Morning Surge in Blood Pressure as a Predictor of Silent and Clinical Cerebrovascular Disease in Elderly Hypertensives

TLDR

Cardiovascular events most frequently occur in the morning hours. The study prospectively examined whether a morning blood‑pressure surge predicts stroke risk in 519 elderly hypertensives monitored with ambulatory BP and brain MRI. Morning BP surge was defined as the mean systolic pressure during the first two hours after awakening minus the mean systolic pressure during the lowest‑BP hour of sleep, and patients were followed prospectively for stroke outcomes. Over a mean 41‑month follow‑up, patients in the top decile of surge had a 2.7‑fold higher stroke risk, a higher prevalence of silent infarcts, and the surge predicted stroke independently of 24‑hour BP, nocturnal dipping, and baseline infarcts, indicating that reducing the surge may lower stroke risk.

Abstract

Cardiovascular events occur most frequently in the morning hours. We prospectively studied the association between the morning blood pressure (BP) surge and stroke in elderly hypertensives.We studied stroke prognosis in 519 older hypertensives in whom ambulatory BP monitoring was performed and silent cerebral infarct was assessed by brain MRI and who were followed up prospectively. The morning BP surge (MS) was calculated as follows: mean systolic BP during the 2 hours after awakening minus mean systolic BP during the 1 hour that included the lowest sleep BP. During an average duration of 41 months (range 1 to 68 months), 44 stroke events occurred. When the patients were divided into 2 groups according to MS, those in the top decile (MS group; MS > or =55 mm Hg, n=53) had a higher baseline prevalence of multiple infarcts (57% versus 33%, P=0.001) and a higher stroke incidence (19% versus 7.3%, P=0.004) during the follow-up period than the others (non-MS group; MS <55 mm Hg, n=466). After they were matched for age and 24-hour BP, the relative risk of the MS group versus the non-MS group remained significant (relative risk=2.7, P=0.04). The MS was associated with stroke events independently of 24-hour BP, nocturnal BP dipping status, and baseline prevalence of silent infarct (P=0.008).In older hypertensives, a higher morning BP surge is associated with stroke risk independently of ambulatory BP, nocturnal BP falls, and silent infarct. Reduction of the MS could thus be a new therapeutic target for preventing target organ damage and subsequent cardiovascular events in hypertensive patients.