CurrentBluecross IdahoPolicy 2.02.32

Leadless Cardiac Pacemakers (Micra, Aveir)

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Medical necessity and coverage criteria for leadless single- and dual-chamber transcatheter pacing systems (Micra and Aveir) for Bluecross Idaho members; describes when devices are considered medically necessary, investigational, contraindications, and policy guidelines.

Policy Summary

PayerBluecross Idaho

PolicyLeadless Cardiac Pacemakers (Micra, Aveir) — medical necessity and coverage criteria for single- and dual-chamber transcatheter pacing systems

Policy CodePolicy 2.02.32

Change TypeNo material changes (routine review)

Effective DateMay 28, 2026

Last ReviewMay 28, 2026

Next Review DateMay 28, 2026

Key ActionDocument guideline-based indication and contraindication to conventional transvenous leads when requesting coverage or prior authorization.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

Micra, AveirDevices addressed

99.2%Implant success (IDE)

96.0%Freedom from major complications (6 mo)

1.6%Cardiac perforation rate

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CurrentBluecross IdahoPolicy 2.02.32

Leadless Cardiac Pacemakers (Micra, Aveir)

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Sign up for Bluecross Idaho Policy 2.02.32 alerts

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Policy Summary

PayerBluecross Idaho

PolicyLeadless Cardiac Pacemakers (Micra, Aveir) — medical necessity and coverage criteria for single- and dual-chamber transcatheter pacing systems

Policy CodePolicy 2.02.32

Change TypeNo material changes (routine review)

Effective DateMay 28, 2026

Last ReviewMay 28, 2026

Next Review DateMay 28, 2026

Key ActionDocument guideline-based indication and contraindication to conventional transvenous leads when requesting coverage or prior authorization.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

Micra, AveirDevices addressed

99.2%Implant success (IDE)

96.0%Freedom from major complications (6 mo)

1.6%Cardiac perforation rate

1.51%30‑day PAR major complication

Medical Necessity and Coverage Criteria

Single-chamber (Micra VR / Aveir single-chamber) medical necessity

Covered when BOTH of the following are met:

Primary clinical indication: The individual has high-grade atrioventricular (AV) block in the presence of atrial fibrillation or has significant bradycardia and: (a) normal sinus rhythm with rare episodes of 2° or 3° AV block or sinus arrest; OR (b) chronic atrial fibrillation; OR (c) severe physical disability.

See Policy Guidelines for definitions of ‘high-grade AV block’ and ‘severe physical disability'.

Contraindication to conventional leads: The individual has a significant contraindication precluding placement of conventional single-chamber ventricular pacemaker leads such as: history of an endovascular or CIED infection or high infection risk; limited transvenous access due to venous anomaly or occlusion or planned use of veins for a semi-permanent catheter or planned/current use of an arteriovenous fistula for hemodialysis; presence of or risk of tricuspid valve replacement or severe tricuspid regurgitation.

Examples listed in Policy Guidelines.

Single-chamber AV (Micra AV) medical necessity

Covered when BOTH of the following are met:

Primary clinical indication: The individual has high-grade AV block in the presence of atrial fibrillation or has significant bradycardia and: (a) normal sinus rhythm with rare episodes of 2° or 3° AV block or sinus arrest; OR (b) chronic atrial fibrillation; OR (c) severe physical disability; OR (d) there is an indication for VDD pacing and the individual may benefit from maintenance of AV synchronous ventricular pacing.

Micra AV supports VDD pacing; see Policy Guidelines.

Contraindication to conventional leads: The individual has a significant contraindication precluding placement of conventional single-chamber ventricular pacemaker leads such as: history of an endovascular or CIED infection or high infection risk; limited transvenous access (venous anomaly/occlusion, planned use of veins for catheter/AV fistula); presence of or risk of tricuspid valve replacement or severe tricuspid regurgitation.

