Stroke: lowering blood pressure acutely does not clearly reduce death or disability and can be harmful

Clinical bottom line (level 1a)

  1. Though several drugs can lower blood pressure in patients with a recent stroke (within 2 weeks), none reduces death or disability.
  2. Some drugs increased mortality
    • streptokinase (NNT = 3 at 3 months)
    • beta-blockers (NNT = 11 at 4 weeks)
The Blood pressure in Acute Stroke Collaboration (BASC) : Cochrane Library 2000; 3 : -
Expires November 2003

The study

Systematic review of all randomised or quasi-randomised trials of
  • Patients: within 2 weeks of an acute ischaemic or haemorrhagic stroke
  • Intervention: interventions that would be expected to alter blood pressure
  • Outcome: death, recurrent stroke

    Articles found in using Cochrane Library, Medline, Embase, BIDS ISI, to 1999 (search terms: searching existing review articles and contacting researchers in the field and pharmaceutical companies. ) and searching stroke overviews, contacting research workers in the field and pharmaceutical companies.

    Selection criteria: 2 reviewers: see above and below
    Appraisal criteria: 2 reviewers: randomisation, concealment of allocation, blinding, intention-to-treat analysis, stroke type, drug use, follow-up
    Articles excluded if:
    • patients aged < 18
    • sub-arachnoid haemorrhage


    32 RCTs involving 5368 patients involving 11 combinations of drug classes and routes of adminitrations, including ACE inhibitors, beta-blockers, calcium-channel blockers and other agents

    The evidence

    Outcome Time to outcome CER OR
    (95% CI)    		 NNT
    (95% CI)
    death: streptokinase 3 months 37/176
    (21.0%)    		 2.06
    (1.31 to 3.25)     		7
    (4 to 21)
    hypotension: streptokinase weeks 10/172
    (5.8%)    		 5.90
    (3.49 to 9.99)     		5
    (3 to 8)
    death: beta-blockers 4 weeks 19/121
    (15.7%)    		 1.77
    (1.05 to 3.00)     		11
    (5 to 150)
    death or disability: DCLHb 3 months 23/45
    (51.1%)    		 4.44
    (1.81 to 10.85)     		3
    (2 to 7)
    death: iv calcium-channel blockers 4 weeks 40/218
    (18.3%)    		 1.02
    (0.63 to )     		340
    (NNT = 17 to infinity;
    NNH = 11 to infinity)
    death: oral calcium-channel blockers 4 weeks 91/907
    (10.0%)    		 0.96
    (0.70 to 1.31)     		-280
    (NNT = 36 to infinity;
    NNH = 37 to infinity)
    death or disability: oral calcium-channel blockers months 14/556
    (26.3%)    		 1.28
    (0.98 to 1.67)     		20
    (NNT = 260 to infinity;
    NNH = 9 to infinity)

    • Blood pressures were significantly mismatched between treatment and control groups for iv calcium-channel blockers, glyceryl trinitrate, prostacyclin.
    • Drugs showing hypotensive properties including calcium-channel blockers, ACE inhibitors, beta-blockers, glyceryl trinitrate, and prostacyclin.
    • No medication was found that reduced subsequent death or disability.

    Comments

    1. The number of trials and subjects with data on blood pressure and outcome were not identical, and the authors were unable to relate differences in blood pressure to differences in outcome.

    Citation

    1. The Blood pressure in Acute Stroke Collaboration (BASC) , : vasoactive drugs for acute stroke (Cochrane Review). Cochrane Library 2000; 3 : -
    Search Terms: stroke in Cochrane Library
    Contributor: Chris Ball, November 2001
    Reviewer:

    Clinical Question.
    Patient
    Intervention or Exposure
    Outcome