Effects of admission hyperglycemia on stroke outcome in reperfused tissue plasminogen activator--treated patients

Abstract

Background and purpose: We sought to investigate the impact of hyperglycemia before reperfusion on long-term outcome in patients treated with intravenous tissue plasminogen activator (tPA).

Methods: Of 268 consecutive patients with a nonlacunar middle cerebral artery (MCA) stroke evaluated at <3 hours after onset, 73 (27.2%) received intravenous tPA. Serum glucose was determined at baseline before tPA administration. Hyperglycemia was defined as a glucose level >140 mg/dL. National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and 24 hours. Transcranial Doppler monitoring of recanalization and reocclusion was conducted during the first 24 hours. Total infarct volume was measured on CT at day 5 to 7. Modified Rankin Scale was used to assess outcome at 3 months.

Results: Median NIHSS score was 17. At baseline, 31 patients (42.5%) were hyperglycemic and 42 (57.5%) normoglycemic. Early reperfusion (<6 hours) occurred in 43 patients (58.9%). Admission blood glucose correlated negatively with the degree of neurological improvement at 24 hours in reperfused (r=-0.43; P=0.019) but not in nonreperfused (r=-0.20; P=0.21) tPA-treated patients. Increased age (P=0.014), history of diabetes mellitus (P=0.043), admission glucose >140 mg/dL (P=0.002), and early reocclusion (P=0.004) were factors associated with poor outcome among reperfused patients. A logistic regression modeling revealed that only admission glucose value >140 mg/dL (odds ratio, 8.4; 95% CI, 1.76 to 40.02; P=0.005) emerged as an independent predictor of poor outcome despite tPA-induced recanalization. In patients with 6-hour persistent MCA occlusion, baseline NIHSS score >15 points (P=0.011) and proximal MCA occlusion (P=0.039) were variables associated with poor outcome on univariate analysis. In a logistic regression model, only NIHSS score >15 points (odds ratio, 11.9; 95% CI, 1.48 to 97.1; P=0.032) remained as an independent predictor of poor outcome and functional dependence at 3 months in nonreperfused tPA-treated patients.

Conclusions: Hyperglycemia before reperfusion may in part counterbalance the beneficial effect of early restoration of blood flow, which translates into a worse outcome in hyperglycemic patients despite tPA-induced recanalization.