Indexed on: 17 Jul '14Published on: 17 Jul '14Published in: Kidney International Supplements
Resistant hypertension, defined as blood pressure (BP) remaining above goal despite the use of 3 or more antihypertensive medications at maximally tolerated doses (one ideally being a diuretic) or BP that requires 4 or more agents to achieve control, occurs in a substantial proportion (>10%) of treated hypertensive patients. Refractory hypertension is a recently described subset of resistant hypertension that cannot be controlled with maximal medical therapy (⩾5 antihypertensive medications of different classes at maximal tolerated doses). Patients with resistant or refractory hypertension are at increased cardiovascular risk and comprise the target population for novel antihypertensive treatments. Device-based interventions, including carotid baroreceptor activation and renal denervation, reduce sympathetic nervous system activity and have effectively reduced BP in early clinical trials of resistant hypertension. Renal denervation interrupts afferent and efferent renal nerve signaling by delivering radiofrequency energy, other forms of energy, or norepinephrine-depleting pharmaceuticals through catheters in the renal arteries. Renal denervation has the advantage of not requiring general anesthesia, surgical intervention, or device implantation and has been evaluated extensively in observational proof-of-principle studies and larger randomized controlled trials. It has been shown to be safe and effective in reducing clinic BP, indices of sympathetic nervous system activity, and a variety of hypertension-related comorbidities. These include impaired glucose metabolism/insulin resistance, end-stage renal disease, obstructive sleep apnea, cardiac hypertrophy, heart failure, and cardiac arrhythmias. This article reviews the strengths, limitations, and future applications of novel device-based treatment, particularly renal denervation, for resistant hypertension and its comorbidities.