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Completed

NCT Number: NCT03643224

DiamondTemp™ System for the Treatment of Persistent Atrial Fibrillation

The purpose of the Diamond-AF II study is to establish the safety and effectiveness of the DiamondTemp Ablation System for the treatment of drug refractory, symptomatic persistent atrial fibrillation in patients.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Southlake Regional Health Center, Newmarket, Ontario, Canada

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About this study

The DIAMOND-AF II Study is a prospective, non-randomized (single-group assignment) trial being performed at multiple centers in the United States, Canada and Europe to evaluate the safety and effectiveness of the DiamondTemp Ablation System for the treatment of patients with persistent atrial fibrillation.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Above eighteen (18) years of age or of legal age to give informed consent specific to state and national law.
  • Subjects with a history of documented symptomatic, persistent Atrial Fibrillation with 1) a physician's note documenting a continuous AF episode lasting longer than 7 days but less than 12 months AND 2) two electrocardiograms from any form of rhythm monitoring showing continuous AF taken at least 7 days apart OR a 24-hour Holter within 180 days of the ablation procedure showing continuous AF.
  • Refractory, intolerant or contraindicated to at least one Class I or III anti-arrhythmic (AAD) drug.
  • Suitable candidate for intra-cardiac mapping and ablation of arrhythmia.
  • Subject agrees to comply with study procedures and be available (geographically stable) for follow-up visits for at least 12 months after enrollment.
  • Subject is willing and able to provide written consent.

Exclusion criteria

At time of enrollment and/or prior to procedure:

  • Continuous AF >12 months (long-standing persistent AF)
  • Paroxysmal AF with longest episode <7 days
  • AF secondary to electrolyte imbalance, thyroid disease or reversible or non-cardiac cause
  • Rheumatic heart disease
  • Severe mitral regurgitation
  • Hypertrophic cardiomyopathy
  • LA diameter >5.5 cm
  • Left ventricular ejection fraction (LVEF) <40%
  • Currently NYHA Class III or IV or exhibits uncontrolled heart failure
  • Body Mass Index (BMI) >42 kg/m2.
  • LA ablation, septal closure device or mitral valve surgical procedure at any time prior to enrollment
  • Presence of intramural thrombus, tumor or abnormality that precludes vascular access, catheter introduction or manipulation
  • Coagulopathy, bleeding diathesis or suspected procoagulant state
  • Sepsis, active systemic infection or fever (>100.5 oF / 38 oC) within a week prior to the ablation procedure
  • Significant restrictive or obstructive pulmonary disease or chronic respiratory condition
  • Renal failure requiring dialysis or renal compromise that in the investigator's judgement would increase risk to the subject or deem the subject inappropriate to participate in the study.
  • Known allergies or intolerance to anticoagulant and antiplatelet therapies to be used in conjunction with the study or contrast sensitivity that cannot be adequately pre-treated prior to the ablation procedure.
  • Positive pregnancy test results for female subjects of childbearing potential or breast feeding.
  • Enrollment in a concurrent clinical study that in the judgement of the investigator would impact study outcomes.
  • Acute or chronic medical condition that in the judgment of the investigator would increase risk to the subject or deem the subject inappropriate to participate in the study.
  • Life expectancy <12 months based on medical history or the medical judgement of the investigator.

Within 1 month of enrollment or just prior to procedure:

  • Documented LA thrombus upon imaging
  • Creatinine >2.5mg/dl or creatinine clearance <30mL/min

Within 3 months of enrollment:

  • Significant gastrointestinal (GI) bleed
  • Myocardial infarction (MI), unstable angina, cardiac surgery or coronary intervention

Within 6 months of enrollment:

  • Coronary artery bypass graft (CABG) procedure
  • Implant procedure performed for ICD, CRT leads or pacemaker
  • Documented stroke, CVA, TIA or suspected neurological event

Treatment and study plan

Radiofrequency Ablation

Device

A procedure will be performed using a radiofrequency ablation catheter.

Primary outcomes

  1. Primary Safety Events

    Time frame: Ablation through 6 months

    Participant count of a composite of safety events including: serious adverse events (SAEs), procedure and/or device-related significant pericardial effusion, severe or clinically symptomatic pulmonary vein stenosis and atrioesophageal fistula

  2. Primary Effectiveness

    Time frame: 12 months

    The primary effectiveness endpoint is defined as freedom from documented AF, Atrial Flutter, (AFL) and Atrial Tachycardia (AT) episodes following the blanking period (3-month follow-up post-ablation procedure) through the end of the effectiveness evaluation period (12-month follow-up post-ablation procedure).

Secondary outcomes

  1. Freedom From a Composite of Serious Adverse Events (SAEs)

    Time frame: Within 30-days post-index ablation

    Freedom from a composite of SAEs occurring within 30-days post-index ablation procedure as adjudicated by an independent CEC for relatedness to the procedure or device.

  2. Freedom From Documented AF/AFL/AT Episodes

    Time frame: Within 3 months

    Freedom from documented AF/AFL/AT episodes during the effectiveness evaluation period lasting ≥ 30 seconds in duration by ECG monitoring.

  3. Freedom From Documented AF/AFL/AT Episodes in the Absence of Class I and III Anti-arrhythmic Drug Therapy.

    Time frame: Within 3 months

    Freedom from documented AF/AFL/AT episodes during the effectiveness evaluation period in the absence of class I and III anti-arrhythmic drug therapy.

