Lower stroke risk with lower blood pressure in hemodynamic cerebral ischemia

Abstract

Objective: To determine whether strict blood pressure (BP) control is the best medical management for patients with symptomatic carotid artery occlusion and hemodynamic cerebral ischemia. Methods:In this prospective observational cohort study, we analyzed data from 91 participants in the nonsurgical group of the Carotid Occlusion Surgery Study (COSS) who had recent symptomatic internal carotid artery occlusion and hemodynamic cerebral ischemia manifested by ipsilateral increased oxygen extraction fraction. The target BP goal in COSS was #130/85 mm Hg. We compared the occurrence of ipsilateral ischemic stroke during follow-up in the 41 participants with mean BP #130/85 mm Hg to the remaining 50 with higher BP.Results: Of 16 total ipsilateral ischemic strokes that occurred during follow-up, 3 occurred in the 41 participants with mean follow-up BP of #130/85 mm Hg, compared to 13 in the remaining 50 participants with mean follow-up BP .130/85 mm Hg (hazard ratio 3.742, 95% confidence interval 1.065-13.152, log-rank p 5 0.027).Conclusion: BPs #130/85 mm Hg were associated with lower subsequent stroke risk in these patients. Classification of evidence:This study provides Class III evidence that control of hypertension #130/85 mm Hg is associated with a reduced risk of subsequent ipsilateral ischemic stroke in patients with recently symptomatic carotid occlusion and hemodynamic cerebral ischemia (increased oxygen extraction fraction). Patients with symptomatic carotid artery occlusion and hemodynamic cerebral ischemia manifested by increased oxygen extraction fraction (OEF) are at 20%-30% risk for ipsilateral stroke within 2 years.1-3 Disagreement exists whether strict blood pressure (BP) control is the best medical management for these patients or whether higher BPs are needed to preserve cerebral perfusion and prevent subsequent stroke. 3,4 To address this issue, we analyzed data from the nonsurgical group of the Carotid Occlusion Surgery Study (COSS). 2METHODS The COSS was a parallel-group, prospective, 1:1 randomized, open-label, blinded-adjudication treatment trial conducted from 2002 to 2010 to test the hypothesis that extracranial-intracranial arterial bypass, when combined with best medical therapy, could reduce by 40% the subsequent occurrence of ipsilateral ischemic stroke at 2 years in patients with recent symptomatic internal carotid artery (ICA) occlusion and ipsilateral increased OEF measured by PET. COSS was carried out at 49 clinical centers and 18 PET centers in the United States and Canada. The majority were academic medical centers. The trial was terminated early for futility. Details of the trial design and results have been reported. 2,5The first follow-up visit was 30-35 days after randomization. Subsequent follow-up visits were at 3-month intervals after randomization until 24 months or the end of the trial. The nonsurgical group remained on the antithrombotic treatment preferred by their physicians. Each follow-up examination included monitoring of the efficacy of risk factor modificati...

Ultrasound and Clinical Predictors of Recurrent Ischemia in Symptomatic Internal Carotid Artery Occlusion

“…[1][2][3][4][5] The risk is likely increased if collateral supply is insufficient resulting in hemodynamic compromise. [6][7][8] Collateral pathways activated in response to ICAO have been categorized as either primary or secondary.…”

Ipsilateral Infarct in Newly Diagnosed Cervical Internal Carotid Artery Atherosclerotic Occlusion

“…A study of a cohort predominantly composed of patients with carotid stenosis >75% or complete occlusion revealed that antihypertensive treatment was associated with significantly reduced recurrent stroke risk [7]. In patients with recently symptomatic CICAO and hemodynamic cerebral ischemia (Carotid Occlusion Surgery Study cohort), controlled hypertension (≤130/85 mm Hg) was associated with a reduced risk of subsequent ischemic stroke [18]. In clinical practice, physicians may be reluctant to treat hypertension to lower blood pressure targets because of concerns about reducing cerebral perfusion pressure in the setting of carotid high-grade stenosis or occlusion.…”

William M. Feinberg Award for Excellence in Clinical Stroke

“…Nevertheless, this study provided Class III evidence by American Academy of Neurology criteria that control of hypertension ≤ 130/85 mm Hg is associated with a reduced risk of subsequent ipsilateral ischemic stroke in patients with recently symptomatic carotid occlusion and hemodynamic cerebral ischemia (increased OEF). 37 COSS patients with increased OEF represent the most extreme case of cerebral hemodynamic compromise. Nevertheless, lower blood pressures were associated with reduced, not increased, stroke risk.…”