Difficult-to-Treat or Resistant Hypertension: Etiology, Pathophysiology, and Innovative Therapies

Despite the many therapeutic options available today for the treatment of hypertension, a sizable number of patients still remain resistant to treatment. The prevalence of resistant hypertension in the general population under optimal conditions is about 3–5%. Although several factors and conditions can be identified and corrected a percentage of hypertensive patients remain with unacceptably high blood pressure levels. The high prevalence of hypertension in the general population renders this small percentage significant, in terms of actual patient numbers. This special issue of the journal expoars a whole spectrum of topics related to resistant hypertension: several articles address pathophysiolog and secondary causes of resistant hypertension and modern approaches to therapy. Of interest is the referance to the newer interventional approaches, that is, Baroreceptor stimulation therapy and catheter based sympathetic renal denervation. 1. Approaches to Diagnosis and Treatment of Difficult-to-Treat or Resistant Hypertension Resistant or difficult-to-control hypertension is becoming an increase burden in our society. Although with the many medical approaches available to us we can currently control the majority of patients with hypertension, a sizable number still remain resistant to treatment. The prevalence of resistant hypertension in the general population is difficult to determine accurately, but depending on the population and the center reporting it ranges from 5% to 30% [1, 2]. In specialized clinics utilizing optimal medical regimens the prevalence is closer to 3–5%. Although several factors and conditions can be identified and corrected (poor patient adherence, physician inertia, inappropriate drug combinations or inadequate dosing, drug-induced hypertension, and secondary causes), the fact is that a percentage of hypertensive patients remain with unacceptably high blood pressure levels. The high prevalence of hypertension in the general population renders this small percentage significant, in terms of actual patient numbers. The above, combined with several limitations in drug therapy (patient adherence, polypharmacy, and drug adverse effects), create the need for other therapeutic options, beyond existing antihypertensive medications, setting the basis for interventional approaches [3–5]. Recently two new innovative, still experimental interventional approaches to treat “resistant or difficult-to-control hypertension” have been explored: the baroreceptor stimulation with the Rheos device and sympathetic renal denervation using radiofrequency