Antihypertensive Treatment Based on Conventional or Ambulatory Blood Pressure Measurement: A Randomized Controlled Trial

Abstract

Context. —Ambulatory blood pressure (ABP) monitoring is used increasingly in clinical practice, but how it affects treatment of blood pressure has not been determined. Objective. —To compare conventional blood pressure (CBP) measurement and ABP measurement in the management of hypertensive patients. Design. —Multicenter randomized, parallel-group trial. Setting —Family practices and outpatient clinics at regional and university hospitals. Participants. —A total of 419 patients (-18 years), whose untreated diastolic blood pressure (DBP) on CBP measurement averaged 95 mm Hg or higher, randomized to CBP or ABP arms. Interventions. —Antihypertensive drug treatment was adjusted in a stepwise fashion based on either the average daytime (from 10 am to 8 pm) ambulatory DBP (n=213) or the average of 3 sitting DBP readings (n=206). If the DBP guiding treatment was above (>89 mm Hg), at (80-89 mm Hg), or below (<80 mm Hg) target, 1 physician blinded to the patients' randomization intensified antihypertensive treatment, left it unchanged, or reduced it, respectively. Main Outcome Measures. —The CBP and ABP levels, intensity of drug treatment, electrocardiographic and echocardiographic left ventricular mass, symptoms reported by questionnaire, and cost. Results. —At the end of the study (median follow-up, 182 days; 5th to 95th percentile interval, 85-258 days), more ABP than CBP patients had stopped anithypertensive drug treatment (26.3% vs 7.3%;P<.001), and fewer ABP patients had progressed to sustained multiple-drug treatment (27.2% vs 42.7%;P<.001). The final CBP and 24-hour ABP averaged 144.1/89.9 mm Hg and 129.4/79.5 mm Hg in the ABP group and 140.3/89.6 mm Hg and 128.0/79.1 mm Hg in the CBP group. Left ventricular mass and reported symptoms were similar in the 2 groups. The potential savings in the ABP group in termsof less intensive drug treatment and fewer physician visits were offset by the costs of ABP monitoring. Conclusions. —Adjustment of antihypertensive treatment based on ABP monitoring instead of CBP measurement led to less intensive drug treatment with preservation of blood pressure control, general well-being, and inhibition of left ventricular enlargement but did not reduce the overall costs of antihypertensive treatment.