HTN Flashcards
Persistently elevated BP an important modifiable risk factor for what conditions
Stroke, MI, HF, AF, kidney disease, cognitive decline
Risk factors for HTN
Age ≥ 65
Male sex
Excess body weight
Sedentary lifestyle
Kidney dysfunction
Psychosocial or socioeconomic factors
Diabetes
High LDL-C/triglycerides
Sustained resting HR < 80
Personal/fam hx CVD/HTN
Early onset menopause
Smoking (current or past)
If a patient has a BP ≥130/80 what 4 things should you do in order to make a diagnosis of HTN?
Confirm elevated BP
Assess CVD risk (incl kidney function)
Determine if any end organ damage (including CKD)
Identify any causes of secondary HTN
How many BP readings do you need to confirm an elevated BP?
≥ 2 measurements, ≥ 2 mins apart + repeated on a different day with appropriately sized BP cuff
(Ideally also do measurement in both arms)
Why would you measure BP in both arms?
Consistent SBP difference ≥10 between arms = increased risk CVD
On average BP is ____________ in clinic vs at home/ambulatory monitoring
5-10 mmHg higher
24hr ambulatory monitoring (gold standard) or home monitoring should be done if able to rule out …..
White-coat HTN (BP elevated despite no obvious risk factors)
Masked HTN (BP normal but clinical features consistent with HTN e.g. end organ damage)
Why include CVDRA as part of the diagnosis of HTN?
CVDRA forms basis for discussions about prognosis + treatment options and provides info about other risk factors affecting cardiovascular management e.g. diabetes, CKD, prevention of MI/CVA
How do you determine if there is any end organ damage?
Urine dip for blood/protein. Send uACR.
Bloods - UEC, lipids, HbA1c
ECG - assess for LVH, AF, evidence of historical IHD. Consider echo if needed.
Sx indicating end organ damage e.g. chest pain, SOB, visual disturbances, transient focal weakness
Ophthalmoscopic exam of fundus esp if visual disturbance
What is the cause of primary (essential) hypertension?
No clinically identifiable cause
Likely a complex interplay of genetic predisposition, environmental factors & age-associated stiffening of blood vessels
How common is secondary hypertension?
~1/10 patients with HTN have an underlying condition or stressor (secondary HTN)
Who should you suspect secondary HTN in?
Young (<30yo) without fam hx HTN or other risk factors
What are the secondary causes of HTN?
High alcohol intake
Illicit drugs e.g. amphetamine or cocaine
Medications
OSA
Aortic coarctation
Renovascular or primary renal disease
Renal parenchymal disease (including glomerulonephritis)
Endocrine disorders
What is considered high alcohol intake as a secondary cause of HTN?
Consistently >10 std drinks per week females; >15 males
What medications can be a cause of secondary HTN?
Oral contraceptives
Corticosteroids
NSAIDs
Ciclosporin
Decongestants
What features would suggest renal parenchymal disease as a secondary cause of HTN?
Hx of UTI or obstruction
Haematuria
Analgesic misuse
Fam hx PKD
What endocrine disorders can be causes of secondary HTN?
Cushing’s syndrome (excessive cortisol production)
Conn’s syndrome (hyperaldosteronism, excessive aldosterone production)
Phaechromocytoma (rare adrenal gland tumour)
Hypo/hyperthyroidism
How common is elevated uACR in HTN?
Elevated uACR is common in HTN. 1:2 newly diagnosed patients have evidence of microalbuminuria and 1:5 have evidence of macroalbuminuria
Definition microalbuminuria and macroalbuminuria
Micro = ACR 3-30
Macro = ACR >30
Elevated uACR is strongly associated with increased risk of __________ and therefore an important part of CVDRA in patients with HTN
CVD and death
If low CVDRA (e.g. <5%) but renal impairment/proteinuria - should you start antihypertensives?
Antihypertensive treatment should still be considered. ACEi/ARB at max tolerated dose should be prioritised to optimise their antiproteinuric effect
Lifestyle management of HTN
Wt loss
Healthy diet (DASH) + reduced sodium
Physical activity
Smoking cessation
Reducing alcohol
How much does weight loss impact BP?
SBP decreases ~1-2mmHg per kg lost.
When to initiate antihypertensive medicines
BP ≥ 160/100 - initiate immediately + lifestyle changes (regardless of CVDRA)
Otherwise if BP persistently ≥ 130/80 → calculate 5yr CVD risk to guide decision
When start start antihypertensives based on CVDRA
Risk <5% = lifestyle changes, medication not recommended
Risk 5 - 15% = consider medication if BP ≥140/90 + lifestyle changes
Risk ≥15% = medication recommended + lifestyle changes
If low CVDRA (<5%) but renal impairment/proteinuria - consider BP medication
What options are available as first line antihypertensives in NZ
ACEi/ARB
CCB
Thiazide and thiazide-like diuretics
All equally effective
Two options for starting antihypertensives
Start with single medication or two low dose (dual antihypertensive treatment)
BP lowering effect of any single antihypertensive at optimal dose ________ on average
<10mmHg
(initial monotherapy unlikely to be effective in many patients)
Half standard dose of any first line med provides _______ BP lowering effect
~80% max
Is it more effective to have 2 low dose antihypertensives or double the dose of one
Two low dose meds used together ~5x more effective at lowering BP than doubling dose of a single antihypertensive (and less risk of adverse effects)
Generally takes _______ weeks to reach max effect from antihypertensive treatment
4 - 6 weeks
When might you consider beta blockers early in antihypertensive treatment
IHD (help decrease HR, increase diastolic filling time, decrease cardiac contractility and reduce myocardial O2 demand)
AF (HR control)
Preferred choice of antihypertensive if also has gout
Losartan (cause excretion uric acid)
Antihypertensive to avoid if also has gout
Thiazide (promote urate reabsorption in proximal renal tubules)
When should you consider referral to secondary services
BP is ≥ 180/110 mmHg and there are signs of end organ damage (malignant hypertension), e.g. abnormalities on ECG
Or if the patient is pregnant.
