DiamondTemp™ System for the Treatment of Persistent Atrial Fibrillation (Diamond-AFII)

A Prospective Clinical Evaluation of the 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.

Study Overview

• Status: Completed
• Conditions: Atrial Fibrillation; Persistent Atrial Fibrillation
• Intervention / Treatment: Device: Radiofrequency Ablation

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 376
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Newmarket, Ontario, Canada, L3Y2P6
      • Southlake Regional Health Center
  • Quebec
    • Montreal, Quebec, Canada, HITC8
      • Montreal Heart Institute
    • Québec, Quebec, Canada, G1V4G5
      • Institut Universitaire de Cardiologie et de Pneumologie de Quebec (IUCPQ)
• Czechia
  • Brno, Czechia, 65691
    • St Ann's University Hospital
  • Czechia
    • Prague, Czechia, Czechia, 14021
      • Institut klinicke a experimentalni mediciny (IKEM)
  • Prague
    • Prague, Prague, Czechia, 15000
      • Na Homolce
• France
  • Nancy, France, 54511
    • CHRU Nancy
  • Perpignan, France, 66000
    • Clinique Saint Pierre
  • Toulouse, France, 31076
    • Clinique Pasteur
  • Lyon
    • Villeurbanne, Lyon, France, 69100
      • Clinique du Tonkin
• Germany
  • Leipzig, Germany, 04289
    • Leipzig Heart Institute GmbH
• Italy
  • Venezia, Italy, 30174
    • Ospedale dell'Angelo
  • Milano
    • Milan, Milano, Italy, 20138
      • Centro Cardiologico Monzino
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35294
      • University of Alabama
    • Birmingham, Alabama, United States, 35242
      • Grandview Medical Center
  • California
    • Los Angeles, California, United States, 90033
      • Keck School of Medicine
  • Florida
    • Orlando, Florida, United States, 32751
      • Advent Health, Florida Hospital Orlando
  • Iowa
    • West Des Moines, Iowa, United States, 50266
      • Iowa Heart Center
  • Kansas
    • Overland Park, Kansas, United States, 66211
      • Kansas City Heart Rhythm Institute
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
  • Mississippi
    • Jackson, Mississippi, United States, 39216
      • Jackson Heart Clinic
    • Tupelo, Mississippi, United States, 38801
      • North Mississippi Medical Center
  • New York
    • New York, New York, United States, 10029
      • Icahn School of Medicine at Mount Sinai
    • New York, New York, United States, 10467
      • Montefiore Medical Center
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina
    • Charleston, South Carolina, United States, 29406
      • Trident Medical Center
  • Texas
    • Austin, Texas, United States, 78705
      • Texas Cardiac Arrhythmia Research Foundation
    • Houston, Texas, United States, 77030
      • Houston Methodist Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Above eighteen (18) years of age or of legal age to give informed consent specific to state and national law.
2. 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.
3. Refractory, intolerant or contraindicated to at least one Class I or III anti-arrhythmic (AAD) drug.
4. Suitable candidate for intra-cardiac mapping and ablation of arrhythmia.
5. Subject agrees to comply with study procedures and be available (geographically stable) for follow-up visits for at least 12 months after enrollment.
6. Subject is willing and able to provide written consent.

Exclusion Criteria:

At time of enrollment and/or prior to procedure:

1. Continuous AF >12 months (long-standing persistent AF)
2. Paroxysmal AF with longest episode <7 days
3. AF secondary to electrolyte imbalance, thyroid disease or reversible or non-cardiac cause
4. Rheumatic heart disease
5. Severe mitral regurgitation
6. Hypertrophic cardiomyopathy
7. LA diameter >5.5 cm
8. Left ventricular ejection fraction (LVEF) <40%
9. Currently NYHA Class III or IV or exhibits uncontrolled heart failure
10. Body Mass Index (BMI) >42 kg/m2.
11. LA ablation, septal closure device or mitral valve surgical procedure at any time prior to enrollment
12. Presence of intramural thrombus, tumor or abnormality that precludes vascular access, catheter introduction or manipulation
13. Coagulopathy, bleeding diathesis or suspected procoagulant state
14. Sepsis, active systemic infection or fever (>100.5 oF / 38 oC) within a week prior to the ablation procedure
15. Significant restrictive or obstructive pulmonary disease or chronic respiratory condition
16. 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.
17. 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.
18. Positive pregnancy test results for female subjects of childbearing potential or breast feeding.
19. Enrollment in a concurrent clinical study that in the judgement of the investigator would impact study outcomes.
20. 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.

