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Systematic Review Protocol Review Title Measurement Accuracy of Non-invasively obtained Central Systolic Blood Pressure and Central Pulse Pressure- A Systematic Review Reviewers Primary Reviewer Hao-min Cheng, M.D. and MSc Clinical Science Candidate. Department of Medical Research and Education Taipei Veterans General Hospital, Taipei, Taiwan; Department of Medicine, National Yang-Ming University, Taipei, Taiwan; The Joanna Briggs Institute, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5005. Contact: [email protected] Secondary Reviewer Dora Lang RN, BSN, Adv Dip Nsg (Oncology) and MSc Clinical Science Candidate. Singapore National University Hospital Centre for Evidence Based Nursing, a collaborating centre of the Joanna Briggs Institute; the Joanna Briggs Institute, Faculty of Health Sciences, The University of Adelaide, Adelaide, SA 5005. Contact: [email protected] Supervisors Prof Alan Pearson AM RN, MSc, PhD, FRCNA, FCN, FAAG, FRCN Joanna Briggs Institute, University of Adelaide, South Australia. Contact: [email protected] Professor Stephen Grant Worthley, M.B., B.S., Ph.D., F.R.A.C.P., F.A.C.C., F.C.S.A.N.Z. Helpman Chair of Cardiovascular Medicine, Discipline of Medicine, The University of Adelaide. Director, Cardiac Catheterization Laboratories; Royal Adelaide Hospital. Director, Cardiovascular Magnetic Resonance Imaging, Royal Adelaide Hospital Contact: [email protected] Catalin Tufanaru. MD, MPH. Research Associate. Synthesis Science Unit (SSU). The Joanna Briggs Institute, Faculty of Health Sciences. The University of Adelaide. Contact: [email protected] Review Objective To synthesise the best available research evidence on the accuracy of current non-invasive measurement methods for central systolic blood pressure and central pulse pressure. Review Question What is the accuracy of current non-invasive measurement methods for central systolic blood pressure and central pulse pressure, compared with invasion measurement techniques? Background Concept of Central Blood Pressure and Pulse Pressure Amplification Blood pressure (BP) measurement has been used extensively in daily clinical practice to characterise the circulatory system as well as to diagnose and manage patients with cardiovascular disease. An arterial pulse can be briefly described by Systolic blood pressure (SBP), which is the peak of an arterial pulse wave and Diastolic blood pressure (DBP), which is the trough of a arterial pulse wave. Pulse pressure (PP) is the difference between SBP and DBP. However, BP determined at different sites can have considerable different values. Generally, from the central aorta to the beginnings of the peripheral artery, such as the brachial and radial arteries, the lack of significant resistance of large conduit arteries keeps mean and diastolic pressures at nearly the same values.1In contrast, peripheral systolic blood pressure (SBP) and pulse pressure (PP) are usually higher than their corresponding values in central arteries.2-4 This “pressure amplification” phenomenon of SBP and PP from the central arteries to the peripheral brachial arteries results from decreased vascular compliance of peripheral arteries as well as distal wave reflections, which distort the propagating arterial pressure wave.4-6 The aorta-brachial PP amplification becomes less obvious with advancing age and the disproportional stiffening of the central elastic versus peripheral muscular arteries, which leads to early return of the prominent reflected waves from the lower body, causing augmentation of the aortic SBP and PP. 5, 7 However, large inter- and intra-individual disparities between the peripheral and central blood pressures in the elderly still exist.7,8,9,10 Recognition of the differences between peripheral and central aortic blood pressures is important because the latter may be more relevant than the former in predicting cardiovascular risk.11-13 Moreover, recent studies suggest that the PP amplification may not be just a mathematical expression but carry additional pathophysiologic and prognostic value beyond that of central and peripheral PP alone.14, 15 Prognostic Importance of Central Blood Pressure Blood pressure in central arteries, such as the ascending aorta and common carotid arteries are directly related to the loads imposed on the heart. The branching structure and mechanical properties of the arterial system cause blood pressure