Office, Central, and Ambulatory Blood Pressure for Predicting First Stroke in Older Adults: A Community-Based Cohort Study

Hypertension is the most prevalent modifiable risk factor for stroke. Office blood pressure (BP) measurements may have limitations in defining the impact of hypertension on stroke. Our aim was to compare the stroke risk for office, central, and ambulatory BP measurements in a predominantly older population-based prospective cohort. Participants in the CABL study (Cardiovascular Abnormalities and Brain Lesions; n=816; mean age, 70.8±9.0 years; 39.8% men) underwent applanation tonometry of the radial artery for central BP and 24-hour ambulatory BP monitoring. During a follow-up of 9.6±3.1 years, stroke occurred in 76 participants (9.3%). Among office BP variables, only diastolic BP was associated with stroke in multivariable competing risk model (P=0.016). None of the central BP variables showed a significant association with stroke. Conversely, all ambulatory systolic and diastolic BP variables were significantly associated with stroke after adjustment for clinical confounders (all P<0.005). In an additional multivariable competing risk model including both ambulatory systolic and diastolic BP values obtained at the same time of the day, diastolic BP was more strongly associated with stroke than systolic BP in 24-hour, daytime, and nighttime periods (all P<0.05). Therefore, in a predominantly older population-based cohort, office diastolic BP was weakly associated with incident stroke; no central BP variable was prognostic of stroke. However, all ambulatory systolic and diastolic BP values were significantly associated with stroke in multivariable competing risk analyses. Moreover, ambulatory diastolic BP was a stronger predictor of stroke than ambulatory systolic BP.