Applications of 24-hour Noninvasive Ambulatory Blood Pressure

REVIEW ARTICLE

Applications of 24-hour Noninvasive Ambulatory Blood Pressure Monitoring Yung-Zu Tseng* Casual blood pressure (CBP) measurements using a standard sphygmomanometer have traditionally constituted the principal modality for the assessment and management of hypertension. However, CBP measurement has shortcomings. Ambulatory blood pressure monitoring (ABPM) provides abundant information on blood pressure (BP), including heart rate, all BP readings for test periods, BP average, BP variability, BP load, load index, distribution pattern of BP, reduction percentage of BP, trough/peak ratio, and summary statistics for overall 24-hour, daytime and nighttime periods. Over the last three decades, ABPM has evolved from a research device to an established and valuable clinical tool for assessment and management of hypertension. This technology has been proven to be useful in terms of the distribution pattern of BP, characterization of BP profiles in normotensive and hypertensive patients, evaluation of patients with mild or labile hypertension, physiologic and psychologic factors for fluctuation of BP, load index study, study of white coatt hypertension, etiology of hypertension, prognosis of hypertension, and assessment of antihypertensive management. Nevertheless, the technology remains underused due to lack of insurance reimbursement in mostt countries. Accordingly, insurance reimbursement is crucial to promote increased utility of ABPM. Clinicians should be familiar with the role of this technology in the care of patients with abnormal BP. This review is an attempt to increase clinicians’’ understanding off ABPM and the appropriate use off this technology. [J Formos Med Assoc 2006;105(12):955–963] Key Words: ABPM, circadian rhythm, dipping, load index, target organ damage

Casual blood pressure (CBP) measurements using a standard sphygmomanometer have traditionally constituted the principal modality for the diagnosis and management of hypertension. There is substantial evidence, however, to suggest that CBP determinations may not always reliably reflect blood pressure (BP) at rest in other settings or during ordinary daily activities. Apparently, casual measurements of BP have shortcomings.1–3 In addition to the rationale that BP varies widely and that CBP measurements are unrepresentative of BP at other times, the superiority of multiple BP measurements rather than a single measurement in

pressure-related morbid events underlies the value of noninvasive ambulatory blood pressure monitoring (ABPM). Over the last three decades, ABPM has evolved from a research device to an established and valuable clinical tool for assessment and management of hypertension,4–10 although the technology remains underused. This review is an attempt to increase clinicians’ understanding of ABPM and the appropriate use of this technology. In the first part of this paper, I describe the devices used in ABPM. Next, I summarize the applications of ABPM and, finally, I mention the problems in the use of ABPM.

©2006 Elsevier & Formosan Medical Association .

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, and Show Chwan Memorial Hospital, Chang Hua, Taiwan. Received: June 5, 2006 Revised: August 1, 2006 Accepted: August 1, 2006

*Correspondence to: Dr Yung-Zu Tseng, Department of Internal Medicine, College of Medicine, National Taiwan University, 7 Chung-Shan South Road, Taipei 100, Taiwan. E-mail: [email protected]

J Formos Med Assoc | 2006 • Vol 105 • No 12

955

Y.Z. Tseng

Applications of ABPM

Figure i 1. Examinee wearing the 24-hour ambulatory blood pressure monitor.

ABPM Devices and Items Ambulatory BP monitors record BP by means of oscillometric or auscultatory methods, or both. Oscillometric monitors perceive arterial pressure vibrations and calculate systolic and diastolic BPs using an algorithmic approach. The readings can be affected by arm movement but not background noise. Auscultatory monitors detect the Korotkoff sounds by using a microphone on the bladder cuff. These monitors may be disturbed by background noise but not arm movement. There are several types of monitors that have been validated by the British Hypertension Society and the Association of Advancement of Medical Instrumentation.11 The examinee wears the ambulatory BP record for a 24-hour period (Figure 1). BPs and heart rates (HRs) are measured usually every 10–20 minutes during daytime hours and every 20–30 minutes during nighttime hours. The examinee is instructed to keep a diary throughout the testing period for evaluation of BP changes. The data are analyzed with a microcomputer. The report provides abundant information on BP, including HR, all BP readings for test periods, BP average, BP variability, BP load, load index, distribution pattern of BP, reduction percentage of BP, trough/peak ratio, and summary statistics for overall 24-hour, daytime, and nighttime periods. Examples of ABPM graphs are shown in Figure 2. Obviously, ABPM can offer data on BP distribution and pattern that cannot be obtained from CBP measurements.12–23 956

ABPM has been proven to be useful in terms of the distribution pattern of BP,15–23 characterization of BP profiles in normotensive and hypertensive patients,15–25 evaluation of patients with mild orr labile hypertension,25,26 physiologic and psychologic factors for fluctuation of BP,12–14,27,28 load index study,29,30 etiology of hypertension,31–36 prognosis of hypertension,37–53 and assessment of antihypertensive management.4,54–60 ABPM has been increasingly used in the assessment of elevated BP in addition to the diagnosis of hypertension.

