The use of ambulatory blood pressure monitoring in managing hypertension according to different treatment guidelines.

OBJECTIVE

To investigate the use of ambulatory blood pressure monitoring (ABPM) in identifying and managing a group of patients referred to a tertiary centre for the assessment of their blood pressure and to illustrate the importance of introducing standardised ABPM treatment guidelines.

PATIENTS AND METHODS

We examined 2000 sequential ABP recordings, 1557 were first time referrals from General Practitioners, Consultants and other hospitals. All patients were referred with suspected hypertension, resistant hypertension, white coat hypertension and for investigations of secondary hypertension. Fully trained nurse specialists fitted the monitors in the hypertension clinic and recordings were performed for 24 h. The data was then analysed and stratified according to treatment guidelines and categorised according to different definitions.

RESULTS

The group of first time referrals (n = 1557) showed an even sex distribution of 789 men and 768 women, mean age 53 +/- 13.8 (12-88 years). Of this group 542 patients (35%) exhibited a white coat effect (WCE), 526 (34%) had a daytime ABP < or =139/89 mm Hg. Of these 81 (15%) had a high clinic blood pressure (ie, white coat hypertension (WCH)) according to our definition. Thirty-five of these patients were not on treatment but may have had it initiated on the basis of their clinic pressures. According to the British Hypertension Society (BHS) guidelines on clinic readings 772 (45%) of our patients would be classified as hypertensive or inadequately treated, 509 (33%) borderline and 326 (21%) as normal. Using daytime ABP levels according to O'Brien: 1031 (67%) would be defined as abnormal, 192 (12%) as borderline and 334 (21%) as normal.

CONCLUSION

These results illustrates how patient management may differ markedly when treating in accordance either with the BHS guidelines for clinic readings or the suggested levels for ABP. More patients had abnormal blood pressure levels according to ABPM, even though it is superior in detecting WCE and WCH. Clear guidelines for ABPM treatment levels need to be established.