IDENTIFYING RISK FACTORS FOR HAEMORRHAGIC TRANSFORMATION AFTER EVT IN ACUTE ISCHEMIC STROKE

Background. Haemorrhagic transformation (HT) is a frequent complication following endovascular thrombectomy
(EVT) in acute ischemic stroke patients and can lead to
worsened clinical outcomes, increased disability, and higher
mortality.
Aim. To identify clinical, imaging, and procedural predictors of HT in successfully recanalised ischemic stroke patients.
Methods. 471 (mean age 71.62 ± 11.64 y, 47% male)
ischemic stroke patients treated with EVT at Pauls Stradiòð
CUH Stroke Centre, Rîga, from 2015 to 2024 were selected
based on successful TICI scores (2b and 3). Presence of HT
was assessed on control CT scans performed 24 h after the
treatment. HT was identified in 120 patients (25%).
Results. Sixteen potential predictors of HT in successfully
recanalised patients, including demographic, procedural, patient-specific, and comorbidity-related variables were suggested: time-to-needle, wake-up stroke, admission NIHSS,
EVT duration, number of EVT passes, use of bridging
thrombolysis, anaesthesia method, stroke aetiology, CTA
collateral status, platelet count, age, sex, as well as hypertension, diabetes, AFib and smoking history.
Six predictors were statistically significant in univariate
analysis:
• Time-to-needle: 280.22 ± 143.51 vs 304.03 ± 148.80 min
(p = 0.047, Mann–Whitney)
• Admission NIHSS: 14.72 ± 5.73 vs 16.27 ± 4.44 (p =
0.002, Mann-Whitney)
• EVT procedure duration: 38.85 ± 24.41 vs 47.69 ± 28.82
min (p = 0.002, Mann–Whitney)
• Number of EVT passes: 1 vs 3 (p < 0.001, Mann–Whitney)
• Sex: Males (n = 227) had HT in 31% of cases, while females (n = 244) had HT in 20% of cases (p = 0.01,
Chi-square)
• CTA collateral status: HT occurred in 15% of patients
with good (n = 163), 27% with poor (n = 222), and 48%
with malignant collaterals (n = 52) (p < 0.001, Kruskal–
Wallis).Proc. Latvian Acad. Sci., Section B, Vol. 79 (2025), No. 1/2. 109
Multivariate logistic regression model identified the most
significant predictors (Acc 76.8%, Se 17.1%, Sp 95.8%,
AUC: 0.713, 95% CI: 0.651–0.775, p < 0.001; HosmerLemeshow: p = 0.494; Nagelkerke R² = 0.15):
• CTA collateral status (p = 0.003):
• Poor vs. good: OR = 4.99 (95% CI: 1.98–12.55, p <
0.001)
• Malignant vs. good: OR = 2.39 (95% CI: 1.19–4.80, p =
0.015)
• Number of EVT passes (p = 0.025):
• 3 vs. 1–2: OR = 2.08 (95% CI: 1.10–3.95, p < 0.001)
Conclusion. HT remains a significant complication following successful EVT. Our analysis confirms that poor and
malignant collaterals significantly increase the risk of HT,
while multiple EVT passes further contribute to its occurrence. Recognising these risk factors is essential for optimising patient selection, refining procedural strategies, and
improving post-thrombectomy management.
We express our gratitude to the medical staff at Pauls
Stradiòð CUH Stroke Centre and Department of Radiology
for their invaluable support in patient care, data collection
and assistance in imaging analysis.