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OpenTrials
Completed

NCT Number: NCT03089281

Strategic Management to Optimize Response To Cardiac Resynchronization Therapy

The primary objective is to evaluate the benefit of the SmartDelay™ algorithm in patients with a prolonged RV-LV interval.

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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

Institut universitaire de Cardiologie et de Pneumologie de Quebec, Québec, Canada

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About this study

The primary hypothesis of SMART CRT is that among cardiac resynchronization therapy defibrillator (CRT-D) patients with prolonged inrerventricular delay between the RV and LV leads, CRT with atrioventricular optimization (AVO) will result in greater reverse LV remodeling compared with CRT programmed at nominal settings (120 ms).

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Subject must be indicated to receive a de novo quadripolar Boston Scientific Cardiac Resynchronization Therapy Defibrillator (CRT-D) in conjunction with an ACUITY X4 LV lead. This includes subjects who are indicated to receive an upgrade to a BSC X4 CRT-D from a previously implanted device.
  • In order to achieve a homogenous population for the study, qualifying subjects are those with heart failure who meet BSC US indications for use defined as those subjects who receive stable optimal pharmacologic therapy (OPT) for heart failure and who meet any one of the following classifications:
  • Moderate to severe heart failure (NYHA Class III-IV) with EF ≤ 35% and QRS duration ≥ 120 ms
  • Left bundle branch block (LBBB) with QRS duration ≥ 130 ms, EF ≤ 30%, and mild (NYHA Class II) ischemic or nonischemic heart failure or asymptomatic (NYHA Class I) ischemic heart failure
  • Subject is age 18 or above, or of legal age to give informed consent specific to each country and national laws
  • Subject is willing and capable of providing informed consent
  • Subject is willing and capable of complying with visits and procedures as defined by this protocol

Exclusion criteria

  • Subjects with documented permanent complete AV block
  • Subjects with permanent or chronic atrial fibrillation (AF) or in AF at the time of enrollment
  • Subjects who have previously received cardiac resynchronization therapy with pacing in the left ventricle
  • Subjects on the active heart transplant list or who has or is to receive ventricular assist device (VAD)
  • Life expectancy shorter than 12 months due to any medical condition (e.g., cancer, uremia, liver failure, etc…)
  • Subject with a known or suspected sensitivity to dexamethasone acetate (DXA)
  • Subject is enrolled in any other concurrent clinical study, with the exception of local mandatory governmental registries and observational studies/registries, without the written approval from Boston Scientific
  • Women of childbearing potential who are or plan to become pregnant during the course of the trial
  • Subjects currently requiring dialysis

Treatment and study plan

CRT-D

Device

Commercially approved quadripolar Boston Scientific Cardiac Resynchronization Therapy Defibrillator (CRT-D) devices and future generations of BSC X4 CRT-D devices approved by the appropriate regulatory bodies will be included in the trial. All devices utilized in the study will include SmartDelay™ and must be capable of providing SmartDelay recommendations for both biventricular pacing (BiV) and Left Ventricular (LV) only pacing. All enrolled subjects with implanted BSC X4 CRT-D system and identified with an RV-LV delay of ≥70ms were 1:1 randomized. Randomization occurred in the electronic data capturing system.

Primary outcomes

  1. CRT Response

    Time frame: Pre-Implant baseline to 6 months

    Comparing cardiac resynchronization therapy (CRT) response rates between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. A negative change in LVESV is considered an improvement; CRT response is defined by a change in Left Ventricular End Systolic Volume (LVESV) < -15% at 6 months compared to pre-implant baseline.

Secondary outcomes

  1. Change in Left Ventricular End Systolic Volume (Absolute Change)

    Time frame: Implant to 6 Months

    Comparing absolute changes in Left Ventricular End Systolic Volume from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 6-Month measurement - Implant measurement, in milliliters. A negative change in LVESV is considered an improvement.

  2. Change in Left Ventricular End Systolic Volume (Relative Change)

    Time frame: Implant to 6 Months

    Comparing relative changes in Left Ventricular End Systolic Volume from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 100*(6-Month measurement - Implant measurement)/(Implant Measurement), in %. A negative change in LVESV is considered an improvement.