Dual-chamber (Aveir DR) medical necessity

Covered when BOTH of the following are met:

Primary clinical indication: The individual exhibits any of: sick sinus syndrome; chronic, symptomatic second‑degree or third‑degree AV block; recurrent Adams‑Stokes syndrome; or symptomatic bilateral bundle branch block when tachyarrhythmia and other causes have been ruled out.

Contraindication to conventional dual‑lead systems: The individual has a significant contraindication precluding placement of conventional dual‑chamber pacing system leads such as: history of an endovascular or CIED infection or high infection risk; limited transvenous access (venous anomaly/occlusion, planned use of veins for catheter/AV fistula); presence of or risk of tricuspid valve replacement or severe tricuspid regurgitation.

Medical eligibility despite conventional eligibility (lifestyle/anatomic reasons)

Alternate coverage when ANY of the following apply:

Lifestyle/anatomic reasons: Micra and Aveir single‑chamber and Aveir DR dual‑chamber systems are considered medically necessary in individuals who are medically eligible for conventional pacing but, because of lifestyle or anatomic reasons, leadless pacing is directed (for example, limited or occluded venous access; active patients in whom avoiding lead/pocket morbidity is clinically valuable).

See Policy Guidelines for examples.

Intended clinical use and regulatory-backed indications

Covered when device use aligns with guideline‑based indications and FDA‑approved device indications:

Regulatory/device‑specific indications: Device selection should align with FDA‑approved indications: Micra for single‑chamber ventricular pacing (Micra AV for AV synchronous pacing); Aveir VR/DR for approved single‑ and dual‑chamber bradycardia indications per PMA approvals and supplements.

See PMA approvals and regulatory status.

Patient clinical indication: The individual has a class I or II guideline‑based indication for implantation of a single‑chamber ventricular pacemaker (or dual‑chamber where Aveir DR indications apply).

Leadless systems are framed as an alternative for individuals meeting guideline indications.

Initial device coverage

Covered when ALL of the following are met:

Eligibility for leadless single‑chamber ventricular pacemaker: Patient has a class I or II guideline‑based indication for implantation of a single‑chamber ventricular pacemaker and is medically eligible to receive a conventional pacing system.

Source: clinical context and populations.

Device type and intent: Therapy considered is a single‑chamber transcatheter (leadless) ventricular pacing system (e.g., Micra or Aveir) intended as an alternative to a conventional single‑chamber pacemaker.

Source: interventions and comparators.

Reported device performance and safety benchmarks

Performance and effectiveness benchmarks reported in trials and registries:

Micra AV performance: In the Micra AV intended‑use population, 1‑month resting atrioventricular synchrony (AVS) was 85.4% (median 90%), with 85.2% of patients achieving >70% resting AVS; 24‑hour ambulatory AVS averaged 74.5%.>70% resting AVS often achieved

AVS measured per study definitions at 1 month; clinical benefit threshold is not fully defined.

Micra AV safety (registry): In a 12‑month Micra AV post‑approval registry (N=801) implantation success was 99.4% and the 12‑month major complication rate was 3.7% versus 8.8% in a historical transvenous comparator; system revision was 1.5% with a projected median battery longevity ~12 years reported.12‑month major complication rate ~3.7%

Registry nonrandomized; limitations include historical comparator and variable follow‑up.

Aveir pivotal outcomes:

The Micra™ and Aveir™ leadless transcatheter pacing systems are considered investigational for any clinical situation that does not meet the specific medical necessity criteria listed in this policy. Requests for implantation outside the enumerated indications (single‑ or dual‑chamber criteria, contraindication or lifestyle/anatomic rationale for avoiding conventional transvenous systems) should be treated as investigational and may be denied.

This policy does not necessarily apply to all Blue Cross lines of business. Benefit exceptions may exist for programs such as the Federal Employee Program, Medicare Supplement, Medicare Advantage, Medicaid, and certain self‑insured groups; plan‑level benefit terms and applicable federal/state mandates determine final coverage.

