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Update on hypertension - diagnosis, monitoring and guideline treatment targets Prof. Richard McManus, Birmingham, United Kingdom.

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Presentation on theme: "Update on hypertension - diagnosis, monitoring and guideline treatment targets Prof. Richard McManus, Birmingham, United Kingdom."— Presentation transcript:

1 Update on hypertension - diagnosis, monitoring and guideline treatment targets Prof. Richard McManus, Birmingham, United Kingdom

2 Overview  Background  Routine measurement of blood pressure (is rubbish)  Diagnosis of hypertension - ABPM?  Management of hypertension – Home ?  Treatment targets – any changes?  Conclusions

3 Stroke Risk increases with age & usual BP Similarly for Heart Disease 40-49 60-69 Low Risk High

4 Bottom line BP vs Risk 10 mmHg 38% stroke risk 18% CHD risk

5 If you live long enough you get hypertension

6 The population is ageing In mid-2008 the median age of the population was 39 years, up from 37 in 1998.

7 Routine measurement is often flawed Same population with routine and research measurement

8 Blood Pressure varies through the day and between seasons Hypertension. 2006;47:155-161

9 Multiple measurements better estimate mean blood pressure

10 This variability means that measurement error can drown out the truth

11 Even on a single occasion BP drops  Approx 1500 patients  24 practices  6 readings at 1min intervals  12 mmHg systolic drop  Stable after 5 th reading

12 Family Practice 1997; 14:130-135 BP takes some time to settle with repeated measurement over weeks/months

13 Many factors affect BP measurement BMJ 2001;322;908-911

14 Diagnosing hypertension  Traditionally based on clinic measurement  Most outcome trials use clinic measures  But –Flawed measure (one off from continuum) –Takes weeks / months to make diagnosis

15 What about ABPM?  Half hourly measurements during the day  Better measure  usual BP  Hourly at night  Main outcome is mean day time ABPM  Other info available (dipping etc)

16 International Thresholds for hypertension diagnosis (clinic and ABPM) Mean daytime BP UK (ABPM) = 135/85 mmHg

17 What’s normal for ABPM (and home)? Based on Head et al BMJ 2010  adjust by 5/5 mmHg at lower threshold (stage 1 hypertension, 140/90 mmHg clinic) –ie < 135/85 mm Hg  10/5 mmHg at higher threshold (stage 2 hypertension, 160/100 mmHg clinic) –Ie < 150/95 mmHg

18 How do clinic and ABPM compare?  Reviewed literature: 2914 studies of which 20 were relevant  7 compared ABPM with clinic monitoring for diagnosis  Full details: BMJ 2011;342:d3621 doi: 10.1136/bmj.d3621

19 Many people currently potentially misdiagnosed... Worse if only studies around diagnostic threshold used: sensitivity of 86% and specificity of 46%

20 What about Home Monitoring? Relative sensitivity and specificity of clinic and home measurement vs ABPM

21 Better correlation with end organ damage and outcome (ABPM) 1963 patients Mean FU 5 yrs Baseline ABPM CVD events

22 1700 patients, 10 years FU, 150 CVAs Screening = 2 clinic measurements one occasion Home = 25 measurements over 4 weeks Journal of Hypertension 2004, 22:1099–1104 Better correlation with end organ damage and outcome (Home)

23 Detection of white coat and masked HT

24 But what about costs?  Treatment – ↓drug costs  Follow up – ↓clinician costs  But do additional costs of ABPM out weigh these?

25 Is ABPM cost effective?  Modelling to evaluate the most cost-effective method of confirming a diagnosis of hypertension in a population suspected of having hypertension  ABPM vs Home vs clinic  Further details Lovibond et al, Lancet 2011

26 Markov Model  Health service perspective  Lifetime horizon  Assume all have raised clinic screening  People aged 40 and over

27 Markov Model  Costs from published sources and NHS  Test performance from systematic review  Risk calculated using Framingham equation

28 Results  ABPM most cost effective for every age group

29 Results  ABPM most cost effective for every age group  Robust to wide range of sensitivity analyses

30 Results – sensitivity analysis

31 Results  ABPM most cost effective for every age group  Robust to wide range of sensitivity analyses  Sensitive to –Assumption of equal test performance –Assumption of no effect of Rx below 140/90 mmHg

32 ABPM  Don’t forget ABPM need to be validated and have yearly calibration (bhsoc.org.uk website)  Lack of night time dipping is additional risk (hence rationale for night readings)  Currently limited in PC as most practices either need to refer or only have one ABPM machine  Commissioners need to consider whole health economy

