Benefit and risk of lower follow-up blood pressure after intracerebral haemorrhage

Abstract

Introduction: Intracerebral haemorrhage (ICH) survivors are prone to recurrent ICH, and blood pressure (BP) control is the sole modifiable risk for ICH recurrence. It remained unclear whether a more intensive BP target during follow-up would be beneficial, with the concern of increased mortality. Hence, we aimed to study the benefit and risks of lower follow-up BP in ICH survivors Methods: We studied the follow-up data of 501 primary ICH survivors from the prospective stroke registry of The University of Hong Kong, who were admitted from January 2011 to March 2019. Follow-up data were retrieved from the electronic patient record system or written medical notes. Our primary end-points were recurrent ICH, cardiovascular mortality, and all-cause mortality. The adjusted hazard ratios (HR) for each BP categories during follow-up were derived using multivariate Cox regression. Results: During a median FU of 4.2 years (interquartile range=2.2-6.1), there were 39 recurrent ICHs. When compared with systolic BP (SBP) of <120 mmHg, higher SBP categories were associated with an increasing risk of recurrent ICH (HR=4.5 for SBP 120-139 mmHg, 95% confidence interval [CI]=1.1-19.1; HR=10.4 for SBP 140-159 mmHg, 95% CI=2.1-50.8; HR=46.6 for SBP ≥160 mmHg, 95% CI=7.7-283.1). Similarly, the recurrent ICH risk increased with higher diastolic BP (DBP) categories. There was a J-shape relationship between SBP and all-cause mortality (HR=1.7 for SBP <120 mmHg, 95% CI=1.1-2.6; HR=2.0 for SBP 140-159 mmHg, 95% CI=1.1-3.3; HR=4.3 for SBP ≥160 mmHg, 95% CI=1.6-12.0), but not for cardiovascular mortality. No J-shape relationship was observed between DBP and all-cause mortality. In the subgroup analysis of patients aged ≤70 years, lower BP did not heighten all-cause mortality risk. Conclusion: A more intensive BP target of below 120/70 should be considered in ICH survivors, especially in patients aged ≤70 years.