The evidence base summarized in this policy is derived primarily from nonrandomized and single‑arm studies of marketed leadless devices. Patients, device models, or indications that were not represented in the selected studies (for example, populations excluded from the systematic reviews or small single‑arm cohorts) are outside the direct evidence base and therefore the policy’s conclusions may not generalize to those situations.

Long‑term device performance and management at end‑of‑life remain incompletely characterized. The pivotal and postapproval literature note inadequate data on long‑term safety, device reliability, incidence of late device failures, and battery longevity, and limited clinical experience with retrieval or management of multiple co‑implanted devices, which constrain definitive long‑term assurances of device durability.

Available studies provide limited follow‑up regarding chronic outcomes. There is limited evidence on long‑term safety, effectiveness, and device reliability, and sparse data on the incidence of late device failures and clinical experience with device retrieval at end‑of‑life; these limitations temper conclusions about long‑term risk and benefit.

Within the cited excerpts there are no additional explicit policy exclusions beyond those already stated; outcome tables and trial summaries report safety and performance metrics but do not provide further exclusion language.

The provided outcome summaries and registries in these excerpts do not state additional explicit coverage exclusions; the text focuses on device performance metrics and adverse event counts.

In these outcome‑focused excerpts there are no explicit coverage exclusions identified; the content is limited to clinical results, complication counts, and follow‑up statistics rather than exclusion criteria.

No explicit coverage exclusions are stated in this excerpt; the material summarizes trial and registry performance (e.g., device success, complication rates) without delineating additional exclusionary policy language.

The provided excerpt does not list specific policy exclusions; it presents postapproval experience and complication incidence estimates rather than explicit exclusion statements.

Use of Micra and Aveir devices for indications that are not specified as medically necessary by this policy (i.e., uses outside the listed device‑ and indication‑specific criteria) is considered investigational and may not meet coverage criteria.

The policy framework disfavors adoption of devices or indications that lack methodologically credible evidence. Where controlled comparative trials or adequate single‑arm longer‑term studies are absent, use of those technologies is considered unsupported by the selected evidence and is discouraged.

These excerpts do not contain explicit 'not medically necessary' determinations; instead they provide trial and registry outcome data without translating those findings into additional negative coverage statements.

Published series of Micra implantation after cardiac surgery and valve interventions are small and heterogeneous. Available reports note events including rehospitalization and mortality in early follow‑up and the authors conclude that more evidence is needed to determine safety in the immediate post‑operative or post‑intervention period, indicating uncertainty about routine safety in this setting.

No explicit 'not medically necessary' statements are present in these outcome tables and summaries; the text reports event rates and confidence intervals without authoring policy‑level negative determinations.

These excerpts do not include explicit 'not medically necessary' language; they present device performance and complication statistics drawn from trials and registries.

Not addressed in the provided excerpt.

Coding and Device Technical Specs

Coding referencemixed

See Codes table

Document references a Codes table for details; codes not contained in this excerpt.

Femoral introducer sheath size — 7.8 mm (23 French)

Femoral introducer sheath size7.8 mm (23 French)

ContextRequired femoral venous anatomy to accommodate a 7.8 mm (23 French) introducer sheath for right‑sided implant

ImplicationAnatomies unable to accommodate this sheath are listed as contraindications per FDA labeling

Micra telemetry distance — < 12.5 cm (4.9 in)

Micra telemetry distance< 12.5 cm (4.9 in)

ContextMorbid obesity that prevents telemetry communication within <12.5 cm is a contraindication per FDA label

Prior Authorization, Documentation, and Operational Steps

Prior Authorization

Prior authorization & coding — follow policy Codes table

Preauthorization is implied by the policy’s coding section: “See the Codes table for details.” Providers should follow the policy and applicable Codes table when submitting claims and authorizations.

Reference the policy Codes table when preparing authorization and billing submissions.