Distribution pattern of BP ABPM has demonstrated that normal people have a BP pattern with suppression at nighttime.14–17,61,62 However, this normal circadian change in BP is not observed in certain groups of people, such as some hypertensive patients,18,19,61,62 patients with diabetes mellitus,63 those with autonomicc dysfunction63,64 or organ transplants65,66 or cerebral vascular accident.67,68 The abnormal circadian change including non-dipping or reversed circadian are associated with target organ complications.42–45,49

White coat hypertension BP is a fluctuating variable that is influenced byy multiple physiologic and psychologic factors. Twenty-four-hour ABPM is more representative off these factors.12–14,27,28 There are some people who have persistently elevated clinic BPs but normal pressures on ABPM. This effect of a physician on BP is often referred to as white coat hypertension (WCH).1,2,69 This phenomenon has been reported in 15–35% of subjects currently labeled and treated as hypertensive.1,70–72 The prevalence of WCH was 21% among our hospital population. Although controversy exists regarding the management off WCH, most studies have suggested that it is a benign condition.73–76 WCH also represents a low w risk stratum of Taiwanese with isolated office hypertension.77 Accordingly, identification of WCH is of medical, social and economic importance. WCH is most dramatically illustrated by using ABPM. J Formos Med Assoc | 2006 • Vol 105 • No 12

Application off ABPM Figure i 2. Parameters off 24-hour ambulatory blood pressure (BP) monitoring: (A) distribution of ambulatory BP; (B) histogram of BP.

Three point running average

A 250

BP (mmHg)

200 150 100 50 0 13.00

16.00

19.00

22.00

1.00 4.00 Time (o’clock)

7.00

10.00

13.00

16.00

B 50% Diastolic Systolic

Percentage of BP

40%

30%

20%

10%

0% 40 50

60

70

80

90 100 110 120 130 140 150 160 170 180 190 200 BP (mmHg)

Etiology and mechanism of hypertension ABPM is also of great value in the investigation of the etiology and mechanism of hypertension, when it correlates other measurements with a subject’s BP profile. Jefferies et al32 found that increased nocturnal BP and reduced nocturnal BP dipping may be risk factors for the later development of hypertension in twins. Significant genetic effects on both systolic BP and diastolic BP by ABPM was found and estimates of genetic effects were higher for daytime than nighttime ABPM values.33 The interaction of adducing gene variants (ADD1 and ADD3) in humans is statistically associated with variation in ABPM values.34 Ramunni and his colleagues35 suggested that factors other J Formos Med Assoc | 2006 • Vol 105 • No 12

than the renin–angiotensin system probably contribute to the increase in renal vascular resistance and to the early development of hypertension evaluated by ABPM. Differences in peritoneal transport properties were also demonstrated to be associated with the development of hypertension in continuous ambulatory peritoneal dialysis patients.36

Diagnosis of hypertension ABPM is a highly useful diagnostic tool as it can distinguish masked hypertension, WCH and sustained hypertension. Therefore, the technology is a more sensitive method for diagnosing hypertension than is sole reliance on office BP in chronicc 957

Y.Z. Tseng

renal disease patients and renal transplant recipients.78–80 Hypertension is linked to increased left ventricular mass, stroke, cardiovascular morbidity and mortality, and progression to end-stage renal disease. ABPM is also a fundamental tool to diagnose resistant hypertension (RH) and to evaluate treatment efficacy.81,82 True RH patients have more target organ damage. The presence of a greater pulse pressure and a lower nocturnal BP reduction in true RH patients may be responsible for this increased cardiovascular risk profile. Morning periods have been associated with a greater risk for cardiovascular events compared with the rest of the 24 hours. The morning surge in BP is believed to contribute to the heightened risk and can only be detected by ABPM.83

Mechanism of myocardial ischemia ABPM is useful in load index study, which is imperative for evaluating the mechanism of myocardial ischemia.15 With Holter monitoring, the prevalence of silent myocardial ischemia in hypertensive patients without coronary artery disease is between 25% and 73%. Silent myocardial ischemia resulting from increased oxygen demand remains to be studied. The combined 24-hour Holter electrocardiography (ECG)/ABPM device is imperative.29 Nowadays, a new device allows simultaneous ST segment analysis with extra BP recordings triggered by episodes of ST segment depression and demonstrated episodes of silent myocardial ischemia during BP and HR increases in a study.30

