Cost-effectiveness of the introduction of home blood pressure measurement in patients with office hypertension

OBJECTIVE: Cost-effectiveness of hypertension treatment is an important social and medical issue in Western as well as in Eastern countries, including Japan. Home blood pressure (HBP) measurements have a stronger predictive power for cardiovascular events than casual clinic blood pressure (CBP) measurements. Therefore, the introduction of HBP measurement for the diagnosis and treatment of hypertension should lead to a decrease in medical expenditure. This study presents calculations of the cost savings likely to take place when HBP is implemented for newly detected hypertensive subjects in Japan. DESIGN AND METHODS: We estimate the cost savings from the perspective of a Japanese healthcare system. To estimate the costs associated with changing from CBP to HBP measurement as the diagnostic tool, we constructed a simulation model using data from the Ohasama study. These calculations are based on current estimates for cost of treatment, prevalence of white-coat hypertension at baseline, and varying the incidence of new hypertension after the initial screening. RESULTS: When HBP measurement is not incorporated into the diagnostic process, the medical cost is estimated at US$10.89 million per 1000 subjects per 5 years. When HBP measurement is incorporated, the medical cost is estimated at US$9.33 million per 1000 subjects per 5 years. The reductions in medical costs vary from US$674,000 to US$2.51 million per 1000 subjects per 5 years for treatment of hypertension, when sensitivity analysis is performed. CONCLUSIONS: The introduction of HBP measurement for the treatment of hypertension is very useful for reducing medical costs.     

Estimate of the benefits of a population-based reduction in dietary sodium additives on hypertension and its related health care costs in Canada

BACKGROUND: Hypertension is the leading risk factor for mortality worldwide. One-quarter of the adult Canadian population has hypertension, and more than 90% of the population is estimated to develop hypertension if they live an average lifespan. Reductions in dietary sodium additives significantly lower systolic and diastolic blood pressure, and population reductions in dietary sodium are recommended by major scientific and public health organizations. OBJECTIVES: To estimate the reduction in hypertension prevalence and specific hypertension management cost savings associated with a population-wide reduction in dietary sodium additives. METHODS: Based on data from clinical trials, reducing dietary sodium additives by 1840 mg/day would result in a decrease of 5.06 mmHg (systolic) and 2.7 mmHg (diastolic) blood pressures. Using Canadian Heart Health Survey data, the resulting reduction in hypertension was estimated. Costs of laboratory testing and physician visits were based on 2001 to 2003 Ontario Health Insurance Plan data, and the number of physician visits and costs of medications for patients with hypertension were taken from 2003 IMS Canada. To estimate the reduction in total physician visits and laboratory costs, current estimates of aware hypertensive patients in Canada were used from the Canadian Community Health Survey. RESULTS: Reducing dietary sodium additives may decrease hypertension prevalence by 30%, resulting in one million fewer hypertensive patients in Canada, and almost double the treatment and control rate. Direct cost savings related to fewer physician visits, laboratory tests and lower medication use are estimated to be approximately $430 million per year. Physician visits and laboratory costs would decrease by 6.5%, and 23% fewer treated hypertensive patients would require medications for control of blood pressure. CONCLUSIONS: Based on these estimates, lowering dietary sodium additives would lead to a large reduction in hypertension prevalence and result in health care cost savings in Canada.     

Treatment of white coat hypertension

White coat hypertension has been defined as the persistent elevation of blood pressure at the clinic or office only. It usually implies that daily ambulatory blood pressure is normal. The accepted cutoff for normal daytime ambulatory blood pressure is 135/85 mm Hg. The prevalence of white coat hypertension is high and varies from 20% to 45%. It appears to be more frequent in women, older patients, and persons with mild hypertension. White coat hypertension should not be confused with the white coat effect. The white coat effect signifies the difference in blood pressure between the office and daytime ambulatory blood pressure and occurs in patients with white coat hypertension as well as in patients with sustained hypertension that is treated or untreated. White coat hypertension is a benign condition, and the incidence of target-organ damage or cardiovascular morbidity and death is not significantly different from that in normotensive persons. Pharmacologic treatment should be withheld; instead, treatment should consist of lifestyle modification, moderate salt restriction, weight reduction, regular exercise, smoking cessation, and correction of glucose and lipid abnormalities. In addition, semiannual or annual follow-up with ambulatory blood pressure monitoring is advised.     

