THE ”MAKING“ OF A PARENCHYMAL HEMATOMA. An early coagulopathy and specific risk factors contribute to grave intracerebral bleeding after intravenous rtPA thrombolysis.
Background : Several factors are suspected in the occurrence of hemorrhages after rtPA thrombolysis in cerebral infarcts, but little is known about coagulation in these patients. Methods and results : One hundred consecutive patients had rtPA at the dose of 0.8 mg/kg infused for 90 minutes.We studied the values of fibrinogen, FDP, aPTT, INR and thrombocyte count before thrombolysis and at 2 and 24 hours. Results: Cerebral bleeding at 24 hours included 16 hemorrhagic infarcts (HI) and 7 parenchymal hematomas (PH). 1. Cerebral bleeding in general. Univariate analysis comparing patientswith HI+PH vs patients without bleeding detected 2 significant factors : severity at entry (p=0.03) and and increased values of FDP at 2 hours (p=0.05). Each early CT symptom and pooled early CT symptoms did not appear as factors of bleeding. Multivariate analysis showed that values of FDP>150mg/L multiplicate the odds of bleeding by 6.9, being then a more powerful factor than severity at entry. 2. Factors of seriousness of bleeding. FDP values>150 mg/L multiplicate the odds of parenchymal hematoma by 17. Comparison of patients with PH and HI only showed one potential factor, the lack of hypercholesterolemia (p=0.06). Interestingly, age, delay, severity at entry, early CT signs of ischemia were not factors of parenchymal invasion. Heparin in the fist 24 hours was a potential factor, but not reaching statistical significance. In a logistic regression model, the lack of hypercholesterolemia multiplicates the risk of PH by 10. Conclusion : The ”making“ of a parenchymal hematoma involves at least 2 phases : (1) an early ”acquired coagulopathy“ characterized by increased FDP values at 2 hours (ie a particularly intense thrombolysis); and (2) an increased vulnerability of the arteriolar wall, possibly related to the lipid content of the vessels. The observation of the ”coagulopathy“ should contraindicate any antithrombotic drug during the first 24 hours and imply a surveyance of haemostasis and cerebral bleeding with T2* gradient-Echo MRI during the following days.