Medtronic announced FDA approval of its DiamondTemp Ablation (DTA) system for treating patients with recurrent, symptomatic paroxysmal atrial fibrillation (AF) who haven't responded to drug therapy. This marks the first FDA-approved, temperature-controlled, irrigated radiofrequency (RF) ablation system with diamonds designed to deliver ablations for AF.
Addressing Atrial Fibrillation with Advanced Ablation Technology
Atrial fibrillation, the most common heart rhythm disorder, affects nearly six million people in the U.S. and over 37 million worldwide. It involves irregular and rapid heart rhythms in the atria. AF ablation, a minimally invasive procedure using radiofrequency energy, creates lesions (scar tissue) to interrupt irregular electrical signals, a process known as pulmonary vein isolation (PVI). PVI via catheter ablation is a cornerstone treatment for AF patients who don't respond to drug therapy.
The DTA system delivers real-time feedback on physical parameters, guiding physicians during lesion creation. Embedded with industrial-grade diamonds, the DTA catheter has 200-400 times greater thermal conductivity than conventional RF ablation catheters. This enables a low irrigation flow-rate and accurate real-time tissue temperature measurements, resulting in more efficient energy delivery. The DTA catheter is also designed for high-resolution electrogram (EGM) signal recording, providing physical indicators of lesion formation and guidance for ablation location.
Clinical Trial Results: DIAMOND-AF
The DIAMOND-AF trial, a prospective, multicenter, single-blind, randomized, controlled trial, compared the DTA system's safety and effectiveness against a contact force-sensing ablation system for treating patients with recurrent, symptomatic, paroxysmal AF unresponsive to drug therapy. The trial enrolled 482 patients across 23 sites in the U.S., Europe, and Canada.
Results demonstrated a freedom from patient complication rate of 96.7% in the DTA group versus 93.4% in the control group (P<0.0001 versus -6.5% non-inferiority margin). Primary effectiveness for AF treatment was met in 79.1% of DTA subjects and 75.7% of control subjects (P<0.0001 versus -12.5% non-inferiority margin).
Procedural Efficiencies and Quality of Life Improvements
The DTA system also demonstrated procedural advantages, including shorter total RF times and individual RF ablation duration, along with a reduction in infused saline volume. Both arms showed clinically meaningful quality-of-life improvements at 6 and 12 months post-ablation. These findings were presented at the 2020 Asia Pacific Heart Rhythm Society (APHRS) Virtual Congress and published in the Journals of the American College of Cardiology Clinical Electrophysiology (JACC EP).
According to Tom McElderry, M.D., University of Alabama, Birmingham, the DIAMOND-AF trial results are encouraging because the DTA system was shown to be safe and effective and underscored significant procedural efficiencies for clinicians. Improved efficiencies, including shorter total RF ablation times and individual RF ablation durations, are important for both patient well-being and physician and lab staff productivity.
