Renal Sympathetic Denervation in the Treatment of Resistant Hypertension

The diagnosis of resistant hypertension is made when a patient's blood pressure(BP)is not under control after taking appropriate lifestyle measures and treatment with optimal or best-tolerated doses of 3 antihypertensive medications (a diuretic should be 1 component) for at least 4 weeks or 4 drugs are required to control BP. The inadequate BP control is confirmed by BP measurements of office and out-of-office (ambulatory BP monitoring and Home BP monitoring). Resistant hypertension lacks effective treatment. As a treatment method of resistant hypertension, the pathophysiology of renal sympathetic denervation(RDN) has been confirmed by basic research. Although early studies using the first-generation came to different conclusions, recent clinical trials have reached a positive result with a radiofrequency ablation system of the second-generation.However, the evaluation method for the activity of the renal sympathetic nerve is not clear so that it is hard to accurately screen out the patients who are appropriate for RDN. The clinical application of RDN is still controversial.