Hypotension based on office and ambulatory monitoring blood pressure. Prevalence and clinical profile among a cohort of 70,997 treated hypertensives

• Hypotension is not necessarily an innocent phenomenon in treated patients.
• Eight percentage of treated hypertensives may be at high cardiovascular risk due to hypotension.
• Sixty-eight percentage of hypotension cases identified outside the office are missed in the office.
• Ambulatory BP monitoring helps identify hypotension cases outside the office.

We aimed to determine the prevalence of hypotension and factors associated with the presence of this condition in treated hypertensive patients undergoing ambulatory blood pressure monitoring (ABPM). Data were taken from the Spanish ABPM Registry. Office blood pressure (BP) and ABPM were determined using validated devices under standardized conditions. Based on previous studies, hypotension was defined as office systolic/diastolic BP <110 and/or 70 mm Hg, daytime ABPM <105 and/or 65 mm Hg, nighttime ABPM <90 and/or 50 mm Hg, and 24-hour ABPM <100 and/or 60 mm Hg. Multivariable logistic regression was performed to determine the variables associated with the presence of hypotension. A total of 70,997 hypertensive patients on treatment (mean age 61.8 years, 52.5% men) were included in the study. The prevalence of hypotension was 8.2% with office BP, 12.2% with daytime ABPM, 3.9% with nighttime ABPM, and 6.8% with 24-hour ABPM. Low diastolic BP values were responsible for the majority of cases of hypotension. Some 68% of the hypotension cases detected by daytime ABPM did not correspond to hypotension according to office BP. The variables independently and consistently associated with higher likelihood of office, daytime, and 24 hour–based hypotension were age, female gender, history of ischemic heart disease, and body mass index <30 kg/m2 (P < .05). In conclusion, in this large cohort of patients in usual daily practice, one in eight treated hypertensive patients are at risk of hypotension according to daytime BP. Two-thirds of them are not adequately identified with office BP. ABPM could be especially helpful for identifying ambulatory hypotension, in particular in patients who are older, women, or with previous ischemic heart disease where antihypertensive treatment should be especially individualized and cautious.