The effect of diffusion-perfusion mismatch on admission blood glucose and blood pressure values of acute stroke patients in the first 12 hours

Hyperglycemia is detected in nearly 20-50% of acute stroke patients admitted to the emergency room, most of whom don?t have diabetes mellitus (DM). In hyperglycemia of acute critical illness, intravenous insulin is actually considered the mainstay of therapy but its safety in acute ischemic stroke patients is not well known. Similarly 75% of acute stroke patients admitted to the emergency room have high blood pressure and about 50% of them have history of hypertension (HT). The pathophsiology of high blood pressure in acute stroke is not well known and the studies trying to explain it have conflicting results. The strategy of treatment of these patients is uncertain. Patients with salvageable brain tissue at admission can have higher glycemic levels and potentially be harmed by or on the contrary benefit the most from insulin therapy. Similarly patients with penumbral tissue at admission can have higher blood pressure levels and potentially be harmed by antihypertensive treatment.In this study we examined the relationship between the existence of diffusion/perfusion mismatch, a potential marker of penumbral tissue, and admission blood glucose (ABGL) or blood pressure level (ABPL) in patients admitted in the first 12 hours after ischemic stroke onset.Data of patients prospectively and consecutively registered to Florence Nightingale Stroke Unit acute stroke database between the years of 2006-2009 were used for the analysis. A PWI/DWI mismatch was considered as present if estimated at least to be approximately 20% by eyeballing the lesions. The ABGL was categorized as >140 mg/dl vs ?140 mg/dl and ABPL was categorized as >140/90 mm Hg vs ?140/90 mm Hg. Correlation between mismatch and ABGL or ABPL was analyzed with multivariate logistic regression analysis. Age, gender, DM history, HT history, Hba1c level, treatment for DM, treatment for HT, index proximal vessel occlusion (iPVO) and other potential correlates of blood glucose and blood pressure level (onset to door time, NIHSS, level of consciousness, stroke type and stroke etiology) were included in the analysis.The sample consisted of 192 patients (105 men and 87 women) with a mean age of 70 (SD: 13). Mean ABGL and ABPL were 137 mg/dl (SD: 44) and 149/84 mmHg (SD:29), respectively. One hundred and six individuals (55%) had mismatch and 121 individuals (63%) had iPVO. The adjusted odds of mismatch in predicting high ABPL was 2,507 (p=0,050, 95%Cl 0 1,000-6,286) in the whole group, and it reached the level of 3,801 in the group of patients with stress hyperglycemia (n: 132, 68%) (p= 0,033, 95%Cl 1,110-13,015). Lower level of consciousness, Hba1c level, history of atrial fibrillation,cardioembolic etiology and posterior circulation syndrome were the other independent predictors of high ABGL. Existence of mismatch was not associated with ABPL. Female gender (p=0,048) and total anterior circulation syndrome (p=0,008) were the only independent predictors found to be associated with higher ABPL.Our findings indicated that hyperacute ischemic stroke patients with PWI/DWI mismatch which is considered as potentially harboring salvageable penumbral brain tissue are more likely to present with hyperglycemia. The safety of parenteral insulin therapy should be specifically investigated in this subpopulation. On the other hand, we have not been able to demonstrate a similar relationship with mismatch and ABPL.