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CompletedNCT02693262CLASSUpdated Aug 5, 2021Results posted

Comparing Rate Response With CLS Versus Accelerometer ICD Settings in Heart Failure Patients With BIOTRONIK CRT-Ds

An interventional study of CLS Mode on Biotronik CRT-D and Accelerometer Mode on Biotronik CRT-D in Heart Failure, ICD and Chronotropic Incompetence, sponsored by University of California, San Diego. Completed at 1 site in United States. Open to participants aged 18 Years to 99 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2021-08-05.

Sponsored by University of California, San Diego · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
12
Allocation
Randomized
Ages
18 Years to 99 Years
Sex
All
01

Study summary

Dr. Jonathan Hsu and Dr. Eric Adler are conducting a research study to find out more about how implantable cardiac defibrillator (ICD) settings can be adjusted to improve patient cardiovascular health and quality of life. Patients are being asked to participate in this study if they have a history of heart failure and have or are scheduled to be implanted with a BIOTRONIK ICD that is capable of closed loop stimulation (CLS). CLS is a device setting that works with the cardiovascular system to optimize their heart rate during physical activity. This study is comparing BIOTRONIK's CLS setting to a standard accelerometer setting, which also is able to adjust the heart rate by movement sensors, when necessary. This study has been initiated by Dr. Hsu and Dr. Adler and is financially supported by BIOTRONIK, Inc. There will be approximately 15 participants in this trial.

Read the detailed description

This study is a prospective, randomized, single-blind crossover study intended to enroll patients who are implanted or are scheduled to be implanted with a Biotronik CLS and accelerometer capable CRT-D device. Patients will serve as their own control group with regard to modes of rate-adaptive pacing. Patients with a previously implanted Biotronik CRT-D device with CLS-capability will be recruited from health care institutions in San Diego and all dedicated functional testing will be performed at the University of California, San Diego (UCSD). The goal enrollment target for analysis will be 15 patients, with up to 20 patients enrolled to allow for withdrawals.

The purpose of this study is to evaluate whether changes to an implanted ICD can improve the functional status of patients with suspected chronotropic incompetence (CI). CI is a condition in which the heart rate is unable to adequately respond to meet the patient's physical demands, such as walking, climbing stairs, or doing household chores. CI is common in patients with cardiovascular disease, particularly in patients with heart failure. Common clinical management of patients with suspected CI is to activate an accelerometer setting in the cardiac resynchronization therapy with defibrillator (CRT-D) device. An accelerometer will adjust the heart rate to fit the physiological circumstances and needs of the patient based on patient movement only. BIOTRONIK is a company that has developed a novel technology included in the settings for CRT-D devices that offers CLS as an alternative to a standard accelerometer. CLS utilizes sensed electrical properties of the heart in order to assess what may be the best heart rate for both physical and mental demands. This study is designed to compare whether patients will benefit from CLS when compared with standard accelerometer technology.

02

Conditions studied

  • Heart Failure
  • ICD
  • Chronotropic Incompetence

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Keywords

  • defibrillator
  • heart failure
  • ICD
  • CRT-D
  • cardiac resynchronization therapy
  • rate response
  • CLS
  • closed-loop stimulation
  • accelerometer
  • chronotropic incompetence
03

In context

Heart Failure

5,701 studies on the registry are indexed under Heart Failure; 1,220 are open to participants now.

This study's enrollment of 12 is below the median of 72 across 3,736 interventional studies indexed under Heart Failure.

Browse Heart Failure studies →

Lead sponsor

University of California, San Diego is the lead sponsor of 958 studies on the registry; 191 are open to participants now.

Of its 110 completed or terminated interventional studies of FDA-regulated products, 70 (64%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 99 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Patients with a BIOTRONIK CRT-D device (capable of CLS and accelerometer rate responsive pacing)
  • Patients at least 18 years old
  • Patients who have plausible symptoms of CI based on previous monitoring and clinical symptoms

Exclusion criteria

Exclusion Criteria:

  • Pregnant patients
  • Patients who are unwilling/unable to provide informed consent
  • Patients who are unable to complete study related procedures
  • Current persistent atrial fibrillation
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Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Single (Participant)
Enrollment
12 participants (actual)

Study arms

  • Experimental
    CLS Mode on Biotronik CRT-D

    All 15 patients will be randomized to this group. Their device will be set in the CLS mode for 1 week.

    Device: CLS Mode on Biotronik CRT-D

  • Active comparator
    Accelerometer Mode on Biotronik CRT-D

    All 15 patients will be randomized to this group. Their device will be set in the accelerometer rate responsive mode for 1 week.

    Device: Accelerometer Mode on Biotronik CRT-D

Interventions

  • DeviceCLS Mode on Biotronik CRT-D

    Setting changed and monitored. Quality of life evaluated through CPET, 6 Minute Walk Test, and Rand 36 Questionnaire.

  • DeviceAccelerometer Mode on Biotronik CRT-D

    Setting changed and monitored. Quality of life evaluated through CPET, 6 Minute Walk Test, and Rand 36 Questionnaire.