Masked hypertension: how can the condition be detected?

Recent evidence demonstrates that masked hypertension is a significant predictor of cardiovascular disease, but the problem for clinical practice is how to identify these patients. Furthermore, the prevalence of masked hypertension in the general population or in subjects with transient blood pressure elevation is still unknown. Data obtained in several cross-sectional studies have demonstrated large differences in the prevalence of masked hypertension, with prevalence rates from a low of 8% to a high of 49%. Two population-based studies performed in Italy and in Japan report prevalence of 9% and of 13.4%, respectively. A 49% frequency of masked hypertension has been found among subjects with transiently elevated clinic blood pressure. Several factors can selectively raise ambulatory blood pressure including age, sex, smoking, alcohol use, contraceptive use in women, and sedentary habits. Reactivity to daily life stressors and behavioural factors are other important determinants of ambulatory blood pressure. On the basis of the available evidence, masked hypertension should be searched for in individuals who are more likely to have this condition or are at increased risk of cardiovascular complications including diabetic individuals and subjects with kidney disease. Further research is needed to determine whether the use of ambulatory blood pressure monitoring is cost-effective in these subjects.     

Guidelines on the clinical utility of ambulatory blood pressure

Ambulatory blood pressure monitoring has made the transition from a technology used almost exclusively in clinical research to one that has numerous applications for clinical practice and the management of hypertension. During the past 8 years, many national working committees have published consensus documents or clinical guidelines on ambulatory blood pressure monitoring in practice. Most of these guidelines, including those published by the American College of Cardiology (1994), the American Society of Hypertension (1996), and the USA's Joint National Committee (1997) support the use of ambulatory blood pressure monitoring for selected patients. Because of increasing evidence that ambulatory blood pressure is an independent risk factor for cardiovascular events, some of the more recent consensus documents have endorsed the more widespread use of ambulatory blood pressure monitoring in clinical practice. However, the growth of ambulatory blood pressure monitoring in practice has generally been limited by the state of the health economy, including lack of reimbursement for the costs of the procedure in most countries.     

Clinical features of 8295 patients with resistant hypertension classified on the basis of ambulatory blood pressure monitoring

We aimed to estimate the prevalence of resistant hypertension through both office and ambulatory blood pressure monitoring in a large cohort of treated hypertensive patients from the Spanish Ambulatory Blood Pressure Monitoring Registry. In addition, we also compared clinical features of patients with true or white-coat-resistant hypertension. In December 2009, we identified 68 045 treated patients with complete information for this analysis. Among them, 8295 (12.2% of the database) had resistant hypertension (office blood pressure ≥140 and/or 90 mm Hg while being treated with ≥3 antihypertensive drugs, 1 of them being a diuretic). After ambulatory blood pressure monitoring, 62.5% of patients were classified as true resistant hypertensives, the remaining 37.5% having white-coat resistance. The former group was younger, more frequently men, with a longer duration of hypertension and a worse cardiovascular risk profile. The group included larger proportions of smokers, diabetics, target organ damage (including left ventricular hypertrophy, impaired renal function, and microalbuminuria), and documented cardiovascular disease. Moreover, true resistant hypertensives exhibited in a greater proportion a riser pattern (22% versus 18%; P<0.001). In conclusion, this study first reports the prevalence of resistant hypertension in a large cohort of patients in usual daily practice. Resistant hypertension is present in 12% of the treated hypertensive population, but among them more than one third have normal ambulatory blood pressure. A worse risk profile is associated with true resistant hypertension, but this association is weak, thus making it necessary to assess ambulatory blood pressure monitoring for a correct diagnosis and management.     

