Is Traditional Clinic Blood Pressure Dead?

Transcription

1 Royal College of Physicans May 16 th 2017 Is Traditional Clinic Blood Pressure Dead? Professor Bryan Williams MD FRCP FAHA FESC Chair of Medicine UCL Director National Institute for Health Research Biomedical Research Centre, University College London Chairman ESC Council on Hypertension

2 Philosophy of treating hypertension Treat those who need treatment and don t treat those who don t Who needs treatment? Patients with an unequivocally elevated blood pressure When you decide to treat, you convert a person into a patient so we have to get this decision right

3 Clinic Blood Pressure Seated clinic BP has been the gold standard for the diagnosis of hypertension for more than 100yrs The most often used method in epidemiology studies and clinical outcome trials Unequivocally linked to clinical outcomes and mortality in a graded way untreated or treated But Often performed badly. Can under-estimate and over-estimate BP even when performed well, when compared to ABPM

4 Categories of Hypertension

5 Categories of Hypertension

6 Categories of Hypertension

7 Categories of Hypertension 25% of Patients usually stage 1 hypertension

8 Categories of Hypertension ~25% of patients Usually pre-hypertensive Clinic BP / 85-89

9 What is the most effective way of establishing the diagnosis of hypertension?

10 Practice for the Diagnosis of Hypertension circa 2011 Screening BP High? Weeks or Months Repeat BP Measurement in Doctor s Office Repeat BP Measurement in Doctor s Office Repeat BP Measurement in Doctor s Office ± Diagnose Hypertension CVD Risk & TOD Assessment

11 NICE Hypertension guideline 2011 How hypertension be diagnosed? Screening BP High? Days or weeks Offer Ambulatory BP Measurement (ABPM) Use Mean daytime ABPM to define hypertension ± Diagnose Hypertension CVD Risk & TOD Assessment A Radical Change in Practice

12 Why ABPM? We should treat patients on the basis of their risk; ABPM is a better predictor of target organ damage than clinic blood pressure; ABPM is a better predictor of adverse cardiovascular outcomes than clinical blood pressure; ABPM records BP in the patients natural setting where they experience cardiovascular events not in the doctor s office E. Dolan, et al. Hypertension, 2005, Hara A, et al. Hypertension, 2012, Ohkubo T, J Hypertension 1997, Staessen JA, JAMA 1999

13 ABPM improves the sensitivity and specificity of diagnosis of hypertension ABPM was the reference standard for this analysis because ABPM is the best predictor of BP-related risk

14 ABPM for the Diagnosis of Hypertension ABPM is a better predictor of clinical outcomes than clinic BP; ABPM is the reference standard used in clinical practice when there is uncertainty about the diagnosis; ABPM improves the specificity and sensitivity of diagnosis versus clinic and home BP measurement; ABPM avoids treatment in people who are not hypertensive as many as 25% with white coat hypertension

15 Is ABPM cost-effective for the diagnosis of hypertension?

16 Interpretation: Ambulatory monitoring as a diagnostic strategy for hypertension, after an initial raised reading in the clinic, would reduce misdiagnosis and save costs. Additional costs from ambulatory monitoring are counterbalanced by cost savings from better targeted treatment. Ambulatory monitoring is recommended for most patients before the start of antihypertensive drugs. Lancet 2011

17 ABPM for the Diagnosis of Hypertension Was cost effective (cost saving to the NHS) versus clinic and home BP measurement; Home BP is an alternative for those who do not tolerate ABPM but thre is not as much data as ABPM; Automated devices cannot be used for people with significant pulse irregularity e.g. Atrial fibrillation use manual auscultation in such patients:

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19 Dolan E, et al. Hypertension 2005 Adjusted 5yr risk of CV death in 5292 patients

20 US Preventive Services Task Force recommends ABPM to confirm Diagnosis of Hypertension Piper MA, et al. Annals Intern Med, 2015

21 Proportion of elevated clinic BP confirmed by ABPM Piper MA, et al. Annals Intern Med, 2015

22 Risk for CVD and mortality outcomes: systolic 24hr ABPM adjusted for Clinic BP Piper MA, et al. Annals Intern Med, 2015

23 Spanish ABPM Registry: Prevalence of White Coat Hypertension in 6,176 untreated hypertensive patients 71% Hypertension Vinyoles E, et al. J Hypertens, % White Coat Hypertension: Elevated Clinic BP >140/90mmHg and Normal ABPM Daytime average; BP < 135/85 Screening for TREAT-CASP study Younger men (<55yrs) White coat hypertension ~25% - uncommon if stage 2 hypertension on office BP

24 Is white coat hypertension benign? Controversy from observational studies NICE systematic review suggests marginal/no excess risk versus ABPM confirmed hypertension; No data on benefit versus harm from intervention trials in this patient group; Most have stage 1 clinic hypertension controversy regarding merits of treating clinic BP defined stage 1 hypertension (Cochrane systematic review 2012). Implications; (i) disease labelling, (ii) no clear evidence of excess risk, (iii) no proven benefit of treatment.