Prior Authorization

Plan may require prior authorization

Plans retain responsibility for determining benefit coverage and may require prior authorization; BCBSA medical reference guidance does not supersede plan‑specific rules or federal/state mandates.

Verify member’s line of business and any plan‑level prior authorization requirements before scheduling implant.

Clinical Background and Evidence Summary

Leadless transcatheter pacemakers such as Micra and Aveir deliver ventricular pacing without transvenous leads or a subcutaneous generator pocket. These devices provide single‑ or dual‑chamber ventricular pacing options and can avoid lead‑ and pocket‑related complications, making them an alternative for patients with infection risk, limited venous access, or specific anatomic or lifestyle considerations.

Reported device performance and safety benchmarks — pivotal trials and registries

Summary of pivotal trial and registry performance benchmarks:

Micra AV AVS benchmarks: Micra AV achieved resting AVS ~85% at 1 month with >70% resting AVS in ~85% of intended‑use patients; ambulatory AVS averaged ~74.5% at 1 month.>70% resting AVS

Derived from Micra AV IDE and post‑approval registry data.

Micra AV registry safety: 12‑month registry data: implantation success 99.4%; major complication rate 3.7% and lower system revision rate versus historical transvenous dual‑chamber pacemakers.12‑month major complication rate ~3.7%

Definitions and Outcome Measures

VDD pacing — definition and purpose

DefinitionVDD pacing senses both atrial and ventricular activity while pacing only the ventricle

PurposePreserves atrioventricular (AV) synchrony to reduce pacemaker syndrome and support coordinated contraction

Device exampleMicra AV supports VDD pacing by mechanically sensing atrial activity

High-grade AV block and AV synchrony — definition and relation to device function

DefinitionHigh‑grade AV block: advanced second‑degree (high‑degree) or third‑degree AV conduction impairment where atrial signals fail to conduct appropriately

Relation to AV synchronyDevices that maintain AV synchrony sense atrial activity and pace the ventricle to preserve coordinated contraction and reduce pacemaker syndrome

Policy Revision History

2026-05-28policy_effective/last_reviewLatest

Policy MP 2.02.32 (Leadless Cardiac Pacemakers) effective and last reviewed on 2026-05-28; Plan-level coverage determinations remain subject to applicable law and member benefit terms.

Policy Summary

PayerBluecross Idaho

PolicyLeadless Cardiac Pacemakers (Micra, Aveir) — medical necessity and coverage criteria for single- and dual-chamber transcatheter pacing systems

Policy CodePolicy 2.02.32

Change TypeNo material changes (routine review)

Effective DateMay 28, 2026

Last ReviewMay 28, 2026

Next Review DateMay 28, 2026

Key ActionDocument guideline-based indication and contraindication to conventional transvenous leads when requesting coverage or prior authorization.

SourceLink

On This Page

In the Aveir IDE pivotal trial the 6‑week freedom from device‑or‑procedure‑related complications was 96% (95% CI, 92.2%–98.2%); composite success at 6 weeks 95.9%; and cardiac perforation/tamponade/pericardial effusion rate 1.5%.

meets pre‑specified performance goals in IDE trial

Long‑term safety and end‑of‑life device management data remain limited.

Distance refers to ability to establish telemetry between external programmers and implanted Micra device

STS predicted operative risk thresholds

High risk (STS) or heart teamSTS predicted operative risk ≥ 8% OR judged by heart team to have expected mortality ≥ 15% for open surgery

Intermediate riskSTS predicted risk of mortality between 3% and 7%

ReferenceFDA definition cited in policy for intermediate/high risk assessment

Verify guideline‑based clinical indication

Prior authorization requests should document that the patient meets a class I or II guideline‑based indication for single‑chamber ventricular pacing and that device selection (leadless vs conventional) and intent for single‑chamber pacing are appropriate.

Confirm and document guideline‑based indication (e.g., high‑grade AV block, symptomatic bradycardia).
Document that the patient is medically eligible for conventional pacing but meets criteria for a leadless system per policy.