Task force IV: Clinical use of ambulatory blood pressure monitoring. Participants of the 1999 Consensus Conference on Ambulatory Blood Pressure Monitoring

OBJECTIVE: To reach a consensus on the clinical use of ambulatory blood pressure monitoring (ABPM). METHODS: A task force on the clinical use of ABPM wrote this overview in preparation for the Seventh International Consensus Conference (23-25 September 1999, Leuven, Belgium). This article was amended to account for opinions aired at the conference and to reflect the common ground reached in the discussions. POINTS OF CONSENSUS: The Riva Rocci/Korotkoff technique, although it is prone to error, is easy and cheap to perform and remains worldwide the standard procedure for measuring blood pressure. ABPM should be performed only with properly validated devices as an accessory to conventional measurement of blood pressure. Ambulatory recording of blood pressure requires considerable investment in equipment and training and its use for screening purposes cannot be recommended. ABPM is most useful for identifying patients with white-coat hypertension (WCH), also known as isolated clinic hypertension, which is arbitrarily defined as a clinic blood pressure of more than 140 mmHg systolic or 90 mmHg diastolic in a patient with daytime ambulatory blood pressure below 135 mmHg systolic and 85 mmHg diastolic. Some experts consider a daytime blood pressure below 130 mmHg systolic and 80 mmHg diastolic optimal. Whether WCH predisposes subjects to sustained hypertension remains debated. However, outcome is better correlated to the ambulatory blood pressure than it is to the conventional blood pressure. Antihypertensive drugs lower the clinic blood pressure in patients with WCH but not the ambulatory blood pressure, and also do not improve prognosis. Nevertheless, WCH should not be left unattended. If no previous cardiovascular complications are present, treatment could be limited to follow-up and hygienic measures, which should also account for risk factors other than hypertension. ABPM is superior to conventional measurement of blood pressure not only for selecting patients for antihypertensive drug treatment but also for assessing the effects both of non-pharmacological and of pharmacological therapy. The ambulatory blood pressure should be reduced by treatment to below the thresholds applied for diagnosing sustained hypertension. ABPM makes the diagnosis and treatment of nocturnal hypertension possible and is especially indicated for patients with borderline hypertension, the elderly, pregnant women, patients with treatment-resistant hypertension and patients with symptoms suggestive of hypotension. In centres with sufficient financial resources, ABPM could become part of the routine assessment of patients with clinic hypertension. For patients with WCH, it should be repeated at annual or 6-monthly intervals. Variation of blood pressure throughout the day can be monitored only by ABPM, but several advantages of the latter technique can also be obtained by self-measurement of blood pressure, a less expensive method that is probably better suited to primary practice and use in developing countries. CONCLUSIONS: ABPM or equivalent methods for tracing the white-coat effect should become part of the routine diagnostic and therapeutic procedures applied to treated and untreated patients with elevated clinic blood pressures. Results of long-term outcome trials should better establish the advantage of further integrating ABPM as an accessory to conventional sphygmomanometry into the routine care of hypertensive patients and should provide more definite information on the long-term cost-effectiveness. Because such trials are not likely to be funded by the pharmaceutical industry, governments and health insurance companies should take responsibility in this regard.     

Arterial hypertension difficult to control in the elderly patient. The significance of the "white coat effect"]

