Resistant High Blood Pressure

What is “Resistant Hypertension”?

A recent article by Dr Malik summaries what we currently do.

Hypertension causes a large disease burden.  It accounts for 62% of strokes and 49% of all cases of heart disease. The aim is to define which group would benefit from specialist therapy. The aim is to get the BP <140/90 is clinic. In addition, if there is renal disease and diabetes, the treatment target is lower, and thus those not meeting the target are more prevalent.

Prevalence is about 8% of the total population. In fact 20% of hypertensives are not adequately controlled in the UK. It could be as high as 35% in other populations. Resistant Hypertension is present in at least 2% of the hypertensives.

 

Definition

 

	BP	Agents	Additional criteria
International Guidelines	Clinic BP >140/90	Three agents including a diuretic
NICE UK guidelines	Clinic BP >140/90	ACEI/ARB plusCCB plusThiazide diuretic	24 HR BP >135/85 (thus excluding white coat effect)

 

Diagnosis

Risk factors for Resistant Hypertension include:

• Demographic:
  • Age>75
  • Female
  • Black
  • Comorbidity
    • Obesity
    • Diabetes mellitus
    • Atherosclerosis
    • Target organ damage
    • Higher baseline Blood pressure/longer duration of High blood pressure
    • High sodium intake
    • Aortic stiffening

 

Step one in diagnosis is to exclude other causes:

Pseudo-resistant Hypertension

1. White coat effect
2. Patient compliance (side effects, cost, understanding (memory/explanation), complicated dosing)
3. Physician factors (poor technique in measuring blood pressure, inadequate dosing, poor combinations)

Investigations

 

• 24 Hour BP monitor to exclude white coat effect
• Discussion with patient to exclude
  • Diet:
    • Excess sodium intake
    • Excess alcohol intake
    • Weight loss advice/DASH diet
    • Liquorice, herbal supplements (bitter orange)
• Drugs
  • Cocaine/amphetamine use
  • Combined contraceptive pill (HRT is not relevant)
  • Steroids
  • Erythropoietin/tacrolimus/ciclosporin
  • Steroids
  • Secondary HT screen
    • Basic screen for complications
      • ECG
      • Echocardiography
      • Urine for protein and blood
      • Basic blood tests for renal disease
      • Fundoscopy
• Glucose/Hba1C for diabetes
• Plasma Renin/Aldosterone to check for rare adrenal tumors
• Urine catecholamines to check for rare adrenal tumors
• HT screen MRI-for Renal artery stenosis/Coarctation/Adrenal adenoma
• Non-pharmacological

Treatments

Address diet sodium/calories/alcohol

Recommend weight loss and exercise

Involve patient in a treatment plan

• Pharmacological
  • After A+C+D therapy consider spironolactone 25-50mg od

If side effects with Spironolactone, the consider epleronone

• Monitor Potassium levels after 2 weeks
• If still not responsive then
  • Betablockers
  • Alpha Blockers
  • MethylDOPA
  • Hydralazine
  • Minoxidil

Device Therapy

Two techniques are available for severe resistant hypertension:

• Renal artery Denervation (RDN)
• Carotid baroreflex activation (CBA)

If you would like to discuss blood pressure with the team please contact us. We offer renal denervation therapy.

 

http://211.144.68.84:9998/91keshi/Public/File/38/345-7884/pdf/bmj.e7473.full.pdf