in peripheral arteries to be amplified and thus peripheral pressure does not necessarily accurately reflect the central pressure.16 Since central blood pressure can be estimated non-invasively,17, 18 it is reasonable to presume and has been shown in population-based studies11, 12, 19 and in hypertension trials,20 that the non-invasively measured central blood pressure has incremental values in predicting cardiovascular outcomes beyond standard brachial blood pressure measurements in various populations. There has been a systematic review investigating the prognostic importance of central SBP and PP demonstrated by these studies.21 However, this recent meta-analysis of longitudinal studies suggested that elevated SBP was not significantly associated with higher relative risk of clinical events as compared to elevated brachial SBP.21 This may cast doubt on the accuracy of the non-invasively estimated central SBP.22,23 Measurements of Central Blood Pressure (illustration of methods in figure 1) Measurement accuracy is the agreement between parameters (continuous variables) measured by a tested method and a reference gold standard method. For the purposes of this review, the gold standard will be the invasive central aortic SBP and PP. Current common methods for the non-invasive estimation of central blood pressure require the acquisition of an arterial pressure waveform by applanation tonometry. Professionals can obtain carotid arterial pressure waveforms directly, which has been shown to be a robust surrogate for central aortic pressure waveforms.12,17,24,25 To measure central SBP or PP, more popularly, the acquired peripheral arterial pressure waveforms can be subsequently transformed into a central aortic pressure waveform using a generalised transfer function26,27. Alternatively, the peripheral waveforms can be directly analysed to identify the late systolic shoulder (SBP2) on them.4 Late systolic shoulder of a peripheral pressure waveform has been shown to approximate the central SBP in previous primary research studies. 4, 9, 28-31 A. Carotid tonometry CSBPc B. Radial tonometry Transfer function CSBPa C. Radial tonometry Radial SBP2 Figure 1. Illustrations of different methodologies for estimating central systolic blood pressure (CSBP). Panel A: Use carotid artery applanation tonometry to obtain calibrated carotid pulse waveform and corresponding CSBP (CSBPc); Panel B: Use radial arterial applanation tonometry and a transfer function to reconstruct aortic pulse waveform and calculate corresponding CSBP (CSBPa); Panel C: Identify late systolic shoulder of radial pulse waveform (radial SBP2) to approximate CSBP; Applanation tonometry To obtain faithful pressure waveforms non-invasively, applanation tonometry, which uses an externally applied micromanometer-tipped probe to continuously record peripheral pulse waveforms, is the current most commonly used and accepted technique.24, 32 The arterial pulse is recorded by the tip of the probe with optimal pressure which makes the corresponding arterial wall become completely flattened (applanated). Therefore, the intra-arterial pressure is equal to the contact pressure.33, 34The optimal state is easily achieved for an exposed vessel, but it is sometimes not the case if there is substantial soft tissue between the external probe tip and the artery in situ, such as a carotid artery. Hence, it always requires a trained professional to obtain reliable and reproducible registration of arterial pressure waveforms. Cuff Blood Pressure (BP) measurements The non-invasively acquired arterial waveforms are voltage signals initially and have to be converted to pressure unit by calibrating to the measured blood pressures from sphygmomanometers (cuff blood pressure). Using the concept of constant mean blood pressure and diastolic blood pressure along the arterial tree, the non-invasive waveforms can be calibrated and regarded as the surrogate of intra-arterial pressure waveforms.34 A. Transfer function Transfer function is a mathematical relationship between two physical properties. In this proposed review, it indicates the mathematic relations between pressure waveforms of central and peripheral arteries. The most common method of measuring central BP utilises applanation tonometry of the radial artery to obtain its pressure waveforms Details of the measurement concept and procedures can be found in research performed with a commercial apparatus (SphygmoCor System; AtCor Medical, Sydney)3, 11, 20, 26, 35-37 It has been the most popular central BP measurement device to date. In brief, with a universal or generalized relationship between radial and central aortic pressure waveforms, we can obtain a central aortic pressure waveform by applying this constant relationship to a non-invasively acquired radial pressure waveform. B. Identification of Peripheral SBP2 SBP2 is late systolic should of a pressure waveform, which is resulted from distal pressure wave reflections. Utilisation of generalised transfer function for measuring central BP has been questioned.38 Another approach has been proposed to bypass the generalised transfer function approach based on the finding that the second radial pressure peak or late SBP2 directly identified from a peripheral pressure waveform agrees well with the peak (SBP) of central aortic pressure waveforms.28,29, 30,31, 9 The commercially available product using this concept for estimation of central blood pressure is OmronHEM-9000AI. C. Carotid Pulse wave obtained by carotid artery tonometry Pressure waveform of carotid artery is a good surrogate for central aortic pressure waveform. 17, 24, 25 Therefore, the central systolic blood pressure refers to SBP of the central aorta or carotid arteries, and central pulse pressure refers to PP of the central aorta or carotid arteries. It requires higher level techniques to perform applanation tonometry on a carotid artery because of the surrounding loose soft tissue. 34. All device equipped with tonometer are capable of acquisition of pressure waveforms of carotid arteries, from which central BP can be measured. Reference standard The real goal standard of the non-invasively obtained central aortic blood pressure for reference should be the invasively obtained counterpart. According to the statement by Association for the Advancement of Medical Instrumentation (AAMI), the intra-arterial pressure can be measured with a saline-filled (fluid-filled) catheter and an external pressure transducer with tip in situ. The characteristics of the pressure system, such as damping coefficients and/or resonant frequency of the invasive blood pressure monitoring equipment, should be provided in the validation process.39 Rationale of Systematic Review The 2007 ESH/ESC Hypertension Guidelines18 addressed the differences between aortic systolic and pulse pressure and the conventionally measured brachial pressure, as well as their dissimilar responses to different antihypertensive drugs. In addition, it also stated that aortic blood pressure may be estimated non-invasively.18 Although the accuracy of these methods have been examined in many previous primary studies, 8,40,38, 41,23, 31,42,30,43,44,22, they have neither been systematically reviewed for their study quality nor metaanalysed for combined accuracy. The warranty of the statement endorsed by the Guideline requires re-evaluation. The present review aims to examine the quality of these studies and to assess the accuracy of these methods in estimating central SBP and PP in participants of different characteristics. An initial search of the Cochrane Library of Systematic Reviews, JBI Library of Systematic Reviews, CRD database, and Medline was performed and no existing systematic review (completed or in progress) nor existing systematic review protocol on this topic was identified. Two existing systematic reviews examined the accuracy of devices utilising different methods for measuring body temperatures in children and young people. 45, 46 In these reviews, a critical appraisal checklist modified from the one used to assess diagnostic studies was used.47 The present review will adapt the methodology proposed in these studies to compare different methods for measuring central SBP and PP presented in previous individual studies. Inclusion criteria Types of Participants This review will consider all studies of adult patients (18+ years old) regardless of clinical diagnosis, co-morbidities, treatments received who have been receiving measurement(s) of central SBP and/or central PP both invasively and non-invasively on the same subjects. Types of Interventions/Phenomena of Interest Studies will be considered for inclusion if the focus of the study is an examination of the accuracy of non-invasive measurement methods using applanation tonometry for central systolic blood pressure and central pulse pressure non-invasive measurement