Prior Authorization

No explicit prior‑auth code lists provided

The document does not provide an explicit list of payer prior authorization codes or a standardized prior authorization form; no payer code lists are specified in the text.

Use plan‑specific prior authorization tools and the policy Codes table where available.

Prior Authorization

Confirm indication and device suitability in prior authorization

When requesting authorization, confirm the patient meets guideline‑based indications for the specific leadless device (e.g., Micra VR/AV or Aveir) and document device suitability and intended pacing mode.

State device model and justification (Micra VR, Micra AV for VDD/AVS, Aveir VR/DR where applicable).
Include any device‑specific suitability considerations and anticipated follow‑up plan.

Prior Authorization

No other prior‑auth requirements specified

No additional prior authorization requirements are specified within the provided sections of the policy.

Follow plan‑level requirements where applicable; the policy’s content here focuses on clinical criteria and outcomes.

Step Therapy

Step requirement — reserve leadless devices for qualifying patients

The policy requires leadless devices to be reserved for individuals who meet the device‑specific medical necessity criteria and who have contraindications to conventional transvenous systems or have lifestyle/anatomic reasons directing leadless use.

Document that both the clinical indication and a contraindication to conventional leads (or lifestyle/anatomic reason) are present per policy.

Note

Therapy purpose — alternative to conventional single‑chamber pacemaker

The therapeutic purpose is to provide an alternative to a conventional single‑chamber ventricular pacemaker for patients with class I or II guideline indications.

Include rationale comparing leadless therapy to conventional single‑chamber pacing in clinical documentation.

Note

Comparator — conventional single‑chamber pacemaker

Comparative therapy is the conventional single‑chamber transvenous pacemaker; consideration of conventional system candidacy should be part of preimplant assessment and documentation.

Document why a conventional single‑chamber pacemaker is unsuitable when selecting leadless therapy.

Step Therapy

Document non‑suitability of transvenous system

Providers should document why a transvenous system is unsuitable when choosing leadless pacing (for example: prior CIED infection, venous occlusion, need to preserve veins for dialysis access, or high infection risk).

Explicitly state the contraindication(s) to conventional transvenous leads in the chart and authorization submission.

Documentation Required

Required clinical documentation — support qualifying indications

Clinical documentation must support qualifying indications (e.g., high‑grade AV block, symptomatic bradycardia, sick sinus syndrome), evidence of contraindication to transvenous leads, and relevant risk factors.

Include diagnosis, guideline indication class, history of CIED infection or infection risk factors, venous access status, and rationale for leadless device selection.

Documentation Required

Document medical necessity and benefit exceptions

Documentation should also reflect benefit/coverage considerations tied to the member’s plan and note any applicable federal/state mandates or line‑of‑business exceptions.

Confirm and document the member’s line of business and any plan‑specific coverage rules or federal/state mandates affecting coverage.

Documentation Required

Required documentation elements for authorization & claims

Include indication consistent with class I or II guideline‑based criteria, implant procedure details, and follow‑up plans including pacing capture thresholds and complication monitoring.

Provide implant procedure note, device model, pacing mode, intraoperative thresholds, and planned follow‑up assessments (e.g., 6‑month PCT assessment).

Documentation Required

Postapproval data collection may require submission of clinical details

Postapproval study procedures outlined for Micra require collection of clinical data when a subsequent device is placed and Micra is deactivated or explanted; implanting centers may be contacted per protocol.

Be prepared to provide clinical data to manufacturer or registry if device revision or explant occurs as part of postapproval commitments.

Documentation Required

Required clinical documentation for implant

For implant requests, document indication for single‑chamber pacing or AV synchrony need, candidacy assessment for leadless versus transvenous systems, perioperative risk assessment, and informed consent addressing device‑specific risks.

Include discussion of perioperative risks (e.g., perforation, vascular access complications, thromboembolism), device retrieval considerations, and planned programming/AVS assessment.

