Blood pressure declines and less favorable outcomes in the NINDS tPA stroke study

Hypertension is the most important modifiable risk factor for secondary stroke prevention but the immediate management of blood pressure after stroke is uncertain. We evaluated outcomes in the NINDS tPA stroke study in relation to blood pressure declines during the first 24 h after randomization.

Declines in blood pressure compared to baseline and preceding time points were analyzed in relationship to favorable outcomes (by a global test), poor outcomes (Rankin scale >3) and death at 3 months.

551 patients did not receive immediate pre-randomization anti-hypertensive treatment and had available blood pressures. Multivariate analysis showed significantly and progressively reducing likelihoods of a favorable outcome with each 10 mmHg decline in systolic blood pressure (SBP) >50 mmHg compared to any preceding measurement. Poor outcomes were significantly more likely in patients with >50 mmHg SBP reduction (or >30 mmHg compared to any immediately preceding measurement). There was an increased risk of death with blood pressure declines >60 mmHg. tPA treatment still produced favorable outcomes compared with placebo even with blood pressure declines. The median largest SBP reduction from baseline in patients treated with tPA was 35 mmHg compared to 30 mmHg in placebo-treated patients (p<0.01).

In this post hoc analysis, progressively reducing likelihoods of a favorable outcome were seen with increasing declines in SBP. Despite a greater likelihood of favorable outcomes, tPA treatment was associated with a greater reduction in blood pressure than placebo. Randomized trials of blood pressure management are needed.