06

What researchers measure

Primary outcomes

  1. Six-minute Walk Distance (6MWD) Test

    Cardiovascular health benefits were measured by the six-minute walk distance (6MWD) test. The 6MWD is a standardized field test to evaluate functional exercise performance. Subjects are instructed to walk as far as possible in 6 min on a flat surface. This test was performed twice, once at the end of each intervention period.

    Time frame: Measured on day 14 and day 21.

  2. RAND-36 Questionnaire

    Quality of life of subjects was measured by the RAND-36 which is a generic 36-item questionnaire that measures eight health-related domains stratified by physical health (physical functioning, role limitations due to physical health, pain, and general health) and emotional health (vitality, role limitations due to emotional problems, social functioning, and mental health). Each scale is directly transformed into a 0-100 scale for a total score range of 0-800. Higher scores represent a more favorable health status. This test was performed twice, once at the end of each intervention period.

    Time frame: Performed on day 14 and day 21.

  3. Cardiopulmonary Exercise Testing (CPET)

    Cardiovascular health benefits were determined by measuring the peak heart rate (HR) during Cardiopulmonary exercise testing (CPET). The CPET is performed on a standard treadmill according to the Naughton protocol. During the test, patients inspired room air through a low-resistance mask, and expired oxygen and carbon dioxide partial pressures were measured with a gas analyzer. HR was recorded every 30 seconds during exercise. All patients were encouraged to exercise to maximal effort. This test was performed twice, once at the end of each intervention period.

    Time frame: Performed on day 14 and day 21.

  4. Patient Preference

    At the end of the study, patients were asked about personal preference regarding CLS over DDDR.

    Time frame: Performed on day 21.

07

Results

Posted Aug 5, 2021

Participant flow

Patients with HFrEF and CI implanted with a CRT-D capable of CLS programming at UCSD were eligible for this study. 102 patients were screened.

Participant flow — Overall Study
MilestoneCLS, Then DDDRDDDR, Then CLS
Started45
Completed45
Not completed00

Outcome measures

PrimarySix-minute Walk Distance (6MWD) Test

Cardiovascular health benefits were measured by the six-minute walk distance (6MWD) test. The 6MWD is a standardized field test to evaluate functional exercise performance. Subjects are instructed to walk as far as possible in 6 min on a flat surface. This test was performed twice, once at the end of each intervention period.

Time frame:
Measured on day 14 and day 21.
Reported as:
Mean · meters
Six-minute Walk Distance (6MWD) Test
metersCLS Mode on Biotronik CRT-DAccelerometer Mode on Biotronik CRT-D
Six-minute Walk Distance (6MWD) Test293.1 ± 90.2315.1 ± 95.5
PrimaryRAND-36 Questionnaire

Quality of life of subjects was measured by the RAND-36 which is a generic 36-item questionnaire that measures eight health-related domains stratified by physical health (physical functioning, role limitations due to physical health, pain, and general health) and emotional health (vitality, role limitations due to emotional problems, social functioning, and mental health). Each scale is directly transformed into a 0-100 scale for a total score range of 0-800. Higher scores represent a more favorable health status. This test was performed twice, once at the end of each intervention period.

Time frame:
Performed on day 14 and day 21.
Reported as:
Mean · score on a scale
RAND-36 Questionnaire
score on a scaleCLS Mode on Biotronik CRT-DAccelerometer Mode on Biotronik CRT-D
RAND-36 Questionnaire550.8 ± 123.9489.3 ± 164.9
PrimaryCardiopulmonary Exercise Testing (CPET)

Cardiovascular health benefits were determined by measuring the peak heart rate (HR) during Cardiopulmonary exercise testing (CPET). The CPET is performed on a standard treadmill according to the Naughton protocol. During the test, patients inspired room air through a low-resistance mask, and expired oxygen and carbon dioxide partial pressures were measured with a gas analyzer. HR was recorded every 30 seconds during exercise. All patients were encouraged to exercise to maximal effort. This test was performed twice, once at the end of each intervention period.

Time frame:
Performed on day 14 and day 21.
Reported as:
Mean · beats per minute
Cardiopulmonary Exercise Testing (CPET)
beats per minuteCLS Mode on Biotronik CRT-DAccelerometer Mode on Biotronik CRT-D
Cardiopulmonary Exercise Testing (CPET)110.7 ± 14.7109.7 ± 14.1
PrimaryPatient Preference

At the end of the study, patients were asked about personal preference regarding CLS over DDDR.

