Background and objective: Ambulatory blood pressure monitoring (ABPM) is a useful diagnostic and therapeutic tool in hypertensive patients. This study reports the clinical characteristics of 31,530 patients included in the Spanish Registry of ABPM.
Patients and method: A total number of 767 investigators recruited patients with suspected or confirmed hypertension to whom an ABPM was indicated with a validated device and included them in the study. Mean blood pressures from daytime, nighttime, and the whole 24-hour period were all measured. Circadian patterns were defined depending on nocturnal systolic blood pressure fall: extreme dipper (> 20%), dipper (10%-20%), non-dipper (< 10%) and riser (nocturnal blood pressure increase).
Results: 24-hour, daytime, and nighttime blood pressure values were lower than those obtained at the office. Twenty percent of patients exhibited elevated office blood pressure with normal values on ABPM (<<white coat>> hypertensives or false resistant) whereas 9% showed increased values on ABPM, but normal at the office (masked hypertension). The non-dipper or riser circadian patterns were present in more than half of the patients (40.2% and 13.4%, respectively) and were associated with an increased cardiovascular risk.
Conclusions: Almost one third of hypertensive patients exhibit blood pressure values that are not concordant between office and ABPM. More than a half of patients, especially those at higher risk, present a circadian pattern with an inadequate nocturnal blood pressure fall.