Night-time ambulatory blood pressure more predictive of death risk

Spain: A recent observational cohort study published in The Lancet has found that ambulatory blood pressure measurements, particularly those taken at night, are more strongly associated with the risk of all-cause and cardiovascular mortality than clinic blood pressure measurements.

The study sought to investigate the relationships between clinic and 24-hour ambulatory blood pressure and all-cause and cardiovascular death in a large cohort of primary care patients referred for hypertension evaluation.

The study, which included data from the Spanish Ambulatory Blood Pressure Registry, analyzed clinic and ambulatory blood pressure data from over 59,124 primary care patients referred for assessment of hypertension.

Cox models were used to estimate associations between blood pressure and mortality, and participants were followed up until death or the end of 2019. Confounders and alternative measures of blood pressure were adjusted for, and five groups were created for each measure of blood pressure based on quintiles among those who subsequently died.

The study revealed the following clinical findings:

1. 59,124 patients were followed up for 9.7 years, during which 12.1% (7,174) died, including 4.0% (2,361) from cardiovascular causes.

2. 24-hour systolic blood pressure was strongly associated with all-cause death (HR 1.41) compared to clinic systolic blood pressure (HR 1.18).

3. Night-time systolic blood pressure was most informative about the risk of all-cause death (591%) and cardiovascular death (604%) compared to clinic blood pressure.

4. Elevated all-cause mortality risks were observed for masked hypertension and sustained hypertension, but not white-coat hypertension.

“The findings suggest that ambulatory blood pressure measurements, particularly those taken at night provide a more comprehensive assessment of blood pressure and are better predictors of health outcomes than clinic or home pressure measurements.” added the researchers of the study.

The study highlights the importance of considering ambulatory blood pressure measurements, particularly those taken at night, in the assessment of hypertension and in predicting the risk of all-cause and cardiovascular mortality. Further research is needed to determine the optimal use of ambulatory blood pressure measurements in clinical practice.

Reference:

Staplin N., de la Sierra A., Ruilope L., Emberson J., Vinyoles E., et al.; Relationship between clinic and ambulatory blood pressure and mortality: an observational cohort study in 59 124 patients; The Lancet Open Access, 2023; doi: https://doi.org/10.1016/S0140-6736(23)00733-X