Effect of renal denervation on long-term outcomes in patients with resistant hypertension

The role of renal denervation in cardiology and beyond: An updated comprehensive review and future directives

Renal denervation (RDN) is a minimally invasive intervention performed by denervation of the nervous fibers in the renal plexus, which decreases sympathetic activity. These sympathetic nerves influence various physiological functions that regulate blood pressure (BP), including intravascular volume, electrolyte composition, and vascular tone. Although proven effective in some trials, controversial trials, such as the Controlled Trial of Renal Denervation for Resistant Hypertension (SYMPLICITY-HTN3), have demonstrated contradictory results for the effectiveness of RDN in resistant hypertension (HTN). In the treatment of HTN, individuals with primary HTN are expected to experience greater benefits compared to those with secondary HTN due to the diverse underlying causes of secondary HTN. Beyond its application for HTN, RDN has also found utility in addressing cardiac arrhythmias, such as atrial fibrillation, and managing cases of heart failure. Non-cardiogenic applications of RDN include reducing the intensity of obstructive sleep apnea (OSA), overcoming insulin resistance, and in chronic kidney disease (CKD) patients. This article aims to provide a comprehensive review of RDN and its uses in cardiology and beyond, along with providing future directions and perspectives.

Controversies in Hypertension IV: Renal Denervation

Renal denervation is not a cure for hypertension. Although more recent sham-controlled trials were positive, a significant minority of patients in each trial were unresponsive. The optimal patient or patients need to be defined. Combined systolic/diastolic hypertension appears more responsive than isolated systolic hypertension. It remains uncertain whether patients with comorbidities associated with higher adrenergic tone should be targeted, including obesity, diabetes, sleep apnea, and chronic kidney disease. No biomarker can adequately predict response. A key to a successful response is the adequacy of denervation, which currently cannot be assessed in real time. It is uncertain what is the optimal denervation methodology: radiofrequency, ultrasound, or ethanol injection. Radiofrequency requires targeting the distal main renal artery plus major branches and accessory arteries. Although denervation appears to be safe, conclusive data on quality of life, improved target organ damage, and reduced cardiovascular events/mortality are required before denervation can be generally recommended.

Catheter-based renal sympathetic nerve denervation on hypertension management outcomes

BACKGROUND

Renal sympathetic denervation (RSD) provides a minimally invasive interventional treatment modality for patients with resistant hypertension. However, the post-operative outcomes remain a key area of investigation since its earliest clinical trials.

AIM

To evaluate patient outcomes after RSD intervention among peer-reviewed patient cases.

METHODS

A systematic review of literature on MEDLINE, Google Scholar, and the Cochrane Database of Systematic Reviews for RSD case studies to assess post-operative hypertension readings and medical management.

RESULTS

Among 51 RSD cases, the post-operative RSD patients report an apparent reduction with a mean number of 3.1 antihypertensive medications. The mean systolic arterial blood pressure 1 year following RSD was 136.0 mmHg (95%CI: 118.7-153.3).

CONCLUSION

The apparent improvements in office systolic blood pressure after 12 month post-operative RSD can support the therapeutic potential of this intervention for blood pressure reduction. Additional studies which utilized a uniform methodology for blood pressure measurement can further support the findings of this systematic review.

The Potential Role of Renal Denervation in the Management of Heart Failure

Sympathetic nervous system activation in patients with heart failure is one of the main pathophysiologic mechanisms associated with the worse outcomes. Pharmacotherapies targeting neurohormonal activation have been at the center of heart failure management. Despite the advancement of therapies and the available treatments, heart failure continues to have an overall poor prognosis. Renal denervation was originally developed to lower systemic blood pressure in patients with poorly controlled hypertension, by modulating sympathetic outflow. However, more recently, multiple studies have investigated the effect of renal denervation in heart failure patients with both preserved (HFpEF) and reduced ejection fractions (HFrEF). This paper provides an overview of the potential effect of renal denervation in altering the various pathophysiologic, sympathetically mediated pathways that contribute to heart failure, and reviews the literature that supports its future use in those patients.