of central BP. Studies will be considered if the non-invasive central SBP and PP measurements have been compared with reference to invasive obtained values. Types of Comparator Invasive central aortic BP Measurement by a fluid-filled system and/or external pressure transducer.39 Types of Outcome Measures This review will consider studies that include the following types of outcome measures: means of differences between the paired measurements of a noninvasive and invasive technique, standard deviation of differences between paired measurements of a non-invasive and invasive technique, correlation coefficients of the paired measurements of a non-invasive and invasive technique, and any other measures for measurement agreement. Types of Studies This review will consider any primary research study using method comparison design examining the agreement between measurements using noninvasive central BP measuring techniques and invasive measurement methods as a reference. Exclusion criteria Studies will be excluded if the non-invasive central BP measurements 1. have been compared to another non-invasive method 2. have not been performed with applanation tonometry, which is a faithful and widely accepted technique Search Strategy The search will be limited to English and Chinese language studies from 1970 to 2011. Research on central blood pressure can date back to 1980, therefore a start date for the search of 1970 was chosen to ensure all relevant publications are identified. The search strategy aims to find both published and unpublished studies. A three-step search strategy will be utilised in this review. An initial limited search of MEDLINE and PUBMED will be undertaken followed by analysis of the text words contained in the title and abstract, and of the index terms used to describe article. A second search using all identified keywords and index terms will then be undertaken across all included databases. Thirdly, the reference list of all identified reports and articles will be searched for additional studies. The following databases will be searched: PubMed CINAHL Cochrane Library (including Cochrane DSR, DARE and CCTR) Chinese Periodicals Index EMBASE Reference lists of identified studies will also be searched for further studies for inclusion. The search for unpublished studies will include the following sources: Any unpublished studies presented in proceedings of conferences will be searched from MEDNAR and websites of meetings held by professional associations such as American Heart Association, European Heart Association, American College of Cardiology, American society of hypertension, and International Society of Hypertension. Grey Literature Report (via New York Academy of Medicine) The initial search terms: Central blood pressure, aortic blood pressure, carotid blood pressure, SBP2, late systolic shoulder, late systolic peak, late upstroke, transfer function, SphygmoCor , method comparison, Bland-Altman analysis, agreement, accuracy, applanation tonometry, arterial tonometry Assessment of Methodological Quality/ Critical Appraisal Research papers selected for retrieval will be assessed by two independent reviewers for methodological validity prior to inclusion in the review using an original specific critical appraisal tool designed for the review. The critical appraisal tool (Appendix I) was developed by consensus of reviewers and supervisors based on the critical appraisal criteria used by Craig et al 200045 and Craig et al 2002.46 These two systematic reviews investigated the measurement accuracy of different body temperature measuring methods. Body temperature was the tested continuous variables and the agreement between new and reference standard methods were examined. The appraisal tool for measurement accuracy studies used in these two systematic reviews was based on the recommendation for critical appraisal of diagnostic studies. 47 Any disagreements that arise between the reviewers will be resolved through discussion, or with a third reviewer. Data Extraction Data will be extracted from papers included in the review using an original data extraction form designed for this review (Appendix II). The data extraction tool (Appendix II) was developed by consensus of reviewers and supervisors based on the previous systematic reviews for measurement accuracy. 