Blood Pressure Variability after ICH Predicts Poor Outcomes

Summary

The Second Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial [INTERACT2; Anderson CS et al. N Engl J Med 2013] showed that early, target-driven (<140 mm Hg) lowering of systolic blood pressure (SBP) was safe and improved functional outcomes compared with guideline-directed BP management (SBP, <180 mm Hg). A post hoc analysis has now shown that within individual variability in SBP during the first 24 hours and days 2 to 7 following acute intracerebral hemorrhage (ICH) predicts outcome [Manning L et al. Lancet Neurol 2014].

  • Neurology Clinical Trials
  • Ischemia
  • Hypertensive Disease
  • Neurology Clinical Trials
  • Ischemia
  • Neurology
  • Hypertensive Disease

The Second Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial [INTERACT2; Anderson CS et al. N Engl J Med 2013] showed that early, target-driven (<140 mm Hg) lowering of systolic blood pressure (SBP) was safe and improved functional outcomes compared with guideline-directed BP management (SBP, <180 mm Hg). A post hoc analysis has now shown that within individual variability in SBP during the first 24 hours and days 2 to 7 following acute intracerebral hemorrhage (ICH) predicts outcome, with a linear relationship between the degree of systolic BP variability (BPV) and risk of death or major disability at 90 days (defined as an mRS score of 3 to 6) [Manning L et al. Lancet Neurol 2014].

During the hyperacute (first 24 hours) and acute (Days 2 to 7) phases, a higher level of maximum SBP also predicted a poor outcome. These BP findings were independent of mean SBP, said Lisa Manning, MD, University of Leicester, Leicester, United Kingdom, who presented the results.

INTERACT2 was an international, multicenter (21 countries, 144 hospitals), randomized, controlled trial of 2839 patients with spontaneous ICH and an SBP ≥150 mm Hg. BP was measured five times on Day 1, and twice daily on Days 2 to 7. In this analysis 2645 patients were included in Study 1, concerned with the effect of BPV during Day 1 on outcome, and 2347 in Study 2, concerned with BPV during Days 2 to 7. Mean age was 64 years, 63% were men, and 69% to 73% were from the Chinese region.

The key BPV index was the standard deviation of SBP (SD-SBP) derived using all available BP measurements in the two study periods. Three logistic regression models were used to determine the association between BPV and outcomes. Model 1 adjusted for age, sex, and randomized treatment. Model 2 adjusted for these, plus region, high NIHSS, and hematoma volume, and Model 3 further adjusted for mean SBP.

The primary outcome was death or major disability at 90 days. To determine the strength of associations, patients were divided into quintiles of SD-SBP, and the lowest quintile was the reference point. In the hyperacute phase in Model 1, there was a linear association between systolic BPV and risk of the primary outcome (p<0.001). In Model 3, the odds ratio (OR) was 1.41 for the highest quintile of BPV (95% CI, 1.05 to 1.90; p=0.017). In the acute phase, the association between systolic BPV and the primary outcome persisted, although it was slightly weaker, said Dr. Manning, with an OR of 1.57 in Model 3 (95% CI, 1.14 to 2.17; p=0.012). Discrimination analyses showed that maximum SBP in the hyperacute phase and SD-SBP in the acute phase were the best predictors of outcome.

These are the first data to show the prognostic value of BPV after ICH. Large fluctuations in SBP and episodic hypertension after ICH represent an increased risk of poor outcome. The rapid lowering of elevated BP early after ICH is important, plus ensuring smooth and sustained control over several days, said Dr. Manning, which may require tailoring the frequency and intensity of BP monitoring.

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