Secondary prevention for stroke and transient ischaemic attacks

Editor—Acute stroke and transient ischaemic attacks are emergencies, and Muir in his editorial has presented recent evidence, showing that reduction of blood pressure and cholesterol, regardless of baseline values, have unequivocal benefit in secondary prevention.¹

There is no real boundary between acute treatment and secondary prevention, which should start very early. This is best done in a dedicated stroke unit, to enhance the multidisciplinary approach and minimise delays, leading to better recovery.²

There is evidence that high blood glucose is detrimental after a stroke. Although exact underlying mechanisms remain unclear, evidence shows clinical worsening, with hyperglycaemia and increased risk of a second stroke with poor long term control.³

Non-fasting total homocysteine is another independent risk factor in both sexes over 60. Screening for elevated homocysteine concentrations and folate therapy may play an important part in secondary prevention. Concentrations higher than 14 μmol/l are associated with an 80% increase in risk.⁴ However, reducing homocysteine has not yet shown a convincing effect, and further data are required.

Although there are resource implications of overdiagnosing transient ischaemic attacks, as Muir says, the estimated risk of a stroke after a transient ischaemic attack or minor stroke is 8-12% at seven days and 11-15% at one month.⁵ Public education for seeking urgent medical attention and better organised stroke services are required so that all suspected transient ischaemic attacks or minor strokes are seen immediately for early secondary prevention.⁵ However, further research will clarify which interventions or combinations thereof offer maximum benefit.