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Completed

NCT Number: NCT04905290

Conduction System Pacing Optimized Therapy

The purpose of the CSPOT study is to determine the best mode of cardiac resynchronization therapy (CRT) pacing for different populations of CRT patients, comparing traditional biventricular or left ventricular pacing (BiV), conduction system pacing (CSP)-only, and conduction system pacing optimized therapy (CSPOT) also known as a combination of conduction system pacing (CSP) and left ventricular (LV) pacing. Additionally, safety of the system will be assessed.

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Key information

Conditions

Heart Failure Cardiovascular Diseases Heart Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Beacon Hospital, Dublin, Ireland

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patient is willing and able to provide written informed consent
  • Subject is at least 18 years of age
  • Patient is willing and able to comply with the protocol, including follow-up visits
  • The patient's medical records must be accessible by the enrolling site over the follow-up period
  • Standard CRT-D or CRT-P indications, with a preference for IVCD and non-LBBB patients, where LBBB is defined according to Strauss criteria.
  • De-novo CRT implant, including upgrade from pacemaker or ICD

Exclusion criteria

  • Subject has persistent or permanent AF (Atrial Fibrillation)/AFL (Atrial Flutter)
  • Subject has 2nd or 3rd degree AV (Atrioventricular) Block
  • Subject has RBBB with no additional conduction block
  • Subject has intrinsic (non-paced) QRS width less than or equal to 120 ms
  • Subject experienced MI within 40 days prior to enrollment
  • Subject underwent valve surgery, within 90 days prior to enrollment
  • Subject is post heart transplantation or is actively listed on the transplantation list
  • Subject is implanted with a LV assist device
  • Subject has severe renal disease
  • Subject is on continuous or uninterrupted infusion (inotropic) therapy for heart failure
  • Subject has severe aortic stenosis (with a valve area of <1.0 cm or significant valve disease expected to be operated within study period)
  • Subject has severe aortic calcification or severe peripheral arterial disease
  • Subject has complex and uncorrected congenital heart disease
  • Subject has mechanical heart valve
  • Pregnant or breastfeeding woman (pregnancy test required for woman of child-bearing potential and who are not on a reliable form of birth regulation method or abstinence)
  • Subject is enrolled in another study that could confound the results of this study without documented pre-approval from Medtronic study manager

Treatment and study plan

Left ventricular coronary sinus (BiV) configuration

Device

For subjects with a pacemaker, pacing of the left ventricular coronary sinus only. For subjects with a defibrillator, biventricular pacing of the left ventricular coronary sinus and the right ventricle. During the acute protocol, the five AV delays for this intervention include the default AV delay setting, default + 30 milliseconds (ms) AV delay, default + 60 ms AV delay, default - 30ms AV delay, default - 60ms AV delay. Patients with a defibrillator will receive two additional delays LV precedes default by 30ms and LV precedes default by 60ms.

Conduction system pacing-only configuration

Device

Conduction System Pacing (CSP) of the left bundle branch. During the acute protocol, the five AV delays for this intervention include the default AV delay setting, default + 30 milliseconds (ms) AV delay, default + 60 ms AV delay, default - 30ms AV delay, and default - 60ms AV delay.

Conduction System Pacing Optimized Therapy (CSPOT) configuration

Device

A combination of Left Ventricle pacing and Conduction System Pacing of the left bundle branch. During the acute protocol, the eight delays for this intervention include the default AV delay setting, default + 30 milliseconds (ms) AV delay, default + 60 ms AV delay, default - 30ms AV delay, default - 60ms AV delay, CSP precedes default by 30ms, LV precedes default by 30ms and LV precedes default by 60ms.

Primary outcomes

  1. Electrical Synchronization Response

    Time frame: At implant during acute protocol

    Standard Deviation of Activation Times (SDAT) is a measurement of dyssynchrony, taken by the ECG belt. As described in the SDAT Acute Protocol (below) and intervention sections, percent change in SDAT from AV-only pacing was calculated for each patient-pacing configuration combination over the 5 AV delays. Within each patient the difference between CSPOT SDAT and CSP SDAT and the difference between CSPOT SDAT and BiV SDAT were taken. The mean of those differences across patients was calculated along with a 95% confidence interval.

  2. Hemodynamic Response

    Time frame: At implant during acute protocol

    Left Ventricular (LV) dP/dt max, a measurement of the initial velocity of myocardial contraction. As described in the LV dP/dt max (below) and intervention sections, percent change in LV dP/dt max from AV-only pacing was calculated for each patient-pacing configuration combination over the 5 AV delays. Within each patient the difference between CSPOT SDAT and CSP SDAT and the difference between CSPOT SDAT and BiV SDAT were taken. The mean of those differences across patients was calculated along with a 95% confidence interval.

