I², 0%).⁴

Two trials investigated mortality, finding no significant difference with SOC at 90 days between patients assigned to a 7-day external loop recorder (ELR)⁸ or 14-day patch monitor.⁹

There was no evidence that screening for AF using a 14-day continuous TNACMD reduces recurrent stroke or TIA.^8,9 The data were from two small RCTs (N = 100, 116), and event rates were low. This may have resulted in underestimating the effect of TNACMD.

Healthcare Utilization

There was no indication, from a single RCT, that screening for AF using a 14-day continuous TNACMD in people ≥70 years of age seen in primary care practice reduces stroke-related hospitalizations.¹⁰ However, the event rates were low, which may have resulted in underestimating the effect of TNACMD.

Undesired Effects

There were no serious adverse events associated with the use of the ELR and patch devices^.7,8,10 A single RCT reported 10.4% of participants experienced a device-related adverse event due to skin irritation from the adhesive material of the wearable patch within 30 days of randomization.⁷

Adherence

Data from a single trial found that among the patients in the intervention group who started to undergo monitoring, 233 of 284 (82.0%) completed 3 or more weeks of monitoring.⁶

Effect Modifiers

No studies were identified.

TNACMD compared to Implantable Cardiac Monitors

Diagnostic Yield

Six systematic reviews evaluated the effectiveness of implantable loop recorder (ILR) versus TNACMD for identifying AF in patients with any type of stroke (e.g., cryptogenic, ischemic) or TIA.^12-17 Broadly, these reviews concluded that for patients with sufficient cognitive and physical ability to comply with the use of TNACMD, a 1- month duration can capture a significant proportion of AF and should be considered in place of ILRs. The choice of specific type of TNACMD should be made based on availability, patient’s preferences, and clinical judgment. ILRs can be considered in patients where a prolonged duration of monitoring (>30 days) is anticipated, if a TNACMD fails to detect any AF after 4 weeks of monitoring, or if there are anticipated issues with compliance.

A single RCT sought to determine, in patients with a recent ischemic stroke, whether 12 months of ILR monitoring detected more occurrences of AF compared with conventional external loop recorder (ELR) monitoring for 30 days.¹⁸ There was a statistically significant between-group difference in the rate of detection of AF or flutter lasting >2 minutes by 12 months (15.3% in the ILR group vs 4.7% in the prolonged ELR group).

Clinical Management

Al Qurashi et al.¹³ conducted a systematic review and meta-analysis to assess the efficacy of implantable cardiac monitors (ICMs) compared to a range of TNACMD in detecting post-stroke AF and the subsequent use of oral anti-coagulant therapy. The review included 3 RCTs of 1233 patients with any type of stroke and no prior AF or flutter. The ICM arm had significantly higher usage of oral anticoagulants as compared to the TNACMD arm. (RR = 2.76, 95% CI: 1.89, 4.02, P < 0.05). Limitations of this review included the small number of eligible studies and the need to assume the baseline characteristics of patients in all the included trials were similar.

Mortality, Stroke, Major Adverse Cardiac Events

A single systematic review and meta-analysis reported showed there were no significant differences between ICMs and TNACMD in the reduction of mortality (RR = 0.67, 95% CI: 0.31, 1.45; P = 0.42; I² = 0%) and in the recurrence of stroke (RR = 0.73, 95% CI: 0.48, 1.10; P = 0.14; I² = 0%).¹³

Healthcare Utilization

No studies found.

Undesired Effects

A systematic review with meta-analysis found ICM usage was associated with a higher incidence of mild to moderate adverse events (RR = 10.52, 95% CI:1.35, 82.14; P = 0.02) and a higher number of severe adverse events as compared to the use of TNACMD (RR = 7.61, 95% CI: 1.36, 42.51; P = 0.02).¹³

Effect Modifiers

Noubiap et al.¹⁷ performed a systematic review and meta-analysis that explored factors influencing AF detection rates. The reviewers found 1) a steady increase of AF rates with duration of monitoring; 2) higher rates of AF in patients with embolic stroke of undeter­mined source (ESUS) com­pared to those with cryptogenic stroke; and 3) the association of older age, CHA₂DS₂-VASc score, PA-TDI Interval, left atrial enlargement, P wave maximal duration, prolonged PR interval and atrial runs with higher rates of AF detection.