Denial Risk

Investigational uses may be denied

Requests for leadless pacemakers that do not meet the policy’s stated medical necessity criteria are considered investigational and may be denied.

Ensure documented clinical indications and contraindications align with policy criteria to avoid investigational determinations.

Denial Risk

Plans determine final coverage and medical necessity

Plan‑level coverage determinations govern final benefit decisions; providers should confirm coverage with the member’s plan because the policy does not override plan terms or legal mandates.

Obtain plan confirmation of coverage and any required authorizations prior to implant.

Note

Benefit exceptions may alter coverage

Benefit exceptions may apply for certain lines of business (for example, Federal Employee Program, Medicare Supplement/Advantage, Medicaid); verify whether exceptions affect coverage or prior authorization requirements.

Confirm whether the member’s line of business has special rules or exceptions before proceeding.

Denial Risk

Indication mismatch — risk of noncoverage if criteria not met

Use of leadless pacemakers in patients without a class I or II guideline‑based indication who are nevertheless medically eligible for a conventional transvenous pacemaker may not be supported by the evidence reviewed and could lead to denial.

Document why a leadless system is chosen when the patient is medically eligible for a conventional device.

Denial Risk

Document procedural risks — complications may trigger detailed review

High rates of early procedural complications and device‑related adverse events reported in postapproval and MAUDE analyses mean detailed documentation of risks, procedural assessment, and informed consent may be required and lack of supporting documentation could prompt detailed review or denial.

Document informed consent discussing risks such as cardiac perforation/tamponade, access site complications, thromboembolism, and device‑specific adverse events.

Nonrandomized registry; historical comparator limitations.

Aveir IDE performance: Aveir IDE met its 6‑week safety and efficacy endpoints with 96% freedom from device‑/procedure‑related complications and 95.9% composite success; cardiac perforation/pericardial effusion rate reported 1.5%.6‑week complication‑free rate ≥96%

Short‑term performance goals met; long‑term data limited.

Long‑term evidence gaps are a recurring theme in the background and evidence summaries. The literature highlights concerns about inadequate long‑term safety data, limited experience with device retrieval at end‑of‑life, and uncertainty about battery longevity and late device failures, all of which influence long‑term clinical management considerations.

Case series of leadless pacemaker implantation performed soon after cardiac surgery or valve procedures are small and report mixed outcomes. The available literature explicitly notes uncertainty regarding safety in the immediate post‑operative or post‑valve intervention setting and advises caution due to limited evidence.

Some outcome data summarized in systematic reviews and meta‑analyses (for example, pooled AV synchrony estimates and reported procedure‑related complications) are presented as clinical outcome information and are not directly linked to explicit coverage determinations in the provided excerpts.

Clinical noteFrequency of episodes and symptom severity guide need for pacing; infrequent episodes may not require implant

Conventional pacemaker — definition

DefinitionConventional pacemaker: a transvenous system with a pulse generator (subcutaneous/infraclavicular) and transvenous leads to sense and pace cardiac chambers

VariantsSingle‑chamber (one lead) or dual‑chamber (two leads: atrial and ventricular)

Clinical roleStandard alternative comparator to leadless systems; may be unsuitable in infection risk or limited venous access

Leadless pacemaker — definition

DefinitionLeadless pacemaker: a self‑contained capsule implanted directly in the heart via femoral venous access that houses battery and electronics and does not require transvenous leads or a subcutaneous pocket

FixationFixation methods differ by device (Micra uses nitinol tines; Aveir uses a screw‑in helix)

Clinical implicationAvoids lead‑ and pocket‑related complications but has limited long‑term retrieval and multiple‑device management data

Micra — device description and features

DeviceMicra — single‑chamber ventricular leadless pacemaker (Medtronic)

Key featuresProgrammable end‑of‑life deactivation; proximal retrieval feature for percutaneous snare removal; fixation via four nitinol tines; steroid eluting cathode

