Safety and performance of diagnostic electrical mapping of renal nerves in hypertensive patients

Aims: The aim of this study was to evaluate the safety and performance of renal nerve stimulation (RNS) for diagnostic mapping of the renal nerves.

Methods and results: In this first-in-man study, twenty hypertensive patients underwent RNS using the ConfidenHT system. Bilateral stimulations were performed at three to four sites per artery at 2 and 4 mA. The primary endpoint was change in systolic blood pressure (SBP). Mean office blood pressure was 156/89 mmHg. No periprocedural adverse events occurred. Stimulation with 2 mA resulted in a maximum change of 8.3±6.3 mmHg in SBP (based on 119 stimulations; p<0.001), while stimulating with 4 mA resulted in a maximum change of 10.1±7.8 mmHg (based on 61 stimulations; p<0.001). The mean change in SBP did not vary between mid, distal or branch sites when stimulating at 2 mA but was significantly higher at ostial (23±14 mmHg) than at non-ostial locations (9±7 mmHg) when stimulating at 4 mA (p=0.003).

Conclusions: RNS can be performed safely and effectively along the renal artery and results in a large variation in temporary BP changes per patient and per anatomic location. RNS might help in optimising treatment effect and selecting potential responders to renal sympathetic denervation.