The LEADLESS II IDE Study for the Nanostim Leadless Pacemaker

The LEADLESS II IDE Study (Phase I): Safety and Effectiveness Trial for the Nanostim Leadless Pacemaker

Prospective, non-randomized, single-arm, international multicenter, clinical safety and effectiveness of a leadless pacemaker system in patients who are indicated for a VVIR pacemaker.

Following completion of enrollments in the IDE, patients will continue to be enrolled in the continued access phase of the study under the same protocol.

Study Overview

• Status: Completed
• Conditions: Bradycardia
• Intervention / Treatment: Device: Leadless Pacemaker

Detailed Description

The purpose of this study is to evaluate the safety and effectiveness of the leadless pacemaker system in treating patients with a slow heart rate or irregular heartbeats. The Nanostim leadless pacemaker provides bradycardia pacing as a pulse generator with built-in battery and electrodes, for permanent implantation in the right ventricle. As a leadless pacemaker, it does not need a connector, pacing lead, or pulse generator pocket, but it has the same operating principles as a conventional pacemaker.

• Study Type: Interventional
• Enrollment (Actual): 952
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Australia
  • Queensland
    • Chermside, Queensland, Australia
      • The Prince Charles Hospital
    • Woolloongabba, Queensland, Australia
      • Princess Alexandra Hospital
  • South Australia
    • Adelaide, South Australia, Australia
      • Royal Adelaide Hospital
• Canada
  • Quebec, Canada
    • Institut de Cardiologie de Quebec (Hospital Laval)
  • Alberta
    • Calgary, Alberta, Canada
      • Foothills Medical Centre
  • British Columbia
    • Vancouver, British Columbia, Canada
      • Vancouver General Hospital (U of BC)
  • Ontario
    • Kingston, Ontario, Canada
      • Kinsgston General Hospital
    • Newmarket, Ontario, Canada
      • Southlake Regional Health Centre
  • Quebec
    • Montreal, Quebec, Canada
      • Institut de Cardiologie de Montreal (Montreal Heart Inst.)
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35294
      • University Hospital - Univ. of Alabama at Birmingham
    • Huntsville, Alabama, United States, 35801
      • Heart Center Research, LLC.
  • California
    • La Jolla, California, United States, 92037
      • Scripps Health
    • Los Angeles, California, United States, 90033
      • USC University Hospital
    • Mountain View, California, United States, 94040
      • El Camino Hospital
    • Newport Beach, California, United States, 92663
      • Premier Cardiology, Inc
    • Pasadena, California, United States, 91105
      • Huntington Memorial Hospital
    • Redwood City, California, United States, 94303
      • Sequoia Hospital
    • Sacramento, California, United States, 95819
      • Mercy Medical Group - Cardiology
  • Colorado
    • Littleton, Colorado, United States, 80120
      • South Denver Cardiology Associates PC
  • Florida
    • Naples, Florida, United States, 34102
      • Naples Community Hospital
    • Orlando, Florida, United States, 32803
      • AdventHealth Orlando
    • Orlando, Florida, United States, 32806
      • Orlando Health
  • Georgia
    • Athens, Georgia, United States, 30306
      • Piedmont Athens Regional Medical Center
    • Rome, Georgia, United States, 30165
      • Redmond Regional Medical Center
  • Illinois
    • Chicago, Illinois, United States, 60637
      • University of Chicago
    • Oak Lawn, Illinois, United States, 60453
      • Advocate Christ Medical Center
  • Indiana
    • Fort Wayne, Indiana, United States, 46845
      • Parkview Research Center
  • Kansas
    • Kansas City, Kansas, United States, 66160
      • Kansas University Medical Center
  • Kentucky
    • Edgewood, Kentucky, United States, 41017
      • St. Elizabeth Medical Center
    • Lexington, Kentucky, United States, 40503
      • Baptist Health Lexington
  • Louisiana
    • New Orleans, Louisiana, United States, 70121
      • Ochsner Medical Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
    • Boston, Massachusetts, United States, 02111
      • Tufts Medical Center
    • Burlington, Massachusetts, United States, 01805
      • Lahey Clinic Medical Center
  • Michigan
    • Detroit, Michigan, United States, 48236
      • St. John Hospital and Medical Center
    • Lansing, Michigan, United States, 48910
      • Sparrow Research
    • Traverse, Michigan, United States, 49684
      • Munson Medical Center
    • Ypsilanti, Michigan, United States, 48197
      • Michigan Heart
  • Minnesota
    • Edina, Minnesota, United States, 55435
      • Fairview Southdale Hospital
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic
  • Missouri
    • Saint Louis, Missouri, United States, 63141
      • Mercy Hospital St. Louis
  • New Jersey
    • Neptune, New Jersey, United States, 07712
      • Jersey Shore University Medical Center
  • New York
    • New York, New York, United States, 10029
      • Mount Sinai Hospital
    • New York, New York, United States, 10021
      • New York Presbyterian Hospital/Cornell University
    • Roslyn, New York, United States, 11576
      • Cardiac Arrhythmia and Pacemaker Center
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke University Medical Center
    • Greensboro, North Carolina, United States, 27401
      • Cone Health Medical Group HeartCare
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • The Cleveland Clinic Foundation
    • Cleveland, Ohio, United States, 44106
      • University Hospitals of Cleveland
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73112
      • INTEGRIS Baptist Medical Center
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • University of Pittsburgh Medical Center
    • York, Pennsylvania, United States, 17405
      • WellSpan Health
  • Tennessee
    • Memphis, Tennessee, United States, 38104
      • Methodist University Hospital
  • Texas
    • Amarillo, Texas, United States, 79106
      • Clinical Tex Research, LLC
    • Houston, Texas, United States, 77380
      • Memorial Hermann Hospital
    • San Antonio, Texas, United States, 78201
      • South Texas Cardiovascular Consultants
  • Utah
    • Murray, Utah, United States, 84107
      • Intermountain Heart Rhythm Specialists
  • Virginia
    • Falls Church, Virginia, United States, 22031
      • Inova Fairfax Hospital
  • Wisconsin
    • Milwaukee, Wisconsin, United States, 53215
      • Aurora Medical Group

