Resistant hypertension

Hypertension, or high blood pressure, is a major public health concern. As a world-wide epidemic, hypertension is estimated to affect 1 billion people and results in approximately 7.1 million deaths per year globally1. Moreover, the prevalence of hypertension elevates with age and it is correlated with cardiovascular complications, diabetes and kidney pathologies (REF-Kearney 2005).
First line therapy for hypertension includes changes in lifestyle and diet, alongside with a variety of anti-hypertensive medications. However, in a significant percentage of patients, hypertension remains uncontrolled despite adherence to these conventional pharmaco-therapy regimens. This population is defined as refractory or resistant hypertensive patients. Recent studies have shown that patients with resistant hypertension were almost 50% more likely to suffer from a cardiovascular event (death or myocardial infarction, heart failure, stroke or chronic kidney disease) over a median 3.8 years of follow-up compared with patients without resistant hypertension. 2
Therefore, there is a vital need to find novel second-line treatments for resistant hypertension. In general, the sympathetic nervous system is responsible for the body reaction to stress (commonly called "fight or flight response"). Animal studies and later human trials demonstrated that the sympathetic nervous system, in particular sympathetic neural signals to and from the kidneys, plays an important role in regulating blood pressure. Conversely, hyperactivity of the sympathetic nervous system contributes to the development and progression of hypertension and associated pathologies (DiBona and Kopp, 1997, Krum et al., 2011).  This led to the discovery that deactivation of the sympathetic nerves around the renal arteries, namely renal denervation, offers an innovative therapy for millions of patients with resistant hypertension. Renal denervation was performed surgically at the 1930-1950s, however with severe complication. Nowadays, renal denervation is performed with minimally invasive catheter-based methods, based on nerve ablation by radiofrequency or ultrasound energy.  Up to date data shows significant and sustained BP reduction for 3 years following catheter-based renal denervation.

 The TIVUS™ System developed by Cardiosonic is a high-intensity, non-focused therapeutic ultrasound catheter and control system. The TIVUS™ System is intended to induce remote tissue ablation to achieve renal denervation in resistant hypertensive patients. The TIVUS™ System enables fast and controlled renal denervation treatment without damaging the arterial wall. Additionally, the TIVUS™ system has the potential to overcome current anatomic and physiologic restrictions and contraindications, what will expand the target patients' populations, which are ineligible to other renal denervation methods.
1 Challenges and Opportunities In The Renal Denervation Market, July 2013, ISBN: 978-1-909584-29-7, Espicom Business Intelligence
2 Incidence and prognosis of resistant hypertension in hypertensive patients, Daugherty SL, Powers JD, Magid DJ, Tavel HM, Masoudi FA, Margolis KL, O'Connor PJ, Selby JV, Ho PM.