Ambulatory BP Is Best Measure.
Ambulatory monitoring automatically measures blood pressure every few minutes using a small device that is worn for 24 hours or longer. Superiority to office measurements has been attributed to the reliability of getting multiple blood pressure readings in the setting of the patient's daily life.
In a prospective cohort of 790 patients with essential hypertension, office and ambulatory blood pressure measurements at baseline and after an average of 4 years of individualized treatment showed that 27% reached blood pressure control by office measures ([less than]140/90 mm Hg), and 37% reached blood pressure control by ambulatory measures ([less than]135/85 mm Hg).
Over a follow-up period of up to 14 years, 58 patients developed a first major cardiovascular event. The rate of cardiovascular events was significantly higher in patients with uncontrolled hypertension based on ambulatory measures, but was not significantly different for patients with and without office blood pressure control, Dr. Paolo Verdecchia reported.
By ambulatory measures, patients with well-controlled blood pressure had 0.71 cardiovascular events per 100 patient-years, and those with uncontrolled hypertension had 1.87 events per 100 patient-years. After adjusting for the effects of age, diabetes, and left ventricular hypertrophy, that translated to a 64% lower risk for those with ambulatory blood pressure control, said Dr. Verdecchia of the University of Perugia (Italy).
Patients whose blood pressure was well-controlled based on in-office measures had 1 cardiovascular event per 100 patient-years, and those with uncontrolled hypertension had 1.16 events per 100 patient-years, a nonsignificant difference.
The study analyzed a subset of the 1998 PIUMA (Progetto Ipertensione Umbria Monitoraggio Ambulatoriale) study, in which 1,296 hypertensive and normotensive patients were followed prospectively for a mean of 10 years.
Joseph E. Schwartz, Ph.D., combined data from the Italian PIUMA study with data on 1,296 hypertensive and normotensive patients followed for an average of 10 years at Cornell University, New York, and reached the same conclusions.
"Once you've got the ambulatory blood pressure, the clinic blood pressure is essentially useless" for predicting cardiovascular risk, concluded Dr. Schwartz, professor of psychiatry and behavioral science at the State University of New York at Stony Brook.
His analysis also revealed that the awake systolic pressure was the most predictive measure for cardiovascular risk. The ambulatory diastolic pressure added no more information for risk prediction.
The results held true for total cardiovascular events, heart attack, and stroke.
The risk of a first cardiovascular event also was greater for men and increased with age, total cholesterol, and cigarettes smoked.
Medicare and most private insurers do not cover the cost of ambulatory blood pressure monitoring, but a Medicare coverage advisory committee recommended earlier this year that coverage be extended to ambulatory blood pressure monitoring in some cases, Dr. Verdecchia said.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||ambulatory blood pressure measurement is best predictor of cardiovascular events|
|Publication:||Internal Medicine News|
|Date:||Sep 1, 2001|
|Previous Article:||Accept a 30% Rise in Baseline Creatinine.|
|Next Article:||Diuretic Cuts Cost, Dose of Angiotensin Receptor Blocker.|
|Ambulatory Monitoring Better For The Elderly.|
|Circadian BP patterns may predict vascular events.|
|Repeated measurements can unveil masked hypertension.|