1. Hypertension, ABPM, targets & when to stop
William Harvey Research Institute
NIHR Bart’s and The London Cardiovascular Biomedical Research Unit
Hypertension, ABPM, targets & when to stop
Dr Melvin D Lobo PhD FRCP FBHS FESC
Director Barts Blood Pressure Clinic
Bart’s Health NHS Trust
Reader in Cardiovascular Medicine
NIHR Barts Cardiovascular Biomedical Research Unit William Harvey Research Institute, QMUL

2. Why bother with hypertension?
Hypertension (high blood pressure) is an important public health challenge worldwide because of its high prevalence and the associated increase in risk of other disease.
It is the most important modifiable risk factor for cardiovascular, cerebrovascular and renal disease,
Hypertension-related morbidity and mortality is preventable

3. Global burden of hypertension
Lancet Jan 15-21;365(9455):217-23
One billion hypertensives worldwide
BP important in 50% of 17.5m deaths
4.5% of global disease burden
2 mm Hg increase in BP = 7% increase in CHD risk and 10% increase in stroke
Treatment ~£1billion P/A in drug costs alone.

4. Health Survey for England 2003-14
In England, the prevalence of HTN in adults has remained at a similar level over the last few years. In 2013 this was 31% (men) and 26% (women).
−  In England, between , the percentage of the population with controlled hypertension increased from 5 – 9% men, and from 6-10% (women).
−  In England, the percentage of men with untreated hypertension decreased from 20% in 2003 to 16% 2013, whilst the percentage of women with untreated hypertension decreased from 16% in 2003 to 11%

5. Cardiovascular Mortality Risk Increases as Blood Pressure Rises*
Lewington S, et al. Lancet. 2002;360: ;
Chobanian AV, et al. JAMA. 2003;289:
Cardiovascular Mortality Risk
Systolic/Diastolic Blood Pressure (mm Hg) 1 2 3 4 5 6 7 8
115/75
135/85
155/95
175/105 2x 4x 8x
*Measurements taken in individuals aged 40–69 years, beginning with a blood
pressure of 115/75 mm Hg.
Cardiovascular Mortality Risk Increases as Blood Pressure Rises
Lewington et al. (2002) evaluated data from approximately 1 million adults who participated in 61 prospective observational studies on blood pressure and mortality. In adults between the ages of 40 and 69 years, each 20/10-mm Hg increase in blood pressure doubled the risk of mortality from stroke, ischemic heart disease, and other vascular causes. This finding was the same for men and women. It is included as a key message in the 2003 JNC-7 report on high blood pressure.
References:
Lewington S, Clarke R, Qizilbash N, Peto R, Collins R, for the Prospective Studies Collaboration. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet. 2002;360:
Chobanian AV, Bakris GL, Black HR, et al, for the National High Blood Pressure Education Program Coordinating Committee. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA. 2003;289: 5

6. BP-lowering meta-analysis
Lowering systolic BP by 10 mm Hg or diastolic BP by 5 mm Hg
at age 65 reduces*:
Risk of stroke by 35%
Risk of IHD by 25%
This applies across all levels of BP in Western populations, not just in hypertension
A reduction in mean population SBP of only 2 mm Hg would save up to lives in the UK
*Lancet 2002; 360:

7. CONVENTIONAL BP MEASUREMENT
LOCATION
TEMPERATURE
HUMIDITY
NOISE
SPHYGMOMANOMETER
HEIGHT
POSITION & TILT
LEVEL OF HG
MAINTENANCE
STETHOSCOPE
OBSERVER
BIAS
DIGIT PREFERENCE
INATTENTION
RAPPORT
HEARING & VISION
DISTANCE
SUBJECT
ANXIETY
RECENT EXERCISE
MEAL OR TOBACCO
OBESITY
ELDERLY
ARRHYTHMIA
POSTURE
ARM LEVEL
ARM SUPPORT
CUFF/BLADDER
CUFF CONDITION
APPLICATION
BLADDER SIZE
BLADDER POSITION
RIGHT OR LEFT?