OBJECTIVE: Previous studies have revealed a high prevalence of white coat effect among treated hypertensive patients. The difference between clinic and ambulatory blood pressure seems to be more pronounced in older patients. This abnormal rise in blood pressure BP in treated hypertensive patients can lead to a misdiagnosis of refractory hypertension. Clinicians may increase the dosage of antihypertensive drugs or add further medication, increasing costs and producing harmful secondary effects. Our aim was to evaluate the discrepancy between clinic and ambulatory blood pressure in hypertensive patients on adequate antihypertensive treatment and to analyse the magnitude of the white coat effect and its relationship with age, gender, clinic blood pressure and cardiovascular or cerebrovascular events. POPULATION AND METHODS: We included 50 consecutive moderate/severe hypertensive patients, 58% female, mean age 68 +/- 10 years (48-88), clinic blood pressure (3 visits) > 160/90 mm Hg, on antihypertensive adequate treatment > 2 months with good compliance and without pseudohypertension. The patients were submitted to clinical evaluation (risk score), clinic blood pressure and heart rate, electrocardiogram and ambulatory blood pressure monitoring (Spacelabs 90,207). Systolic and diastolic 24 hour, daytime, night-time blood pressure and heart rate were recorded. We considered elderly patients above 60 years of age (80%). We defined white coat effect as the difference between systolic clinic blood pressure and daytime systolic blood pressure BP > 20 mm Hg or the difference between diastolic clinic blood pressure and daytime diastolic blood pressure > 10 mm Hg and severe white coat effect as systolic clinic blood pressure--daytime systolic blood pressure > 40 mm Hg or diastolic clinic blood pressure--daytime diastolic blood pressure > 20 mm Hg. The patients were asked to take blood pressure measurements out of hospital (at home or by a nurse). The majority of them performed an echocardiogram examination. RESULTS: Clinic blood pressure was significantly different from daytime ambulatory blood pressure (189 +/- 19/96 +/- 13 vs 139 +/- 18/78 +/- 10 mm Hg, p < 0.005). The magnitude of white coat effect was 50 +/- 17 (8-84) mm Hg for systolic blood pressure and 18 +/- 11 (-9 +/- 41) mm Hg for diastolic blood pressure. A marked white coat effect (> 40 mm Hg) was observed in 78% of our hypertensive patients. In elderly people (> 60 years), this difference was greater (50 +/- 15 vs 45 +/- 21 mm Hg) though not significantly. We did not find significant differences between sexes (males 54 +/- 16 mm Hg vs 48 +/- 17 mm Hg). In 66% of these patients, ambulatory blood pressure monitoring showed daytime blood pressure values < 140/90 mm Hg, therefore refractory hypertension was excluded. In 8 patients (18%) there was a previous history of ischemic cardiovascular or cerebrovascular disease and all of them had a marked difference between systolic clinic and daytime blood pressure (> 40 mm Hg). Blood pressure measurements performed out of hospital did not help clinicians to identify this phenomena as only 16% were similar (+/- 5 mm Hg) to ambulatory daytime values. CONCLUSIONS: Some hypertensive patients, on adequate antihypertensive treatment, have a significant difference between clinic blood pressure and ambulatory blood pressure measurements. This difference (White Coat Effect) is greater in elderly patients and in men (NS). Although clinic blood pressure values were significantly increased, the majority of these patients have controlled blood pressure on ambulatory monitoring. In this population, ambulatory blood pressure monitoring was of great value to identify a misdiagnosis of refractory hypertension, which could lead to improper decisions in the therapeutic management of elderly patients (increasing treatment) and compromise cerebrovascular or coronary circulation.     

The economic impact of the introduction of home blood pressure measurement for the diagnosis and treatment of hypertension

OBJECTIVES: To investigate the economic consequences resulting from introduction of home blood pressure measurement in diagnosis of hypertension instead of casual clinic blood pressure measurement. METHODS: We constructed a decision tree model using data from the Ohasama study and a Japanese national database. The Ohasama study provided the prognostic value of home blood pressure as compared with clinic blood pressure measurement. RESULTS: It is predicted that the use of home blood pressure for hypertension diagnosis results in a saving of 9.30 billion US dollars (1013.6 billion yen) in hypertension-related medical costs in Japan. Most of this was attributable to medical costs saved by avoiding the start of treatment for untreated individuals who were diagnosed as hypertensive by clinic blood pressure but whose blood pressures were in the normal range when based on home blood pressure; that is, the so called white-coat hypertension. Furthermore, it could be expected that adequate blood pressure control mediated by the change in the diagnostic method from clinic to home blood pressure measurement would improve the prognosis for hypertension. We estimated that the prevention of hypertensive complications resulted in a reduction of annual medical costs by 28 million US dollars (3.0 billion yen). In addition, stroke prevention due to adequate blood pressure control based on home blood pressure measurement reduced annual long-term care costs by 39 million US dollars (4.2 billion yen). A per-person break-even cost for introducing home blood pressure monitoring was calculated as 409 US dollars (44,580 yen). CONCLUSIONS: The introduction of home blood pressure measurement for the diagnosis and treatment of hypertension would be very effective to save costs.     