  4. Acute Procedural Success

    Time frame: Day of index ablation procedure

    Participant count of acute procedural success, defined as confirmation of electrical isolation of PVs via assessment of entrance block at least 20 minutes following the last ablation around the respective PV

  5. Single Procedure Success With Freedom From AF/AT/AFL

    Time frame: 12 months after the index ablation procedure

    Participant count of single procedure success defined as the rate of subjects treated with one single ablation procedure for the entire enrollment period and with freedom from documented symptomatic AF, AT and AFL* at 12 months.

  6. Single Procedure Success With Freedom From All Primary Effectiveness Failures

    Time frame: 12 months

    Participant count of single procedure success with freedom from all primary effectiveness failure criteria.

  7. AFEQT Quality of Life, Baseline

    Time frame: Day of index ablation procedure

    QOL using the AFEQT Questionnaire, baseline questionnaires.

    The scale is the AF Effect on Quality-of-Life (AFEQT) score. Higher scores are better. Minimum value: 0. Maximum value: 100.

  8. AFEQT Quality of Life, 6-month Follow-up

    Time frame: 6 months after index ablation procedure

    QOL using the AFEQT Questionnaire, 6 month questionnaires.

    The scale is the AF Effect on Quality-of-Life (AFEQT) score. Higher scores are better. Minimum value: 0. Maximum value: 100.

  9. AFEQT Quality of Life, 12-month Follow up

    Time frame: 12 months after index ablation procedure

    QOL using the AFEQT Questionnaire, 12-month questionnaires.

    The scale is the AF Effect on Quality-of-Life (AFEQT) score. Higher scores are better. Minimum value: 0. Maximum value: 100.

  10. Change in AFEQT Quality of Life From Baseline to 12-month

    Time frame: Index ablation procedure through 12 months

    Changes in QOL using the AFEQT Questionnaire between 12-month and baseline questionnaires.

    The scale is the AF Effect on Quality-of-Life (AFEQT) score. Higher scores are better. Minimum value: 0. Maximum value: 100.

  11. National Institutes of Health Stroke Scale, Pre-discharge

    Time frame: Day of index ablation procedure

    Neurological changes measured using the National Institutes of Health Stroke Scale (NIHSS)

    The NIHSS which is comprised of 11 items, each of which scores a specific ability between a 0 and 4. For each item, a score of 0 typically indicates normal function in that specific ability, while a higher score is indicative of some level of impairment. The individual scores from each item are summed in order to calculate a patient's total NIHSS score. The maximum possible score is 42, with the minimum score possible is 0.

  12. National Institutes of Health Stroke Scale, One- Month Follow up

    Time frame: One month after index ablation procedure

    Neurological changes measured using the National Institutes of Health Stroke Scale (NIHSS)

    The NIHSS which is comprised of 11 items, each of which scores a specific ability between a 0 and 4. For each item, a score of 0 typically indicates normal function in that specific ability, while a higher score is indicative of some level of impairment. The individual scores from each item are summed in order to calculate a patient's total NIHSS score. The maximum possible score is 42, with the minimum score possible is 0.

  13. National Institutes of Health Stroke Scale, 12-month Follow-up

    Time frame: 12 months after the index ablation procedure

    Neurological changes measured using the National Institutes of Health Stroke Scale (NIHSS)

    The NIHSS which is comprised of 11 items, each of which scores a specific ability between a 0 and 4. For each item, a score of 0 typically indicates normal function in that specific ability, while a higher score is indicative of some level of impairment. The individual scores from each item are summed in order to calculate a patient's total NIHSS score. The maximum possible score is 42, with the minimum score possible is 0.

Other outcomes

  1. Total Procedure Time (Minutes)

    Time frame: Immediately after the index ablation procedure

    Total procedure time (minutes), defined as time of investigational catheter insertion into the vasculature to time of last procedural ablation catheter removed.

  2. Total Treatment Device Time (Minutes)

    Time frame: Day of index ablation procedure

    Total treatment device time (minutes), defined as time of delivery of first RF ablation with investigational catheter to removal of the investigational catheter.

  3. Cumulative RF Time

    Time frame: Day of index ablation procedure

    Mean cumulative RF Time (minutes).

  4. Duration of RF Ablations (Seconds)

    Time frame: Day of index ablation procedure

    Mean duration of RF ablations (seconds)

  5. Fluid Infused Through the Investigational Catheter (mL)

    Time frame: Day of index ablation procedure

    Total fluid infused through the investigational catheter (mL)

  6. Fluoroscopy Time (Minutes)

    Time frame: Day of index ablation procedure

    Total fluoroscopy exposure time (minutes)

  7. Incidence of Re-hospitalizations Due to Atrial Fibrillation Recurrence.

    Time frame: Between the blanking period (3-month follow-up post-ablation procedure) through the end of the effectiveness evaluation period (12-month follow-up post-ablation procedure).

    Number of subjects who were re-hospitalized due to atrial fibrillation recurrence after blanking period.

Sponsors and collaborators

Lead sponsor

Medtronic Cardiac Ablation Solutions

Industry

Registry information

Official study title

A Prospective Clinical Evaluation of the DiamondTemp™ System for the Treatment of Persistent Atrial Fibrillation

Acronym: Diamond-AFII

Important dates

Study start
2018
Primary completion
2024
Study completion
2024
First posted
Aug 22, 2018
Registry last updated
Oct 23, 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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