Time frame:
Performed on day 21.
Reported as:
Count of participants · Participants
Patient Preference
ParticipantsCLS Mode on Biotronik CRT-DAccelerometer Mode on Biotronik CRT-D
Patient Preference54

Adverse events

Collected over Patients were followed during the whole 3 week study period for any adverse events, assessed on day 0, day 7, day 14 and day 21.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
CLS Mode on Biotronik CRT-D0/9 (0%)0/9 (0%)0/9 (0%)
Accelerometer Mode on Biotronik CRT-D0/9 (0%)0/9 (0%)0/9 (0%)

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)All Study Participants
<=18 years0
Between 18 and 65 years1
>=65 years8
Age, Continuous
Age, Continuous(years)All Study Participants
Mean69 (63.5 to 76.5)
Sex: Female, Male
Sex: Female, Male(Participants)All Study Participants
Female4
Male5
Race/Ethnicity, Customized
Race/Ethnicity, Customized(Participants)All Study Participants
White6
Other3
Region of Enrollment
Region of Enrollment(Participants)All Study Participants
United States9
08

Study locations

1 site
  • Sulpizio Cardiovascular Center
    La Jolla, California 92037, United States
09

References and documents

Publications

  • Alt E. What is the ideal rate-adaptive sensor for patients with implantable cardioverter defibrillators: lessons from cardiac pacing. Am J Cardiol. 1999 Mar 11;83(5B):17D-23D. doi: 10.1016/s0002-9149(98)01038-8. PubMed 10089835 ↗
  • Epstein AE, DiMarco JP, Ellenbogen KA, Estes NA 3rd, Freedman RA, Gettes LS, Gillinov AM, Gregoratos G, Hammill SC, Hayes DL, Hlatky MA, Newby LK, Page RL, Schoenfeld MH, Silka MJ, Stevenson LW, Sweeney MO, Smith SC Jr, Jacobs AK, Adams CD, Anderson JL, Buller CE, Creager MA, Ettinger SM, Faxon DP, Halperin JL, Hiratzka LF, Hunt SA, Krumholz HM, Kushner FG, Lytle BW, Nishimura RA, Ornato JP, Page RL, Riegel B, Tarkington LG, Yancy CW; American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices); American Association for Thoracic Surgery; Society of Thoracic Surgeons. ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons. Circulation. 2008 May 27;117(21):e350-408. doi: 10.1161/CIRCUALTIONAHA.108.189742. Epub 2008 May 15. No abstract available. Erratum In: Circulation.2009 Aug 4; 120(5):e34-5. PubMed 18483207 ↗
  • Freedman RA, Hopper DL, Mah J, Hummel J, Wilkoff BL. Assessment of pacemaker chronotropic response: implementation of the Wilkoff mathematical model. Pacing Clin Electrophysiol. 2001 Dec;24(12):1748-54. doi: 10.1046/j.1460-9592.2001.01748.x. PubMed 11817808 ↗
  • Maass AH, Buck S, Nieuwland W, Brugemann J, van Veldhuisen DJ, Van Gelder IC. Importance of heart rate during exercise for response to cardiac resynchronization therapy. J Cardiovasc Electrophysiol. 2009 Jul;20(7):773-80. doi: 10.1111/j.1540-8167.2008.01422.x. Epub 2009 Feb 2. PubMed 19207785 ↗
  • Coenen M, Malinowski K, Spitzer W, Schuchert A, Schmitz D, Anelli-Monti M, Maier SK, Estlinbaum W, Bauer A, Muehling H, Kalscheur F, Puerner K, Boergel J, Osswald S. Closed loop stimulation and accelerometer-based rate adaptation: results of the PROVIDE study. Europace. 2008 Mar;10(3):327-33. doi: 10.1093/europace/eun024. Epub 2008 Feb 13. PubMed 18272507 ↗
  • Tse HF, Siu CW, Lee KL, Fan K, Chan HW, Tang MO, Tsang V, Lee SW, Lau CP. The incremental benefit of rate-adaptive pacing on exercise performance during cardiac resynchronization therapy. J Am Coll Cardiol. 2005 Dec 20;46(12):2292-7. doi: 10.1016/j.jacc.2005.02.097. PubMed 16360061 ↗
  • Keteyian SJ, Isaac D, Thadani U, Roy BA, Bensimhon DR, McKelvie R, Russell SD, Hellkamp AS, Kraus WE; HF-ACTION Investigators. Safety of symptom-limited cardiopulmonary exercise testing in patients with chronic heart failure due to severe left ventricular systolic dysfunction. Am Heart J. 2009 Oct;158(4 Suppl):S72-7. doi: 10.1016/j.ahj.2009.07.014. PubMed 19782792 ↗
  • Hsu JC, Darden D, Alegre M, Birgersdotter-Green U, Feld GK, Hoffmayer KS, Han F, Krummen D, Raissi F, Ho G, Taub PR, Urey MA, Adler E. Effect of closed loop stimulation versus accelerometer on outcomes with cardiac resynchronization therapy: the CLASS trial. J Interv Card Electrophysiol. 2021 Sep;61(3):479-485. doi: 10.1007/s10840-020-00829-4. Epub 2020 Aug 5. PubMed 32757086 ↗

Study documents

  • Protocol and statistical analysis plan · Mar 20, 2016

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 5, 2021, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT02693262
Lead sponsor
University of California, San Diego
Collaborators
Biotronik, Inc.
Responsible party
Jonathan Hsu (Assistant Professor of Medicine, University of California, San Diego) — Principal investigator
First posted
Feb 26, 2016
Start date
Jul 2016
Primary completion
Jul 24, 2020
Completion
Jul 24, 2020
Results posted
Aug 5, 2021
Last update
Aug 5, 2021

Study contacts

Jonathan Hsu, MD
principal investigator · University of California, San Diego

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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