Treating hypertension to prevent stroke

• hypertension is the most important treatable risk factor for the prevention of stroke and its recurrence, and antihypertensive therapy significantly reduces the risk (1)
• following acute stroke blood pressure levels are often raised and fall spontaneoulsy over the next few days. Both high and low blood pressure levels immediately post-stroke are associated with an adverse prognosis
• at present there is no definitive evidence as to whether antihypertensive drugs should be started immediately after a stroke or if current medication should be continued in the acute post-ictal phase
  • in a study investigating the treatment of hypertension post stroke (patients over 18 years admitted to hospital with a clinical diagnosis of suspected stroke and symptom onset < 36 hours and hypertension, defined as systolic BP (SBP) < 160 mmHg) (2)
    • oral and sublingual lisinopril and oral and intravenous labetalol were effective BP-lowering agents in acute cerebral infarction and haemorrhage and did not increase the likelihood of early neurological deterioration
      • study was not sufficiently powered to detect a difference in disability or death at 2 weeks
• thiazide/thiazide-lie diuretics and/or angiotensin-converting enzyme inhibitors reduce the risk of stroke recurrence and major cardiovascular events by approximately 20-30% in those with a history of stroke or transient ischaemic attack whether normotensive or hypertensive at follow up. These benefits are seen irrespective of baseline BP, and are more likely to be due to BP lowering (1)
• in order to realize the full potential in both primary and secondary prevention of stroke then other cardiovascular disease risk factors must be treated

Reference:

• 1. Williams B, Poulter NR, Brown MJ, Davis M, McInnes GT, Potter JF, et al. Guidelines for management of hypertension: report of the fourth working party of the British Hypertension Society, 2004 - BHS IV. J Hum Hypertens 2004;18: 139-85
• 2. Poter JF et al. Controlling hypertension and hypotension immediately post stroke (CHHIPS)--a randomised controlled trial. Lancet Neurol 2009;8:48-56.