Therapeutic potential of renal sympathetic denervation in patients with chronic heart failure

Renal denervation in patients who do not respond to cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) reduces the morbidity and mortality in advanced heart failure (HF) in about two-thirds of the patients. Approximately one-third of the patients do not respond to CRT. The overactivity of sympathetic nervous system is associated with advanced HF and deteriorates the hemodynamic state. We tested the hypothesis that controlling sympathetic overactivity by renal denervation (RDN) could be beneficial in nonresponders for CRT. In our HeartF-RDN study (ClinalTrials.gov. NCT02638324), RDN could not reverse the progression of HF in subjects with New York Heart Association Classification (NYHA) III-IV stage symptoms.

Autonomic Modulation of Cardiac Arrhythmias: Methods to Assess Treatment and Outcomes

The autonomic nervous system plays a central role in the pathogenesis of multiple cardiac arrhythmias, including atrial fibrillation and ventricular tachycardia. As such, autonomic modulation represents an attractive therapeutic approach in these conditions. Notably, autonomic modulation exploits the plasticity of the neural tissue to induce neural remodeling and thus obtain therapeutic benefit. Different forms of autonomic modulation include vagus nerve stimulation, tragus stimulation, renal denervation, baroreceptor activation therapy, and cardiac sympathetic denervation. This review seeks to highlight these autonomic modulation therapeutic modalities, which have shown promise in early preclinical and clinical trials and represent exciting alternatives to standard arrhythmia treatment. We also present an overview of the various methods used to assess autonomic tone, including heart rate variability, skin sympathetic nerve activity, and alternans, which can be used as surrogate markers and predictors of the treatment effect. Although the use of autonomic modulation to treat cardiac arrhythmias is supported by strong preclinical data and preliminary studies in humans, in light of the disappointing results of a number of recent randomized clinical trials of autonomic modulation therapies in heart failure, the need for optimization of the stimulation parameters and rigorous patient selection based on appropriate biomarkers cannot be overemphasized.

Heart failure with preserved ejection fraction: mechanisms, clinical features, and therapies

The clinical syndrome comprising heart failure (HF) symptoms but with a left ventricular ejection fraction (EF) that is not diminished, eg, HF with preserved EF, is increasingly the predominant form of HF in the developed world, and soon to reach epidemic proportions. It remains among the most challenging of clinical syndromes for the practicing clinician and scientist alike, with a multitude of proposed mechanisms involving the heart and other organs and complex interplay with common comorbidities. Importantly, its morbidity and mortality are on par with HF with reduced EF, and as the list of failed treatments continues to grow, HF with preserved EF clearly represents a major unmet medical need. The field is greatly in need of a more unified approach to its definition and view of the syndrome that engages integrative and reserve pathophysiology beyond that related to the heart alone. We need to reflect on prior treatment failures and the message this is providing, and redirect our approaches likely with a paradigm shift in how the disease is viewed. Success will require interactions between clinicians, translational researchers, and basic physiologists. Here, we review recent translational and clinical research into HF with preserved EF and give perspectives on its evolving demographics and epidemiology, the role of multiorgan deficiencies, potential mechanisms that involve the heart and other organs, clinical trials, and future directions.

Application in Hypertension of Renal Sympathetic Denervation - A Review

Afferent and efferent sympathetic nerves of the kidney located in the adventitia of the renal artery are involved in the regulation of blood pressure and play a pathophysiological role in the progression and maintenance of hypertension. Renal sympathetic denervation is a potent and safe catheter-based therapeutic approach for the treatment of patients with resistant hypertension. Clinical trials of renal sympathetic denervation have shown significant reduction in blood pressure, which was associated with a reduction in local renal norepinephrine spillover as well as a reduction of whole body sympathetic activation in resistant hypertensive patients.