Effects of Renal Sympathetic Denervation on the Cardiac and Renal Functions in Patients With Drug-resistant Hypertension Through MRI Evaluation

Inclusion Criteria: * Subject must be able and willing to comply with the required follow-up schedule * Therapeutic Goods Association approved indications for EnligHTN™ Renal Denervation System * Subject is ≥ 18 years of age at time of consent Subject has office SBP ≥ 160 mmHg (except for subjects with Diabetes Mellitus who must demonstrate an office SBP of ≥ 150 mm Hg) within 14 days of the procedure ◦Subject is taking ≥ 3 antihypertensive medications concurrently at maximum tolerated dose (this must include one diuretic) or subject has a documented intolerance to at least 2 out of the 4 major classes of anti-hypertensives (ACE/ARB, CCB, Diuretics, Beta Blockers and is unable to take 3 antihypertensive drugs. Exclusion Criteria: * Standard CMR exclusions; * implanted cardiac device * intracranial metallic implants * claustrophobia -Gadolinium-specific: estimated GFR \<60 mls/min (usual clinical cut-off is \<30 mls/min). * Adenosine-specific: * asthma / reactive airways disease * \>first degree atrioventricular block * concomitant use of dipyridamole or theophylline consumption of caffeine within 48 hours of proposed investigation * EnligHTN™ Renal Denervation System exclusion criteria: Subject has an identified cause of secondary hypertension * Subject has an estimated GFR \<45 mL/min per 1.73 m2 using the MDRD formula * Subject has undergone prior renal angioplasty, indwelling renal stents, and/or aortic stent grafts * Subject has haemodynamically significant valvular heart disease * Subject has a life expectancy less than 12 months, as determined by the PI * Subject is participating in another clinical study Subject is pregnant, nursing, or of childbearing potential and is not using adequate contraceptive methods * Subject has renal arteries with diameter(s) \< 4 mm in diameter