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Subject must have one of the clinical indications before device implant in adherence with Medicare, ACC/AHA/HRS/ESC single chamber pacing guidelines including:

   • Chronic and/or permanent atrial fibrillation with 2 or 3° AV or bifascicular bundle branch block (BBB block), including slow ventricular rates (with or without medication) associated with atrial fibrillation; or
   • Normal sinus rhythm with 2 or 3° AV or BBB block and a low level of physical activity or short expected lifespan (but at least one year); or
   • Sinus bradycardia with infrequent pauses or unexplained syncope with EP findings; and
2. Subject ≥18 years of age; and
3. Subject has life expectancy of at least one year; and
4. Subject is not enrolled in another clinical investigation; and
5. Subject is willing to comply with clinical investigation procedures and agrees to return for all required follow-up visits, tests, and exams; and
6. Subject has been informed of the nature of the study, agrees to its provisions and has provided written informed consent, approved by the IRB; and
7. Subject is not pregnant and does not plan to get pregnant during the course of the study.

Exclusion Criteria:

1. Subject has pacemaker syndrome, has retrograde VA conduction or suffers a drop in arterial blood pressure with the onset of ventricular pacing; or
2. Subject is allergic or hypersensitive to <1 mg of dexamethasone sodium phosphate; or
3. Subject has a mechanical tricuspid valve prosthesis; or
4. Subject has a pre-existing endocardial pacing or defibrillation leads; or
5. Subject has current implantation of either conventional or subcutaneous implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT); or
6. Subject has an implanted vena cava filter; or
7. Subject has evidence of thrombosis in one of the veins used for access during the procedure; or
8. Subject has an implanted leadless cardiac pacemaker; or
9. Subject had recent cardiovascular or peripheral vascular surgery within 30 days of enrollment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Leadless Pacemaker; VVIR pacing	Device: Leadless Pacemaker; Patients will undergo an attempted leadless pacemaker implant

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Complication-Free Rate	Complication is any device-or-procedure related serious adverse event, or serious adverse device effect, including those that prevented initial implantation. Percentage of participants free from complications are reported	6 months
Pacing Thresholds and R-wave Amplitudes Within the Therapeutic Range	Success Rate is percentage of subjects who have acceptable pacing threshold and sensing amplitudes, which are defined as pacing threshold <=2.0V at 0.4 ms pulse width and R-wave amplitude either =>5.0 mV at the 6 month visit or => value at implant.	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Appropriate and Proportional Rate Response During Graded Exercise Testing	Temperature-based rate response feature was evaluated to determine whether an appropriate and proportional rate response was achieved during maximal effort graded treadmill exercise testing protocol (CAEP). All capable subjects who have completed the 6-minute walk test (6MWT) were asked to perform a maximal effort CAEP exercise protocol to demonstrate an appropriate and proportional response of sensor-indicated rate in graded exercise tests. Data from subjects who have completed the 6MWT and have completed at least stage 3 of the CAEP exercise protocol, or 3.6 metabolic equivalent of task (METs), were included in the analysis.	3-6 months

Collaborators and Investigators

• Sponsor: Abbott Medical Devices
• Investigators: Principal Investigator: Vivik Reddy, MD, Mount Sinai Hospital

Publications and helpful links

General Publications

• Reddy VY, Miller MA, Knops RE, Neuzil P, Defaye P, Jung W, Doshi R, Castellani M, Strickberger A, Mead RH, Doppalapudi H, Lakkireddy D, Bennett M, Sperzel J. Retrieval of the Leadless Cardiac Pacemaker: A Multicenter Experience. Circ Arrhythm Electrophysiol. 2016 Dec;9(12):e004626. doi: 10.1161/CIRCEP.116.004626.
• Reddy VY, Exner DV, Cantillon DJ, Doshi R, Bunch TJ, Tomassoni GF, Friedman PA, Estes NA 3rd, Ip J, Niazi I, Plunkitt K, Banker R, Porterfield J, Ip JE, Dukkipati SR; LEADLESS II Study Investigators. Percutaneous Implantation of an Entirely Intracardiac Leadless Pacemaker. N Engl J Med. 2015 Sep 17;373(12):1125-35. doi: 10.1056/NEJMoa1507192. Epub 2015 Aug 30.

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2014
• Primary Completion (Actual): June 1, 2015
• Study Completion (Actual): July 15, 2022

Study Registration Dates

• First Submitted: January 6, 2014
• First Submitted That Met QC Criteria: January 6, 2014
• First Posted (Estimated): January 8, 2014

Study Record Updates

• Last Update Posted (Actual): July 9, 2025
• Last Update Submitted That Met QC Criteria: June 20, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Bradycardia
• Other Study ID Numbers: DC-02374

Drug and device information, study documents

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