Assessment of antihypertensive management A relevant analogy to the use of Holter ECG monitoring for evaluating response to antiarrhythmic therapy is the use of ABPM for monitoring response to antihypertensive medications. ABPM has been used in the evaluation of the pharmacologically antihypertensive effects of various antihypertensive agents, including monotherapy or combination therapy,4,54–60 in special hypertensive groups.63,84 This technology has also been proven to be useful in the evaluation of antihypertensive duration of long-acting antihypertensive drugs. It has demonstrated that some 958

long-acting antihypertensive drugs cannot control BP throughout the day or night or both periods.56 ABPM can provide the trough/peak ratio of various antihypertensive drugs and, thus, the optimal BP control.85,86 ABPM is also used to study the mechanism of BP lowering effect.60

Prognostic implications Another important use of ABPM is in the prediction of target organ damage and cardiovascularr morbidity. In every study in which ABPM has been compared with CBP, ABPM has been shown to be superior in predicting either target organ damage38,42–47,50–53 or morbid events.37,39–41,48,49 In a study,42 24-hour ABPM revealed a close relationship between hypertensive target organ damage (ECG and chest roentgenographic evidence of leftt ventricular hypertrophy, proteinuria and retinopathy) and the parameters of such measurements in terms of BP pattern (reversed circadian pattern, non-dip), comparisons between CBP and ambulatory BP (ABP) in addition to BP load and BP average. ABPM measurements such as BP pattern, comparisons between CBP and ABP, and BP load correlate more closely to the surrogates of cerebrovascular (CVA) and cardiovascular disease than office BP.67,68

Comparison between CBP and ABP In normal conditions, ABP is lower than CBP. In cases where ABP is higher than CBP, there was significantly greater presence of target organ damage or cardiovascular morbidity and mortality.42 A subject with reversed WCH—normal CBP and variable fraction of abnormally high ABP—mayy have greater target organ damage than those with normal ABP.87

Circadian rhythm BP in normotensive subjects is characterized by a clear circadian pattern, with values tending to peak during the day but falling to a nadir at midnight. However, some hypertensive patients have a reversed circadian pattern where BP values fall to a nadir during the day and reach a peak at midnight. The frequency of a reversed circadian rhythm J Formos Med Assoc | 2006 • Vol 105 • No 12

Application off ABPM

is significantly higher in patients with target organ damage.42,48,49 Reversed circadian rhythm is found more frequently in organ transplant recipients65,66 and patients with cerebral stroke.67,68 In acute CVA disorders, the risk for loss of circadian change in BP was strongly inversely correlated with the distance between the lesion and hypothalamus.68

Dipping Verdacchia et al43 found that a nocturnal reduction in systolic and diastolic BP of more than 10% (dipping), could delay or prevent the development of left ventricular hypertrophy. In contrast, a nocturnal BP reduction of less than 10% of the daytime value (non-dipping) was closely associated with target organ damage.42,45,49 In patients with CVA disorder, there was a close correlation between the distance from the lesion to the hypothalamus and the ratio of nocturnal BP reduction (circadian index). ABPM may be useful in localization of the CVA lesion.68

Verification of hypertension in organ transplant recipients In renal transplant recipients, hypertension is common and associated with increased cardiovascular and allograft rejection risks. Nocturnal hypertension is an underestimated phenomenon in this population.78 The later serum creatinine correlated positively with 24-hour systolic BP load and ABPM-derived pulse pressure.88 However, BP control is not optimal in one-third of this population. Therefore, ABPM is required for accurate diagnosis and optimal treatment of hypertension to reduced cardiovascular events in this population.72 ABPM is also useful in evaluating the circadian rhythms of BP in liver allograft recipients.66

Table 1.

Application in pediatrics Varda and Gregoric89 suggested that ABPM is applicable in the assessment of BP in very young children. Wuhl et al90 found that ABPM provided superior information for diagnosis and treatmentt of pediatric hypertension. They suggested that neither CBP nor home BP detected hypertension with enough sensitivity or specificity to replace ABPM. ABPM is useful in evaluation of the relationship between BP measured with ABPM and the progression of renal damage in normotensive children with reflux nephropathy and in selecting children at risk of hypertension.91

Problems in the Use of ABPM Although ABPM is a useful modality for stratifying cardiovascular risk and guiding therapeuticc decisions, the technology remains underused. Problems hindering the widespread use of ABPM include technology, the normal values of ABP, and its cost-benefit.