Comparison of Different Types of TNACMD

A network meta-analysis found that LTCM and ELR devices were equally effective in their ability to detect symptomatic cardiac arrhythmias.⁵

Reynolds et al.¹⁹ retrospectively analyzed the USA National Medicare claims data of 287,789 beneficiaries without a preceding established arrhythmia diagnosis. The aim of the study was to make comparisons among different device types (ELRs, LTCM, Holter, and MCT) across a range of outcomes. The device-specific analysis showed that compared to Holter, ELR, MCT, or other LTCM manufacturers, a specific LTCM (Zio® XT 14-day patch, iRhythm Technologies, San Francisco, CA) had the highest adjusted odds of AF detection and lowest adjusted odds of TNACMD retesting. Findings were consistent for specific arrhythmia diagnoses of ventricular tachycardia, atrioventricular block, and paroxysmal atrial fibrillation. The annualized all-cause inpatient hospitalizations during the follow-up period were lowest in the LTCM and Holter cohorts (mean = 0.45 stays for both cohorts), followed by the ELR and MCT cohorts (mean 0.60 stays for both cohorts). Annualized follow-ups for all-cause ED visits were lowest in the LTCM cohort (mean = 0.70 visits). Meanwhile, outpatient visits were lowest in the Holter and ELR cohorts (mean = 24.5 visits for both cohorts); however, patients in the LTCM cohort experienced the smallest increase in outpatient visits over baseline (mean change = 3.11 for the LTCM cohort). This study included limitations inherent in retrospective observational designs, the inability to adjust for the duration of monitoring, potential for industry funded bias (6 of 8 authors were affiliated with the sponsor), and the likelihood of confounding due to the influence of patient, provider, and system factors.

Summary of Main Results

Prolonged cardiac monitoring with TNACMD is more effective than SOC in the detection of AF in patients after stroke or TIA, or with symptoms associated with an increased risk of AF. For patients with the ability to comply with the use of TNACMD, a 30-day duration can capture a significant proportion of AF and should be considered in lieu of ILRs. Patients using TNACMD are more likely to receive guideline-concordant anti-coagulant treatment compared to those undergoing SOC. In contrast, individuals with ICMs are more likely to be prescribed timely anti-coagulant therapy than those wearing TNACMD. There were no significant differences between SOC, ICMs and TNACMD in the reduction of mortality, or the recurrence of stroke or TIA. The likelihood of AF detection steadily increases with the duration of monitoring and patient age. It is uncertain whether any type of TNACMD is clinically superior to other externally wearable devices.

Applicability of Evidence

The included studies were highly applicable to the Medicare beneficiary population. The largest study explicitly focused on the Medicare population. Most trials were multi-centered and took place in North America. The mean/median ages of participants ranged from 64.1 to 75 years. The included studies reported on multi-morbid patients.

Quality of Evidence

The overall certainty of evidence was rated as moderate for clinical, healthcare management/utilization, and undesirable effects outcomes. There were some concerns about the risk of bias (selection and performance bias). There was no serious indirectness, inconsistency, imprecision, or risk of publication bias.

The certainty of evidence for the comparative effectiveness of different TNACMD was judged to be very low (observational data, high risk of confounding, and the potential for industry funding bias).

Clinical Guidelines and Positions of National and Specialty Organizations

A total of 21 publications developed by 15 professional societies or agencies were identified to supplement the summary of evidence [Table 5].^27-47 These guidelines encompassed a broad range of disorders (stroke, TIA, cardiac arrhythmias, cardiac conduction delay, syncope, silent cerebrovascular disease, hypertrophic cardiomyopathy) and monitoring during AF ablation.

Collectively, there was a strong consensus in favor of extended cardiac monitoring in situations where AF cannot readily be diagnosed with standard ECG. There was limited explicit guidance regarding the optimal monitoring devices. Most guidance recommended that the frequency of symptoms should dictate the type of monitoring device. A single guideline proposed a clinical workflow commencing with continuous (short-term 24 hour and up to 7 days) ambulatory ECG monitoring, which if unsuccessful, is followed by intermittent external loop recording (long term from weeks to months). For those individuals remaining undiagnosed after prolonged noninvasive monitoring, ILR may be necessary.⁴¹

This analysis of evidence provides moderate certainty evidence that TNACMD demonstrate consistent improvements in diagnostic yield and clinical management without significant undesirable effects in patients who are representative of U.S. Medicare beneficiaries. TNACMD are as effective in detecting arrhythmias as ICM and have an increased the odds of atrial fibrillation detection as compared to monitoring for <48 hours. Professional guidelines include evidence-informed recommendations for the appropriate timing and the type of monitoring device in clinical practice. Consequently, this evidentiary review advises for the inclusion of TNACMD as reasonable and necessary for the detection of cardiac arrhythmias in appropriately selected patients.

