Referral of women to ambulatory blood pressure monitoring.

Referral of Women to Ambulatory Blood Pressure Monitoring To the Editor: We are intrigued by several issues reported by Boggia et al1 and raised in the accompanying editorial commentary.2 First, the IDACO (International Database on Ambulatory blood pressure in relation to Cardiovascular Outcomes) investigators confirm and generalize the chief observation from our published report on a smaller (n 3957) single-center cohort that a reduced absolute risk among women is in large part accounted by findings in ambulatory blood pressure monitoring, which therefore emerges as an important risk assessment tool in women.3 Thus, although ours was a cohort of referred patients, inevitably biased by the referring physicians’ perception of overall risk, IDACO participants were sampled randomly from 11 populations. This difference is probably responsible for the opposing trends between gender and baseline clinical parameters in the 2 reports (with monitored women being older and sicker in our cohort but younger and healthier in IDACO). Nonetheless, the conclusion and perspectives are in harmony: a sense of underuse of ambulatory blood pressure monitoring in women (among referred patients) and appreciation of the opportunity to prevent cardiovascular events in women using ambulatory blood pressure monitoring (arising from the population samples). Second, a point that can be added to the mechanistic editorial comments is that women in general may have poorer sleep4 and hence a higher nighttime heart rate3,5 and lesser dipping of heart rate.5 Such lack of heart rate dipping adds to the importance of nocturnal monitoring in women because it may be an independent risk marker.5 It would be interesting to learn the IDACO findings in this matter. Finally, the report by Boggia et al once again stresses the exclusivity of 24-hour ambulatory blood pressure monitoring, currently the only clinical tool that allows accurate measurement of sleep blood pressure. In view of the fact that outcome events are consistently reported to be in a steeper association with sleep blood pressure compared with other blood pressure indices, wider adoption of ambulatory blood pressure monitoring in clinical practice is warranted, especially in women.