Technology A minority of examinees do not sleep well with the records and tend to have somewhat unstable BP values. Rarely, examinees may not be able to tolerate the test or they may develop erythema in the area distal to cuff placement. However, these problems should disappear as the technologyy improves.92

Normal values of ABP The definition of normal ABP remains to be established. Many large population studies have been carried out to define normal ABP (Table 1).93–96 All

Ambulatory blood pressure of normotensive subjects

93

O’Brien et al Imai et al94 Staessen et al95 Mancia et al96

24-hr SBP/DBP (mmHg)

Daytime SBP/DBP (mmHg)

Nighttime SBP/DBP (mmHg)

118 ± 11/72 ± 7 118 ± 11/69 ± 7 116 ± 10/70 ± 7 118 ± 11/74 ± 7

124 ± 12/78 ± 8 121 ± 12/72 ± 7 122 ± 11/75 ± 8 123 ± 11/79 ± 8

106 ± 11/61 ± 8 106 ± 11/61± 7 106 ± 11/61 ± 8 108 ± 11/64 ± 8

SBP = systolic blood pressure; DBP = diastolic blood pressure.


959

Y.Z. Tseng

Table 2.

Normal reference values for mean 24-hour ambulatory blood pressure

O’Brien et al93 Staessen et al95 Mancia et al96 Ohkubo et al97 JNC VI8

Authority

SBP/DBP (mmHg)

Allied Irish Bank study International database PAMELA study Cohort of Ohasama JNC VI

134/84 134/82 130/81 134/79 135/85 (awake) 120/75 (asleep)

SBP = systolic blood pressure; DBP = diastolic blood pressure; JNC VI = The sixth report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure.

960

of the studies have shown that ABP averages are lower than CBP averages in normal subjects. Several methods have also attempted to define the normal values of ABP, with similar results. Table 2 shows the diagnostic thresholds for ABPM currently agreed on by the British Hypertension Society and the American Society of Hypertension.8,93,95–97

therapy, reimbursement for ABPM is imperative. Accordingly, national insurance coverage is crucial to promote the increased clinical utility of ABPM. However, in case of widespread clinical use off ABPM, clinicians should use the technologyy judiciously.

Cost-benefit issues

References

The issue of cost-benefit is controversial. ABPM has been considered to be an investigative technology and its cost is not reimbursed in most countries. This lack of reimbursement underlies the low use of ABPM. Moser98 emphasized that ABPM performed on hypertensive patients each year would add to treatment expenditure, while other studies99,100 have shown that appropriate use of ABPM does not increase the cost of care. Cost savings would be found in people assessed with ABPM compared with CBP measurement.55,99 In addition to lower cost of medications and physician fees, reducing the unnecessary prescription of medications for the highly prevalent WCH population would be the most important source of cost savings. More recently, the value of ABPM has been recognized and it has been approved for reimbursement by the center for Medicare and Medicaid Services of the United States. Currently, ABPM is only recommended for the evaluation of WCH, patients with drug resistance, hypotension with antihypertensive medications, episodic hypertension and autonomic dysfunction.8 As ABPM is still useful in identifying those who truly require antihypertensive therapy and those who may best be managed with non-pharmacologic

1. Pickering TG, James GD, Boddie C, et al. How common is white coat hypertension? JAMA 1988;259:225–8. 2. White WB, Schulman P, McCabe EJ, et al. Average daily blood pressure not office blood pressure, determines cardiac function in patients with hypertension. JAMA 1989; 261:873–7. 3. Staessen JA, Celis H, DenHond E, et al. Comparison of conventional and automated blood pressure measurements: interim analysis of the THOP trial. Blood Press Monitt 2002;7:61–2. 4. Drayer JIM, Weber MA, DeYoung JL, et al. Long-term BP monitoring in the evaluation of antihypertensive therapy. Arch Intern Med 1983;143:898–901. 5. Sheps SG, Clement DL, Pickering TG, et al. Ambulatory blood pressure monitoring. Hypertensive Diseases Committee, American College of Cardiology. J Am Coll Cardiol 1994;23:1511–3. 6. Pickering TG. Recommendations for the use of home (self) and ambulatory blood pressure monitoring. Am J Hypertens 1996;9:1–11. 7. Zanchetti A. The role of ambulatory blood pressure monitoring in clinical practice. Am J Hypertens 1997;10: 1069–80. 8. Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Arch Intern Med 1997;157:2413–46. 9. Staessen JA, Beilin L, Parati G, et al. Task force IV: clinical use of ambulatory blood pressure monitoring. Participants



10.

