Ambulatory blood pressure monitoring in acute stroke: pathophysiology of the time rate of blood pressure variation and association with the 1-year outcome.

OBJECTIVES

Time rate of blood pressure (BP) variation is a measure of the speed of BP fluctuations derived from a computerized analysis of ambulatory BP monitoring. The aim of this study was to identify pathophysiological differences in the time rate of BP variation between stroke subtypes, on the basis of the Trial of Org 10172 in Acute Stroke Treatment criteria, in the acute phase and to examine the impact of time rate of BP variation on outcome at 1 year after stroke.

PATIENTS AND METHODS

A consecutive series of 109 first-ever stroke patients, who fulfilled our inclusion criteria, underwent 24 h ambulatory BP monitoring within 24 h after the onset of stroke. On the basis of the patients' Modified Rankin Scale score at 1 year after stroke, the study population was divided into two groups: patients with a positive (n=73) and those with a negative outcome (n=36).

RESULTS

The 24-h rate of systolic BP variation is higher in patients with large artery atherosclerosis [0.692 mmHg/min; 95% confidence interval (CI) 0.627-0.757] compared with those with lacunar strokes (0.609 mmHg/min; 95% CI 0.579-0.640) or strokes of unknown etiology (0.586 mmHg/min; 95% CI 0.522-0.649). Moreover, patients with higher 24-h rates of systolic BP variation were more likely to have a negative outcome at 1 year (odds ratio 1.96; 95% CI 1.16-3.32). Moreover, each 0.1 mmHg/min increase in the 24-h rate of SBP variation was associated with a 1.96-fold increase in the odds of a negative outcome (95% CI 1.16-3.32).

CONCLUSION

Time rate of BP variation shows significant differences between stroke subtypes in the acute phase of the event, and it is associated with outcome at 1 year. Lowering the time rate of BP variation, in the acute phase, might lead to better outcomes in patients who have had a cerebrovascular incident.