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As the exact location of renal nerves cannot be visualized, renal sympathetic denervation (RDN) remains a so-called blind procedure. The aim to the present study is to assess the safety and feasibility of renal nerve stimulation using the ConfidenHTTM mapping system. The technology could help to improve RDN procedures by providing: (1) better patient selection, and (2) intra-procedural guidance and feedback to optimize success rates.
The Confiden(HT) study is a prospective first-in-man multicenter study designed to assess the safety and feasibility of renal nerve mapping using the ConfidenHT™ system in 20 hypertensive patients with an indication for coronary angiography or a planned RDN. The Console delivers electrical energy to the catheter using a multi-channel stimulator, and a real time intra-arterial Blood Pressure (BP) monitor, which records, analyzes and displays the stimulation outcome (BP and/or heart rate changes) during the mapping phase. The flexible multi-electrode ConfidenHT™ catheter is compatible with an 8Fr guiding catheter and 0.014” guide wire. Stimulations were performed in left and right renal arteries at 3 to 4 sites per artery, including branches at 2 and 4 mA resulting in up to 8 mapped sites per patient. The primary efficacy endpoint was the chance in systolic blood pressure during stimulation. All patients were followed up to 3 months.
Mean age of the patiens included was 58±12 years, 11/20 patients were female. Mean office blood pressure was 156±23mmHg and GFR was 78±13mL/min/1.73m2. All procedures were performed under local anesthesia with mild conscious sedation. The use of the system appeared safe with no peri-procedural adverse events and no signs of angiographically visible spasms/thrombus or dissection post procedure. Creatinine levels remained within the normal range. Mean individual systolic BP responses varied between 3.5 and 18 mmHg while mean individual mean arterial pressure responses varied between 2.4 and 11.3 mmHg. The average time to maximal response was 45 seconds. The mean change in systolic BP response did not vary between proximal, mid, distal or branch sites when stimulating at 2mA.
The results of the present study suggest that renal nerve mapping using the ConfidenHTTM system technology is feasible and safe and offers promising diagnostic electrical renal nerve mapping opportunities in hypertensive patients, which could help in optimizing the result of renal sympathetic denervation.