21. 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:

22. Documented LA thrombus upon imaging

23. Creatinine >2.5mg/dl or creatinine clearance <30mL/min

    Within 3 months of enrollment:

24. Significant gastrointestinal (GI) bleed

25. Myocardial infarction (MI), unstable angina, cardiac surgery or coronary intervention

    Within 6 months of enrollment:

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

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: Experimental; Radiofrequency Ablation. Catheter ablation to treat persistent atrial fibrillation using temperature-controlled ablation catheter	Device: Radiofrequency Ablation; A procedure will be performed using a radiofrequency ablation catheter.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary Safety Events	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	Ablation through 6 months
Primary Effectiveness	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).	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Freedom From a Composite of Serious Adverse Events (SAEs)	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.	Within 30-days post-index ablation
Freedom From Documented AF/AFL/AT Episodes	Freedom from documented AF/AFL/AT episodes during the effectiveness evaluation period lasting ≥ 30 seconds in duration by ECG monitoring.	Within 3 months
Freedom From Documented AF/AFL/AT Episodes in the Absence of Class I and III Anti-arrhythmic Drug Therapy.	Freedom from documented AF/AFL/AT episodes during the effectiveness evaluation period in the absence of class I and III anti-arrhythmic drug therapy.	Within 3 months
Acute Procedural Success	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	Day of index ablation procedure
Single Procedure Success With Freedom From AF/AT/AFL	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.	12 months after the index ablation procedure
Single Procedure Success With Freedom From All Primary Effectiveness Failures	Participant count of single procedure success with freedom from all primary effectiveness failure criteria.	12 months
AFEQT Quality of Life, Baseline	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.	Day of index ablation procedure
AFEQT Quality of Life, 6-month Follow-up	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.	6 months after index ablation procedure
AFEQT Quality of Life, 12-month Follow up	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.	12 months after index ablation procedure
Change in AFEQT Quality of Life From Baseline to 12-month	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.	Index ablation procedure through 12 months
National Institutes of Health Stroke Scale, Pre-discharge	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.	Day of index ablation procedure
National Institutes of Health Stroke Scale, One- Month Follow up	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.	One month after index ablation procedure
National Institutes of Health Stroke Scale, 12-month Follow-up	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 months after the index ablation procedure

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Procedure Time (Minutes)	Total procedure time (minutes), defined as time of investigational catheter insertion into the vasculature to time of last procedural ablation catheter removed.	Immediately after the index ablation procedure
Total Treatment Device Time (Minutes)	Total treatment device time (minutes), defined as time of delivery of first RF ablation with investigational catheter to removal of the investigational catheter.	Day of index ablation procedure
Cumulative RF Time	Mean cumulative RF Time (minutes).	Day of index ablation procedure
Duration of RF Ablations (Seconds)	Mean duration of RF ablations (seconds)	Day of index ablation procedure
Fluid Infused Through the Investigational Catheter (mL)	Total fluid infused through the investigational catheter (mL)	Day of index ablation procedure
Fluoroscopy Time (Minutes)	Total fluoroscopy exposure time (minutes)	Day of index ablation procedure
Incidence of Re-hospitalizations Due to Atrial Fibrillation Recurrence.	Number of subjects who were re-hospitalized due to atrial fibrillation recurrence after blanking period.	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).

Collaborators and Investigators

• Sponsor: Medtronic Cardiac Ablation Solutions
• Investigators: Principal Investigator: Atul Verma, MD, Medical Director, Heart Rhythm Program, Southlake Regional Health Centre; Principal Investigator: Andrea Natale, MD, Director, Electrophysiology, Texas Cardiac Arrhythmia Institute at St. David's Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): September 19, 2018
• Primary Completion (Actual): October 31, 2024
• Study Completion (Actual): October 31, 2024

Study Registration Dates

• First Submitted: August 20, 2018
• First Submitted That Met QC Criteria: August 21, 2018
• First Posted (Actual): August 22, 2018

Study Record Updates

• Last Update Posted (Estimated): October 23, 2025
• Last Update Submitted That Met QC Criteria: October 7, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: atrial fibrillation; electrophysiology; ablation; persistent; catheter
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation; Therapeutics; Surgical Procedures, Operative; Ablation Techniques; Radiofrequency Therapy; Radiofrequency Ablation
• Other Study ID Numbers: TP01071

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No