11.

12.

13.

14.

15.

16.

17. 18.

19.

20.

21.

22.

23. 24.

25.

26.

of the 1999 Consensus Conference on Ambulatory Blood Pressure Monitoring. Blood Press Monit 1999;4:319–31. O’Brien E, Coats A, Owens P, et al. Use and interpretation of ambulatory blood pressure monitoring: recommendations of the British Hypertension Society. BMJ 2000;320:1128–34. O’Brien E, Petrie J, Littler WA, et al. An outline of the revised British Hypertension Society protocol for the evaluation of blood pressure measuring devices. J Hypertens 1993;11:677–9. Pickering TG, Harshfield GA, Kleinert HD, et al. Blood pressure during normal daily activities, sleep, and exercise: comparison of values in normal and hypertensive subjects. JAMA 1982;247:992–6. Messerli FH, Glade LB, Ventura HO, et al. Diurnal variations of cardiac rhythm, arterial pressure, and urinary catecholamines in borderline and established essential hypertension. Am Heart J 1982;104:109–14. Chiang FT, Tseng CD, Hsu KL, et al. Circadian variations of atrial natriuretic peptide in normal people and its relationship to arterial blood pressure, plasma renin activity and aldosterone level. Int J Cardiol 1994;46:229–33. Kennedy HL, Horan MJ, Sprague MK, et al. Ambulatory blood pressure in healthy normotensive males. Am Heart J 1983;106:717–22. Weber MA, Drayer JIM, Nakamura DK, et al. The circadian blood pressure pattern in ambulatory normal subjects. Am J Cardiol 1984;54:115–9. Lin LJ, Tseng YZ, Chiang FT, et al. Ambulatory blood pressure in normal Chinese. J Formos Med Assoc 1990;89:90–6. Tseng YZ, Tseng CD, Chiang FT, et al. The normalcy of blood pressure in well-controlled hypertensive patients. Am J Noninvas Cardiol 1992;6:95–8. Drayer JIM, Weber MA, DeYoung JL, et al. Circadian blood pressure patterns in ambulatory hypertensive patients. Am J Med 1982;73:493–9. Hany S, Baumgart P, Frielingsdorf J, et al. Circadian blood variability in secondary and essential hypertension. J Hypertens 1987;5(Suppl 5):S487–9. Imai Y, Abe K, Sasaki S, et al. Alternated circadian blood pressure rhythm in patients with Cushing’s syndrome. Hypertension 1988;12:11–9. Kobrin I, Oigman W, Kumar A, et al. Diurnal variation of blood pressure in elderly patients with essential hypertension. J Am Geriatr Soc 1984;32:896–9. Millar–Craig MW, Bishop CN, Raftery EB. Circadian variation of blood pressure. Lancet 1978;1:795–7. Mancia G, Ferrari A, Gregorini L, et al. Blood pressure and heart rate variabilities in normotensive and hypertensive human beings. Circ Res 1983;53:96–104. Sokolow M, Perloff D, Cowan R. Contribution of ambulatory blood pressure to the assessment of patients with mild to moderate elevation of office blood pressure. Cardiovasc Rev Rep 1980;1:295–303. Waeber B, Jacot Des Combes B, Porchet M, et al. Ambulatory blood pressure recording to identify hypertensive


27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37. 38.

39.

40.

41.

42.