8. BP MEASUREMENT: KEY TECHNIQUES
 BP (mm Hg) if not done
Rest ≥ 5 min, quiet
↑ 12/6
Seated, back supported
↑ 6/8
Cuff at midsternal level
↑ ↓ 2/inch
Correct cuff size (undercuffing)
↑ 6-18/4-13
Bladder center over artery
↑ 3-5/2-3
Deflate 2 mm Hg/sec
↑ SBP/↓ DBP
If initial BP > goal BP:
1st reading higher
3 readings, 1 min apart
 “Alerting response”
Discard 1st, average last 2
Hypertension 2005; 45: J Hypertens 2005; 23: Can J Card 2007; 23:529

9. NICE 2011 Diagnosis of hypertension (1)
If the clinic blood pressure is 140/90 mmHg or higher, offer ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension.
Evidence ABPM is superior to clinic blood pressure and in most studies home blood pressure monitoring for diagnosis
ABPM is gold standard – HBPM is a less good alternative if not available or possible
NOTES FOR PRESENTERS:
Recommendation [new 2011] in full: shown on the slide.
Related new recommendations
When considering a diagnosis of hypertension, measure blood pressure in both arms. If the difference in readings between arms is more than 20 mmHg, repeat the measurements. If the difference in readings between arms remains more than 20 mmHg on the second measurement, measure subsequent blood pressures in the arm with the higher reading. [new 2011] [1.2.1]
If blood pressure measured in the clinic is 140/90 mmHg or higher take a second measurement during the consultation. If the second measurement is substantially different from the first, take a third measurement. Record the lower of the last two measurements as the clinic blood pressure. [new 2011] [1.2.2]
If a person is unable to tolerate ABPM, home blood pressure monitoring (HBPM) is a suitable alternative to confirm the diagnosis of hypertension. [new 2011] [1.2.4]
If the person has severe hypertension, consider starting antihypertensive drug treatment immediately, without waiting for the results of ABPM or HBPM. [new 2011] [1.2.5]
While waiting for confirmation of a diagnosis of hypertension, carry out investigations for target organ damage (such as left ventricular hypertrophy, chronic kidney disease and hypertensive retinopathy) (see recommendation 1.3.3, slide 19) and a formal assessment of cardiovascular risk using a cardiovascular risk assessment tool (see recommendation 1.3.2, slide 19). [new 2011] [1.2.6]
Additional information
See slide 18 for recommendations about measuring blood pressure.

10. NICE 2011 Diagnosis of Hypertension(2)
When using the following to confirm diagnosis, ensure:
ABPM:
at least two measurements per hour during the person’s usual waking hours, average of at least 14 measurements to confirm diagnosis
HBPM:
two consecutive seated measurements, at least 1 minute apart
blood pressure is recorded twice a day for at least 4 days and preferably for a week
measurements on the first day are discarded – average value of all remaining is used.
NOTES FOR PRESENTERS:
Recommendations in full:
When using ABPM to confirm a diagnosis of hypertension, ensure that at least two measurements per hour are taken during the person’s usual waking hours (for example, between 08:00 and 22:00). Use the average value of at least 14 measurements taken during the person’s usual waking hours to confirm a diagnosis of hypertension. [new 2011] [1.2.9]
When using HBPM to confirm a diagnosis of hypertension, ensure that:
for each blood pressure recording, two consecutive measurements are taken, at least 1 minute apart and with the person seated and
blood pressure is recorded twice daily, ideally in the morning and evening and
blood pressure recording continues for at least 4 days, ideally for 7 days.
Discard the measurements taken on the first day and use the average value of all the remaining measurements to confirm a diagnosis of hypertension. [new 2011] [1.2.10]
Related new recommendations
If hypertension is not diagnosed but there is evidence of target organ damage such as left ventricular hypertrophy, albuminuria or proteinuria, consider carrying out investigations for alternative causes of the target organ damage. [new 2011] [1.2.7]
If hypertension is not diagnosed, measure the person’s clinic blood pressure at least every 5 years subsequently, and consider measuring it more frequently if the person’s clinic blood pressure is close to 140/90 mmHg. [new 2011] [1.2.8]
Additional information:
An extensive review of the evidence by the guideline development group has identified that ABPM multiple blood pressure measurements away from the clinic setting are the best predictor of blood pressure-related clinical outcomes. They concluded that ABPM appeared to provide the best method of confirming a diagnosis of hypertension. They stated that ABPM would not only be a more effective means of diagnosis but also, a more cost-effective means of establishing the diagnosis of hypertension.
Recommendations and covering specialist assessment and investigation have been amended since the previous guideline in It is possible that this amendment may reflect a change in practice.

