Hypertension

Diagnosing hypertension

• Definition: BP >140/90 (isolated systolic hypertension sBP>160; dBP<90)
• No target end organ damage – 3 visits of sBP>160 or dBP>100
• Target end organ damage (CAD, cerebrovascular disease, peripheral vascular disease, renal insufficiency) – diagnosed after 3 visits
• Global cardiovascular risk (age, males, postmenopausal, smoking, high cholesterol, glucose intolerance, family history, obesity)

Primary vs Secondary causes

• 90% primary (essential)
• Secondary
  • Renal 5%
  • Endocrine 5% (BCP, primary hyperaldosteronism, pheochromocytoma, Cushing’s, hyperparathyroidism)
  • Coarctation (0.2%)
  • Drug induced (corticosteroids, NSAIDs, MAOI, cocaine, amphetamines)
  • Obstructive sleep apnea
  • Enzymatic defects
  • Neurologic disorders

 

Appropriate treatment for primary hypertension

• Sodium reduction, weight loss, alcohol reduction, exercise, diet (DASH)
• Lifestyle modifications – follow 3-6months
  • Sodium 90-130 mmol/day
  • Lose weight – goal BMI ≤25
  • Exercise 50-60 minutes, moderate intensity, 3-4 times/week
  • Alcohol ≤2 drinks/day (weekly: no more than 14 in men, 9 in women)
  • Canadian food guide to healthy eating
• On medical therapy follow monthly until 2 readings below target, then at 3-6 month intervals
  • Indications: dBP>90 with target end organ damage; without target end organ damage or CAD risk factors dBP>100 or sBP>160
  • First line: thiazide diuretic, beta-blocker, ACEi, long acting dihydropyridine CCB, AR
    • Partial response: consider combination (thiazide/CCB + ACEi/ARB/BB)
  • For ISH first line: thiazide diuretic, long acting dihydropyridine CCB, ARB
  • For stable angina first line: beta blockers or long acting CCB (if >55yo consider adding ACEi)
  • Recent MI first line: beta blockers, ACEi or both
  • Heart failure first line: ACEi, beta blockers, diuretics
  • Renal disease first line: ACEi
  • Diabetes first line: ACEi or ARB; consider adding both, thiazide, long acting CCB

Common medication doses

• Thiazide diuretics: Hydrochlorothiazide 12.5 – 25 mg/day
• ACEi:
  • Enalapril (Vasotec) 2.5-40mg daily or divided bid
  • Ramipril (Altace) 2.5-20 mg daily or divided bid
  • Quinapril (Accupril) 10-80mg daily or divided bid
• ARB:
  • Candesartan (Atacand)
  • Losartan (Cozaar)
  • Valsartan (Diovan)
  • Irbesartan (Avapro)
  • Telmisartan (Micardis)
• Beta blockers: Metoprolol, Bisoprolol, Atenolol
• Long acting CCB:
  • Amlodipine (Norvasc)
  • Nifedipine (Adalat CC)

Management of chronic hypertension

• Goal BP: <140/90 (in DM or renal disease <130/80)

Side effects of hypertensive medications

• Thiazide diuretics: erectile dysfunction, hypokalemia, renal dysfunction, dylipidemia, hyperglycemia
• ACEi: cough, hyperkalemia, metallic taste, dizziness, kidney failure, decrease in WBCs, angeioedema
• ARB: cough, hyperkalemia, metallic taste, dizziness, kidney failure, decrease in WBCs, angeioedema
• Beta blockers: depression, fatigue, nightmares, sexual impotence in males, increased wheezing in people with asthma
• Long acting CCB: ankle swelling, arrhythmia, tachycardia, breathing difficulty, diarrhea/constipation, flushing, headache, swollen joints

Investigations

• Routine laboratory tests for the investigation of all patients with hypertension:
• Urinalysis
• Complete blood cell count
• Blood chemistry (potassium, sodium, and creatinine)
• Fasting glucose
• Fasting total cholesterol and high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, triglycerides
• ECG

For specific patient subgroups:

• For those with diabetes or renal disease: assess urinary protein excretion, since lower blood pressure targets are appropriate if proteinuria is present.
• For those with an increased creatinine, history of renal disease or proteinuria: renal ultrasound to assess kidney size and exclude obstruction.