Prognostic value of ambulatory blood pressure measurement in France

Rationale : Ambulatory blood pressure measurement (ABPM) is commonly used i n clinical practice, whereas its added value to the management of hypertens ion is not definitely documented. Objective : the OCTAVE II study was launched in 1991 to explore the prognos tic value of ABPM, compared to that of the gold standard, the clinical bloo d pressure measurement. Methods: Two hundred and six French cardiologists recruited 3569 participan ts over 18 years of age, provided they deemed ABPM was useful (mean age of 56 years, 52% of men, 65% already treated by antihypertensive drugs). The p rognostic value of various blood pressure measurements, systolic or diastol ic, clinical or ambulatory (diurnal, nocturnal or during 24 hours), has bee n assessed in multivariate models adjusted on the baseline characteristics associated with risk. The outcome was the occurrence of a major cardiovascu lar event, including stroke, myocardial infarction and cardiovascular death . Results : after an average follow-up of five years, cardiovascular morbidit y was known for 85% of the participants, and their vital status for 91%. On the whole population, the best prognostic indicators were systolic blood p ressure compared with diastolic, ABPM compared with clinical blood pressure measurement, and nocturnal ABPM compared with diurnal ABPM. In the untreat ed participants at baseline, cardiovascular risk regularly-increased among the four groups : normotensives, white-coat hypertensives, dippers, non-dip pers. Between the extreme categories, the cardiovascular event rate was mul tiplied by 6.5. Conclusion : in this French population, ABPM and most of all its nocturnal component, was better correlated with cardiovascular prognosis. It remains to assess : 1) the general value of our findings, 2) the respective values of self blood pressure measurement versus ABPM, and 3) whether ABPM allows a better risk prevention.