title: Short-term blood pressure variability in acute stroke: post hoc analysis of the controlling hypertension and hypotension immediately post stroke and continue or stop post-stroke antihypertensives collaborative study trials.
abstract: OBJECTIVE
  Short-term blood pressure variability (BPV) may predict outcome in acute stroke. We undertook a post hoc analysis of data from 2 randomized controlled trials to determine the effect of short-term BPV on 2-week outcome.
  
  
  METHODS
  Controlling Hypertension and Hypotension Immediately Post Stroke (CHHIPS) was a trial of BP-lowering, enrolling 179 acute stroke patients (onset<36 hours). Continue or Stop Post-Stroke Antihypertensives Collaborative Study (COSSACS) compared a strategy of continuation versus temporarily stopping prestroke antihypertensive therapy in 763 acute stroke patients (onset<48 hours). BPV at baseline (defined as SD, coefficient of variation, variation independent of the mean, and average real variability) was derived from standardized casual cuff BP measures (6 readings<30 minutes). Adjusted logistic regression models were used to assess the relation between BPV and death and disability (modified Rankin scale>3) at 2 weeks.
  
  
  RESULTS
  Seven hundred six (92.5%) and 171 (95.5%) participants were included in the analysis for the COSSACS and CHHIPS data sets, respectively. Adjusted logistic regression analyses revealed no statistically significant associations between any of the included BPV parameters with 2-week death or disability in either study data set: COSSACS, odds ratio SD systolic BP 0.98 (0.78-1.23); CHHIPS, odds ratio SD systolic BP 0.97 (0.90-1.11).
  
  
  CONCLUSIONS
  When derived from casual cuff BP measures, short-term BPV is not a useful predictor of early (2 weeks) outcome after acute stroke. Differing methodology may account for the discordance with previous studies indicating long-term (casual BPV) and short-term (beat-to-beat BPV) prognostic value.
  
  
  BACKGROUND
  COSSACS was registered on the International Standard Randomised Controlled Trial Register; URL: http://www.isrctn.com. Unique identifier: ISRCTN89712435. CHHIPS was registered on the National Research Register; URL: http://public.ukcrn.org.uk. Unique identifier: N0484128008.
authors.affiliation: From the Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, United Kingdom (L.S.M., A.K.M., T.G.R.); Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich, United Kingdom (J.P.); and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom (P.M.R.). lm313@le.ac.uk.
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Manning
authors.affiliation: From the Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, United Kingdom (L.S.M., A.K.M., T.G.R.); Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich, United Kingdom (J.P.); and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom (P.M.R.).
authors.forename: Amit K
authors.initials: AK
authors.lastname: Mistri
authors.affiliation: From the Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, United Kingdom (L.S.M., A.K.M., T.G.R.); Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich, United Kingdom (J.P.); and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom (P.M.R.).
authors.forename: John
authors.initials: J
authors.lastname: Potter
authors.affiliation: From the Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, United Kingdom (L.S.M., A.K.M., T.G.R.); Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich, United Kingdom (J.P.); and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom (P.M.R.).
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rothwell
authors.affiliation: From the Department of Cardiovascular Sciences and NIHR Biomedical Research Unit in Cardiovascular Disease, University of Leicester, Leicester, United Kingdom (L.S.M., A.K.M., T.G.R.); Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich, United Kingdom (J.P.); and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom (P.M.R.).
authors.forename: Thompson G
authors.initials: TG
authors.lastname: Robinson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D066264:Datasets as Topic; D018572:Disease-Free Survival; D004311:Double-Blind Method; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D007022:Hypotension / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D008875:Middle Aged; D020521:Stroke / Q000150:complications / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D015996:Survival Rate; D006113:United Kingdom
keywords: blood pressure; stroke