Update on BP Measurement, ABPM, home/self and clinic...how does office automated fit in?

Transcription

1 Update on BP Measurement, ABPM, home/self and clinic...how does office automated fit in? 8.00 to slides Maximum Blood Pressure is a Moving Target

2 Disclosures Martin Dawes Family Doctor (just) Head of Family Practice at UBC No Pharma work for 3 years Expert 24 company to help with risk prediction algorithms for Norwich Union and others every year

3 Blood Pressure is a Moving Target

4 Digit Preference (Random popn)

5 Hypertensive? Or Normotensive? 5

6 Ambulatory BP Gold Standard (unless intra arterial considered) $599 to $1700 Use one used in trials FDA approved with a BHS AAMI algorithm connects to a computer Don t use without a computer Use just the averages

7 Hazard ratios (95%ci) by systolic blood pressure adjusted for age and gender, and stratified by cohort. (I) Clinic BP Hazard ratio (95% CI) This steeper gradient of hazard ratios through the range indicates that ABP is a stronger predictor of mortality Ambulatory BP Hazard ratio (95% CI) ( 0.57, 1.25) ( 0.52, 1.06) ( 0.47, 0.94) ( 0.57, 1.10) ( 0.57, 1.10) ( 0.59, 1.19) ( 0.54, 1.14) 200+ mmhg 1.13 ( 0.80, 1.59) ( 0.68, 1.16) ( 0.70, 1.16) ( 0.75, 1.24) ( 0.91, 1.53) ( 1.08, 1.86) ( 1.27, 2.30) ( 1.33, 2.81) 200+ mmhg 1.95 ( 1.28, 2.97) Hazard ratio Hazard ratio 7

8 What is WCH? White coat hypertension is defined when a patient has a persistently elevated clinic BP and a normal home or ambulatory BP day time average i.e. <135/85mmHg. Hypertension (WCH) 15% to 30% of the population It is more common in pregnancy and with increasing age.

9 White Coat Hypertension is Safe Prognostic Value of White-Coat and Masked Hypertension Diagnosed by Ambulatory Monitoring in Initially Untreated Subjects: An Updated Meta Analysis Sante D. Pierdomenico and Franco Cuccurullo

10 Masked Hypertension where clinic BP is normal but ABPM and/or HBPM measurements are elevated Prevalence ~20%

11 The prognosis of masked hypertension Prevalence of masked hypertension is approximately 10% in the general population but is higher in patients with diabetes J Hypertension 2007;25:

12 Masked Hypertension Prognostic Value of White-Coat and Masked Hypertension Diagnosed by Ambulatory Monitoring in Initially Untreated Subjects: An Updated Meta Analysis Sante D. Pierdomenico and Franco Cuccurullo

13 National Institute of Clinical Excellence 2011 If the first and second blood pressure measurements taken during a consultation are both higher than 140/90 mmhg, offer 24-hour ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension.

14 Better testing cost less The savings with ambulatory monitoring compared with monitoring in the clinic and the home were primarily because of the costs of hypertensive treatment that were avoided because of the higher specificity of ambulatory monitoring. The discounted treatment costs for men aged 60 years were 776 for monitoring in the clinic compared with 744 for monitoring in the home and 631 for ambulatory monitoring.

15 Why?: Cost effectiveness Lovibond, K., Jowett, S., Barton, P., Caulfield, M., Heneghan, C., Hobbs, F. R., Hodgkinson, J., et al. (2011). Cost-effectiveness of options for the diagnosis of high blood pressure in primary care: a modelling study. The Lancet. doi: /s (11)61184

16 Office Cannot detect WCH or Masked Hypertension But ABPM is expensive The equipment Needs computer analysis Two appointments Plan B Automated Office BP

17 Home BP Needs a valid tool Readings recorded in duplicate in the morning (from 6 to 10 a.m.) and night (from 8 p.m. to 12 p.m.) with an interval of 2 min between each, for 3 consecutive days (on weekdays if the patient works, or according to their normal activity if they are retired). To calculate the mean BP, the readings of the first day are excluded and the first and second readings of each morning night period of the second and third days were used.

18 Ambulatory blood pressure monitoring versus selfmeasurement of blood pressure at home: correlation with target organ damage. Gaborieau, Valerie; Delarche, Nicolas; Gosse, Philippe Journal of Hypertension. 26(10): , October DOI: /HJH.0b013e32830c Lippincott Williams & Wilkins, Inc. Published by Lippincott Williams & Wilkins, Inc. 2

19 Cut Point for WCH Home blood pressure self-monitoring: diagnostic performance in white-coat hypertension. Bayo, Joan; Cos, Francesc; Roca, Carme; Dalfo, Antoni; Martin-Baranera, Maria; Albert, Botey Blood Pressure Monitoring. 11(2):47-52, April DOI: /01.mbp Fig. 1 Receiver operating characteristic curve comparing different blood pressure cut-off points in the diagnosis of white-coat hypertension (BP <135/85 mmhg for ABPM )with home blood pressure self-monitoring (hbpsm). Black dots represent normality cut-off points for hbpsm in mmhg. 190 patients Two tests (hbpsm and ABPM) were compared in a series of patients aged from 18 to 80 years with mild moderate hypertension selected consecutively and without previous antihypertensive treatment. Recruited in primary care 2006 Lippincott Williams & Wilkins, Inc. Published by Lippincott Williams & Wilkins, Inc. 2

20 Automated Office Measures BP alone Does it 6 times BPTru Does it three times with Intellisense Takes averages

21 ROC Curves for AOBP and Home BP for detecting raised ABPM very similar diagnostic characteristics (if done well) Beckett (AOBP) ->Systolic Target Achieved on ABPM (<135 mmhg mean daytime blood pressure) Bayo -> (Home) The normality cut-off point for outpatient tests in the comparative study was a mean diurnal BP <135/ 85 mmhg for ABPM

22 Sensitivity ROC Curves for AOBP and Home BP for detecting raised ABPM Bayo 135 Beckett Log. (Bayo) 125 Log. (Beckett) Specificity

23 Diagnostic algorithm for high Blood Pressure including Office, ABPM and Home Blood Pressure Measurement BP: / Clinic BP ABPM (If available) HBPM Hypertension visit SBP or 100 DBP < 160 / 100 or Hypertension visit 4-5 Diagnosis of HTN ABPM or HBPM Awake BP < 135/85 and 24-hour < 130/80 Awake BP 135 SBP or 85 DBP Or 24-hour 130 SBP or 80 DBP or < 135/ SBP or DBP SBP or 90 DBP Diagnosis of HTN Continue to followup Diagnosis of HTN Continue to follow-up Diagnosis of HTN < 140 / 90 Continue to follow-up

24 My Own Proposed Algorithm for AOBP/Home BP in Clinical Practice in non diabetic or renal patients (not validated and not policy) AOBP/Home < 130/80 > 140/90 Continue to follow / h ABPM Diagnosis of Hypertension Awake BP < 135/85 and 24-hour < 130/80 Awake BP 135 SBP or 85 DBP Or 24-hour 130 SBP or 80 DBP