ambulatory blood pressure report

7/28/2019 Ambulatory Blood Pressure Report

1/12


2/12

Patients wear the monitor for a 24-hour period, usually during a working day. The monitor is preprogrammed to record blood pressure, usually every 15 to 20 minutes

during daytime hours and every 20 to 30 minutes during nighttime hours. Patients are instructed to keep an activity log throughout the testing period for evaluation of

stress- and activity-related blood pressure changes.

The cuff is attached to a small central unit containing the pump and memory chip (Fig. 1). Deflation rates, frequency of measurement, and maximal-minimal inflation

pressure are programmable. The blood pressure recordings are retrieved by interfacing the monitor with a desktop sof tware program. A report is generated containing allblood pressure readings for the testing period, heart rate, mean arterial pressure, blood pressure load, and summary statistics for overall 24-hour, daytime, and nighttime

periods. Figure 2 shows examples of ABPM graphs generated.

Ambulatory blood pressure monitor. (Courtesy of SpaceLabs Medical, Inc., Redmond, WA.)

http://www.medscape.com/viewarticle/457522_print

2 of 12 6/18/2013 11:40 PMh // d / i i l / i


3/12

Sample graphs of ambulatory blood pressure monitoring reports. A, normal 24-hour blood pressure with dipping; B, abnormal 24-hour blood pressure with dipping; C,

abnormal 24-hour blood pressure, nondipping; D, white coat hypertension. (Reprinted with permission from BMJ 2001;322:1110-1114.)

Ambulatory blood pressure monitoring is well tolerated. In a study of 672 patients, sleep disturbance was commonly reported followed by pressure from the cuff,

awkwardness of the machine, diff iculty in driving, local discomfort, and noise.[8] However, more than 90% of patients would agree to a second recording if it were

necessary.

Published recommendations exist for the clinical use of ABPM.[1-6] The most recent Joint National Committee report outlines clinical situations where ABPM may be

helpful, including suspected white-coat hypertension, drug resistance, hypotensive symptoms, episodic hypertension, and autonomic dysfunction.[3] These and other

indications are shown in .

Table 2. Clinical Situations in Which Ambulatory Blood Pressure Monitoring May Be Helpful


3 of 12 6/18/2013 11:40 PM


4/12


5/12

http://www medscape com/viewarticle/457522 print


6/12

and cerebrovascular events. The authors also found that for every 10-mm Hg increase in nighttime systolic blood pressure, the hazard rate was 1.20 (95% CI, 1.08-1.35)

for cardiovascular events and 1.31 (95% CI, 1.06-1.62) for cerebrovascular events.

Although evidence supports the role of ABPM in the diagnosis and management of hypertension, the technology remains underused. These barriers primarily include

lack of experience interpreting the results of ABPM, lack of familiarity with the technology, and economic issues.

The incorporation of ABPM into routine clinical practice requires that criteria be adopted for defining normal and abnormal ABP. Several large population studies have

attempted to define "normal" ABPM results.[30-35] All of the studies have found that both normotensive and hypertensive patients have blood pressure readings

measured by ABPM that are lower than office blood pressure. The main reason for this finding is that ABPM measures blood pressure during sleep. Therefore, clinicians

should not equate blood pressure obtained from ABPM with office blood pressure. Several methods have been used to define normal ABP, including averaging the 95th

percentiles of ABP for normotensive subjects in large-scale studies, and performing regression equations linking clinic blood pressure with ABP. In truth, the different

methods result in similar values. shows the operational thresholds for ABPM currently agreed on by the British Hypertension Society and the American Society of

Hypertension.

Table 3. Diagnostic thresholds for ambulatory blood pressure monitoringa


6 of 12 6/18/2013 11:40 PM

http://www.medscape.com/viewarticle/457522 print


7/12

The charge for ABPM in the United States usually ranges f rom $100 to $350.[36] Until recently, many third-party insurers, including Medicare, would not pay for the test

because it was labeled as "investigative" technology. This lack of reimbursement probably explains the lower use of ABPM in the United States compared with other

countries, where cost is not prohibitive. Reimbursement policies for ABPM are now changing. Medicare has announced plans to begin reimbursing for ABPM performed

in patients with suspected white-coat hypertension. This policy change will likely lead to increased demand and use of ABPM services.

The issue of cost effectiveness is controversial. Moser argued that ABPM performed on 3 to 5 million hypertensive patients each year would add an additional $600

million to the cost of treatment.[37] However, several studies have demonstrated that ABPM used appropriately does not increase the cost of care.[38-40] In the

Ambulatory Blood Pressure Monitoring and Treatment of Hypertension trial,[14, 38]

the cost of medication was less for people assessed with ABPM compared with officeblood pressure measurement ($4,188 versus $3,390/100 patients/mo), and physician fees were less because patients returned less frequently for evaluation of blood

pressure. Pierdomenico et al[40] performed ABPM on 255 consecutive untreated patients and evaluated the impact on cost of care of ABPM of two strategies: treating all


7 of 12 6/18/2013 11:40 PM

http://www.medscape.com/viewarticle/457522 print


8/12

patients according to casual blood pressure, or ABPM followed by drug treatment in sustained hypertensives only. Of the patients studied, 21% were determined to have

white-coat hypertension. The authors estimated that the strategy of monitoring all patients and treating only sustained hypertensives would result in cost savings of

$110,000 over 6 years. It is important to note that many patients do not need ABPM. Given the potential impact of widespread clinical use of ABPM, it is imperative that

clinicians use the technology judiciously. Figure 3 shows a strategy for the appropriate clinical use of ABPM.

p p _p

8 of 12 6/18/2013 11:40 PM


9/12


10/12


11/12



12/12

Reprint Address

Reprint requests to Michael E. Ernst, PharmD, BCPS, Department of Family Medicine/01287 PFP, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City,

IA 52242. Email: [email protected]

South Med J. 2003;96(6) 2003 Lippincott Williams & Wilkins

Pierdomenico SD, Mezzetti A, Lapenna D, Guglielmi MD, Mancini M, Salvatore L, et al. "White-coat" hypertension in patients with newly diagnosed hypertension:

Evaluation of prevalence by ambulatory monitoring and impact on cost of health care. Eur Heart J 1995; 16: 692-697.

40.

12 of 12 6/18/2013 11:40 PM

ambulatory blood pressure report

Documents