Ambulatory blood pressure monitoring to study white coat syndrome in patients with hypertension seen in primary care

INTRODUCTION AND OBJECTIVES: The white coat phenomenon is said to occur when the difference between systolic/diastolic blood pressure measured during visits to the doctor's office and in ambulatory recordings is greater than 20/10. These absolute differences, known as the white coat effect, may lead to normotensive patients being classified as having white coat hypertension (WCH). We used ambulatory blood pressure monitoring (ABPM) to monitor the prevalence and response (white coat effect, white coat hypertension or white coat phenomenon) in patients during pharmacological treatment for grade 1 or 2 hypertension, and 4 weeks after treatment was suspended under medical supervision. PATIENTS AND METHOD: Ambulatory blood pressure monitoring was used in 70 patients with hypertension that was well controlled with treatment. Blood pressure was recorded during treatment (phase 1) and 4 weeks after treatment was stopped (phase 2). RESULTS: 18 (26%) of the 70 patients did not participate in phase 2 because when medication was withdrawn, their blood pressure values became unacceptable and it was necessary to restart treatment. The white coat effect was significantly stronger in phase 1, and the prevalence of white coat phenomenon and white coat hypertension did not differ significantly between phases. At the end of phase 2 the prevalence of white coat hypertension was 33%. CONCLUSIONS: Withdrawal of antihypertensive medication in patients with well controlled grade 1 or grade 2 hypertension did not significantly modify the prevalence of white coat phenomenon or white coat hypertension. The white coat effect was greater while patients were on pharmacological treatment. One third of our patients were considered to have been mistakenly diagnosed as having hypertension.     

Effects of time of day of treatment on ambulatory blood pressure pattern of patients with resistant hypertension

Patients with resistant hypertension present high prevalence of a non-dipper blood pressure pattern. Recent results indicate that non-dipping is related partly to the absence of 24-hour therapeutic coverage in patients treated with single morning doses. Accordingly, we investigated the impact of treatment time on the blood pressure pattern in 700 patients with resistant hypertension on the basis of clinic measurements who were studied by 48-hour ambulatory monitoring. Among them, 299 patients received all their medication on awakening, and 401 were taking > or =1 antihypertensive drug at bedtime. The percentage of patients with controlled ambulatory blood pressure was double in patients taking 1 drug at bedtime (P=0.008). Among the 578 patients with true resistant hypertension, subjects receiving 1 drug at bedtime showed a significant reduction in the 24-hour mean of systolic and diastolic blood pressure (3.1 and 1.6 mm Hg, respectively; P<0.011). This reduction was much more prominent during nighttime (5.1 and 3.0 mm Hg; P<0.001). Accordingly, the diurnal/nocturnal blood pressure ratio was significantly increased by 2.7 and the prevalence on non-dipping reduced (56.9 versus 81.9%; P<0.001) in patients taking 1 drug at bedtime. Compared with patients receiving all drugs on awakening, subjects with 1 drug at bedtime also showed significant reductions in the average values of glucose, cholesterol, fibrinogen, and urinary albumin excretion (P<0.011). In patients with resistant hypertension, pharmacological therapy should take into account when to treat with respect to the rest-activity cycle of each patient to improve control and to avoid the non-dipper pattern associated to higher cardiovascular risk.     

