Ilana Spokoyny, MD
Kim JT, Jahan R, Saver JL, and for the SWIFT Investigators. Impact of Glucose on Outcomes in Patients Treated With Mechanical Thrombectomy: A Post Hoc Analysis of the Solitaire Flow Restoration With the Intention for Thrombectomy Study. Stroke. 2016
The medical management of patients post-stroke is critical to improving their functional outcomes. Stroke patients treated in dedicated stroke units have been shown to have better outcomes than those treated in general medical wards. Aside from blood pressure optimization, preventing infection, and avoiding fevers, glucose management has been a focus in predicting functional outcomes following stroke. Hyperglycemia predicts poor outcomes after ischemic strokes but while it is intuitive to think that tighter glucose control improves outcomes, a recent Cochrane review did not show benefit of maintaining normoglycemia. The authors hypothesized that reperfusion status should be taken into account, so chose to conduct an analysis on patients who underwent mechanical thrombectomy.
This study evaluated outcomes of 143 stroke patients treated with mechanical thrombectomy in the SWIFT trial (Solitaire vs. Merci) to determine if presenting with hyperglycemia (glucose > 140 mg/dl) was associated with worse outcomes, and how the degree of reperfusion played into this relationship. Only half of the cohort also received IV tPA.
Hyperglycemia at presentation was associated with worse functional outcome at 90 days. The hyperglycemic patients were more likely to be disabled, and less likely to have an excellent functional outcome (mRS 0-1) at 3 months. Overall, for every 10mg/dl increase in presenting glucose level, a patient was 13% less likely to have an excellent outcome (mRS 0-1 at 90 days). This approached significance (p=0.054). No effects of hyperglycemia were seen on intracranial bleeding or death.
The presenting glucose level did not affect the rate of complete reperfusion. Previous studies of IV tPA showed reduced rates of recanalization in hyperglycemic patients. This result suggests that using mechanical thrombectomy overcomes these barriers.
Among patients with complete reperfusion, there was a trend toward worse outcomes in those presenting with hyperglycemia, but this was not statistically significant. However, among patients with incomplete reperfusion, higher presenting glucose levels were associated with worse 90 day outcomes. In fact, for every 10mg/dl increase in the glucose, a patient (with incomplete reperfusion) was 42% less likely to achieve excellent outcome. This is consistent with previous studies showing larger infarct formation in hyperglycemic non-recanalized pateints.
A previous randomized trial showed that there was no benefit to tight glucose management post stroke. However, that trial did not take into account reperfusion status, and based on the results of this study, further research is warranted to determine whether tight glucose control improves outcomes specifically in those patients with incomplete reperfusion, as they may be more prone to the deleterious effects of hyperglycemia.