Renal Sympathetic Denervation in Patients with Resistant Hypertension: A Feasibility Study

Investigation and management of resistant hypertension: British and Irish Hypertension Society position statement

People living with resistant hypertension (RH) are at high risk of adverse cardiovascular events. The British and Irish Hypertension Society has identified suspected RH as a condition for which specialist guidance may improve rates of blood pressure control and help clinicians identify those individuals who may benefit from specialist review. In this position statement we provide a practical approach for the investigation and management of adults with RH. We highlight gaps in the current evidence and identify important future research questions. Our aim is to support the delivery of high-quality and consistent care to people living with RH across the UK and Ireland.

Renal denervation in the management of hypertension

Arterial hypertension is a global leading cause of cardiovascular, cerebrovascular, and renal disease, as well as mortality. Although pharmacotherapy is safe and effective in lowering blood pressure (BP) and cardiovascular disease risk, BP control remains poor, and the mortality rates associated with high BP have been steadily increasing. Device-based therapies have been investigated to overcome barriers to pharmacotherapy, including non-adherence and low rates of persistence to daily medications. Among these device-based therapies, catheter-based renal denervation (RDN) has been most extensively examined over the past 15 years. In this state-of-the-art article, we summarise the rationale for RDN, review the available evidence, provide recommendations for a safe procedure, and discuss the role of RDN in current guidelines and clinical practice.

Current Status and Future Perspectives of Renal Denervation

Despite the availability of numerous antihypertensive medications, hypertension treatment and control rates remain low, and uncontrolled hypertension is well-known to be one of the most important cardiovascular risk factors. Endovascular catheter-based renal denervation (RDN) has been developed to be a complementary or alternative treatment option for patients who cannot take medication, poor adherence, or have resistant hypertension despite the use of maximal doses of medications. Recently, several randomized trials for evaluating the efficacy and safety of second-generation RDN devices consistently show solid evidence for their blood pressure-lowering efficacy. This review summarizes the current evidence and future perspectives of RDN.

Catheter-based renal denervation (RDN) therapy, a new procedure that uses radiofrequency ablation to interrupt efferent and afferent renal sympathetic nerve fibers, is a complementary or alternative treatment to antihypertensive medications for optimal control of blood pressure (BP). Although several single-arm early proof-of-concept studies showed significant BP reduction, the largest sham-controlled study using the first-generation RDN device (SYMPLICITY HTN-3) failed to significantly reduce BP in patients with resistant hypertension who were taking the guideline-based combination of antihypertensive medications. Since then, new devices and techniques have been developed to improve the efficacy and safety of RDN procedures. Sham-controlled trials using second-generation RDN devices (radiofrequency- and ultrasound-based) have provided solid evidence for their BP-lowering efficacy with and without the use of concomitant antihypertensive medication. Moreover, the safety profile of RDN in several registries and clinical trials appears to be excellent. This review summarizes the current evidence for RDN and discusses its current issues, future trials, Asian perspectives, and potential roles in both hypertension and other morbidities.

Recent trends in renal denervation devices for resistant hypertension treatment

Hypertension is one of the most important risk factors for cardiovascular disease, which is the leading cause of mortality. The World Health Organization (WHO) estimated that in 2019 more than 1.13 billion people worldwide were suffering from hypertension. In spite of the advances in new medical therapies, control of hypertension remains suboptimal. Renal denervation (RDN) neuromodulation treatment was primarily developed to treat resistant hypertension and is potentially a new method for treating congestive heart failure, diabetes, and chronic renal failure. RDN consists of passing a catheter into the renal arteries and ablating their sympathetic nerves using radiofrequency or ultrasound energy. Despite promising results in initial trials, RDN failed to achieve its efficacy endpoints as a treatment for resistant hypertension, but the recent series of successful trials show that RDN is back as a serious treatment alternative. This paper reviews the current state-of-the-art RDN devices including Symplicity Flex, Symplicity Spyral, Vessix, EnligHTN, Iberis, TIVUS system, and Paradise. The paper also provides an in-depth review of future RDN devices which include Cryo-RDN, Golden Leaf Catheter, Synaptic, SyMapCath, ConfidenHT System, and Grizzly Microwave Ablation system.