Appendix

GRADE certainty of evidence classification scheme

Source: Schünemann H, Brozek J, Guyatt G, Oxman A, editors. GRADE handbook for grading quality of evidence and strength of recommendations. Updated October 2013. The GRADE Working Group, 2013. Available from guidelinedevelopment.org/handbook.

GRADE Domains

ACIP GRADE Handbook for Developing Evidence-based Recommendations: Formulating questions, conducting the systematic review, and assessing the certainty of the evidence using GRADE. Chapter 8: Domains Decreasing Certainty in the Evidence. Updated April 22, 2024; U.S. Centers of Disease Control and Prevention: ACIP GRADE Handbook.

Tables

Table 1. Characteristics of systematic reviews with or without meta-analysis

AF = atrial fibrillation; AFL = atrial flutter; CS = cryptogenic stroke; ECG = electrocardiogram; ELR = external loop recorder; ESUS = embolic stroke of undetermined source; ILR = implantable loop recorder; MCOT = mobile cardiac outpatient telemetry; MCT = mobile cardiovascular telemetry; N/R = not reported; NRSI = non-randomized study of an intervention; RCT = randomized controlled trial; SOC = standard of care; TIA = transient ischemic attack

Table 2. Findings of systematic reviews with or without meta-analysis

AE = adverse events; AF = atrial fibrillation; AFL = atrial flutter; CI = confidence interval; CS = cryptogenic stroke; ECG = electrocardiogram; ELR = external loop recorder; ESUS = embolic stroke of undetermined source; ILR = implantable loop recorder; MCOT = mobile cardiac outpatient telemetry; MCT = mobile cardiovascular telemetry; N/R = not reported; NRSI = non-randomized study of an intervention; OAC = oral anti-coagulants; OR = odds ratio; RCT = randomized controlled trial; SOC = standard of care; SMD = standardized mean difference; TIA = transient ischemic attack; USPSTF = U.S. Preventative Services Task Force

Table 3. Characteristics of randomized controlled trials

AE = adverse events; AF = atrial fibrillation; AFL = atrial flutter; COI = conflicts of interest; ECG = electrocardiogram; ECM = external cardiac monitor; ELR = external loop recorder; ICM = implantable cardiac monitor; ILR = implantable loop recorder; LTCM = long term cardiac monitor; MCOT: mobile cardiac outpatient telemetry; N/R = not recorded; POAF = postoperative atrial fibrillation PPM = permanent pacemaker; SOC = standard of care; VAS = visual analog scale

Table 4. Findings of randomized controlled trials

AE = adverse events; AF = atrial fibrillation; AFL = atrial flutter; CAM = Carnation Ambulatory Monitor; CI = confidence interval; ECG = electrocardiogram; ED = emergency department; ELR = external loop recorder; ILR = implantable loop recorder; MI = myocardial infarction; OAC = oral anti-coagulants; NV = NUUBO vest; PAF = paroxysmal atrial fibrillation; ROB = risk of bias; RT = Novacor ‘R’ Test 4 event monitor; SOC = standard of care; TIA = transient ischemic attack; ZM = ZIO XT monitor

Table 5. Summary of clinical practice guidelines by professional society

AECG = ambulatory electrocardiograph; AEM = ambulatory event monitor; AF = atrial fibrillation; EAEM = external ambulatory event monitor; ECG = electrocardiograph; HCM = hypertrophic cardiomyopathy; ICM = implantable cardiac monitor; N/A =not applicable; N/S = not stated; NSVT = non-sustained ventricular tachycardia; PVCs = premature ventricular contractions; TIA = transient ischemic attack; VA = ventricular arrhythmia; VT = ventricular tachycardia

N/A

N/A

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