Intended useDelivered via femoral venous access and affixed in right ventricle; supports VDD mode in Micra AV model

Aveir — device description and features

DeviceAveir — single‑ and dual‑chamber leadless pacemaker family (Abbott)

Key featuresMapping capability for positioning; screw‑in helix fixation; designed for retrieval/replacement when therapy evolves

Intended useDelivered via femoral venous access and affixed in the right ventricle; Aveir DR provides dual‑chamber functionality in approved indications

Major complication (IDE and PAR definition)

DefinitionMajor complication: event resulting in death, permanent loss of device function due to mechanical/electrical dysfunction, hospitalization, prolonged hospitalization (≥48 h), or system revision (reposition, replacement, explant)

ContextThis IDE/PAR definition was used as the safety endpoint for the Micra pivotal trial

ImplicationMajor complications form the basis for trial performance goals (e.g., freedom from major complications >83% at 6 months)

Pacing capture threshold (PCT) — definition and relevance

DefinitionPacing capture threshold (PCT): the minimum energy (voltage) needed to capture myocardial tissue electrically

RelevanceLower PCT (<2.0 V) implies longer device longevity; efficacy endpoint in IDE trials required majority with adequate PCT

Trial useMicra IDE efficacy endpoint: adequate PCT in 98.3% at 6 months (≤2.0 V)

Atrioventricular synchrony (AVS) — percent of ventricular paced beats synchronized with atrial activity

DefinitionAtrioventricular synchrony (AVS): percent of ventricular paced beats that are synchronized with atrial mechanical activity

MeasurementMeasured by device markers (e.g., ventricular marker preceding a P wave within 300 ms) or correlated to ECG; reported as percent at rest or ambulatory over 24 hr

Clinical goalHigher AVS preserves coordinated contraction and may reduce pacemaker syndrome; Micra AV reported >70% resting AVS in most intended‑use patients

Composite success (Aveir IDE) — definition of composite effectiveness metric

DefinitionComposite success (Aveir IDE): a composite effectiveness metric including pacing capture thresholds and sensed R‑wave amplitude meeting prespecified criteria at 6 weeks

Trial performanceAveir IDE reported composite success of 95.9% at 6 weeks compared with performance goal of 85%

PurposeUsed to demonstrate device effectiveness alongside safety endpoints

Freedom from system- or procedure-related major complications — trial composite outcome definition

DefinitionFreedom from system‑ or procedure‑related major complications: the percentage of patients without such major complications at a specified timepoint (e.g., 6 weeks or 6 months)

Trial examplesAveir IDE: 96% freedom at 6 weeks; Micra IDE: 96.0% freedom at 6 months

UsePrimary safety endpoint in pivotal trials against predefined performance goals

Adequate pacing capture threshold — proportion meeting prespecified capture threshold

DefinitionAdequate pacing capture threshold: proportion of patients with capture thresholds meeting prespecified criteria (example: ≤2.0 V at 6 months)

Trial resultMicra IDE: 98.3% achieved ≤2.0 V at 6 months

SignificanceUsed as primary efficacy endpoint reflecting electrical pacing effectiveness and impact on battery longevity

TMCs — Total mechanical complications (counts and percent examples)

DefinitionTMCs: Total mechanical complications reported as event counts and percentages in trial/registry datasets

ExamplesMicra IDE: TMCs reported as 28 events in 25 patients (3.5%); other series report 32 TMCs in 29 patients (4.0%)

ContextTMCs include device‑ or procedure‑related mechanical adverse events such as dislodgement, groin site events, or device malfunction

Capture threshold — reported electrical threshold in volts at follow-up

DefinitionCapture threshold: electrical pacing capture threshold reported in volts at follow‑up (e.g., ≤2.0 V considered success in trials)

Reported valueMicra IDE: 98.3% of patients had ≤2.0 V at 6 months

ImplicationLower capture thresholds support device longevity and are a primary efficacy measure in IDE studies