33 Self Monitoring reduces BP Bray et al. Annals of Medicine 2010  Small reductions in blood pressure from self-monitoring: –SBP by 3.8 mmHg –DBP by 1.5 mmHg

34 Self monitoring costs equivalent to usual care BMJ 2005;331;493

35 How many measurements? Conclusion = at least 4 days monitoring and discard 1 st European (& UK) Guideline is 1 week, 2 readings bd, discard day 1, take mean (limited rationale)

36 What is the place of home monitoring?  Management after diagnosis, especially if proven significant white coat effect  More outcome and test performance data needed for diagnosis  Adjunct to other co-interventions and self management...

37 Co-interventions enhance self monitoring effect 5.3 mmHg 2.5 mmHg

38 What’s a co-intervention?  Nurses  Telemonitoring  Patient Education  Self Management

39 Theoretical basis for self management Patients  Increased patient involvement in management decisions will result in: Cues to action Adherence Increased self efficacyBehaviour change  Better use of medication likely to have most effect Professionals  Systematic titration of medication effective  Evidence of clinical inertia

40

41 TASMINH2 Research Questions Does self management with telemonitoring and titration of antihypertensive medication by people with poorly controlled treated hypertension result in: 1.Better control of blood pressure? 2.Changes in reported adverse events or health behaviours or costs? 3.Is it achievable in routine practice and is it acceptable to patients?

42 The Trial  Eligibility –Age 35-85 –Treated hypertension (no more than 2 BP meds) –Baseline BP >140/90 mmHg –Willing to self monitor and self titrate medication  Patients individually randomised to self-management vs usual care stratified by practice and minimised on sex, baseline SBP, DM status,  Practice GPs determine management

43 Intervention  Self Monitoring – 1 st week of every month

44 Intervention  Blood Pressure Targets: –NICE (140/90 or 140/80 mmHg) –minus 10/5 mmHg i.e. 130/85 mmHg or 130/75 mmHg  Patients agreed titration schedule with their GP after randomisation  Traffic Light system to adjust medication

45 Outcomes  Follow up at 6 & 12 months  Main outcome Systolic Blood Pressure  Secondary outcomes: Diastolic BP / costs / anxiety / health behaviours/ patient preferences / systems impact  Recruitment target 480 patients (240 x 2)  Sufficient to detect 5mmHg difference between groups

46 Results Invited (n = 7637) Declined Invitation (n = 5987) Assessed for eligibility (n = 1650) Excluded (n = 1123) Not Eligible (n = 1044) Declined to participate (n=79) Control (n = 264) Received usual care (n = 264) Randomised (n = 527) Analysed (n = 246) Incomplete cases excluded (n = 18) Did not attend follow up (n=14)* Discontinued usual care (n = 0) Intervention (n = 263) Received intervention training (n = 241) Did not attend follow up (n=26)# Discontinued intervention (n = 53) Analysed (n = 234) Incomplete cases excluded (n = 29) 110% recruitment 91% follow up 80% completed intervention

47 Baseline Results

48 Results - primary outcome SBP

49 Results – secondary outcomes DBP

50 Results - subgroups

51 Results - medications  212 (80%) self managed for full 12 months  148 (70%) made at least one medication change  At 12m intervention group prescribed 0.46 (0.34, 0.58) additional antiHT (p=0.001)  Main changes seen in thiazides and calcium channel blockers (60% on ACEI/ARB at baseline)

52 Results – side effects  Similar side effects in intervention vs control

53 Treatment targets  Observational data shows that achieved blood pressure correlates with CVD outcome  Wald meta analysis suggests that treatment effects similar regardless of baseline –But low baseline BP trials almost exclusively secondary prevention

54 Treatment targets  Little convincing benefit from lower than 140/90 mmHg target in uncomplicated HT  Evidence for systolic targets sparse  Note reduced targets if out of office measure

55 What about old people? Meta analysis – 6701 patients; mean FU 3.5 yrs; mean entry SBP 175 Target 150 mmHg systolic; Mean reduction SBP around 12mmHg Journal of Hypertension 2010, 28:1366–1372

56 Bottom Line  Consider enhanced use of out of office measurement, especially for diagnosis  Ambulatory monitoring for diagnosis is cost effective due to better targeting of treatment  Home monitoring useful for ongoing management  Patients can do it too!  140/90 mmHg best evidence target unless secondary prevention or over 80


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