Stroke Prognosis and Abnormal Nocturnal Blood Pressure Falls in Older Hypertensives

TLDR

The prognostic impact of abnormal nocturnal blood‑pressure dipping patterns on stroke risk is unclear. The study followed 575 older Japanese hypertensive patients, classifying them by nocturnal systolic BP fall (extreme‑dippers, dippers, nondippers, reverse‑dippers) and monitoring stroke outcomes over an average of 41 months. Extreme dipping was linked to a higher stroke risk (12 %) and a tendency toward sleep‑time ischemic strokes, while reverse dipping was associated with a markedly higher hemorrhage risk (22 %) and intracranial hemorrhage, revealing a J‑shaped relationship between dipping status and stroke outcomes.

Abstract

It remains uncertain whether abnormal dipping patterns of nocturnal blood pressure influence the prognosis for stroke. We studied stroke events in 575 older Japanese patients with sustained hypertension determined by ambulatory blood pressure monitoring (without medication). They were subclassified by their nocturnal systolic blood pressure fall (97 extreme-dippers, with ≥20% nocturnal systolic blood pressure fall; 230 dippers, with ≥10% but <20% fall; 185 nondippers, with ≥0% but <10% fall; and 63 reverse-dippers, with <0% fall) and were followed prospectively for an average duration of 41 months. Baseline brain magnetic resonance imaging (MRI) disclosed that the percentages with multiple silent cerebral infarct were 53% in extreme-dippers, 29% in dippers, 41% in nondippers, and 49% in reverse-dippers. There was a J-shaped relationship between dipping status and stroke incidence (extreme-dippers, 12%; dippers, 6.1%; nondippers, 7.6%; and reverse-dippers, 22%), and this remained significant in a Cox regression analysis after controlling for age, gender, body mass index, 24-hour systolic blood pressure, and antihypertensive medication. Intracranial hemorrhage was more common in reverse-dippers (29% of strokes) than in other subgroups (7.7% of strokes, P =0.04). In the extreme-dipper group, 27% of strokes were ischemic strokes that occurred during sleep (versus 8.6% of strokes in the other 3 subgroups, P =0.11). In conclusion, in older Japanese hypertensive patients, extreme dipping of nocturnal blood pressure may be related to silent and clinical cerebral ischemia through hypoperfusion during sleep or an exaggerated morning rise of blood pressure, whereas reverse dipping may pose a risk for intracranial hemorrhage.