11. Definitions Stage 1 hypertension:
Clinic blood pressure (BP) is 140/90 mmHg or higher and
ABPM or HBPM average is 135/85 mmHg or higher.
Stage 2 hypertension:
Clinic BP 160/100 mmHg is or higher and
ABPM or HBPM daytime average is 150/95 mmHg or higher.
Severe hypertension:
Clinic BP is 180 mmHg or higher or
Clinic diastolic BP is 110 mmHg or higher.
NOTES FOR PRESENTERS:
Definitions
In this guideline the following definitions are used:
Stage 1 hypertension Clinic blood pressure is 140/90 mmHg or higher and subsequent ambulatory blood pressure monitoring (ABPM) daytime average or home blood pressure monitoring (HBPM) average blood pressure is 135/85 mmHg or higher.
Stage 2 hypertension Clinic blood pressure is 160/100 mmHg or higher and subsequent ABPM daytime average or HBPM average blood pressure is 150/95 mmHg or higher.
Severe hypertension Clinic systolic blood pressure is 180 mmHg or higher or clinic diastolic blood pressure is 110 mmHg or higher.
Additional information:
ABPM – ambulatory blood pressure monitoring
HBPM – home blood pressure monitoring

12. NICE Guidelines - Hypertension Targets
Aim for a target clinic BP < 140/90 mmHg in people aged under 80 years with treated hypertension.
Aim for a target clinic BP < 150/90 mmHg in people aged 80 years and over, with treated hypertension.
When using ABPM or HBPM to monitor response to treatment (for example, in people identified as having a white coat effect and people who choose to monitor their BP at home), aim for a target average BP during the person's usual waking hours of:
< 135/85 mmHg for people aged under 80 years
< 145/85 mmHg for people aged 80 years and over.

13. Current ESC/ESH guidelines for BP targets (2013)
Mancia et al ESH/ESC guidelines for the management of arterial hypertension. European Heart Journal.2013; 34:

14. ABPM – the origins...

15. ABPM 2016

16. Case examples

17. Standard ABPM report – normal BP result
Daytime Mean 128/78 mm Hg
Nocturnal Mean 110/62 mm Hg

18. White COAT HYPERTENSION
20 -25% hypertensive population
OBP 156/88 mm Hg
Initial ABPM reading 205/100 mm Hg
Daytime Mean 128/68 mm Hg
Nocturnal Mean 112/54 mm Hg
The ABPM shows marked white-coat hypertension (205/100 mmHg) with otherwise normal 24-hour systolic & diastolic blood pressure (128/68 mmHg daytime and 112/54 mmHg night-time).
OFFICE HYPERTENSION
156/88 mmHg
AMBULATORY NORMOTENSION
128/68 mmHg
© 2011 dabl® Limited

19. White coat hypertension Initial ABPM reading 175/95 mm Hg Daytime Mean 133/71 mm Hg Nocturnal Mean 119/59 mm Hg ******************** White coat effect Initial ABPM reading 187/104 mm Hg Daytime Mean 149/87 mm Hg Nocturnal Mean 121/67 mm Hg

20. Hypertension – varying severity
D. Borderline
DM 135/57 mm Hg
NM 132/81 mm Hg
E. Moderate systo-diastolic HTN
DM 147/93 mm Hg
NM 111/66 mm Hg
F. Severe systo-diastolic HTN
DM 164/112 mm Hg
NM 157/101 mm Hg

21. Isolated Systolic Hypertension
Daytime Mean 176/68 mm Hg
Nocturnal Mean 169/70 mm Hg

22. DIPPING PATTERN
Daytime Mean 181/117 mm Hg
Nocturnal Mean 111/68 mm Hg

23. NON-DIPPING PATTERN
The ABPM shows severe 24-hour systolic & diastolic hypertension (210/134 mmHg daytime and 205/130 mmHg night-time).
© 2011 dabl® Limited

24. Hypotension

25. Masked Hypertension

26. WHITE COAT HYPERTENSION CBPM ~ INCORRECT DIAGNOSIS
Ambulatory Blood Pressure – uncovers the truth!
WHITE COAT HYPERTENSION
20 – 25%
MASKED HYPERTENSION
10 – 15%
CBPM ~ INCORRECT DIAGNOSIS
30 – 40%

28. Standardising ABPM reporting
Report (requires 14 day time readings to be completed)
Record name of patient and date of study
Daytime Mean and heart rate then night time mean and heart rate
Comment on presence/absence of nocturnal dipping
Presence/absence of white coat effect (note the highest WC BP)
Comment on BP variability (SD of mean)
The 24 hr ABPM on Mr XX was done on and showed a daytime mean of 132/78 mm Hg with a heart rate of 85 bpm. There was well preserved nocturnal dipping to an ideal mean of 119/72 mm Hg with HR of 65 bpm. There was pronounced white coat effect with an initial reading of 178/105 mm Hg. The study demonstrated physiological variability of ABP and DBP during the day and night.
Conclusion – this study demonstrates white coat hypertension with high resting HR

