Background: Outpatient monitoring of blood pressure (OPMBP) allows more precise values to be obtained and to observe the oscillations over 24 hours. Although this is widely used in the estimation of the antihypertensive efficacy of drugs, few studies have been performed on the evaluation of the control in treated patients.
Methods: One hundred eight patients (M/F 55/53, mean age 50 +/- 11 years, body mass index 29.7 +/- 4.4) with essential high blood pressure (HBP) were included in the study fulfilling the criteria of: a) DBP > 95 mmHg on 3 visits over a 2 month period, b) antihypertensive treatment maintained over 2 months and c) normal renal function (Cr < 115 mumol/l). Twenty-five patients were considered as having resistant HBP on presenting BP > 150/100 mmHg during the course of treatment with well combined and adequately dosed drugs, one of which was a diuretic. Twenty-four hour OPMBP was carried out in all the patients on a normal work day with a SpaceLabs 90202 monitor. Acceptable control was considered when the mean of the DBP throughout the day (08:00-22:00) was < 85 mmHg.
Results: Out of all the patients studied, 67 (62%) showed acceptable control and 27 (25%) showed normotensive values. Among the 25 refractory hypertensive patients 20 (40%) showed an acceptable control and 7 (28%) normotensive values. The only clinical difference between both groups was the presence of a greater degree of organic repercussion in the inadequately controlled group (chi 2 p < 0.05). Eight patients showed medium values of SBP over 24 h < 120 mmHg and 2 medium values of DBP over 24 h < 70 mmHg.
Conclusions: Outpatient monitoring of blood pressure may be useful in the evaluation of the control of high blood pressure in patients submitted to pharmacologic treatment who do not present an adequate reduction in the values of blood pressure.