title: Prognostic value of premorbid hypertension and neurological status in aneurysmal subarachnoid hemorrhage: pooled analyses of individual patient data in the SAHIT repository.
abstract: OBJECTIVE
  The literature has conflicting reports about the prognostic value of premorbid hypertension and neurological status in aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to investigate the prognostic value of premorbid hypertension and neurological status in the SAH International Trialists repository.
  
  
  METHODS
  Patient-level meta-analyses were conducted to investigate univariate associations between premorbid hypertension (6 studies; n = 7249), admission neurological status measured on the World Federation of Neurosurgical Societies (WFNS) scale (10 studies; n = 10,869), and 3-month Glasgow Outcome Scale (GOS) score. Multivariable analyses were performed to sequentially adjust for the effects of age, CT clot burden, aneurysm location, aneurysm size, and modality of aneurysm repair. Prognostic associations were estimated across the ordered categories of the GOS using proportional odds models. Nagelkerke's R(2) statistic was used to quantify the added prognostic value of hypertension and neurological status beyond those of the adjustment factors.
  
  
  RESULTS
  Premorbid hypertension was independently associated with poor outcome, with an unadjusted pooled odds ratio (OR) of 1.73 (95% confidence interval [CI] 1.50-2.00) and an adjusted OR of 1.38 (95% CI 1.25-1.53). Patients with a premorbid history of hypertension had higher rates of cardiovascular and renal comorbidities, poorer neurological status (p ≤ 0.001), and higher odds of neurological complications including cerebral infarctions, hydrocephalus, rebleeding, and delayed ischemic neurological deficits. Worsening neurological status was strongly independently associated with poor outcome, including WFNS Grades II (OR 1.85, 95% CI 1.68-2.03), III (OR 3.85, 95% CI 3.32-4.47), IV (OR 5.58, 95% CI 4.91-6.35), and V (OR 14.18, 95% CI 12.20-16.49). Neurological status had substantial added predictive value greater than the combined value of other prognostic factors (R(2) increase > 10%), while the added predictive value of hypertension was marginal (R(2) increase < 0.5%).
  
  
  CONCLUSIONS
  This study confirmed the strong prognostic effect of neurological status as measured on the WFNS scale and the independent but weak prognostic effect of premorbid hypertension. The effect of premorbid hypertension could involve multifactorial mechanisms, including an increase in the severity of initial bleeding, the rate of comorbid events, and neurological complications.
authors.affiliation: Division of Neurosurgery and the.
authors.forename: Blessing N R
authors.initials: BN
authors.lastname: Jaja
authors.forename: Hester
authors.initials: H
authors.lastname: Lingsma
authors.forename: Tom A
authors.initials: TA
authors.lastname: Schweizer
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Thorpe
authors.forename: Ewout W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: R Loch
authors.initials: RL
authors.lastname: Macdonald
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D023261:Glasgow Outcome Scale; D006801:Humans; D006973:Hypertension / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000379:methods*; D019635:Neurosurgical Procedures; D011237:Predictive Value of Tests; D011379:Prognosis; D012042:Registries; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: C-1 = CONSCIOUS I trial; CHF = congestive heart failure; CI = confidence interval; D-SAT = University of Washington database of subarachnoid treatment; DIND = delayed ischemic neurological deficit; GOS = Glasgow Outcome Scale; HHU = Heinrich Heine University Concomitant Intraventricular Fibrinolysis and Low-Frequency Rotation after Severe Subarachnoid Hemorrhage Trial; IHAST = Intraoperative Hypothermia for Aneurysm Surgery Trial; IMASH = Intravenous MASH; ISAT = International Subarachnoid Aneurysm Trial; IVH = intraventricular hemorrhage; MASH = Magnesium Sulfate in Aneurysmal Subarachnoid Hemorrhage; OR = odds ratio; RCT = randomized controlled trial; SAH = subarachnoid hemorrhage; SAHIT = SAH International Trialists; SHOP = Subarachnoid Hemorrhage Outcomes Project; WFNS = World Federation of Neurosurgical Societies; hypertension; meta-analysis; neurological status; outcomes; prognostic factors; subarachnoid hemorrhage; vascular disorders