patients who truly need therapy. J Chronic Dis 1984; 37:55–7. Littler WA, Honour AJ, Sleight P. Direct arterial pressure, pulse rate and electrocardiogram during micturition and defecation in unrestricted man. Am Heart J 1974;88: 205–10. Rowlands DB, Stallard TJ, Watson RD, et al. The influence of physical activity on arterial pressure during ambulatory recordings in man. Clin Sci 1980;58:115–7. Uen S, Vetter H, Mengden T. Simultaneous recording off blood pressure and ST-segment with combined, triggered ambulatory 24-h devices. Blood Press Monit 2003;8:41–4. Uen S, Baulmann J, Düsing R, et al. ST-segment depression in hypertensive patients is linked to elevations in blood pressure, pulse pressure and double product by 24-h Cardiotens monitoring. J Hypertens 2003;21:977–83. Sowers JR, Stern N, Nyby MD, et al. Dopaminergic regulation of circadian rhythms of blood pressure, renin and aldosterone in essential hypertension. Cardiovasc Res 1982;16:317–23. Jefferies CA, Hofman PL, Wong W, et al. Increased nocturnal blood pressure in healthy prepubertal twins. J Hypertens 2003;21:1319–24. Jedrusik P, Januszewicz A, Busjahn A, et al. Genetic influence on blood pressure and lipid parameters in a sample off Polish twins. Blood Press 2003;12:7–11. Lanzani C, Citterio L, Jankaricova M, et al. Role of the adducin family genes in human essential hypertension. J Hypertens 2005;23:543–9. Ramunni A, Saracino A, Esposito T, et al. Renal vascular resistance and renin–angiotensin system in the pathogenesis of early hypertension in autosomal dominant polycystic kidney disease. Hypertens Res 2004;27:221–5. Tonbul Z, Altintepe L, Sozlu C, et al. The association of peritoneal transport properties with 24-hour blood pressure levels in CAPD patients. Perit Dial Int 2003;23:46–52. Perloff D, Sokolow M, Cowan R. The prognostic value off ambulatory blood pressures. JAMA 1983;249:2792–8. Parati G, Pomidossi G, Albini F, et al. Relationship of 24-hour blood pressure mean and variability to severity of targetorgan damage in hypertension. J Hypertens 1987;5:93–8. Pickering TG, Devereux RB. Ambulatory monitoring off blood pressure as a predictor of cardiovascular risk. Am Heart J 1987;114:925–8. Perloff D, Sokolow M, Cowan R. The prognostic value off ambulatory blood pressure monitoring in treated hypertensive patients. J Hypertens 1991;9(Suppl 1):S33–40. Mann S, Millar-Craig MW, Raftery EB. Superiority of 24-hour measurement of blood pressure over clinic values in determining prognosis in hypertension. Clin Exp Hypertens – Part A, Theory & Pract 1985;7:279–81. Tseng YZ, Tseng CD, Lo HM, et al. Characteristic abnormal findings of ambulatory blood pressure indicative of hypertensive target organ complications. Eur Heart J 1994; 15:1037–43.

961

Y.Z. Tseng

43. Verdecchia P, Schillaci G, Guerrieri M, et al. Circadian blood pressure changes and left ventricular hypertrophy in essential hypertension. Circulation 1990;81:528–36. 44. Rahman M, Griffin V, Heyka R, et al. Diurnal variation of blood pressure: reproducibility and association with left ventricular hypertrophy in hemodialysis patients. Blood Press Monit 2005;10:25–32. 45. Cicconetti P, Morelli S, Ottaviani L, et al. Blunted nocturnal fall in blood pressure and left ventricular mass in elderly individuals with recently diagnosed isolated systolic hypertension. Am J Hypertens 2003;16:900–5. 46. Cuspidi C, Michev I, Meani S, et al. Left ventricular hypertrophy in treated hypertensive patients with good blood pressure control outside the clinic, but poor clinic blood pressure control. J Hypertens 2003;21:1575–81. 47. Redon J, Liao Y, Lozano JV, et al. Ambulatory blood pressure and microalbuminuria in essential hypertension: role of circadian variability. J Hypertens 1994;12:947–53. 48. Timio M, Venanzi S, Lolli S, et al. Night-time blood pressure and progression of renal insufficiency. High Blood Press Cardiovasc Prev 1994;3:39–44. 49. Liu M, Takahashi H, Morita Y, et al. Non-dipping is a potent predictor of cardiovascular mortality and is associated with autonomic dysfunction in haemodialysis patients. Nephrol Dial Transplant 2003;18:563–9. 50. Lengyel Z, Rosivall L, Nemeth C, et al. Diurnal blood pressure pattern may predict the increase of urinary albumin excretion in normotensive normoalbuminuric type 1 diabetes mellitus patients. Diabetes Res Clin Pract 2003;62: 159–67. 51. O’Sullivan C, Duggan J, Lyons S, et al. Hypertensive targetorgan damage in the very elderly. Hypertension 2003;42: 130–5. 52. Cuspidi C, Meani S, Fusi V, et al. Isolated ambulatory hypertension and changes in target organ damage in treated hypertensive patients. J Human Hypertens 2005; 19:471–7. 53. Shimada K, Kawamoto A, Matsubayashi K, et al. Diurnal blood pressure variations and silent cerebrovascular damage in elderly patients with hypertension. J Hypertens 1992; 10:875–8. 54. Gould BA, Mann S, Kieso H, et al. The 24-hour ambulatory blood pressure profile with verapamil. Circulation 1982; 65:22–8. 55. Staessen JA, Byttebier G, Buntinx F, et al. Antihypertensive treatment based on conventional or ambulatory blood pressure measurement: a randomized controlled trial. JAMA 1997;278:1065–72. 56. Tseng CD, Tseng YZ, Lo HM, et al. Ambulatory blood pressure monitoring for evaluation of long-acting beta-blockers in Taiwan. J Formos Med Assoc 1996;95: 320–4. 57. Smith DHG, Neutel JM, Lacourcière Y, et al. Prospective, randomized, open-label, blinded-endpoint (PROBE) designed trials yield the same results as double-blind,

962

58.

