Associations Between Elevated Systolic Blood Pressure and Outcomes in Critically Ill Patients: A Retrospective Cohort Study and Propensity Analysis

Abstract

Introduction: Studies have shown nonlinear relationships between systolic blood pressure (SBP) and outcomes, with increased risk observed at both low and high blood pressure levels. However, the relationships between cumulative times at different SBP levels and outcomes in critically ill patients remain unclear. We hypothesized that an appropriate SBP level is associated with a decrease in adverse outcomes after intensive care unit (ICU) admission. Methods: This study was a retrospective analysis of data from the Medical Information Mart for Intensive Care (MIMIC) III database, which includes more than 1,000,000 SBP records from 12,820 patients. Associations of cumulative times at four SBP ranges (<100 mm Hg, 100-120 mm Hg, 120-140 mm Hg, and 140 mm Hg) with mortality (12-, 3-, 1-month mortality and in-hospital mortality) were evaluated. Restricted cubic splines and multivariable Cox regression models were employed to assess associations between mortality and cumulative times at SBP levels (4 levels: <2, 2-12, 12-36, and 36 h) over 72 h of ICU admission. Additionally, 120 mm Hg to 140 mm Hg was subdivided into <12 h (Group L) and 12 h (Group M) subsets and subjected to propensity-score matching and subgroup analyses. Results: At 120 mm Hg to 140 mm Hg, level-4 SBP was associated with lower adjusted risks of mortality at 12 months (OR, 0.71; CI, 0.61-0.81), 3 months (OR, 0.72; CI, 0.61-0.85), and 1 month (OR, 0.61; CI, 0.48-0.79) and in the hospital (OR, 0.71; CI, 0.58-0.88) than level-1 SBP. The cumulative times at the other 3 SBP ranges (<100 mm Hg, 100-120 mm Hg, and 140 mm Hg) were not independent risk predictors of prognosis. Furthermore, Group M had lower 12-month mortality than Group L, which remained in the propensity-score matched and subgroup analyses. Conclusions: SBP at 120 mm Hg to 140 mm Hg was associated with decreased adverse outcomes. Randomized trials are required to determine whether the outcomes in critically ill patients improve with early maintenance of a SBP level at 120 mm Hg to 140 mm Hg.

Hypotension during intensive care stay and mortality and morbidity: a systematic review and meta-analysis

“…1 PRISMA flow diagram of included studies. Of the two articles analyzing the Medical Information Mart for Intensive Care (MIMIC) cohort and reporting data on mortality [ 8 , 20 ], one could be included in the meta-analysis [ 8 ]. The article with the highest NOS score was used in the summary table [ 20 ].…”

The baseline and repeated measurements of DBP to assess in-hospital mortality risk among critically ill patients with acute myocardial infarction: A retrospective cohort study

“…[19,20] BP has been shown to be an important determinant of adverse cardiovascular events in patients. [18] Data from a small retrospective study of patients with cardiogenic shock concluded that, of several hemodynamic parameters, only DPB (particularly DPB < 40 mm Hg in the 24 hours prior to ICU P value: as for the difference between survivors and non-survivors; Kruskal-Wallis test was applied for the variables with a skewed distribution. DBP = diastolic blood pressure.…”

“…We demonstrated that there was a nonlinear association between baseline DBP and in-hospital death among patients with AMI, with increased risk observed at both low and high BP values. [ 18 ] Moreover, the DBP that was dynamic during the first 3 days of ICU stay also seems to be a meaningful prognostic factor in patients with AMI. We discovered that DBP in the deaths decreased within the first 3 days after ICU stay, but the changes in DBP of the surviving group were smaller and slower.…”

“…[ 19 , 20 ] BP has been shown to be an important determinant of adverse cardiovascular events in patients. [ 18 ] Data from a small retrospective study of patients with cardiogenic shock concluded that, of several hemodynamic parameters, only DPB (particularly DPB < 40 mm Hg in the 24 hours prior to ICU admission) was independently associated with 28-day mortality in patients with cardiogenic shock. [ 21 ] Then, in another study of 3943 patients with AMI treated at a tertiary hospital, DBP < 60 mm Hg was associated with a poorer outcome.…”

Sex differences in the association between blood pressure and atrial fibrillation: A case-control study

“…However, it is uncertain above which BP level the risk of AF is significantly increased. Also, the extent to which BP control reduces AF in hypertensive patients is unknown, despite clear evidence that BP control reduces target organ damage and improves overall survival ( 9 – 11 ). Though some researches demonstrated an ideal BP in patients with AF ( 12 ), most current HBP guidelines do not specify BP-lowering goals for patients with AF ( 13 – 16 ).…”