Laboratory factors associated with symptomatic hemorrhagic conversion of acute stroke after systemic thrombolysis

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 the laboratory factors predisposing to HC in AIS patients receiving IVT.

Methods: We retrospectively reviewed the medical records of patients who received IV tPA for AIS at our comprehensive stroke center over a 9.6-year period. Besides age, gender, NIHSS, history of diabetes mellitus (DM), history of atrial fibrillation (Afib), we gathered their laboratory data including International Normalized Ratio (INR), lipid panel, serum albumin, serum creatinine, hemoglobin A1c (HbA1c), and admission blood glucose. Post-thrombolysis brain imagings were reviewed to evaluate for symptomatic ICH (sICH). The mean values of above mentioned laboratory data were compared between the group with sICH and patients with no sICH. 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 the univariate analysis, patients who developed sICH had significantly higher NIHSS on admission (14.2 ± 5.4 vs 11.2 ± 6.5, p < .001), LDL-cholesterol (113.3 mg/dl ±36.9 vs. 101.8 mg/dl ± 38.2, p = .032), HbA1c (6.9% ± 2.3 vs. 6.1 ± 1.3, p = .003) and lower levels of Albumin (3.5 g/dl ±0.4 vs. 3.9 g/dl ± 0.5, p < .001). Furthermore, a higher prevalence of history of DM (45% vs. 21.6%, p = .020) and Afib (25.4% vs. 10.4%, p = .028) was found in subjects who developed sICH. There were no significant group differences regarding age, sex, total cholesterol, blood glucose on admission, serum creatinine or INR levels (p > .05). After adjusting for multiple covariates, lower Albumin level and and higher HbA1c were significantly associated with an increased risk for sICH development (p < .05). Chances of sICH increased by 33% for every 1 g/dl below a normal albumin level of 4.0 g/dl (p < .05).

Conclusion: Lower endogenous albumin level and higher HbA1c have shown to predispose to a higher risk of sICH after IVT for AIS and might be good predictors of sICH post IVT.