45, 46 The data extracted will include specific details about the methods for measurements of central SBP and PP, population characteristics and the actual results of measurements. Data Synthesis Quantitative papers will, where possible be pooled in statistical meta-analysis using the Joanna Briggs Institute Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). An alternative meta-analysis (MetaAnalyst48) software will be used if MAStARI is not appropriate for the analysis of specific measurement accuracy data. Where statistical pooling is not possible the findings will be presented in narrative form. Subgroup analysis will be performed if preliminary results suggest any group characteristics might interfere in outcome interpretation. Conflicts of interests None Acknowledgements This work will contribute to a Masters in Clinical Sciences for the primary reviewer and therefore a secondary reviewer will be used for critical appraisal and data extraction only. Appendices Appendix I: Critical Appraisal Instrument(S)45, 46, 49 Reviewer Date Authors Year Record Number Criteria and Rationale for Assessing Methodological Quality of Method Yes No Comparison Studies* .Were cuff BP measurements performed using validated BP monitors over arms?﹟50, 51 BP monitors are very popular and unvalidated BP monitors produce unreliable and invalid results .Were all measurements carried out concurrently or immediately sequentially?﹟ Where there is a delay between the two readings, any difference in results could potentially be attributed to a change in actual blood pressure. .Were acquisition of waveforms performed by trained professionals? Where there is a statement that the waveform acquisition was performed by professionals who have received training and were experienced in these procedures. .Were acquired waveforms examined for its reliability? Where there is statement reporting the reproducibility of measurements .Were the reference standard results interpreted without knowledge of the results of the index test? Were the index test results interpreted without knowledge of the results of the reference standard? Independently refers to the fact that operators performing test and reference standard should not be aware of the results from each other .Did patients receive the same reference standard regardless of the index test result? (differential verification) .Was the second reading taken before any interventions were given? Avoid treatment paradox .Were statistical method appropriately performed? *Criteria was graded as yes, no, or not stated ﹟ Criteria modified specifically for blood pressure No Stated Appendix II: Data Extraction Instrument Reviewer Date Authors Year Record Number Study Method (Design) Setting Center Participants Recruitment Sampling Flow Chart Country of Study Measurement Method Data collection Inclusion Criteria exclusion Criteria □ Based on presenting symptoms or other test results □ Others □ Consecutive enrolled based on defined criteria □ Others methods for futher selection: □ No._____ of participants satisfying the criteria for inclusion but not undergoing the study and stated the reason______ □ Prospective Trained Professionals executing the □ noninvasive measurements □ Retrospective Trained Professionals □ executing the invasive measurements Number of trained professionals Study Duration □ Methods for calculating reproducibility Year to Month □ Central BP Measured by Transfer function □ Sphygmocor Other □ methods using TF □ Central BP Measured by Carotid tonometry □ Central BP Measured by SBP2 □ Central BP Measured by NPMA method to Tested Device Procedures Type of cuff BP monitor Site of cuff BP measured Calibration method Number of participants Any interval and treatment between invasive and noninvasive tests Reference Invasive Standard Procedures □ Cuff BP measured over arms □ Cuff BP measured over wrists □ Arm □ SBP/DBP □ □ Yes □ External Pressure name Catheter □ Fluid filled pressure damping transducer system coefficient resonant frequency □ Radial artery approach □ femoral artery approach Outcome Population description Number of total participants age range of participants mean age of participants BMI Arm circumferences Proportions (%) of male among participants Proportions (%) HTN Proportions (%) CAD Proportions (%) Type 2 Diabetes Mellitus Proportions (%) Dyslipidemia Proportions (%) Chronic renal failure Proportions (%) Smoking Proportions (%) Calcium channel blocker MBP/DBP □ SD SD SD Other □ No □ Wrist Other Proportions (%) Angiotensin converting enzyme blockade Proportions (%) Diuretics Proportions (%) Betablocker Proportions (%) alpha blockade Proportions (%) Angiotensin-II receptor blockade Proportions (%) Statin Proportions (%) antiplatelet agents Outcome (Agreement) description 1 Means of differences 95% CI SD of differences Pearson r of correlations Outcome (Agreement) description 2 Means of differences 95% CI SD of differences Pearson r of correlations Outcome (Agreement) description 3 Means of differences 95% CI SD of differences Pearson r of correlations Outcome (Agreement) description 4 Means of differences 95% CI SD of differences Pearson r of correlations Outcome (Agreement) description 5 Tested Device Means of measurement SD of measurement 95% CI of measurement Reference Standard Means of measurement SD of measurement 95% CI of measurement Outcome (Agreement) description 6 Tested Device Means of measurement SD of measurement 95% CI of measurement Reference Standard Means of measurement SD of measurement 95% CI of measurement Adverse events Subgroup analysis performed for variability Author Conclusion(discussion for clinical applicability) Comments □ yes □ no References (1) Nichols WW, O'Rourke MF. McDonald's Blood Flow in Arteries: Theoretic, Experimental and Clinical Principles. 3 ed. Philadelphia: Lea & Febiger; 1990. (2) Krooker EJ, Wood EH. Comparison of simultaneously recorded central and peripheral arterial pressure pulses during rest, exercise and tilted position in man. Circ Res 1955;3:623-32. (3) Nichols WW, O'Rourke MF. McDonald's Blood Flow in Arteries: Theoretic, Experimental and Clinical Principles. 4 ed. London: Arnold; 2005. (4) Takazawa K, Tanaka N, Takeda K, Kurosu F, Ibukiyama C. Underestimation of vasodilator effects of nitroglycerin by upper limb blood pressure. Hypertension 1995;26(3):520-3. (5) Segers P, Mahieu D, Kips J, Rietzschel E, De Buyzere M, De Bacquer D, Bekaert S, De Backer G, Gillebert T, Verdonck P, Van Bortel L. Amplification of the pressure pulse in the upper limb in healthy, middle-aged men and women. Hypertension 2009 June 22;54(2):414-20. (6) Kelly RP, Gibbs HH, O'Rourke MF, Daley JE, Mang K, Morgan JJ, Avolio AP. Nitroglycerin has more favourable effects on left ventricular afterload than apparent from measurement of pressure in a peripheral artery. Eur Heart J 1990;11:138-44. (7) Avolio AP, Van Bortel LM, Boutouyrie P, Cockcroft JR, McEniery CM, Protogerou AD, Roman MJ, Safar ME, Segers P, Smulyan H. Role of pulse pressure amplification in arterial hypertension. Experts' opinion and review of the data. Hypertension 2009 June 29;54(2):375-83. (8) Ohte N, Saeki T, Miyabe H, Sakata S, Mukai S, Hayano J, Niki K, Sugawara M, Kimura G. Relationship between blood pressure obtained from the upper arm with a cuff-type sphygmomanometer and central blood pressure measured with a cathetertipped micromanometer. Heart Vessels 2007 November;22(6):410-5. (9) Cheng HM, Wang KL, Chen YH, Lin SJ, Chen LC, Sung SH, Ding PY, Yu WC, Chen JW, Chen CH. Estimation of central systolic blood pressure using an oscillometric blood pressure monitor. Hypertens Res 2010 March 26;33(6):592-9. (10) McEniery CM, Yasmin, McDonnell B, Munnery M, Wallace SM, Rowe CV, Cockcroft JR, Wilkinson IB. Central pressure: variability and impact of cardiovascular risk factors: the Anglo-Cardiff Collaborative Trial II. Hypertension 2008 June;51(6):1476-82. (11) Roman MJ, Devereux RB, Kizer JR, Lee ET, Galloway JM, Ali T, Umans JG, Howard BV. Central pressure more strongly relates to vascular disease and outcome than does brachial pressure: the Strong Heart Study. Hypertension 2007 July;50(1):197-203. (12) Wang KL, Cheng HM, Chuang SY, Spurgeon HA, Ting CT, Lakatta EG, Yin FCP, Chou P, Chen CH. Central or peripheral systolic or pulse pressure: which best relates to target organs and future mortality? J Hypertens 2009;27:461-7. (13) Pini R, Cavallini MC, Palmieri V, Marchionni N, Di Bari M, Devereux RB, Masotti G, Roman MJ. Central but not brachial blood pressure predicts cardiovascular events in an unselected geriatric population: the ICARe Dicomano Study. J Am Coll Cardiol 2008 June 24;51(25):2432-9. (14) Safar ME, Blacher J, Pannier B, Guerin AP, Marchais SJ, Guyonvarc'h PM, London GM. Central pulse pressure and mortality in end-stage renal disease. Hypertension 2002 March 1;39(3):735-8. (15) Benetos A, Thomas F, Joly L, Blacher J, Pannier B, Labat C, Salvi P, Smulyan H, Safar ME. Pulse pressure amplification a mechanical biomarker of cardiovascular risk. J