REN and hypertensive disorder: R-HTN is considered when failing to lower BP below 140/90 mmHg despite adequate lifestyle measures and optimal treatment with at least three antihypertensive medications of different classes, including a diuretic, typically a blocker of the renin-angiotensin system (angiotensin converting enzyme inhibitor or angiotensin receptor blocker) and a long-acting calcium channel blocker (CCB), at maximum or maximally tolerated daily doses administered at the appropriate dosing interval [4].