29. A few words about When to stop…

30. Summary of antihypertensive drug treatment
Aged over 55 years or black person of African or Caribbean family origin of any age
Aged under 55 years
Summary of antihypertensive drug treatment A C2
Step 1
Key
A – ACE inhibitor or low-cost angiotensin II receptor blocker (ARB)1
C – Calcium-channel blocker (CCB)
D – Thiazide-like diuretic
A + C2
Step 2
A + C + D
Step 3
Key priority recommendations are identified with [KPI] in these notes.
Step 3 treatment
Before considering step 3 treatment, review medication to ensure step 2 treatment is at optimal or best tolerated doses. [new 2011] [1.6.16]
If treatment with three drugs is required, the combination of ACE inhibitor (or angiotensin-II receptor blocker), calcium-channel blocker and thiazide-like diuretic should be used. [2006] [1.6.17]
Step 4 treatment
Regard clinic blood pressure that remains higher than 140/90 mmHg after treatment with the optimal or best tolerated doses of an ACE inhibitor or an ARB plus a CCB plus a diuretic as resistant hypertension, and consider adding a fourth antihypertensive drug and/or seeking expert advice. [new 2011] [1.6.18]
For treatment of resistant hypertension at step 4:
Consider further diuretic therapy with low-dose spironolactone4 (25 mg once daily) if the blood potassium level is 4.5 mmol/l or lower. Use particular caution in people with a reduced estimated glomerular filtration rate because they have an increased risk of hyperkalaemia.
Consider higher-dose thiazide-like diuretic treatment if the blood potassium level is higher than 4.5 mmol/l. [new 2011] [1.6.19] [KPI]
When using further diuretic therapy for resistant hypertension at step 4, monitor blood sodium and potassium and renal function within 1 month and repeat as required thereafter. [new 2011] [1.6.20]
If further diuretic therapy for resistant hypertension at step 4 is not tolerated, or is contraindicated or ineffective, consider an alpha- or beta-blocker. [new 2011] [1.6.21]
If blood pressure remains uncontrolled with the optimal or maximum tolerated doses of four drugs, seek expert advice if it has not yet been obtained. [new 2011] [1.6.22]
Footnotes
(1) Choose a low-cost ARB. (2) A CCB is preferred but consider a thiazide-like diuretic if a CCB is not tolerated or the person has oedema, evidence of heart failure or a high risk of heart failure. (3) Consider a low dose of spironolactone4 or higher doses of a thiazide-like diuretic. (4) At the time of publication (August 2011), spironolactone did not have a UK marketing authorisation for this indication. Informed consent should be obtained and documented. (5) Consider an alpha- or beta-blocker if further diuretic therapy is not tolerated, or is contraindicated or ineffective.
Resistant hypertension
A + C + D + consider further diuretic3, 4 or alpha- or beta-blocker5
Consider seeking expert advice
Step 4
See slide notes for details of footnotes 1-5

31. Increased Cardiovascular Risk in RHTN
CV EVENTS:
Fatal/non-fatal MI
Coronary revascularisation
Peripheral revascularisation
Hospitalised heart Failure
Fatal/non-fatal stroke
CKD requiring dialysis
1715 Italian hypertensives from general community clinic subjected to ABPM
Mean follow up 5yrs
After adjusting for several covariates Incl OBP, Cox regression analysis showed CV risk much higher in Masked HTN and RHTN
***
Pierdomenico SL et al., Am J Hyp 2005; 18:

32. Strategies for medical evaluation
Before committing your patient to further investigation and additional antihypertensive medication decide:
Is this true RHTN or is this pseudoresistance?
Risk factors for RHTN
Older age >75 yrs
Females
Black ethnicity
Higher baseline BP and chronic uncontrolled HTN
Diabetes
Obesity
Atherosclerotic vascular disease and aortic stiffening
Existing target organ damage: LVH, CKD, retinopathy
Excessive salt intake

33. Factors associated with Pseudo- Resistant Hypertension
Physician-related
Patient-related
White coat effect
Non-adherence to therapy
Poor concordance
Medication intolerance
Lifestyle issues
Costs of drugs
Inappropriate BP measurement Under-cuffing Use of automated methods in arrhythmias Lack of ABP to r/o WCH Physician inertia Inappropriate medication classes/doses Suboptimal consultations
Clinic reading 168/92 mm Hg
Daytime Mean 117/77 mm Hg
Up to 1/3 of apparent RHTN is controlled when ABP is used (de la Sierra)
Myat et al. BMJ 2012;345:e7473

34. In conclusion... Hypertension diagnosis now requires ABPM or HBPM
Standardise reporting of ABPM – it will be easier to interpret!
Patients are keen to adopt HBPM but need to be properly educated
in BP measurement
Difficult hypertension can be treated with α/β-blockers/spironolactone but best to refer to specialist clinic