Secondary outcomes

  1. Left Ventricular Ejection Fraction (LVEF)

    Time frame: Baseline and 6 months

    Left ventricular ejection fraction will be measured, based on echocardiography, at the baseline visit and again at the 6-month follow-up visit. Change will be calculated as the value observed at baseline subtracted from the value observed at 6 months.

  2. Left Ventricular End Systolic Volume (LVESV)

    Time frame: Baseline and 6 months

    Left ventricular end systolic volume will be measured, based on echocardiography, at the baseline visit and again at the 6-month follow-up visit. The change will be calculated as difference between the 6-month and baseline values, divided by the baseline value.

  3. Clinical Composite Score (CCS)

    Time frame: 6 months

    The Clinical Composite Score (CCS) is a validated 3-level categorical variable that can take the values - Improved, Unchanged, or Worsened - at each follow-up visit. It is based on mortality, HF events, termination of device function, NYHA score, and patient global assessment. Briefly, the scoring system is as follows:

    • A patient is considered "worsened" if they die, demonstrate a worsened NYHA class, report at least moderately worsened heart-failure symptoms, or are hospitalized or permanently discontinue therapy because of or associated with worsening heart-failure
    • A patient is considered "improved" if they have not "worsened" and either demonstrate improvement in NYHA class or report at least moderately improved heart-failure symptoms
    • A patient is considered "stabilized" if they have not "worsened" or "improved"
    • A patient is considered "unavailable" if they did not complete 6-month visit and was not "worsened"

  4. Absolute Percent Change in SDAT by QRS Subgroup

    Time frame: At Implant during acute protocol

    Percent change in SDAT (as described in Primary Outcome 1: Arm/Group Description) by baseline QRS subgroup for each pacing configuration CSP, BiV, CSPOT during acute protocol at implant.

    The QRS subgroups were subjects with QRS width greater than 171ms and QRS width less than or equal to 171ms as measured by 12-lead ECG

  5. Absolute Percent Change in SDAT Split by Subjects With Pure LBBB and With Other Conduction Disorders

    Time frame: At Implant during acute protocol

    Percent change in SDAT (as described in Primary Outcome 1: Arm/Group Description) split by subjects with pure Left Bundle Branch Block (LBBB) and with other Conduction Disorders for each pacing configuration CSP, BiV and CSPOT during acute protocol.

  6. Absolute Percent Change in SDAT Split by Subjects With Ischemic Cardiomyopathy and Those With Non-Ischemic Cardiomyopathy

    Time frame: At Implant during acute protocol

    Absolute Percent change in SDAT (as described in Primary Outcome 1: Arm/Group Description) split by subjects with Ischemic Cardiomyopathy and those with Non-Ischemic Cardiomyopathy for each pacing configuration CSP, BiV and CSPOT during acute protocol.

  7. Percent Change in LV dP/dt Max Split by Subjects With Ischemic Cardiomyopathy and Those With Non-Ischemic Cardiomyopathy

    Time frame: At Implant during acute protocol

    Percent change in LV dP/dt max (as described in Primary Outcome 2: Arm/Group Description)split by subjects with Ischemic Cardiomyopathy and those with Non-Ischemic Cardiomyopathy for each pacing configuration CSP, BiV and CSPOT during acute protocol.

  8. Percent Change in LV dP/dt Max Split by Subjects With Pure Left Bundle Branch Block (LBBB) and With Other Conduction Disorders (NIVCD)

    Time frame: At Implant during acute protocol

    Percent change in LV dP/dt max (as described in Primary Outcome 2: Arm/Group Description) split by subjects with pure Left Bundle Branch Block (LBBB) and with other Conduction Disorders (NIVCD) for each pacing configuration CSP, BiV and CSPOT during acute protocol

  9. Improvement in LV dP/dt Max by QRS Subgroup

    Time frame: At Implant during acute protocol

    Percent change in LV dP/dt max (as described in Primary Outcome 2: Arm/Group Description) by QRS subgroup for each pacing configuration CSP, BiV and CSPOT during acute protocol. The QRS subgroups were subjects with QRS width greater than 171ms and QRS width less than or equal to 171ms as measured by 12-lead ECG

Sponsors and collaborators

Lead sponsor

Medtronic Cardiac Rhythm and Heart Failure

Industry

Registry information

Official study title

Conduction System Pacing Optimized Therapy Study

Acronym: CSPOT

Important dates

Study start
2021
Primary completion
2023
Study completion
2023
First posted
May 27, 2021
Registry last updated
Apr 15, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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