Consensus Conference on Self-blood pressure measurement. Clinical applications and diagnosis

The present study was aimed at reviewing the medical literature devoted to the clinical applications of self-blood pressure monitoring (SBPM) and at providing some recommendations regarding the use of SBPM for diagnostic purposes. The lack of reliability of conventional blood pressure (BP) measurement is largely related to the extreme variability of BP over time. SBPM provides a large number of readings and can be used to predict the results of repeated clinical measurements. The use of SBPM in the diagnosis of white coat hypertension can be proposed as a screening test: if it gives a positive result (a low home BP), it should be confirmed by ambulatory BP monitoring (ABPM). SBPM could improve patients' compliance with medication. Last, SBPM may be cost-effective for the management of hypertensive patients, by reducing costs of medication, number of clinic visits and costs of cardiovascular morbidity. Compared with ABPM, SBPM seems to have a less value for the initial diagnosis of hypertension and for predicting prognosis. In contrast, it should be of more value for the long term follow-up of patients with white coat hypertension and for the evaluation of treatment efficacy in patients with sustained hypertension. The use of SBPM in diabetic hypertensives, in pregnant women and in the elderly is encouraged, but needs further evaluation.     

Direct access ambulatory BP monitoring--the Edinburgh experience

The use of electronic measurement of blood pressure and, in particular, ambulatory blood pressure monitoring offers the opportunity to determine which patients with apparent hypertension have truly sustained elevation of their blood pressure levels. Given the high prevalence of hypertension and the even larger number of individuals who appear to be hypertensive but may not be so, it is difficult to deliver ambulatory blood pressure monitoring to all individuals who might benefit from it.In Edinburgh, Scotland, we have piloted a system of direct access ambulatory blood pressure monitoring whereby physicians in primary care can request of the hospital service, an ambulatory monitor on their patient without the patients attending a formal hospital clinic. In the 7 years since the service was first instituted, almost 6,000 monitors have been performed with referrals running at approximately 100 per month in recent times. The present study was set up to assess the impact of the ambulatory monitor result on clinical decision making in primary care. The referral form invited primary care physicians to indicate their planned management if an ambulatory monitor had not been available and we thereafter audited patient records to determine what ultimately happened following the advice given on the basis of the ambulatory monitoring record.A random sample of results was obtained on untreated patients and approximately 500 were analysed.It was clear that if the advice to the primary care physician based upon the ABPM was not to treat, that this was largely followed with some 94% of patients not receiving treatment within 3 months of the monitor. If, however, the advice given was to start treatment, this was less reliably followed and in only 76% of patients treatment was started within 3 months. At the time of the audit this figure had increased to 82%.Primary care physicians had indicated that they would have treated 60% of the individuals referred and in reality only treated 40%.The potential saving in drug costs from the reduction by 20% of those treated would have significant impact on health care budgets.     

家庭血压监测的临床应用

血压测量是诊断高血压病的基本手段,目前主要有三种方法评价血压：诊所偶测血压、动态血压监测和家庭血压监测。家庭血压监测方便、经济,已有大量数据表明：与诊所偶测血压相比,家庭血压监测是评估心血管疾病风险的一个更好的预测因子。同时它能改善高血压患者的治疗依从性,有利于血压控制,监测降压药物疗效,减少医疗费用。另外对鉴别白大衣高血压和隐性高血压也很有帮助。     

The PHARAO study: prevention of hypertension with the angiotensin-converting enzyme inhibitor ramipril in patients with high-normal blood pressure: a prospective, randomized, controlled prevention trial of the German Hypertension League

BACKGROUND: The prevention of hypertension with the angiotensin-converting enzyme inhibitor ramipril in patients with high-normal blood pressure study addresses the issue of whether progression to manifest hypertension in patients with high-normal blood pressure can be prevented with treatment. METHODS: A total of 1008 participants with high-normal office blood pressure were randomized to ramipril treatment group (n = 505) and a control group (n = 503). The patients were followed up for 3 years. Primary endpoint was to prevent or delay the progression to manifest hypertension. Secondary endpoints were reduction in the incidence of cerebrovascular and cardiovascular events, as well as the development of hypertension as defined by ambulatory blood pressure monitoring. FINDINGS: One hundred and fifty-five patients (30.7%) in the ramipril group, and 216 (42.9%) in the control group reached the primary endpoint (relative risk reduction 34.4%, P = 0.0001). Ramipril also proved to be more effective in reducing the incidence of manifest office hypertension in patients with baseline ambulatory blood pressure monitoring high-normal blood pressure. The incidence of cerebrovascular and cardiovascular events showed no statistically significant differences between the two groups. Cough was more frequent in the ramipril group (4.8 vs. 0.4%). INTERPRETATION: There is now good clinical evidence that patients with high-normal blood pressure (prehypertension) are more likely to progress to manifest hypertension than patients with optimal or normal blood pressure. Additional ambulatory blood pressure monitoring seems to be essential to achieve correct diagnosis. Treatment of patients with high-normal office blood pressure with the angiotensin-converting enzyme inhibitor was well tolerated, and significantly reduced the risk of progression to manifest hypertension.     