59.

60.

61.

62.

63.

64.

65.

66.

67.

68.

69.

70.

placebo-controlled trials with respect to ABPM measurements. J Hypertens 2003;21:1291–8. Smith DHG, Dubiel R, Jones M. Use of 24-hour ambulatory blood pressure monitoring to assess antihypertensive efficacy: a comparison of olmesartan medoxomil, losartan potassium, valsartan and irbesartan. Am J Cardiovasc Drugs 2005;5:41–50. Andreadis EA, Tsourous GI, Marakomichelakis GE, et al. High-dose monotherapy vs. low-dose combination therapy of calcium channel blockers and angiotensin receptor blockers in mild to moderate hypertension. J Human Hypertens 2005;19:491–6. Ruilope LM, Heintz D, Brandao AA, et al. 24-hour ambulatory blood-pressure effects of valsartan and hydrochlorothiazide combinations compared with amlodipine in hypertensive patients at increased cardiovascular risk: a VAST sub-study. Blood Press Monit 2005;10:85–91. Floras JS, Jones JV, Johnston JA, et al. Arousal and the circadian rhythm of blood pressure. Clin Sci Mol Med 1978; 4(Suppl):395S–7S. Richards AM, Nicholls MG, Espiner EA, et al. Diurnal patterns of blood pressure, heart rate and vasoactive hormones in normal man. Clin Exp Hypertens – Part A, Theory & Pract 1986;8:153–66. Yasuda G, Hasegawa K, Kuji T, et al. Perindopril effects on ambulatory blood pressure: relation to sympathetic nervous activity in subjects with diabetic nephropathy. Am J Hypertens 2004;17:14–20. Guasti L, Simoni C, Mainardi LT, et al. Circadian blood pressure variability is associated with autonomic and baroreflex-mediated modulation of the sinoatrial node. Acta Cardiologica 2005;60:319–24. Reeves RA, Shapiro AP, Thompson ME, et al. Loss of nocturnal decline in blood pressure after cardiac transplantation. Circulation 1986;73:401–8. Martínez-Rey C, Otero-Antón E, Tomé S, et al. Circadian variability of blood pressure in liver transplant recipients without antihypertensive therapy. Transplant Proc 2005;37: 1515–6. Lin LJ, Tseng YZ, Chiang FT, et al. Altered circadian rhythm of blood pressure in patients with cerebral stroke. Am J Noninvas Cardiol 1992;6:62–5. Wang TL, Chiang FT, Hsu KL, et al. Abnormal circadian blood pressure changes in patients with acute cerebrovascular disorders. J Formos Med Assoc 1997;96: 710–7. Julius S, Mejia A, Jones K, et al. “White coat” versus “sustained” borderline hypertension in Tecumseh, Michigan. Hypertension 1990;16:617–23. Schrader J, Lüders S, Züchner C, et al. Practice vs. ambulatory blood pressure measurement under treatment with ramipril (PLUR Study): a randomised, prospective longterm study to evaluate the benefits of ABPM in patients on antihypertensive treatment. J Human Hypertens 2000; 14:435–40.



