Frequency and predictors of spontaneous hemorrhagic transformation in ischemic stroke and its association with prognosis.

Few prospective studies have examined the frequency, predictors and long-term outcomes of spontaneous hemorrhagic transformation (HT) in patients with ischemic stroke not receiving thrombolytic treatment. We prospectively enrolled a consecutive cohort of 407 patients with ischemic stroke who were admitted within one month of stroke onset. In patients who developed spontaneous HT, the area of the infarct and HT were examined by computed tomography (CT) or magnetic resonance imaging (MRI). Univariate analysis was used to correlate clinical characteristics with appearance of HT, then multivariate logistical regression was used to identify independent predictors of spontaneous HT and factors that predict 3-month prognosis of ischemic stroke. Spontaneous HT was observed in 50 patients (12.3 %), comprising 33 cases (66 %) of hemorrhagic infarction, 17 (34 %) of parenchymal hematoma, 32 (64 %) of non-symptomatic HT, and 18 (36 %) of symptomatic HT. In 40 % of HT cases, the condition was detected by CT or MRI within 4-7 days of symptom onset. Multivariate logistic regression identified atrial fibrillation (OR 4.88, 95 % CI 1.83-13.00, P = 0.002) and infarct area (OR 4.48, 95 % CI 1.85-10.85, P = 0.001) as independent predictors of HT in ischemic stroke. Multivariate analysis also found that spontaneous HT was not independently associated with a worse 3-month prognosis for ischemic stroke (OR 1.59, 95 % CI 0.38-6.69, P = 0.527). Spontaneous HT occurred in 12.3 % of our patients with ischemic stroke, and atrial fibrillation and large infarct area were independent predictors. Spontaneous HT was not an independent predictor of a worse 3-month prognosis for ischemic stroke.