New Insights into Blood Pressure Control for Intracerebral Haemorrhage

Although blood pressure (BP) levels may rise in the weeks preceding intracerebral haemorrhage (ICH), in contrast to findings in the ischaemic stroke population, the initial post-ICH BP is often much higher than the last pre-morbid level. Elevated BP is therefore common in acute ICH, often with markedly elevated levels, and is associated with poor outcomes, though the exact pathophysiological mechanisms remain unclear. The Antihypertensive Treatment of Acute Cerebral Haemorrhage (ATACH) trial and the INTEnsive blood pressure Reduction in Acute Cerebral haemorrhage Trial (INTERACT) demonstrated that early and intensive lowering of elevated BP in the acute ICH period is feasible and safe. Importantly, recent CT perfusion studies have shown that early, intense BP reduction does not reduce cerebral blood flow or promote cerebral ischaemia. The recent, large INTERACT2 trial confirmed the safety of early BP lowering in ICH and suggested that intensive target-driven BP reduction may improve outcomes, with a non-significant trend towards reduced death and major disability and a significant favourable shift of scores on the modified Rankin scale compared with guideline-based treatment. BP lowering in acute ICH may reduce haematoma growth, particularly when target levels are achieved early and are sustained, though the evidence is partly conflicting. Other aspects of BP may also be important following acute ICH, with maximum systolic BP and systolic BP variability being independent predictors of poor outcomes in a recent study. This chapter gives an overview of the current evidence regarding BP in ICH and covers the following topics: the incidence of elevated BP in acute ICH and the patterns of BP observed before and after the event; the effect of elevated BP on outcomes in ICH and the potential underlying pathophysiological mechanisms; the safety and feasibility of BP lowering; the effects of BP lowering on clinical and radiological outcomes; other important aspects of BP in ICH; and the choice of antihypertensive agent.