What antihypertensive/s may be preferred in a patient with CKD
Prioritise ACEi/ARB (max tolerated dose)
Calcium channel blockers
Loop diuretics (if eGFR < 30)
What antihypertensive/s should you avoid in patients with CKD
Thiazides in patients with more than mild renal impairment
What antihypertensive/s may be preferred in a patient with diabetes
Prioritise ACEi or ARB
Thiazide (or thiazide-like) diuretic
Calcium channel blocker
What antihypertensive/s should you avoid in patients with diabetes
Beta-blockers
High dose thiazide diuretics (low doses are acceptable)
What antihypertensive/s may be preferred in a patient with HF or asymptomatic LV dysfunction
ACEi/ARB or ARNI first line
What antihypertensive/s should you avoid in patients with HF or asymptomatic LV dysfunction
Non-dihydropyridine calcium channel blockers (e.g. diltiazem, verapamil)
Beta-blockers in patients with uncontrolled HF
What antihypertensive/s may be preferred in a patient with acute MI
B-blockers without intrinsic sympathomimetic activity, e.g. carvedilol
ACE inhibitors or ARBs
What antihypertensive/s should you avoid in patients with acute MI
No specific cautions
What antihypertensive/s may be preferred in a patient with AF
Beta-blockers
Rate limiting CCB e.g. diltiazem
ACE inhibitors or ARBs
What antihypertensive/s should you avoid in patients with AF
No specific cautions
What antihypertensive/s may be preferred in a patient with angina
Beta-blockers
Calcium channel blockers
ACE inhibitors or ARBs
What antihypertensive/s should you avoid in patients with angina
No specific cautions
What antihypertensive/s may be preferred in a patient with stroke
ACE inhibitors or ARBs
Calcium channel blockers
Low-dose thiazide diuretics
What antihypertensive/s should you avoid in patients with stroke
Beta-blockers
Thiazide diuretics in very elderly or poor daily fluid intake as they could contribute to hypoperfusion
What antihypertensive/s may be preferred in a patient with asthma/COPD
No specific recommendations
What antihypertensive/s should you avoid in patients with asthma/COPD
B-blockers, however, low-dose bisoprolol (or metoprolol) can be used if required in patients with asthma/COPD and HF
What antihypertensive/s may be preferred in a pregnant patient
Labetalol, Nifedipine, Methyldopa
What antihypertensive/s should you avoid in pregnant patients
ACE inhibitors and ARBs
Target BP based on NZ MoH 2018 guidelines
<130/80 for most people
International guidelines recommend _________ BP targets based on _________
Individualised BP targets based on CVD risk, comorbidities and treatment objectives
Individualised BP target for high CVD risk
<130/80 (clinic)
<125/80 (24 hour ambulatory)
What is considered high CVD risk for individualised BP targets
Current atherosclerotic CVD
HF
Reduced EF
Diabetes
CKD
≥ 65yo
5yr CVD risk ≥ 15%
Individualised BP target for low CVD risk
< 140/90 mmHg (clinic)
< 135/90 mmHg (24 hour ambulatory)
What is considered low CVD risk for individualised BP targets
None of the risk factors mentioned for high risk
What other situations might an individualised BP target be lower/different
Frailty
Dementia
Limited life expectancy
Should you be concerned about giving antihypertensives in elderly?
No reason to withhold antihypertensives based on age alone
BP management one of the few interventions that reduces mortality risk in frail elderly
How can you reduce adverse effects in elderly when prescribing antihypertensives
Start with low dose monotherapy. Gradually reducing BP less likely to cause adverse effects e.g. postural hypotension
Close monitoring and more lenient targets appropriate. Treatment intensity should be reduced if concerning emerging features e.g. cognitive impairment, more frail
F/up timing when starting antihypertensives
Every 4-6 weeks (or sooner if BP significantly elevated at baseline)
Once BP target achieved review 3-6 monthly or annually if stable and good adherence
Definition of resistant hypertension
BP remains >140/90 despite treatment with ACEi/ARB, CCB and thiazide at optimal dose
Management of resistant hypertension
Check adherence & possible secondary causes. Emphasize lifestyle changes. Specialist advice.
What additional medications may be considered for resistant hypertension
Spironolactone
Betablocker
Alpha blocker e.g. doxazosin
