Abstract WP444: Older Age, Hypertension and Diabetes Influence the Proportion of Salvageable Ischemic Tissue Following Stroke
Objective: Increasing age, hypertension (HTN), diabetes (DM), hyperlipidemia, smoking and chronic kidney disease are implicated in endothelial dysfunction. Our hypothesis was that endothelial dysfunction would decrease the amount of salvageable ischemic tissue (penumbra) in patients with acute ischemic stroke.
Methods: Patients with ischemic stroke that underwent perfusion computed tomography (PCT) at admission from August 2011 to March 2012 were reviewed. Demographics and risk factors were abstracted. PCT protocol included 4 supratentorial slices, 8 mm thick. Areas of increased mean transit time were traced and marked as ischemic area. Corresponding area of preserved cerebral blood volume was labeled as penumbra area. The ischemic and penumbra areas in four slices were added and multiplied by the slice thickness (0.8 cm) to give ischemic volume (IV) and penumbra volume (PV) respectively. The proportion of penumbra (penumbra/ischemia volume) was calculated and compared across the different risk factors.
Results: Of the 47 patients that underwent PCT, 43 (22 males; mean age 61.6 ±12.6 years) had perfusion abnormalities. Subjects younger than 45 years had significantly higher median IV (118.8 cm3 vs. 58.4 cm3; p=0.01) and median PV (97.9 cm3 vs. 38.7 cm3; p<0.01). The median proportion of penumbra, was significantly lower in subjects older than 45 years (72.2% vs. 82.0%; p=0.04). Other factors that demonstrated trends toward a decrease in proportion of penumbra, but did not reach statistical significance due to small numbers: HTN (72.8% vs. 80.0% ; p=0.20) and DM (67.5% vs. 75.7%; p=0.56). In our subset, smoking, hyperlipidemia and kidney disease did not affect the penumbra proportion.
Conclusion: Older patients and those with HTN or DM are less likely to have a large proportion of salvageable penumbra. While endothelial dysfunction may be a common denominator to these risk factors, the biological mechanisms underlying this phenomenon need to be elucidated.
- © 2012 by American Heart Association, Inc.