ISCHEMIC STROKE / PREVENTION / RISK FACTORS

Arterial hypertension

Created 20/02/2023, last revision 28/04/2023

2022 – WHO guideline for the pharmacological treatment of hypertension in adults

2018 – ESC/ESH Guidelines for the management of arterial hypertension

Definition of hypertension

hypertension is defined as office SBP values ≥ 140 mmHg and/or diastolic BP (DBP) values ≥ 90 mmHg (ESC 2018)
this is based on evidence from multiple RCTs that treatment is beneficial in patients with these BP levels

Hypertension and the risk of stroke

arterial hypertension is the major cardiovascular risk factor
treatment of hypertension reduces the risk of stroke and cerebrovascular mortality and slows the progression of potential carotid stenosis
- the HOPE (Heart Outcomes Prevention Evaluation) trial demonstrated the effect of ramipril 10mg in the prevention of stroke – a 31%/5 year decrease in RR (156 vs. 226 events, ARR 1.5%, p = 0.0002). About 46% of the study population was hypertensive [Bosch, 2002]
- PROGRESS (Perindopril protection against recurrent stroke study) – 28% rel. stroke risk reduction in 4 years, ARR 4%/4 years
- LIFE (losartan) – 21% stroke risk reduction [Dahlöf, 2002]
- SYST-EUR – 42% stroke risk reduction in elderly patients with systolic hypertension [Staessen, 1997]
the benefit is also present in people > 80 years of age (HYVET trial)
in the prevention of stroke, it is the absolute value of the blood pressure reduction that is important, not the type of antihypertensive drug
- BP control must be consistent to reduce the risk of vascular events [Towfighi, 2014]
BP lowering in stroke prevention is also beneficial in normotensive patients (see HOPE, PROGRESS)
according to the SPRINT trial, CV risk reduction is more pronounced with a target SBP < 120 mm Hg compared to SBP < 140 mm Hg

hypertension and stroke risk - Lewington

Blood pressure classification

it is recommended that BP be classified as optimal, normal, high–normal, or grades 1–3 hypertension, according to office BP (ESC 2018 I/A)

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Diagnostic evaluation

the purpose of the clinical evaluation is to:
- determine the diagnosis and grade of hypertension
- screen for potential secondary causes of hypertension
- identify factors potentially contributing to the development of hypertension (lifestyle, concomitant medications, or family history),
- identify concomitant CV risk factors (including lifestyle and family history)
- identify comorbidities
- establish whether there is evidence of hypertension-mediated organ damage (HMOD) or existing cardiovascular, cerebrovascular, or renal disease

Cut-offs for diagnosis of hypertension

Definition of hypertension according to different methods of BP measurement
Category	Systolic BP (mmHg)	Diastolic BP (mmHg)
Office BP	≥ 140	≥ 90
ABPM, daytime mean	≥ 135	≥ 85
ABPM, nighttime mean	≥ 120	≥ 70
ABPM, 24h mean	≥ 130	≥ 80
HBPM (home measurement)	≥ 135	≥ 85

all hypertensive patients	in selected patients
medical history and physical examination	HBPM, ABPM
office BP measurement	ABI
urine analysis: microscopic examination; urinary protein by dipstick test or, ideally, albumin: creatinine ratio	fundoscopy
fasting blood glucose and glycated HbA1c	microalbuminuria detection
Na, K, urea, uric acid	echocardiography
liver function tests	carotid ultrasound
creatinine and eGFR	abdominal ultrasound and Doppler studies
CBC	cognitive function testing
lipids (total cholesterol, LDL, HDL, triglycerides)
12-lead ECG

Blood pressure measurement techniques

a sphygmomanometer is a device used to measure blood pressure
it consists of:
- an inflatable rubber cuff (of proper size)
- the machine that records the pressure
- the mechanism for inflation (manually operated bulb+valve or an electrically operated pump)
manual vs. digital
- manual (stethoscope using the auscultatory technique)
  - aneroid (mechanical types with a dial) – may require calibration checks
  - mercury (gold standard) – the pressure is indicated by a column of mercury; it does not require recalibration and has high accuracy
- digital (oscillometric)
  - may use manual or automatic inflation, but both types are electronic, easy to operate without training, and can be used in noisy environments
  - calibration is also a concern

