Background: Laboratory factors associated with hemorrhagic conversion (HC) after Intravenous thrombolysis with rtPA (IVT) for Acute Ischemic Stroke(AIS) remain nebulous despite advances in our knowledge of AIS. This study aimed to investigate laboratory factors predisposing to HC in AIS patients receiving IVT or IAT.
Methods: We retrospectively reviewed the medical records of patients who received IV tPA for AIS at our comprehensive stroke center from 01/2006 till 07/2015. Besides age, gender, NIHSS, history of DM, history of atrial fibrillation (Afib), we gathered their laboratory data including INR, lipid panel, serum albumin, serum creatinine, hemoglobin A1c, and admission blood glucose. Post-thrombolysis brain imaging was reviewed to evaluate for any symptomatic ICH (sICH). The mean values of above mentioned laboratory data were compared between the group with sICH and non-bleeders. Univariate and multivariate logistic regression were performed to evaluate the association of the laboratory findings with presence of sICH. sICH was defined as ICH causing an increase in NIHSS ≥4.
Results: Of the 794 subjects in this study 51 (6.4%) had sICH. In univariate analysis, patients who had sICH had significantly higher NIHSS on admission (14.2±5.4 vs 11.2±6.5, p<.001), LDL (113.3 mg/dl ±36.9 vs. 101.8±38.2, p=.032), HbA1c (6.9 %±2.3 vs. 6.1±1.3, p=.003) and lower levels of Albumin (3.5 mg/dl ±0.4 vs. 3.9±0.5, p<.001) compared to subjects with non-bleeders. Furthermore, a higher prevalence of history of DM (34.8% vs. 22.2%, p=.020) and Afib (19.7% vs. 10.7%, p=.028) was found in subjects presenting with sICH. There were no significant group differences regarding age, sex, total cholesterol, blood glucose on admission, Creatinine or INR levels ( p>.05). After adjusting for covariates , Lower Albumin levels, higher LDL, higher total Cholesterol and higher HbA1c were significantly associated with an increased risk for sICH development. Chance of sICH decreased by 77% for every increase by 1mg/dl towards a normal albumin level (p<0.05).
Conclusion: Multiple laboratory factors including lower endogenous albumin levels and higher HbA1C have shown to predispose to a higher risk of HC after IV thrombolysis and might be good predictor of of sICH post IV thrombolysis.