24-Hour Ambulatory Blood Pressure Monitoring in Primary Care
24-Hour Ambulatory Blood Pressure Monitoring in Primary Care
Background: Both the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension in Adults and the British Hypertension Society have made recommendations for the use of ambulatory blood pressure monitoring (ABPM) in select patient populations. This demonstration project explores the feasibility of a 24-hour ABPM service in assisting physicians with decisions regarding the implementation and modification of antihypertensive therapy.
Methods: After physician referral, patients met with a pharmacist for evaluation of their blood pressure. The pharmacist obtained a medication profile and instructed each patient on the proper use of the monitor. Patients completed an activity diary while wearing the monitor. After analysis of the reports, the pharmacist forwarded recommendations and the 24-hour blood pressure data to the referring physician.
Results: Sixty patients took part in the demonstration project. The primary reasons for referral included evaluation of suspected isolated office hypertension, drug resistance, blood pressure control in diabetic patients, and suspected drug-induced orthostatic hypotension. The referring physicians accepted 100% of the pharmacists' therapeutic recommendations. Unnecessary therapy was avoided in 12 of 40 of patients with suspected isolated office hypertension (30%), and more aggressive treatment was started in 6 of 7 of patients with type 2 diabetes (87.5%).
Conclusions: This project shows that a 24-hour ABPM consultation service can provide useful information for determining which patients have isolated office hypertension and in guiding drug regimen modification for patients with diabetes, suspected resistant hypertension, or drug-induced alterations in blood pressure.
The use of 24-hour ambulatory blood pressure monitoring (ABPM) in the clinical setting has been gaining acceptance for a number of reasons. First, clinic blood pressure measurements often overesti-mate a patient's baseline blood pressure value. This isolated office hypertension has been found to occur in up to 32% of patients. Second, 24-hour ABPM provides a means of delineating circadian variations in blood pressure. On arising, a neurohormonal surge is associated with higher blood pressure values during the first few hours of the wake cycle. This process contributes to the higher incidence of cardiovascular sequelae, including myocardial infarction.
Throughout the course of a day, numerous extenuating circumstances (emotions, activity, and work, among others), can alter blood pressure as well. An additional benefit of ABPM is determining what percentage of the day blood pressure is elevated above predefined normotensive values (ie, blood pressure load). Two approaches have been used to determine blood pressure load. The first approach calculates blood pressure load by determining the percentage of blood pressure readings higher than 140/90 mm Hg during the entire 24 hours. The second approach determines the percentage of blood pressure readings higher than 140/90 mm Hg during the day and the percentage of readings higher than 120/80 mm Hg at night. Elevated blood pressure load correlates with end organ damage, such as ventricular hypertrophy and proteinuria.
Several clinical trials have provided evidence that ABPM is "particularly valuable to refine cardiovascular risk stratification in untreated subjects with office hypertension and in those with resistant hypertension." In a normotensive person, ABPM should show mean values less than 135/85 mm Hg during waking and less than 120/75 mm Hg during sleeping hours. Thus, a patient's overall blood pressure status can be more fully assessed with 24-hour ABPM than with clinic blood pressure measurements. Although not indicated for every patient, 24-hour ABPM can be a useful tool in the evaluation and treatment of hypertension.
The sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) supports the use of 24-hour ABPM for patients whose blood pressure readings conform with one of the following five categories: (1) suspected isolated office hypertension, (2) autonomic dysfunction, (3) drug-induced orthostatic hypotension, (4) episodic hypertension, or (5) resistant hypertension (blood pressure >140/90 mm Hg, or >160 mm Hg for isolated systolic hypertension on an almost maximum dose of a triple-drug regimen, including a diuretic). Various practitioners also use 24-hour ABPM to characterize more fully the hypertensive profiles of selected patients.
A MEDLINE search failed to find any published studies describing the role of 24-hour ABPM in the office setting to improve management of suspected or established hypertension in their patients. This article describes an interdisciplinary approach to evaluating and managing hypertension with the aid of 24-hour ABPM. A clinical pharmacy consultation service was established to assist physicians in evaluating or optimizing the blood pressure control of patients who met the JNC VI criteria for 24-hour ABPM. Long-term plans include a pharmaco-economic evaluation of this service. Eventual reimbursement from third party payers is dependent on cost justification.
