Hypertension
Overview
Aim for 120/80 if able but a general target <140/90 is acceptable. Damage starts above 115/75. Every 20/10 above this doubles the risk of a cardiovascular event.
Definition
Normal = <120/80
Elevated = 120-129/80
Hypertension
Stage 1 = SBP 130-139 or DBP 80-89
Stage 2 = SBP >140 or DBP > 90
24-hour ambulatory definitions of HTN
Average of >125/75
Day >130/80
Night >110/65
Primary HTN Risk Factors:
Age
Obesity
Family history
Fewer nephrons
High sodium diet
Excess alcohol
Physical inactivity
Social determinants
Secondary causes
Medications
Oral contraceptive
NSAIDs
Antidepressants
Corticosteroids
Decongestants
Weight loss medications
Stimulants
Illicit drugs
Primary kidney disease
Primary aldosteronism
Renovascular hypertension
Obstructive sleep apnoea
Phaeochromocytoma
Coarctation of the aorta
Endocrine conditions
Cushing’s Syndrome
Hypothyroidism
Hyperthyroidism
Hyperparathyroidism
Complications of HTN
Risk begins to start with blood pressure >115/75
For every 20/10 increase, the risk of death from heart disease doubles
Left ventricular hypertrophy
Heart failure
Ischaemic stroke
Intracerebral bleed
Ischaemic heart disease
Chronic kidney disease
Evaluation
Once established check for
The extent of end-organ damage
Presence of CVD or CKD
Check cardiovascular risk factors
Lifestyle factors that could contribute
Potential interfering substances
Tests
FBC, UEC, Lipids, Glucose, TSH, CMP
ECG
Calculate 10-year risk
Urinalysis + ACR
Consider echo
Consider testing secondary causes but these are rare
Lifestyle
Weight Loss - Best goal is ideal body weight. If above a healthy weight range, expect roughly a 1 point drop for every 1 kg weight lost. Drop of 5 points for 5kg loss
Healthy Diet - Diet rich in fruits, vegetables, whole gains, low-fat dairy, and reduced saturated and total fat. Drop of 11 points.
Less Salt - Optimal goal is <1.5g total salt per day. But aim for a reduction of at least 1g / day. Drop of 5 points
More Potassium - Aim for 3.5 to 5g per day, preferably by increasing potassium in the diet. Drop of 4 points
Exercise - Aerobic or resistance exercise for 90 to 150 minutes per week. Drop of 4 to 8 points
Less Alcohol - In people who drink alcohol, reduce alcohol to <2 drinks per day for men and <1 drink per day for women. Drop of 4 points
Outcomes
Treatment with medication produces
50% risk reduction in heart failure
35% risk reduction in stroke
25% risk reduction in heart attack
This means 100 patients need to be treated for 5 years to prevent an adverse cardiovascular event in 2 patients.
Medication
Three primary options for most patients
ACEI or ARB
Calcium channel blocker
Thiazide
Start at the lowest dose
If not to target add 2nd agent
Titrate up one of the agents
If still not at target, add a third agent
Combinations to avoid
ACE inhibitor or ARB plus potassium-sparing diuretic – risk of hyperkalaemia.
beta blocker plus verapamil or diltiazem – risk of heart block.
ACE inhibitor plus ARB – increased risk of hypotensive symptoms, syncope, and renal dysfunction.
Thiazide diuretic and beta-blocker – not recommended in patients with glucose intolerance, metabolic syndrome, or established diabetes.
NSAIDs with ACE inhibitors, ARB, diuretics, and beta blockers.
Effective combinations
ACEI or ARB and Ca2+ blocker – Diabetes or lipid abnormalities
ACEI or ARB and thiazide diuretic – Heart failure, or post stroke
ACEI or ARB and beta-blocker – Myocardial infarction (MI) or heart failure
Beta-blocker and dihydropyridine calcium channel blocker – Heart disease
Reference:
Hypertension - UpToDate
Hypertension - HNE Pathways