GOLDART--Gold Alloy Versus Platinum-Iridium Electrode for Ablation of AVNRT

Radiofrequency (RF) catheter ablation targeting the slow pathway is currently the most effective treatment for patients with atrioventricular nodal reciprocating tachycardia (AVNRT). Gold exhibits a more than four times greater thermal conductivity than platinum, and the creation of deeper lesions was demonstrated in ex vivo animal experiments. The current clinical trial was initiated to compare gold catheters with standard platinum-iridium (Pt-Ir) material and to analyze differences in the increase of power or temperature as a function of time during RF ablation.

A prospective, randomized multicenter study design was used to compare RF deliveries at the slow pathway with standard Pt-Ir tip catheters (128 patients), as well as gold alloy tip electrodes (124 patients) during AVNRT ablation.

Although there was a trend towards higher power delivery in the gold group (4.96 vs. 4.28 W/s), this trend was not statistically significant. Likewise, cumulative duration of all RF ablations, total procedure time, and power delivered at other time points were not significantly different between the groups. Also, the occurrence of AV-block and sensations of pain were similar in both treatment groups. However, charring on the catheter tip after the intervention was observed eightfold more frequently in the Pt-Ir group.

In conclusion, power delivery cannot be significantly increased by RF ablation of AVNRT with gold electrodes. But the electrode material seems to be safe and well-tolerated and specifically did not increase the risk of AV-block. The significant reduction of coagulum formation on gold tips suggests a possible advantage of this material beyond its better conduction properties.