White-coat hypertension: not guilty when correctly defined

The coexistence of persistently high office blood pressure with normal blood pressujre outside the medical setting is often referred to as 'white-coat', 'office' or 'isolated clinic' hypertension. The definition of normal blood pressure outside the medical setting is controversial. In our experience, not only the prevalence of white-coat hypertension, but also left ventricular mass measured echocardiographically and the prevalence of left ventricular hypertrophy in this condition markedly vary on going from more restrictive (lower) to more liberal (higher) limits of ambulatory blood pressure normalcy over quite a narrow range. In a prospective study, cardiovascular morbidities of healthy normotensive controls and subjects with white-coat hypertension did not differ. A more recent analysis of our database supports the use of qujite a restrictive definition of white-coat hypertension (average daytime blood pressure < 130/80 mmHg) in order to identify the minority of subjects who have a low risk of cardiovascular morbid events during the subsequent years. A recent document published by the American Society of Hypertension suggests that slightly higher upper limits of ambulatory blood pressure normalcy (i.e. average daytime blood pressure < 135 mmHg systolic and 85 mmHg diastolic) should be used. In a follow-up study by our group, 37% of subjects with white-coat hypertension spontaneously evolved into cases of ambulatory hypertension, with accompanying increases in left ventricular mass. In that study, the probability of a subject developing ambulatory hypertension increased with the baseline values of ambulatory blood pressure and it was quite low (20%) for those with daytime blood pressures below 130/80 mmHg. In two recent controlled studies, the rate of development of ambulatory hypertension over time for untreated subjects did not differ between the normotensive control group and the group with white-coat hypertension. A final answer regarding the clinical significance of white-coat hypertension will come from very large surveys of the natural history of this condition in the long term. For now, we suggest a verdict of innocence for white-coat hypertension when low values of daytime ambulatory blood pressure (i.e. < 130/80 mmHg) and absence of organ lesions and other risk factors coexist.     

The Economic Impact of Hypertension

High blood pressure is the most common chronic medical problem prompting visits to primary health care providers, yet it is estimated that only 34% of the 50 million American adults with hypertension have their blood pressure controlled to a level of <140/90 mm Hg. Thus, about two thirds of Americans with hypertension are at increased risk for cardiovascular events. The medical, economic, and human costs of untreated and inadequately controlled high blood pressure are enormous. Adequate management of hypertension can be hampered by inadequacies in the diagnosis, treatment, and/or control of high blood pressure. Health care providers face many obstacles to achieving blood pressure control among their patients, including a limited ability to adequately lower blood pressure with monotherapy and a typical reluctance to increase therapy (either in dose or number of medications) to achieve blood pressure goals. Patients also face important challenges in adhering to multidrug regimens and accepting the need for therapeutic lifestyle changes. Nonetheless, the achievement of blood pressure goals is possible, and, most importantly, lowering blood pressure significantly reduces cardiovascular morbidity and mortality, as proved in clinical trials. The medical and human costs of treating preventable conditions such as stroke, heart failure, and end-stage renal disease can be reduced by antihypertensive treatment. The recurrent and chronic morbidities associated with hypertension are costly to treat. Pharmacotherapy for hypertension therefore offers a substantial potential for cost savings. Pharmacoeconomic analyses regarding antihypertensive drug therapies, their costs, and the relevant reductions in health care expenditures are a useful framework for optimizing current strategies for hypertension management.     

