Secondary hypertension

Epidemiology

In ALLHAT trial, about 30% of patients had resistant hypertension
In a hypertension clinic, 6% of patients referred to them had secondary hypertension

Medication/lifestyle non-adherence
- Salt intake
- NSAIDs
- Stimulants
- Alcohol
- Withdrawal from medications or recreational drugs
- Pain
Poor medication choice
- White coat hypertension
- Transient hypertension
Drugs: glucocorticoids, stimulants (including caffeine, pseudephedrine, cocaine), OCP, NSAIDs
Renal causes
- Renal artery stenosis
- Fibromuscular dysplasia (FMD)
- Polyarteritis nodosa (PAN)
- Systemic sclerosis
- Intrauterine growth restriction (IUGR)
Endocrine causes
- Hyperaldosteronism
- Pheochromocytoma
- Thyroid disease
- Hyperparathyroidism
Other
- Obstructive sleep apnea
- Drugs/alcohol

All patients should be screened for OSA and intrinsic renal disease with urinalysis
Symptomatic presentation with urgency or emergency
Younger than 20 years or older than 50 years
Unprovoked hypokalemia or hypokalemia on low-dose diuretic

BMI and waist circumference
Proper BP including bilateral and orthostatic
ABPM is best >> AOBP > ROBP > casual office BP
- Ideally includes nocturnal sleeping BP
Evidence of end-organ damage
Evidence of endocrine/secondary causes
- Cushingoid?
- Coarctation
RAS

Urinalysis in all people
STOP-BANG or sleep study in all people
Electrolytes, creatinine, CBC
TSH, calcium/albumin, urinalysis, A1c, lipids
Consider
- CXR showing rib notching for coarctation (from enlarged intercostal arteries)
- Renin-aldosterone (renin better than aldo, if only one is available)
If renin suppressed, is essentially diagnostic for primary hyperaldosteronism
Try to get them off RAS-inhibiting therapies (use alpha-blockers and CCBs instead)