TMCs — alternate chunk example of total mechanical complications

Example (alternate)TMCs reported as 32 TMCs in 29 patients (4.0%) in some postapproval datasets

ContextCounts vary across datasets and follow‑up intervals; reported alongside hospitalization and perforation events

UseUseful for comparing mechanical complication burden across cohorts and timepoints

TMCs — total major complications reported in registries (counts and % example)

Registry exampleTotal major complications reported in registries: e.g., TMCs 28 in 25 patients (3.5%) reported in IDE cohort; other series report 32 in 29 (4.0%)

ContextReported with other outcomes such as cardiac perforation (11 events, 1.6%) and hospitalizations

InterpretationRegistry TMC rates provide postapproval safety context but may reflect heterogeneous reporting

Prolonged hospitalization — hospitalization >=48 hours definition

DefinitionProlonged hospitalization: hospitalization lasting ≥48 hours as used in trial safety outcome definitions

Trial reportingMicra IDE reported prolonged hospitalization in 16 patients (2.6%) at 6 months

RoleIncluded within major complication composite (IDE/PAR definitions)

TMCs — total monitoring complications reported in postapproval experience

Postapproval reportingTMCs reported in postapproval experience (examples: 32 in 29 patients, 4.0%)

ComponentsIncludes events such as DVT, pulmonary thromboembolism, groin puncture site events, cardiac perforation, pacing issues, and others

ImplicationPostapproval TMC counts illustrate real‑world mechanical complication burden beyond IDE trial data

TMCs — reported 'TMCs: 32 in 29 patients (4.0)' statement

Reported statementTMCs: 32 in 29 patients (4.0%) reported in some datasets

ContextPresented alongside other outcome counts such as cardiac perforation (11 events, 1.6%) and hospitalizations

SourcePostapproval/registry summaries in the policy document

Prolonged hospitalization — hospitalization >=48 hours reported in outcomes

Example reportProlonged hospitalization (≥48 h) reported as 16 patients (2.6%) in Micra IDE at 6 months

ContextProlonged hospitalization is included in major complication composite used for safety endpoint

Clinical relevanceIndicator of more severe perioperative or device‑related adverse events

System revision — surgical/procedural revision of implanted leadless pacemaker system

DefinitionSystem revision: surgical or procedural revision of implanted leadless pacemaker system (reposition, replacement, explant)

Trial reportingMicra IDE reported system revision in 3 patients (0.4%) at 6 months

ImplicationSystem revision events constitute major complications in IDE/PAR definitions

Prolonged hospitalization — hospitalization >=48 hours as reported (counts/% )

Prolonged hospitalization (reported)Prolonged hospitalization (≥48 h) reported in outcomes as 16 patients (2.6%) in Micra IDE datasets

Use in summariesOften reported alongside hospitalization, system revision, and perforation counts

InterpretationUsed as indicator of severity in safety outcome composites

TMCs — term appears as 'TMCs' with counts; explicit definition not provided in these chunks

Term usageTMCs appears repeatedly with counts in multiple datasets (e.g., 13 in 12 patients; 28 in 25 patients; 32 in 29 patients)

Definition notePolicy text presents TMCs as 'Total mechanical complications' in some sections but does not always provide an explicit definition in every chunk

Reporting implicationCounts and percentages vary by study and follow‑up; interpret in study context

Chronic complications CIF Estimates — CIF estimates of chronic complications reported as percentages with 95% CIs

DefinitionChronic complications CIF estimates: cumulative incidence function estimates of chronic complications reported as percentages with 95% CIs

ExamplesOverall CIF: 7.1% (95% CI 6.7 to 7.6%); Device‑related complications: 5.2% (95% CI 5.1 to 5.3%)

ComponentsIncludes embolism/thrombosis (0.3%), pericarditis (0.9%), hemothorax (0.9%) with 95% CIs