Update on advanced interventional neuromodulatory approaches to lower blood pressure

Herein, we review interventional peripheral neuromodulatory approaches to reduce blood pressure (BP), specifically focusing on catheter-based renal denervation (RDN), as well as the latest data from recent clinical trials underpinning its clinical use. Given the apparent failure of established lifestyle measures and pharmacologic BP-lowering approaches to improve hypertension (HTN) control rates, the past decade has seen remarkable scientific efforts to explore the utility of interventional strategies for BP management. Experimental studies and human clinical trials have demonstrated the crucial role of the sympathetic nervous system in the development and mainenance of HTN - consequently, most recent interventional technologies aimed primarily at modulating neural pathways. Advanced approaches that were rigorously tested in human studies include RDN, endovascular baroreflex amplification, baroreflex activation therapy and cardiac neuromodulation stimulation.Amongst these, RDN is by far the most established technology. With recent robust evidence from clinical trials and real-world data showing the safety and efficacy of both ultrasound and radiofrequency-based approaches, a recent clinical consensus statement of the European Society of Cardiology Council on Hypertension and the European Association of Percutaneous Cardiovascular Interventions concludes that RDN represents an ancillary therapeutic option in patients with uncontrolled resistant HTN confirmed by ambulatory blood pressure measurement and in spite of attention to lifestyle changes and optimised pharmacological treatment. Furthermore, RDN could alos be considered for patienst unlikley to adhere to or tolerate long-term antihypertensive drug treatment. Very recent data indicate long-term safety and efficacy up to 10 years. Appropriate implementation of RDN into clinical practice is now warranted.For all other interventions additional data from adequately designed human studies are required to establish their safety and clinical utility for potential future use in routine practice.

A system of real-time neural recording and stimulation and its potential application in blood pressure modulation

Hypertension is one of the most prevalent chronic diseases that affects more than 20% of the adult population worldwide, but fortunately, most of their blood pressure can be effectively controlled via drug treatment. However, there still remains 5–30% of patients clinically who do not respond well to conventional medication, while the non-drug treatments currently existing are struggling with major drawbacks like irreversible nerve damage, huge side effects, and even non-effectiveness. In this study, based on the physiological regulation mechanism of blood pressure and state-of-the-art neuromodulation technique, we worked along with the vagus nerve stimulation scheme, developed, and explored whether and how a real-time neural recording and stimulation system could provide an insight into self-adaptive modulation in the blood pressure, in the hope to crack a crevice in the closed-loop treatment for resistant hypertension. Unlike traditional neuromodulation devices, additional signal recording and real-time wireless transmission functions are added to the same device to realize the features of a dynamic monitor and modulator. The system is tested both in vitro and in vivo, showing decent electrical performance of 8 kHz sampling rate and flexible stimulation outputs which sufficiently covers our needs in manipulating neural activities of interest. A relatively stable drop in the blood pressure resulting from stimulation was observed and specific patterns in the vagus nerve signals relating to blood pressure could also be primarily identified. This laid a solid foundation for further studies on the final realization of closed-loop automatic adjustment for resistive hypertension treatment.