Background: Both the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension in Adults and the British Hypertension Society have made recommendations for the use of ambulatory blood pressure monitoring (ABPM) in select patient populations. This demonstration project explores the feasibility of a 24-hour ABPM service in assisting physicians with decisions regarding the implementation and modification of antihypertensive therapy.
Methods: After physician referral, patients met with a pharmacist for evaluation of their blood pressure. The pharmacist obtained a medication profile and instructed each patient on the proper use of the monitor. Patients completed an activity diary while wearing the monitor. After analysis of the reports, the pharmacist forwarded recommendations and the 24-hour blood pressure data to the referring physician.
Results: Sixty patients took part in the demonstration project. The primary reasons for referral included evaluation of suspected isolated office hypertension, drug resistance, blood pressure control in diabetic patients, and suspected drug-induced orthostatic hypotension. The referring physicians accepted 100% of the pharmacists' therapeutic recommendations. Unnecessary therapy was avoided in 12 of 40 of patients with suspected isolated office hypertension (30%), and more aggressive treatment was started in 6 of 7 of patients with type 2 diabetes (87.5%).
Conclusions: This project shows that a 24-hour ABPM consultation service can provide useful information for determining which patients have isolated office hypertension and in guiding drug regimen modification for patients with diabetes, suspected resistant hypertension, or drug-induced alterations in blood pressure.
The use of 24-hour ambulatory blood pressure monitoring (ABPM) in the clinical setting has been gaining acceptance for a number of reasons. First, clinic blood pressure measurements often overesti-mate a patient's baseline blood pressure value. This isolated office hypertension has been found to occur in up to 32% of patients. Second, 24-hour ABPM provides a means of delineating circadian variations in blood pressure. On arising, a neurohormonal surge is associated with higher blood pressure values during the first few hours of the wake cycle. This process contributes to the higher incidence of cardiovascular sequelae, including myocardial infarction.
Throughout the course of a day, numerous extenuating circumstances (emotions, activity, and work, among others), can alter blood pressure as well. An additional benefit of ABPM is determining what percentage of the day blood pressure is elevated above predefined normotensive values (ie, blood pressure load). Two approaches have been used to determine blood pressure load. The first approach calculates blood pressure load by determining the percentage of blood pressure readings higher than 140/90 mm Hg during the entire 24 hours. The second approach determines the percentage of blood pressure readings higher than 140/90 mm Hg during the day and the percentage of readings higher than 120/80 mm Hg at night. Elevated blood pressure load correlates with end organ damage, such as ventricular hypertrophy and proteinuria.
Several clinical trials have provided evidence that ABPM is "particularly valuable to refine cardiovascular risk stratification in untreated subjects with office hypertension and in those with resistant hypertension." In a normotensive person, ABPM should show mean values less than 135/85 mm Hg during waking and less than 120/75 mm Hg during sleeping hours. Thus, a patient's overall blood pressure status can be more fully assessed with 24-hour ABPM than with clinic blood pressure measurements. Although not indicated for every patient, 24-hour ABPM can be a useful tool in the evaluation and treatment of hypertension.
The sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) supports the use of 24-hour ABPM for patients whose blood pressure readings conform with one of the following five categories: (1) suspected isolated office hypertension, (2) autonomic dysfunction, (3) drug-induced orthostatic hypotension, (4) episodic hypertension, or (5) resistant hypertension (blood pressure >140/90 mm Hg, or >160 mm Hg for isolated systolic hypertension on an almost maximum dose of a triple-drug regimen, including a diuretic). Various practitioners also use 24-hour ABPM to characterize more fully the hypertensive profiles of selected patients.
A MEDLINE search failed to find any published studies describing the role of 24-hour ABPM in the office setting to improve management of suspected or established hypertension in their patients. This article describes an interdisciplinary approach to evaluating and managing hypertension with the aid of 24-hour ABPM. A clinical pharmacy consultation service was established to assist physicians in evaluating or optimizing the blood pressure control of patients who met the JNC VI criteria for 24-hour ABPM. Long-term plans include a pharmaco-economic evaluation of this service. Eventual reimbursement from third party payers is dependent on cost justification.