Shock index predicts up to 90-day mortality risk after intracerebral haemorrhage

Background: Shock index (SI - heart rate/systolic blood pressure) has been studied as a measure of haemodynamic status. We aimed to determine whether SI measures within 72 h of admission were associated with adverse outcomes in intracerebral haemorrhage (ICH).

Methods: Patients were drawn from the Virtual International Stroke Trials Archive-Intracerebral Haemorrhage (VISTA-ICH). Multivariable Cox regressions modelled the relationship between SI (on admission, 24, 48, 72 h) and mortality (at 3-, 7-, and 90-days), 90-day incident pneumonia and cardiovascular events (MACE). Ordinal logistic regressions modelled the relationship between SI and 90-day modified Rankin Scale (mRS).

Results: 979 patients were included. Baseline SI was not associated with mortality. 24 h SI > 0.7 was associated with 7-day mortality (hazard ratio (95% confidence interval) = 3.14 (1.37-7.19)). 48 h and 72 h SI > 0.7 were associated with 7-day (4.23 (2.07-8.66) and 3.24 (1.41-7.42) respectively) and 90-day mortality (2.97 (1.82-4.85) and 2.05 (1.26-3.61) respectively). SI < 0.5 at baseline, 48 h and 72 h was associated with decreased pneumonia risk. 24 h and 48 h SI > 0.7was associated with increased MACE risk. 48 h and 72 h SI > 0.7 was associated with increased odds of higher 90-day mRS.

Conclusion: Higher-than-normal SI subsequent to initial encounter was associated with higher post-ICH mortality at 3, 7, and 90 days. Lower-than-normal SI was associated with a decreased risk of incident pneumonia.