Is lowering blood pressure hazardous in patients with significant ipsilateral carotid stenosis and acute ischaemic stroke? Interim assessment in the ‘Efficacy of Nitric Oxide in Stroke’ Trial

BackgroundHigh blood pressure (BP) in acute stroke patients is both common and associated with a poor outcome, although best management remains unclear. Particular uncertainty exists in patients with carotid stenosis in whom lowering BP might reduce cerebral perfusion and worsen outcome. MethodsEfficacy of Nitric Oxide in Stroke (ENOS) is an international, randomized controlled trial investigating the effect of lowering BP with glyceryl trinitrate in 5000 patients with acute stroke. This analysis is based on patients with ischaemic stroke for whom information on the carotid status was available. Neurological impairment (Scandinavian Stroke Scale) and rate of recurrent stroke were assessed on day 7, and the functional outcome (modified Rankin score) was determined on day 90. ENOS is ongoing, therefore analyses are blinded to treatment. ResultsAt the time of analysis, 565 patients with ischaemic stroke had been randomized into ENOS and data on carotid status were available in 394 (70%) of these patients. Ipsilateral stenosis ≥50% was present in 50 patients (13%). Six of 344 (2%, 95% confidence interval: 0.7, 4%) patients with ipsilateral stenosis <50% had a recurrent stroke by 7 days as compared with none of 50 patients (0%, 95% confidence interval: 0, 9%) (P=0.73) with stenosis ≥50%. No significant difference in impairment was present on day 7; mean Scandinavian Stroke Scale with stenosis 38.3 versus no stenosis 43.2 (P=0.48). Adjusted functional outcome after 90 days was worse in those with a baseline carotid stenosis ≥50%; median modified Rankin score 3.0 versus 2.0 (P=0.03). ConclusionInterim data provide reassurance that it is reasonable to continue including patients with carotid stenosis into trials of acute BP lowering (such as ENOS).