  3. Change in Left Ventricular Ejection Fraction (Absolute Change)

    Time frame: Implant to 6 Months

    Comparing absolute changes in Left Ventricular Ejection Fraction from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 6-Month measurement - Implant measurement, in % of blood ejected during LV contraction. A positive change in LVEF is considered an improvement.

  4. Change in Left Ventricular Ejection Fraction (Relative Change)

    Time frame: Implant to 6 Months

    Comparing relative changes in Left Ventricular Ejection Fraction from Implant to 6 Months between AV Delay programming schemes defined by SmartDelay or a Fixed AV Delay of 120ms. Change is defined as 100*(6-Month measurement - Implant measurement)/(Implant Measurement), in %. A positive change in LVEF is considered an improvement.

  5. Clinical Composite Score (CCS)

    Time frame: Implant to 6 Months

    Th CCS combines four metrics: all-cause mortality, heart failure hospitalization (HFH), New York Heart Association (NYHA) Class, and quality of life as measured with the patient global assessment (GA) instrument.

    The CCS categorizes each subject into one of three groups: Improved, Unchanged or Worsened.

    • Improved: Subjects that survived without a HFH through the 6-month visit window and had either an improvement in NYHA class or responded to GA with "much better" or "very much better".
    • Unchanged: All patients that reached the end of 6-month visit window that were not categorized as either "Improved" or "Worsened".
    • Worsened: Subjects that died or had HFH within 6-month visit window or had either a worsening in NYHA class or responded to GA with "much worse" or "very much worse".

  6. Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Overall Summary Score

    Time frame: Implant to 6 Months

    The KCCQ is a disease-specific instrument for monitoring the health status and quality of life of subjects with congestive heart failure. It includes a total of 23 items that assess quality of life in the following domains: physical function, symptom frequency and severity, symptom stability, self-efficacy and knowledge, social function, and overall quality of life. These domains can be combined into a functional status summary score (derived from the physical function and symptom scales) and an overall summary score which combines the physical function, symptom, social function and quality of life domains.

    KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Other outcomes

  1. Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Social Limitation Score

    Time frame: Implant to 6 Months

    The KCCQ Social Limitation Domain quantifies the extent to which heart failure symptoms impair patients' ability to interact in a number of gender-neutral social activities.

    KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

  2. Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Quality of Life Score

    Time frame: Implant to 6 Months

    KCCQ Quality of Life Domain is designed to reflect patients' assessment of their quality of life, given the current status of their heart failure.

    KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

  3. Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Self-Efficacy Score

    Time frame: Implant to 6 Months

    KCCQ Self-efficacy Domain quantifies patients' perceptions of how to prevent heart failure exacerbations and manage complications when they arise. This scale is not included in the summary scores.

    KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

  4. Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Symptom Frequency Score

    Time frame: Implant to 6 Months

    KCCQ Symptom Domain quantifies the frequency of clinical symptoms in heart failure, including fatigue, shortness of breath, paroxysmal nocturnal dyspnea and patients' edema/swelling.

    KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

  5. Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Symptom Burden Score

    Time frame: Implant to 6 Months

    KCCQ Symptom Domain quantifies the burden of clinical symptoms in heart failure, including fatigue, shortness of breath, paroxysmal nocturnal dyspnea and patients' edema/swelling.

    KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

  6. Change in Kansas City Cardiomyopathy Questionnaire (KCCQ) Physical Limitation Score

    Time frame: Implant to 6 Months

    KCCQ Physical Function Domain measures the limitations patients experience, due to their heart failure symptoms, in performing routine activities. Activities are common, gender-neutral, and generalizable across cultures, while also capturing a range of exertional requirements.

    KCCQ scores have a minimum of 0 and a maximum of 100. Higher score indicates better quality of life.

Sponsors and collaborators

Lead sponsor

Boston Scientific Corporation

Industry

Registry information

Acronym: SMART CRT

Important dates

Study start
2017
Primary completion
2020
Study completion
2020
First posted
Mar 24, 2017
Registry last updated
Apr 5, 2022

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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