Acute BP variability after ischaemic stroke predicts worse functional outcomes

High blood pressure (BP) variability within 24 hours of admission for acute ischaemic stroke correlates with worse functional outcomes 30 days after, a recent study has found.

A total of 174 patients (median age, 71 years; 54 percent male) participated in the present retrospective study. Supine BP was measured every 4 hours during the first 24 hours of admission, and parameters for analysis included systolic (SBP) and diastolic (DBP), mean arterial pressure (MAP), and pulse pressure (PP). Functional outcome was measured using the modified Rankin Scale (mRS).

The researchers also used six indices to assess BP variability: standard deviation (SD), successive variation (SV), maximal successive change (MSC), coefficient of variation (CV), average real variability (ARV), and the difference between the maximum and minimum values of BP (DMM).

After 30 days, 100 patients scored ≤2 on the mRS and were deemed to have favourable functional outcomes; the remaining 74 scored 3–6 and had unfavourable outcomes.

Mean SBP (p=0.003), DBP (p=0.012), and MAP (p=0.002) differed significantly between outcome groups, such that measurements were slightly lower among those with favourable outcomes. The same was true for several measures of BP variability.

For instance, SD of SBP (p=0.025) was significantly higher among patients with unfavourable outcomes, as were the CV (p=0.005), ARV (p=0.001), and SV (p=0.000) of PP. The MSC of DBP was also significantly heightened in patients with poorer functional outcomes at 30 days. Notably, the DMM of all BP indices was significantly elevated in the group with unfavourable outcomes.

Logistic regression analysis confirmed these findings. In the completely adjusted model, higher SD (p=0.009), SV (p=0.014), ARV (p=0.019), MSC (p=0.012), and DMM (p=0.008) all significantly aggravated the risk of worse functional outcome, but only when looking at PP. No such effect was reported for the other BP indices.