Results of the REDUCED 1 Study Assessing the TIVUS System in Renal Denervation

Published Congress: EuroPCR 2024

 Dr. Seda Tanyeri Üzel

 Introduction:
The REDUCED 1 pilot study was conducted to evaluate the effectiveness and safety of TIVUS™ (Therapeutic Invasive Ultrasonic System) system renal denervation in patients with uncontrolled stage 2 hypertension. Hypertension is a common health problem worldwide and can lead to serious complications such as cardiovascular diseases, kidney diseases and stroke. Despite available treatment methods, some patients cannot achieve adequate blood pressure control. Therefore, more effective treatment options are needed.
The TIVUS™ system targets and denervates renal nerves using high-intensity unfocused ultrasonic energy. This system has advantages such as deeper ablative penetration, a faster and safer procedure time, free-floating catheter structure, and passive cooling of the surface tissue using blood flow. The REDUCED 1 study is one of the first studies to evaluate the clinical efficacy and safety of this new system.
The REDUCED 1 study demonstrates the potential benefits of the TIVUS™ system, potentially offering a new treatment option for patients with uncontrolled stage 2 hypertension. This study provides an important basis for future studies in the field of renal denervation.

Objective :
The REDUCED 1 pilot study was developed to evaluate the effectiveness and safety of renal denervation of the TIVUS™ system in patients with uncontrolled stage 2 hypertension. The study aims to determine how much the TIVUS™ system can reduce daytime systolic ambulatory blood pressure (ABPM) over a 3-month period and its safety and effectiveness parameters during a 6-month follow-up period.

Methods:
This study has a prospective, randomized and controlled design. A total of 40 patients were included in the study; 25 of them are from the USA and 15 are from Israel. Included patients were those with uncontrolled stage 2 hypertension with office systolic blood pressure (SBP) between 140-180 mmHg and office diastolic blood pressure (DBP) between 90-110 mmHg and using at least one antihypertensive medication. The study period includes 3 and 6 months of follow-up.
The primary endpoint was to measure change in daytime ABPM after 3 months. Secondary endpoints were to evaluate ABPM change at 6 months and the safety and effectiveness of the procedure.
During the screening phase, informed consent forms were obtained from patients based on office blood pressure. This phase was followed by a period in which the current drug treatment was continued for 4 weeks and ambulatory blood pressure was measured at the end of 4 weeks. Eligibility checks were carried out in two stages: In the first stage, an assessment was made based on ambulatory blood pressure and a renal artery computed tomography scan was performed; In the second stage, renal angiography was performed.
Patients who met all eligibility criteria underwent renal artery denervation using the TIVUS™ system. During this procedure, renal nerves were targeted and denervation was achieved using high-intensity unfocused ultrasonic energy.

Results:
The results of the REDUCED 1 study demonstrate the efficacy and safety of the TIVUS™ system in patients with uncontrolled stage 2 hypertension. In the study, an average decrease of 12.0 mmHg in daytime ABPM was observed during the 3-month follow-up period. During the 6-month follow-up period, this decrease reached 13.9 mmHg. The primary endpoint of the study, a decrease of at least 5 mmHg, was achieved in 78.4% of patients at 3 months and in 82.6% at 6 months.
No serious device-related adverse events have been reported during or after renal denervation with the TIVUS™ system. However, post-procedural side effects such as pseudoaneurysm (21 days after the procedure) and eGFR decrease (4 days after the procedure) were observed in some patients. Specific patient numbers regarding adverse events were not given, but these events were evaluated by the CEC (Clinical Events Committee).

Comment
Results from the REDUCED 1 study indicate that the TIVUS™ system is a promising treatment option for patients with uncontrolled stage 2 hypertension. The data obtained in this study demonstrate that the TIVUS™ system significantly reduces daytime systolic ambulatory blood pressure and does so safely. In particular, the absence of serious adverse events emphasizes the safety of the system. The results of the study show that the TIVUS™ system has positive effects on hemodynamic parameters and may improve clinical outcomes in patients with uncontrolled hypertension. These findings indicate that, when supported by larger-scale and long-term studies in the future, the TIVUS™ system may have an important place in the treatment of hypertension.