Abstract
Objective: To investigate the rate of hemorrhagic transformation (HT) during hospitalization and its impact on early prognosis (within 30 days) in patients with acute ischemic stroke (AIS). The study also aims to identify factors associated with HT in patients with AIS due to cerebral artery occlusion.
Subjects and methods: This was a cross-sectional descriptive study with longitudinal follow-up, including patients diagnosed with acute ischemic stroke treated at the Cardiology Institute, Bach Mai Hospital, from March 2023 to March 2024. Convenient sampling was used. All patients were recorded for clinical and subclinical characteristics, and HT was assessed by brain CT or MRI following standard protocols during hospitalization and at 30 days post-discharge. The data were used to analyze HT characteristics, 30-day outcomes, and use of antithrombotic agents for secondary stroke prevention.
Results: The rate of HT in the study population was 41 patients (24.1%). Types of HT were distributed as follows: HI1 (31.7%), HI2 (41.1%), PH1 (9.7%), PH2 (9.7%), and symptomatic intracerebral hemorrhage (sICH) in 2 patients (4.8%). A total of 75.6% of HT cases occurred within 24–48 hours after symptom onset; the remaining 24.4% occurred after 48 hours. A significantly higher proportion of patients with a history of hypertension (HTN) was observed in the HT group compared to the non-HT group (p = 0.025).
Several factors were found to increase the risk of HT after AIS:
- History of hypertension: 1.45 times higher risk (p < 0.05)
- Age > 70 years: 1.45 times higher risk (p < 0.05)
- Admission systolic blood pressure > 140 mmHg: 1.47 times higher risk (p < 0.05)
Other potential risk factors (although not statistically significant, p > 0.05) included:
- Thrombolysis (OR = 2.34)
- Mechanical thrombectomy (OR = 1.9)
- Admission NIHSS ≥ 6 (OR = 1.67)
- Large infarct size (≥2 lobes) (OR = 1.76)
The overall mortality rate in the cohort was 1%, attributed to symptomatic HT. There was no significant difference in hospital stay duration, disability (Rankin score, Barthel Index), or major adverse cardiovascular events (MACE: death, readmission, recurrent stroke, myocardial infarction) between HT and non-HT groups at 30-day follow-up.
A total of 108 patients (64%) received antithrombotic therapy for secondary stroke prevention. Antithrombotic use was significantly higher in the non-HT group compared to the HT group (78% vs. 23%, p < 0.05). When comparing non-HT and symptomatic HT groups:
- Antiplatelet use was higher in the non-HT group (55% vs. 15%, p < 0.05)
- Dual antiplatelet therapy was significantly more common (100% vs. 0%, p < 0.05)
Among 27 patients receiving oral anticoagulants, 67% were on vitamin K antagonists, and 33% on NOACs. The HT group had a higher rate of anticoagulant use, but the difference was not statistically significant (p > 0.05).
Conclusion: Hemorrhagic transformation after acute ischemic stroke is a common complication in clinical practice. Patients with symptomatic HT tend to have worse clinical outcomes. The use of antithrombotic agents after AIS remains a clinical challenge, requiring further research and clinical trials to evaluate the safety and efficacy of different antithrombotic strategies in this patient population.