Normal Ambulatory Blood Pressure: A Clinical-Practice-Based Analysis of Recent American Heart Association Recommendations

Purpose The American Heart Association Council on High Blood Pressure Research recently issued recommendations for blood pressure measurement in humans. According to these recommendations, normal 24-hour ambulatory blood pressure is defined as less than 130/80 mm Hg. Concurrently, normal daytime and nighttime blood pressure levels are defined as less than 135/85 mm Hg and less than 120/70 mm Hg, respectively. Our aim was to investigate the intrinsic compatibility of these blood pressure cutoffs in clinical practice. Subjects and methods We analyzed 4121 consecutive ambulatory blood pressure measurement sessions. Age was 57 ± 7 years, 53% were female, and 64% and 9% were treated for hypertension and diabetes, respectively. Body mass index was 27 ± 4 kg/m2, and manual blood pressure was 148 ± 22/85 ± 12 mm Hg. Subjects were classified as having normal 24-hour blood pressure if the corresponding value was less than 130/80 mm Hg. Normal awake-sleep blood pressure was diagnosed if awake blood pressure was less than 135/85 mm Hg and sleep blood pressure was less than 120/70 mm Hg. Results Concordance between the cutoffs was found in 92% of the subjects (kappa = 0.77). Among the 8% of discordant subjects, only 1% were hypertensive applying the 24-hour (but not awake-sleep) blood pressure values, whereas 7% were hypertensive according to awake-sleep but not 24-hour blood pressure values (P<.0001). Conclusions In real-life ambulatory blood pressure measurement, a generally good agreement was found between the recently issued ambulatory blood pressure normality suggestions. However, some subjects are classified as hypertensive only according to one of these methods, more often by the awake-sleep cutoff of 135/85 and 120/70 mm Hg. This discordance may be significant in large-scale clinical blood pressure monitoring.