Protocol for a prospective collaborative systematic review and meta-analysis of individual patient data from randomized controlled trials of vasoactive drugs in acute stroke: The Blood pressure in Acute Stroke Collaboration, stage-3.

Rationale Despite several large clinical trials assessing blood pressure lowering in acute stroke, equipoise remains particularly for ischemic stroke. The "Blood pressure in Acute Stroke Collaboration" commenced in the mid-1990s focussing on systematic reviews and meta-analysis of blood pressure lowering in acute stroke. From the start, Blood pressure in Acute Stroke Collaboration planned to assess safety and efficacy of blood pressure lowering in acute stroke using individual patient data. Aims To determine the optimal management of blood pressure in patients with acute stroke, including both intracerebral hemorrhage and ischemic stroke. Secondary aims are to assess which clinical and therapeutic factors may alter the optimal management of high blood pressure in patients with acute stroke and to assess the effect of vasoactive treatments on hemodynamic variables. Methods and design Individual patient data from randomized controlled trials of blood pressure management in participants with ischemic stroke and/or intracerebral hemorrhage enrolled during the ultra-acute (pre-hospital), hyper-acute (<6 h), acute (<48 h), and sub-acute (<168 h) phases of stroke. Study outcomes The primary effect variable will be functional outcome defined by the ordinal distribution of the modified Rankin Scale; analyses will also be carried out in pre-specified subgroups to assess the modifying effects of stroke-related and pre-stroke patient characteristics. Key secondary variables will include clinical, hemodynamic and neuroradiological variables; safety variables will comprise death and serious adverse events. Discussion Study questions will be addressed in stages, according to the protocol, before integrating these into a final overreaching analysis. We invite eligible trials to join the collaboration.