Association between baseline pulse pressure and hospital mortality in non-traumatic subarachnoid hemorrhage patients: a retrospective cohort study

Abstract

Background and purposePrevious studies have described an association between pulse pressure (PP) level and mortality in stroke patients. Evidence of associations between PP level and the risk of mortality remains unknown in non-traumatic subarachnoid hemorrhage (SAH) patients. We aimed to explore the relationship between the baseline PP level and hospital mortality.MethodsThis cohort study of 693 non-traumatic SAH adults used Medical Information Mart for Intensive Care (MIMIC-IV) data from 2008–2019 admissions to Intensive Care Unit (ICU). PP level was calculated as the first value after admission to the ICU. The endpoint of the study was in-hospital mortality. Cox proportional hazards models were utilized to analyze the association between baseline PP level and hospital mortality. Restricted Cubic Splines (RCS) analysis was utilized to determine the relationship curve between hospital mortality and PP level and examine the threshold saturation effect. We further applied Kaplan–Meier survival curve analysis to examine the consistency of these correlations. The interaction test was used to identify subgroups with differences.ResultsThe mean age of the study population was 58.8 ± 14.6 years, and 304 (43.9%) of participants were female. When baseline PP level was assessed in quartiles, compared to the reference group (Q1 ≤ 56 mmHg), the adjusted hazard ratio (HR) in Q2 (57–68 mmHg), Q3(69–82 mmHg), Q4 (≥83 mmHg) were 0.55 (95% CI: 0.33–0.93, p = 0.026), 0.99 (95% CI, 0.62–1.59, p = 0.966), and 0.99 (95% CI: 0.62–1.59, p = 0.954), respectively. In the threshold analysis, for every 5 mmHg increase in PP level, there was an 18.2% decrease in hospital mortality (adjusted HR, 0.818; 95% CI, 0.738–0.907; p = 0.0001) in those with PP level less than 60 mmHg, and a 7.7% increase in hospital mortality (adjusted HR, 1.077; 95% CI, 1.018–1.139; p = 0.0096) in those with PP level was 60 mmHg or higher.ConclusionFor patients with non-traumatic SAH, the association between baseline PP and risk of hospital mortality was non-linear, with an inflection point at 60 mmHg and a minimal risk at 57 to 68 mmHg (Q2) of baseline PP level.

Relationship between baseline bicarbonate and 30-day mortality in patients with non-traumatic subarachnoid hemorrhage

“…This is generally consistent with the ratio reported in previously published studies of non-traumatic SAH using the MIMIC-IV database. The proportion of endovascular therapy and clipping surgery reported by Jiuling Liu et al was 29.1 and 5.2%, respectively ( 42 ). Intracranial aneurysmal SAH is the most common cause of non-traumatic SAH.…”

Hypothermia on the first day of ICU admission leads to increased in-hospital mortality in patients with subarachnoid hemorrhage

“…To sum up, considering the problems of statistical efficacy, p -value, and multicollinearity, we finally selected 11 variables from the results of Univariate analysis, including age, ethnicity, heart rate, RR, SpO 2 , blood glucose, WBC, Charlson comorbidity index, Cr, endovascular therapy, and GCS. Although univariate analysis showed no significant association between sex and in-hospital mortality (HR: 0.86, 95%CI: 0.61,1.23, p = 0.411), as an important demographic feature, has been included in the Multivariate analysis Model in other published relevant literature (although there is no correlation in univariate analysis) 23 – 25 , so we also take sex as one of the covariables. Therefore, a total of 12 covariates are adjusted in Model II.…”

“…Therefore, a total of 12 covariates are adjusted in Model II. We adjust for sex, age, and race in Model I by referring to published papers 23 – 25 . Otherwise, DCI and intracranial hypertension are important variables affecting prognosis and mortality and should be collected and included in multivariate models.…”