Diamond-AF Clinical Trial
Comparing the DiamondTemp™ ablation system versus a contact force-sensing ablation system (CF-RF).
Study Background and Design
Background
Tissue temperature is a well-established biophysical parameter of irreversible tissue damage. Irrigated RF was introduced to mitigate the risk of char and thrombus formation; however, thermal acuity is disrupted.
To address these limitations, the DiamondTemp ablation system (DTA) was designed to accurately measure tip-tissue temperature during energy delivery.
Design
The DIAMOND-AF trial was an FDA-regulated, prospective, multicenter, non-inferiority, randomized, controlled trial which compared safety and effectiveness of DTA and a contact force-sensing ablation system (TactiCath™) (Control).
482 paroxysmal AF patients were randomized (239 DTA and 243 control) for PVI at 23 sites in the United States, Europe, and Canada. Patients were followed for 12 months.
Key Findings
Primary Safety and Efficacy Endpoint Achieved
DTA demonstrated comparable efficacy and both cohorts required very few repeat procedures. Safety and efficacy of the DTA system proved non-inferior to contact force-sensing RF ablation for the treatment of patients with paroxysmal AF.
Primary Safety Endpoint Met 3.3%
Safety event rate compared with 6.6% with contact force-sensing RF.
Primary Effectiveness Endpoint Met 79.1%
Compared with 75.7% with contact force-sensing RF.
Efficiency Data Versus CF-RF
The DTA system demonstrated procedural efficiencies compared to CF-RF.1
- 40% reduction in RF time
- 55% reduction in individual RF ablation duration
- 58% reduction in saline infusion
| Metric | DTA Group | Control Group | % Reduction with DTA* |
|---|---|---|---|
| Total RF Time | 17.9 ± 8.1 min | 29.8 ± 14 min | 39.9% |
| Individual RF ablation duration | 14.7 ± 5.3 s | 32.6 ± –25.3 s | 54.9% |
| Saline infusion volume | 332.2 ± 120.8 ml | 785.5 ± –351.5 ml | 57.7% |
*Calculation based on manuscript values.
Endpoints
Effectiveness
The primary effectiveness endpoint was freedom from recurrence of an atrial arrhythmia (AF, AFL, AT) during the effectiveness period. This was a composite endpoint of seven (7) failure criteria.
Safety
The primary safety endpoint is defined as freedom from a composite of serious adverse events (SAE) occurring within 30 days and clinically symptomatic pulmonary vein stenosis through 6 months post-index ablation procedure.
Primary Effectiveness Endpoint
Freedom from recurrence of atrial arrhythmias (AF/AFL/AT)
1. Blanking period
Effectiveness Failure Criteria
- Inability to isolate all PVs
- Use of a non-study device
- > 1 repeat procedure
2. Effectiveness Period
Effectiveness Failure Criteria
- Documented ≥ 30 sec of AF/AFL/AT
- New or modification to pre-existing Class I-IV AAD
- DCCV
- Repeat procedure
Study Population
Key Inclusion Criteria
- Symptomatic paroxysmal AF
- At least two self-terminating AF episodes reported in last 6 months
- At least one ECG documented episode in last 12 months
- Prior Class I-IV AAD failure
- ≥ 18 years of age
Key Exclusion Criteria
- Prior cardiac interventions
- Neurological events within 6 months
- Class III/IV or uncontrolled heart failure
- Left ventricular ejection fraction < 35%
- Left atrial diameter > 5.5 cm
Additional Resources
*Calculation based on manuscript values.
Reference
1
Kautzner J, Albenque JP, Natale A, et al. A Novel Temperature-Controlled Radiofrequency Catheter Ablation System Used to Treat Patients With Paroxysmal Atrial Fibrillation. JACC Clin Electrophysiol. Published online January 27, 2021.