A scoping review of neuromodulation techniques for controlling blood pressure: what are the ups and downs to this approach?

Background and objectives: While there has been rapid progress in research aimed at developing device-based neuromodulation therapies for blood pressure (BP) disorders, there is a paucity of FDA-approved therapies. Currently, the only approved devices for treating resistant hypertension use renal denervation, however, this could soon change as clinical research progresses. With the evolution of interventional strategies for BP regulation, it is important to comprehend the developments to date in order to gauge directions for future research. The objective of this scoping review was to provide the current range of device-based BP neuromodulation approaches, overview salient characteristics of the included studies, address limitations, and detail avenues of further investigation.

Methods: Our review was conducted using the Preferred Reporting Items for Reviews and and Meta-analysis framework. The literature search was performed across the Web of Science Core Collection, Scopus, and Pubmed databases. The search yielded 3503 studies, of which 100 studies remained following the screening process. In the last 10 years, there has been an increase in the number of experimental neurostimulation studies detailing increases and decreases in BP. Of all the included studies, most adopted a non-randomized experimental approach (89%), used animal participants (65%), used invasive neuromodulation methods (74%), and performed acute experiments (84%). More studies documented only depressor responses (49%) compared to pressor responses (35%), and 13% reported both pressor and depressor responses using multiple neural targets.

Conclusions: This review addressed developments in device-based BP neuromodulation, highlighting a dominant focus on treating resistant hypertension compared to hypotensive disorders. While advancements in implantable electrodes have improved spatial selectivity of stimulation, non-invasive neurostimulation devices have become increasingly popular in recent years.