Office BP measurement

the auscultation method is more accurate than the oscillometric method
adequate cuff size is required (the cuff’s bladder length should be at least equal to 80% of the upper arm circumference )
- arm circumference < 35 cm – cuff 16×30 cm (for most patients)
- arm circumference 35-44 cm – cuff 16×36 cm
- arm circumference > 45 cm – cuff 16×42 cm
the cuff should be positioned at heart level, with the back and arm supported to avoid muscle contraction and isometric exercise-induced increases in BP

the patient should be seated comfortably for 5-10 min before beginning BP measurements; the forearm is loosely supported at heart level
measure BP on both arms at the first visit
- use the arm with the higher readings as the reference
three BP measurements should be recorded, 1–2 min apart; BP is recorded as the average of the last two BP readings
- additional measurements are suggested only if the first two readings differ by >10 mmHg
auscultatory methods use phase I (appearance) and V (sudden reduction/disappearance) Korotkoff sounds to identify SBP and DBP, respectively
- in patients with high cardiac minute volume or peripheral vasodilation, Korotkov sounds are sometimes audible down to 0 mm Hg (infinite tone phenomenon). In these situations, we read the diastolic BP as phase IV Korotkov phenomena (sudden attenuation of the sound)
measure BP 1 min and 3-5 min after standing from a sitting position in all patients at the first visit to exclude orthostatic hypotension
lying and standing BP measurements should also be considered in subsequent visits in the elderly, those with diabetes and other conditions in which orthostatic hypotension is common
record the heart rate and use pulse palpation to exclude arrhythmia

Ambulatory BP Monitoring (ABPM)

Indication for 24h Holter monitoring

increased BP variability
discrepancies between home and office BP (white coat phenomenon)
masked hypertension – higher home BP and normal office BP
treatment resistance
suspected episodes of hypotension (especially in the elderly and diabetics)
elevated BP in pregnancy and suspected eclampsia

Normal BP

24-hour average BP ≤ 130/80 mm Hg
daily average ≤135/85 mm Hg
nighttime average BP ≤ 120/70 mm Hg

Home BP Monitoring (HBPM)

improves patient cooperation and compliance, reduces the effect of white coat syndrome, reveals daytime BP fluctuations
measurement technique:
- rest 5-10 minutes before measurement + no major physical activity 30 minutes before measurement
- sitting upright, feet on the floor, uncrossed
- arms supported on a table at heart level
- 2 measurements 1 minute apart, morning and evening
- record the results in BP diary

Cardiovascular risk assessment

hypertension rarely occurs in isolation and often clusters with other CV risk factors such as dyslipidemia and glucose intolerance (metabolic syndrome)
the metabolic risk factor clustering has a multiplicative effect on CV risk
CV risk assessment with the SCORE system (i.e., the likelihood of a person developing a CV event over a defined period of time) is recommended for hypertensive patients who are not already at high or very high risk due to established CVD, renal disease, or diabetes, a markedly elevated single risk factor (e.g., cholesterol), or hypertensive LVH

Management

Target BP values

the general principle is to initiate pharmacologic antihypertensive treatment in all patients with SBP ≥140 mmHg or DBP ≥90 mmHg
target BP value for people at particular risk (including a history of stroke/TIA, diabetes, CKD): < 130/80 mmHg
- supported by data from a large meta-analysis of RCTs [Katsanos, 2016]
- in patients with increased vascular risk, initiate therapy at BP > 130 mmHg!
in patients with the steno-occlusive carotid disease or advanced arteriolopathy, BP should be lowered slowly and cautiously because of the increased risk of hypoperfusion (individual BP target around 135-139/85-89 mmHg )
the effect of therapy does not depend on the type of antihypertensive but on the blood pressure achieved
- when choosing a drug, consider comorbidities, interactions, and patient preferences

ESC guidelines 2018

the first objective is to lower BP to <140/90 mmHg
- high normal BP (130–139/85–89 mmHg) – drug treatment may be considered when CV risk is very high due to established CVD, especially CAD
patients <65 years of age: SBP should be lowered to 120–129 mmHg in most patients if tolerated
patients >65 years: target SPB 130–139 mmHg
patients >80 years: target SPB 130–139 mmHg if tolerated
target DPB <80 mmHg should be considered for all hypertensive patients, regardless of risk level and comorbidities

WHO guidelines 2022

Lifestyle modification and treatment of other vascular risk factors

→ screening and management of other modifiable vascular risk factors

Antihypertensive drugs

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