Asian management of hypertension: Current status,home blood pressure,and specific concerns in Thailand

The prevalence of hypertension is increasing, but rates of awareness, treatment, and blood pressure (BP) control are also increasing. In terms of cardiovascular disease, the prevalence of coronary artery disease (CAD) and stroke is similar, but stroke mortality is higher than that from CAD. Home BP monitoring (HBPM) is an important tool for determining the presence of white‐coat or masked hypertension, facilitating drug cost savings or effective cardiovascular risk management strategies, respectively. However, there are a number of barriers to use of HBPM in Thailand. These include lack of availability (particularly in lower socioeconomic groups), lack of awareness of the importance of white‐coat and masked hypertension, and concerns about device reliability. The latest Thai Hypertension Society guidelines recommend that physicians and nurses encourage their patients to use their HBPM devices, and these are increasingly being utilized in clinical practice for both diagnostic purposes and therapeutic monitoring. Calcium channel blockers are the most commonly used antihypertensive agents in Thailand, followed by angiotensin receptor blockers, ß‐blockers, and diuretics. Angiotensin‐converting enzyme inhibitors are used less often due to drug‐related cough, and the use of fixed drug combinations is low because of their high cost and more complex reimbursement process. Ongoing work is needed to improve the primary prevention and effective treatment of hypertension in Thailand.     

Ambulatory Blood Pressure Monitoring in Hypertension

Ambulatory blood pressure monitoring generates a greater interest among investigators and clinicians because of its potential to 1) study the mechanisms involved in cardiovascular control in daily life (particularly if monitoring is performed on a beat-to-beat basis) and 2) improve the diagnosis of hypertension, the estimate of the patient's risk and the assessment of the efficacy of antihypertensive treatment. This paper will discuss the evidence pros and cons the latter indications of this approach. It will be shown that 24 hour blood pressure values correlate more closely than clinic blood pressure with various measures of the end organ damage of hypertension, suggesting that it may reflect better than traditional blood pressure measurements the cardio-vascular consequences of this condition. Wider use of ambulatory blood pressure monitoring in the medical practice, however, must await a more clear demonstration of its prognostic importance, by longitudinal studies based on cardiovascular morbidity and mortality or on surrogate end points with undisputable clinical significance (e.g. left ventricular hypertrophy). It must also await clear definition of ambulatory blood pressure normality based on population studies. Until then ambulatory blood pressure monitoring should be employed to resolve special problems, e.g. identification of white coat hypertension and false non response to treatment.     

Ambulatory blood pressure during diseases of the kidney.

During the last few years there has been a renewal of interest in blood-pressure-induced kidney damage due to a progressive increase in the incidence and prevalence of hypertension and vascular diseases as a cause of end-stage renal disease (ESRD). The need to prevent ESRD demands a continuation of effort to make the early identification of hypertensives who are at risk possible and to provide them with effective antihypertensive therapy. Since ambulatory blood pressure monitoring has been used successfully to assess blood pressure and identify risk markers for cardiovascular diseases, a logical approach would be to use it also to identify the risk markers for ESRD. Higher than normal percentages of non-dippers have been found among subjects with renal failure, during dialysis (haemofiltration, peritoneal dialysis and continuous ambulatory peritoneal dialysis), among cases of renovascular hypertension or cystic kidney disease and among cases of renal transplantation. Although this non-dipping pattern might be related to the presence of severe hypertension in some patients, such as those who have renovascular hypertension, in other cases the abnormal circadian variability is present with milder forms of hypertension or even in the absence of hypertension. Monitoring ambulatory blood pressure could offer advantages for protection of renal function during antihypertensive treatment of subjects with mild renal insufficiency. Furthermore, ambulatory blood pressure monitoring seems to have been prognostic for the development of proteinuria in a group of refractory hypertensives. Whether higher than normal nocturnal blood pressures and the non-dipping pattern are causes or consequences of renal disease should be addressed in prospective studies. The above notwithstanding, assessment of nocturnal blood pressure seems to be an important aid in the management of patients with hypertension-related renal disease and of patients who are susceptible to developing it.