Am Coll Cardiol 2010 March 9;55(10):1032-7. (16) Agabiti-Rosei E, Mancia G, O'Rourke MF, Roman MJ, Safar ME, Smulyan H, Wang JG, Wilkinson IB, Williams B, Vlachopoulos C. Central blood pressure measurements and antihypertensive therapy: a consensus document. Hypertension 2007 July;50(1):154-60. (17) Benetos A, Tsoucaris-Kupfer D, Favereau X, Corcos T, Safar M. Carotid artery tonometry: an accurate non-invasive method for central aortic pulse pressure evaluation. J Hypertens 1991;9(suppl 6):S144-S145. (18) Mancia G, De Backer G, Dominiczak A, Cifkova R, Fagard R, Germano G, Grassi G, Heagerty AM, Kjeldsen SE, Laurent S, Narkiewicz K, Ruilope L, Rynkiewicz A, Schmieder RE, Struijker Boudier HA, Zanchetti A, Vahanian A, Camm J, De Caterina R, Dean V, Dickstein K, Filippatos G, Funck-Brentano C, Hellemans I, Kristensen SD, McGregor K, Sechtem U, Silber S, Tendera M, Widimsky P, Zamorano JL, Kjeldsen SE, Erdine S, Narkiewicz K, Kiowski W, Agabiti-Rosei E, Ambrosioni E, Cifkova R, Dominiczak A, Fagard R, Heagerty AM, Laurent S, Lindholm LH, Mancia G, Manolis A, Nilsson PM, Redon J, Schmieder RE, StruijkerBoudier HA, Viigimaa M, Filippatos G, Adamopoulos S, Agabiti-Rosei E, Ambrosioni E, Bertomeu V, Clement D, Erdine S, Farsang C, Gaita D, Kiowski W, Lip G, Mallion JM, Manolis AJ, Nilsson PM, O'Brien E, Ponikowski P, Redon J, Ruschitzka F, Tamargo J, van Zwieten P, Viigimaa M, Waeber B, Williams B, Zamorano JL. 2007 Guidelines for the management of arterial hypertension: The Task Force for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Eur Heart J 2007 June;28(12):1462-536. (19) Jankowski P, Kawecka-Jaszcz K, Czarnecka D, Brzozowska-Kiszka M, Styczkiewicz K, Loster M, Kloch-Badelek M, Wilinnski J, Curylo AM, Dudek D. Pulsatile but not steady component of blood pressure predicts cardiovascular events in coronary patients. Hypertension 2008 February 11;51:848-55. (20) Williams B, Lacy PS, Thom SM, Cruickshank K, Stanton A, Collier D, Hughes AD, Thurston H, O'Rourke M. Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFE) study. Circulation 2006 March 7;113(9):1213-25. (21) Vlachopoulos C, Aznaouridis K, O'Rourke MF, Safar ME, Baou K, Stefanadis C. Prediction of cardiovascular events and all-cause mortality with central haemodynamics: a systematic review and meta-analysis. Eur Heart J 2010 August;31(15):1865-71. (22) Cloud GC, Rajkumar C, Kooner J, Cooke J, Bulpitt CJ. Estimation of central aortic pressure by SphygmoCor requires intra-arterial peripheral pressures. Clin Sci (Lond) 2003 August;105(2):219-25. (23) Zuo JL, Li Y, Yan ZJ, Zhang RY, Shen WF, Zhu DL, Gao PJ, Chu SL. Validation of the central blood pressure estimation by the SphygmoCor system in Chinese. Blood Press Monit 2010 March 30. (24) Chen CH, Ting CT, Nussbacher A, Nevo E, Kass DA, Pak P, Wang SP, Chang MS, Yin FCP. Validation of carotid artery tonometry as a means of estimating augmentation index of ascending aortic pressure. Hypertension 1996;27:168-75. (25) Segers P, Rietzschel E, Heireman S, De Buyzere M, Gillebert T, Verdonck P, Van Bortel L. Carotid tonometry versus synthesized aorta pressure waves for the estimation of central systolic blood pressure and augmentation index. Am J Hypertens 2005 September;18(9 Pt 1):1168-73. (26) Karamanoglu M, O'Rourke MF, Avolio AP, Kelly RP. An analysis of the relationship between central aortic and peripheral upper limb pressure waves in man. Eur Heart J 1993;14:160-7. (27) Chen CH, Nevo E, Fetics B, Pak PH, Yin FCP, Maughan WL, Kass DA. Estimation of central aortic pressure waveform by mathematical transformation of radial tonometry pressure: validation of generalized transfer function. Circulation 1997;95:1827-36. (28) Pauca AL, Kon ND, O'Rourke MF. The second peak of the radial artery pressure wave represents aortic systolic pressure in hypertensive and elderly patients. Br J Anaesth 2004 May;92(5):651-7. (29) Adji A, O'Rourke MF. Determination of central aortic systolic and pulse pressure from the radial artery pressure waveform. Blood Press Monit 2004 June;9(3):115-21. (30) Munir S, Guilcher A, Kamalesh T, Clapp B, Redwood S, Marber M, Chowienczyk P. Peripheral augmentation index defines the relationship between central and peripheral pulse pressure. Hypertension 2008 January;51(1):112-8. (31) Takazawa K, Kobayashi H, Shindo N, Tanaka N, Yamashina A. Relationship between radial and central arterial pulse wave and evaluation of central aortic pressure using the radial