71. Sorof JM. White coat hypertension in children. Blood Press Monit 2000;5:197–202. 72. Brown MA, Mangos G, Davis G, et al. The natural history of white coat hypertension during pregnancy. BJOG 2005;112:601–6. 73. Gosse P, Promax H, Durandet P, et al. ‘White coat’ hypertension. No harm for the heart. Hypertension 1993;22: 766–70. 74. Hoegholm A, Kristensen KS, Bang LE, et al. Left ventricular mass and geometry in patients with established hypertension and white coat hypertension. Am J Hypertens 1993;6:282–6. 75. Björklund K, Lind L, Vessby B, et al. Different metabolic predictors of white-coat and sustained hypertension over a 20-year follow-up period. A population-based study of elderly men. Circulation 2002;106:63–8. 76. Polónia JJ, Gama GM, Silva JA, et al. Sequential follow-up clinic and ambulatory blood pressure evaluation in a low risk population of white-coat hypertensive patients and in normotensives. Blood Press Monit 2005;10:57–64. 77. Tseng YZ, Chiang FT, Hsu KL, et al. Low frequency of target organ damage in Taiwanese with white coat hypertension. J Formos Med Assoc 2005;104:327–32. 78. Covic A, Segall L, Goldsmith DJA. Ambulatory blood pressure monitoring in renal transplantation: should ABPM be routinely performed in renal transplant patients? Transplantation 2003;76:1640–2. 79. Haydar AA, Covic A, Jayawardene S, et al. Insights from ambulatory blood pressure monitoring: diagnosis of hypertension and diurnal blood pressure in renal transplant recipients. Transplantation 2004;77:849–53. 80. Mitsnefes MM, Portman RJ. Ambulatory blood pressure monitoring in pediatric renal transplantations. Pediatr Transplant 2003;7:86–92. 81. Brown MA, Buddle ML, Martin A. Is resistant hypertension really resistant? Am J Hypertens 2001;14:1263–9. 82. Muxfeldt ES, Bloch KV, Nogueira AR, et al. Twenty-four hour ambulatory blood pressure monitoring pattern of resistant hypertension. Blood Press Monit 2003;8:181–5. 83. Kario K, Pickering TG, Umeda Y, et al. Morning surge in blood pressure as a predictor of silent and clinical cerebrovascular disease in elderly hypertensives: a prospective study. Circulation 2003;107:1401–6. 84. Laurent S. Very low-dose combination of perindopril and indapamide: efficacy on blood pressure and target-organ damage. J Hypertens 2003;21(Suppl 3):S11–8. 85. Celentano A, Crivaro M, Perticone F, et al. Anti-hypertensive effect of manidipine: 24 hours monitoring evaluation and Doppler-echocardiographic remarks. Blood Press 1996;5(Suppl):29–35. 86. Mallion JM, Chamontin B, Asmar R, et al. Twenty-fourhour ambulatory blood pressure monitoring efficacy of perindopril/indapamide first-line combination in


87.

88.

89.

90.

91.

92.

93.

94.

95.

96.

97.

98.

99.

100.

hypertensive patients: the REASON study. Am J Hypertens 2004;17:245–51. Ohkubo T, Kiyuya M, Metoki H, et al. Prognosis off “masked” hypertension and “white coat” hypertension detected by 24-h ambulatory blood pressure monitoring 10-year follow-up from the Ohasama study. J Am Coll Cardiol 2005;46:508–15. Haydar AA, Covic A, Agharazii M, et al. Systolic blood pressure diurnal variation is not a predictor of renal target organ damage in kidney transplant recipients. Am J Transplant 2004;4:244–7. Varda NM, Gregoric A. Twenty-four-hour ambulatory blood pressure monitoring in infants and toddlers. Pediatr Nephrol 2005;20:798–802. Wühl E, Hadtstein C, Mehls O, et al. Home, clinic and ambulatory blood pressure monitoring in children with chronic renal failure. Pediatr Res 2004;55:492–7. Lama G, Tedesco MA, Graziano L, et al. Reflux nephropathy and hypertension: correlation with the progression of renal damage. Pediatr Nephrol 2003;18: 241–5. Mallion JM, de Gandemaris R, Bagnet JP, et al. Acceptability and tolerance of ambulatory blood pressure measurement in the hypertensive patient. Blood Press Monit 1996;1:475–80. O’Brien E, Murphy J, Tyndall A, et al. Twenty-four-hour ambulatory blood pressure in men and women aged 17 to 80 years: the Allied Irish Bank Study. J Hypertens 1991;9:355–60. Imai Y, Nagai K, Sakuma M, et al. Ambulatory blood pressure of adults in Ohasama, Japan. Hypertension 1993;22:900–12. Staessen JA, O’Brien E, Amery AK, et al. Ambulatory blood pressure in normotensive and hypertensive subjects: results from an international database. J Hypertens 1994;12(Suppl 7):S1–12. Mancia G, Sega R, Bravi C, et al. Ambulatory blood pressure normality: results from the PAMELA study. J Hypertens 1995;13:1377–90. Ohkubo T, Imai Y, Tsuji I, et al. Reference values for 24–hour ambulatory blood pressure monitoring based on a prognostic criterion: the Ohasama study. Hypertension 1998;32:255–9. Moser M. Hypertension can be treated effectively without increasing the cost of care. J Human Hypertens 1996; 10(Suppl 2):S33–8. Pierdomenico SD, Mezzetti A, Lapenna D, et al. “Whitecoat” hypertension in patients with newly diagnosed hypertension: evaluation of prevalence by ambulatory monitoring and impact on cost of health care. Eur Heartt J 1995;16:692–7. Krakoff LR. Cost-effectiveness of ambulatory blood pressure. A reanalysis. Hypertension 2006;47:29–34.

963