Variability of and maximum systolic blood pressure strong predictors of stroke

January 01, 0001

Variability of and maximum systolic blood pressure strong predictors of stroke

Guidelines for diagnosis and treatment focus only on underlying mean blood pressure. The researchers from UK, Ireland and Sweden aimed to reliably establish the prognostic significance of visit-to-visit variability in blood pressure, maximum blood pressure reached, untreated episodic hypertension, and residual variability in treated patients. They determined the risk of stroke in relation to visit- to-visit variability in blood pressure (expressed as standard deviation, SD, and parameters independent of mean blood pressure) and maximum blood pressure in patients with previous transient ischaemic attack (TIA) and in patients with treated hypertension. 24 hour ambulatory blood-pressure monitoring (ABPM) was also studied.

In each TIA cohort, visit-to-visit variability in systolic blood pressure (SBP) was a strong predictor of subsequent stroke (eg, top-decile HR for SD SBP over seven visits: 6.22, significant), independent of mean SBP, but dependent on precision of measurement (top-decile HR over ten visits: 12.08, significant). Maximum SBP reached was also a strong predictor of stroke (HR for top-decile over seven visits: 15.01, significant, after adjustment for mean SBP). Residual visit- to-visit variability in SBP on treatment was also a strong predictor of stroke and coronary events (eg, top-decile HR for stroke: 3.25, significant), independent of mean SBP in clinic or on ABPM. Variability on ABPM was a weaker predictor, but all measures of variability were most predictive in younger patients and at lower ( less than median) values of mean SBP in every cohort.

The researchers concluded: "Visit-to-visit variability in SBP and maximum SBP are strong predictors of stroke, independent of mean SBP. Increased residual variability in SBP in patients with treated hypertension is associated with a high risk of vascular events."

There has been recent argument for not monitoring blood pressure after an antihypertensive is commenced. This study suggests more monitoring may help at surgery visit. This may be extrapolated such that there may be a new wave of ambulatory monitoring and of designs of the devices.

For the full abstract, click here.

The Lancet 375(9718):895-905, 13 March 2010 © 2010 Elsevier Limited
Prognostic significance of visit-to-visit variability, maximum systolic blood pressure, and episodic hypertension, cohort study. Peter M Rothwell, Sally C Howard, Eamon Dolan et al. Correspondence to Peter Rothwell: [email protected]

Category: K. Circulatory. Keywords: prognostic significance, variability, maximum, systolic blood pressure, episodic, hypertension, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 2 April 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.