arterial pulse wave. Hypertens Res 2007 March;30(3):219-28. (32) Kelly RP, Hayward C, Ganis J, Daley J, Avolio AP, O'Rourke MF. Noninvasive registration of the arterial pressure pulse waveform using high-fidelity applanation tonometry. J Vasc Med Biol 1989;1:142-9. (33) Drzewiecki GM, Melbin J, Noordergraaf A. Arterial tonometry: review and analysis. J Biomech 1983;16:141-52. (34) Kelly RP, Karamanoglu M, Gibbs H, Avolio AP, O'Rourke MF. Noninvasive carotid pressure wave registration as an indicator of ascending aortic pressure. J Vasc Med Biol 1989;1:241-7. (35) Fetics B, Nevo E, Chen CH, Kass DA. Parametric model derivation of transfer function for noninvasive estimation of aortic pressure by radial tonometry. IEEE Trans Biomed Eng 1999 June;46(6):698-706. (36) Williams B, O'Rourke M. The Conduit Artery Functional Endpoint (CAFE) study in ASCOT. J Hum Hypertens 2001 August;15 Suppl 1:S69-S73. (37) Roman MJ, Okin PM, Kizer JR, Lee ET, Howard BV, Devereux RB. Relations of central and brachial blood pressure to left ventricular hypertrophy and geometry: the Strong Heart Study. J Hypertens 2010 February;28(2):384-8. (38) Hope SA, Meredith IT, Tay D, Cameron JD. 'Generalizability' of a radial-aortic transfer function for the derivation of central aortic waveform parameters. J Hypertens 2007 September;25(9):1812-20. (39) Association for the Advancement of Medical Instrumentation. American National Standard. Electronic or automated sphygmomanometers. Arlington, VA: AAMI; 2009. (40) Davies JI, Band MM, Pringle S, Ogston S, Struthers AD. Peripheral blood pressure measurement is as good as applanation tonometry at predicting ascending aortic blood pressure. J Hypertens 2003 March;21(3):571-6. (41) Papaioannou TG, Protogerou AD, Stamatelopoulos KS, Vavuranakis M, Stefanadis C. Non-invasive methods and techniques for central blood pressure estimation: procedures, validation, reproducibility and limitations. Curr Pharm Des 2009;15(3):245-53. (42) Mahieu D, Kips J, Rietzschel ER, De Buyzere ML, Verbeke F, Gillebert TC, De Backer GG, De Bacquer D, Verdonck P, Van Bortel LM, Segers P. Noninvasive assessment of central and peripheral arterial pressure (waveforms): implications of calibration methods. J Hypertens 2010 February;28(2):300-5. (43) Cheng HM, Wang KL, Chen YH, Lin SJ, Chen LC, Sung SH, Lee WS, Ding YA, Yu WC, Chen JW, Chen CH. Accurate Estimation of Central Systolic Blood Pressure Using an Oscillometric Blood Pressure Monitor. Annual Meeting of the Taiwan Society of Cardiology . 2008. Ref Type: Abstract (44) Cheng HM, Sung SH, Hsu PF, Wang KL, Lee WS, Yu WC, Lin YP, Chen CH. Estimation of Central Blood Pressure by Carotid tonometry, Radial tonometry, and Brachial Plethysmography: A Comparative study. Annual Scientific Session Program of American College of Cardiology . 2010. Ref Type: Abstract (45) Craig JV, Lancaster GA, Williamson PR, Smyth RL. Temperature measured at the axilla compared with rectum in children and young people: systematic review. BMJ 2000 April 29;320(7243):1174-8. (46) Craig JV, Lancaster GA, Taylor S, Williamson PR, Smyth RL. Infrared ear thermometry compared with rectal thermometry in children: a systematic review. Lancet 2002 August 24;360(9333):603-9. (47) Cochrane Methods Working Group on systematic review of screening and diagnostic tests: recommended methods. Checklist for studies of diagnostic accuracy. Cochrane Library, Oxford; 1996. (48) Wallace BC, Schmid CH, Lau J, Trikalinos TA. Meta-Analyst: software for metaanalysis of binary, continuous and diagnostic data. BMC Med Res Methodol 2009;9:80. (49) Bossuyt PM FAU - Reitsma J, Reitsma JB FAU - Bruns D, Bruns DE FAU - Gatsonis C, Gatsonis CA FAU - Glasziou P, Glasziou PP FAU - Irwig L, Irwig LM FAU Lijmer J, Lijmer JG FAU - Moher D, Moher DF, Rennie DF, de Vet HC. Towards complete and accurate reporting of studies of diagnostic accuracy: The STARD Initiative.(1539-3704 (Electronic)). (50) Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL, Jr., Jones DW, Materson BJ, Oparil S, Wright JT, Jr., Roccella EJ. The seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure: the JNC 7 report. JAMA 2003 May 14;289(19):2560-72. (51) Pickering TG, Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, Jones DW, Kurtz T, Sheps SG, Roccella EJ. Recommendations for blood pressure measurement in humans and experimental animals: part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Circulation 2005 February 8;111(5):697-716.