IMPACT OF AMBULATORY BLOOD PRESSURE MONITORING IN THERAPEUTIC DECISION-MAKING: THE HYGIA PROJECT: PP.3.94

Objectives: In hypertensive patients, the correlation between the blood pressure (BP) level and target organ damage, cardiovascular risk, and long-term prognosis is higher for ambulatory (ABPM) than for clinical measurements. We investigated the influence of ABPM on therapeutic decision-making in hypertensive subjects participating in the Hygia Project, designed to evaluate prospectively cardiovascular risk by ABPM in primary care centers of Northwest Spain. Methods: We evaluated 1671 hypertensive subjects (874 men), 61.8 ± 12.6 years of age. BP was measured every 20-min from 07:00 to 23:00 h and every 30-min at night for 48 h. The physicians registered via web the clinical information for each patient, including anthropometric variables; factors influencing prognosis (family history, diabetes, subclinical organ damage, established cardiovascular, cerebrovascular or renal disease); current treatment; analytical parameters; and clinic BP (three measurements). The physicians provided the therapeutic strategy for each patient based on all this clinical information but before having access to the data from ABPM, and once again after visualizing the ABPM report. Results: After using the ABPM report, the therapeutic scheme was changed in 1033 (62%) subjects. The most prevalent change was the timing of antihypertensive treatment (81% of the cases), giving priority to treatment at bedtime. Among those who changed their therapeutic scheme, 20% moved from no-treatment to treatment of some kind, and 10% from treatment to no-treatment. Among the 279 subjects with changed scheme where the number and class of medications was unchanged, 27% increased the dose, 24% decreased the dose, and 49% changed dosing-time, mainly increasing treatment at bedtime. Conclusions: This prospective blind study is the first to investigate the impact of ABPM on therapeutic decision-making. While discrepancies in diagnosis of hypertension between clinic and ambulatory BP measurements (isolated office and masked hypertension) account for just about 25% of the population, almost two-thirds of the patients in this study had their therapeutic scheme changed on the basis of ABPM. This study indicates that ABPM should be required for therapeutic decision-making in hypertension.