Resistant Hypertension

[ See Hypertension*]
Terminology sBP dBP  
Normal < 120 < 80  
Pre-hypertension 120-139 80-89  
Hypertension stage 1 140-159 90-99  
Hypertension stage 2 ≥ 160 ≥ 100  
Hypertensive Crisis
(malignant Hypertension)
≥ 180 ≥ 110 NO
end-organ injury
Hypertensive Emergency ≥ 180 ≥ 110 PLUS
End-organ damage


Secondary hypertension young adults
(age 19–39)
Coarctation of the aorta  
Thyroid dysfunction TSH
Rrenal parenchymal disease  
Fibromuscular dysplasia = Renal Artery Stenosis
Middle-aged adults
(age 40–64)
Primary aldosteronism Aldosterone/renin ratio:
- A ratio <20 (when plasma aldosterone is reported in ng/dL and plasma renin activity is in ng/mL/hr) effectively rules out primary hyperaldosteronism.
- A ratio >20 with a serum aldosterone level >15 ng/dL suggests aldosteronism,
- A salt suppression test must be done for confirmation

Treatment: Spironolactone 12.5 - 50 mg po qd (MAX: 200mg/day)
Sleep apnea Sleep Study
Pheochromocytoma Elevated metanephrines
Cushing’s syndrome Elevated 24-hour urinary cortisol

Causes of Secondary HTN

Features of secondary hypertension Possible etiologies
Sudden onset of severe hypertension or newly diagnosed in those <30 yr or >60 yr Renal vascular disease or renal parenchymal disease
Abnormal urinalysis Renal parenchymal/glomerular disease
Hypokalemia and ARR >66.9 ng/dL* Primary hyperaldosteronism
Hypercalcemia Hyperparathyroidism
Fine tremor, heat intolerance, ↓ TSH, ↑ fT4 Hyperthyroidism
Paroxysmal severe HTN, palpitations, HA Pheochromocytoma
Abdominal mass Polycystic kidney disease
Flank bruit Renal artery stenosis
↑ glucose, striae, truncal obesity, etc. Cushing syndrome
Resistant hypertension on three meds Renal vascular/parenchymal disease
Markedly decreased femoral pulses Coarctation of aorta
Central obesity, loud snoring, daytime hypersomnolence, nonrestorative sleep Obstructive sleep apnea

  • Drugs for Resistant Hypertension
    • Treatment options:
        – Typically inadequate diuresis
        – Move to loop diuretic
        – Add spironolactonem OR Chlorthalidone
        – Consider vasodilating β-blocker (carvedilol, labetalol, nebivolol)
        – Consider clonidine, hydralazine, α-blocker


    JAMA 2003:289:2560; NEJM 2003;348:610; JAMA 2002;288:2981; J Clin Hypertension 2007;9:10; Circulation 2007;115:2761.