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 DAF 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 atrial fibrillation (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 in post-hoc analysis.1

  • 40% reduction in RF time
  • 55% reduction in individual RF ablation duration
  • 58% reduction in saline infusion

 

Metric

DTA group1

Control group1

% reduction

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

785.2 ± 351.5 ml

57.7%


Primary effectiveness and safety 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 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
  • Greater than one repeat procedure

2. Effectiveness period

Effectiveness failure criteria

  • Documented greater than or equal to 30 seconds 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
  • Greater than or equal to 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 less than 35%
  • Left atrial diameter greater than 5.5 cm

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