25 Hypertension participants, 714 events

26 Do we know the appropriate diagnostic BP threshold for ABPM?

27 Blood Pressure Thresholds for Diagnosis and Treatment of Hypertension NICE Guidelines Stage of Hypertension Office BP (mmhg) 24hr. Daytime ABPM Average Home ABPM Average Stage 1 Hypertension 140 /90 but <160/ /85 135/85 Stage 2 Hypertension 160 / /95 150/95

28 2013 ESH/ESC Hypertension Guidelines Definitions of hypertension by office and outof-office BP levels Category Systolic BP (mmhg) Diastolic BP (mmhg) Office BP 140 and/or 90 Ambulatory BP Daytime (or awake) 135 and/or 85 Night-time (or asleep) 120 and/or h 130 and/or 80 Home BP 135 and/or ESH/ESC Guidelines J Hypertens 2013;31: , Eur Heart J 2013; Epub ahead of print

29 NICE: ABPM for the diagnosis of hypertension When using ABPM to confirm a diagnosis of hypertension, ensure that at least two measurements per hour are taken during normal waking hours (for example, daytime between 08:00 and 22:00); Use the average of at least 14 readings during these waking hours blood pressure measurements to confirm a diagnosis of hypertension; Some people will wear the monitor for 24hrs (i.e. starts monitoring session in the afternoon) but this is not essential;

30 NICE: Home BP Monitoring Protocol When using home blood pressure monitoring (HBPM) to confirm a diagnosis of hypertension, ensure that: For each blood pressure measurement, two consecutive measurements are taken, at least 1 minute apart and with the person seated; Blood pressure measurements are taken twice daily, ideally in the morning and evening; Blood pressure measurement 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;

31 2013 ESH/ESC Hypertension Guidelines ABPM / HBPM Methodological Aspects ABPM Measurement extended to hours (includes the night) Diary of events potentially influencing BP can be useful Measurements to be made at same frequency (e.g. every 20 min) during day and night - Excessive intervals to be avoided Recording satisfactory if 70% of values available Home BP To be measured on at least 3-4 days (preferably 7 days) Morning / evening values (seated in a quiet environment ) Values to be reported in standardized logbook or storage in memory equipped device Possible advantage of telemonitoring Data interpretation always by physician 2013 ESH/ESC Guidelines J Hypertens 2013;31: , Eur Heart J 2013; Epub ahead of print

32 Advantages / Disadvantages of ABPM versus HBPM ABPM Advantages Stronger evidence Objective data Night-time readings Single session, usual activity, high volume data Disadvantages Expensive / Availability Can be uncomfortable HBPM Advantages Cheap & widely available Measurement in usual setting Patient engagement Disadvantages Only seated BP Operator dependent No nocturnal Readings

33 Blood Pressure Treatment targets Use Clinic BP to monitor BP control; Optimal Clinic BP control is <140/90mmHg; In people with white coat effect, i.e. clinic BP is 20/10mmHg more than ABPM or Home average, use Home BP average to monitor treatment target home BP average of <135/85mmHg; Review BP control at least annually once BP treatment is stable.

34 Conclusion The prevalence of masked suboptimal BP control in patients with treated and well-controlled clinic BP is high. Clinic BP monitoring alone is thus inadequate to optomise BP control because many patients, especially those at high cardiovascular risk, have an elevated nocturnal BP. These findings suggest that ABPM should become more routine to confirm BP control, especially in higher risk groups and/or those with borderline control of clinic BP.

35 Spanish ABPM Registry: Prevalence of Masked UnControlled Hypertension MUCH in 14,840 patients with a treated and controlled seated clinic BP (<140/90mmHg) 69% Controlled 31% MUCH Masked UnControlled Hypertension MUCH ABPM 24hr Average >130/90 mmhg Despite seemingly well controlled clinic BP<140/90 mmhg Banegas JR, et al. Eur Heart J 2014

36 Bryan Williams. Circulation, December 2016