Hypoperfusion intensity ratio and hemorrhagic transformation in patients with successful recanalization after thrombectomy

ABSTRACT

BACKGROUND AND PURPOSE:

Hemorrhagic transformation remains a potentially devastating complication of acute ischemic stroke. We aimed to evaluate whether the hypoperfusion intensity ratio (HIR), a parameter derived from CT perfusion imaging, is associated with the development of hemorrhagic transformation in patients with anterior large-artery occlusion who had undergone thrombectomy.

MATERIALS AND METHODS:

We retrospectively reviewed data from consecutive acute ischemic stroke patients who had achieved successful recanalization (thrombolysis in cerebral infarction score ≥ 2b) between January 2020 and December 2023. HIR was defined as the ratio of the volume of lesions with a time-to-maximum (TMax) > 6 s to those with a Tmax > 10 s delay. The primary outcome, based on the European Cooperative Acute Stroke Study, was hemorrhagic transformation (HT), diagnosed by follow-up imaging assessment in 24 h windows, and radiologically classified as hemorrhagic infarction (HI) and parenchymal hematoma (PH). The secondary outcome was a 3-month mRS score of ≥3.

RESULTS:

Among 168 patients, 35/168 developed hemorrhagic transformation HT; 14/168 developed hemorrhagic infarction HI, and 21/168 developed parenchymal hematoma PH. After adjusting the latent covariates, increased hypoperfusion intensity ratio (per 0.1, adjusted OR [aOR] 1.68, 95% CI 1.26–2.25), ASPECTS (aOR 0.44, 95% CI 0.27–0.72), onset-to-puncture (aOR 1.01, 95% CI 1.00–1.02), and cardioembolism (aOR 5.6, 95% CI 1.59–19.7) were associated with hemorrhagic transformation in multivariable regression. The receiver operating characteristic curve indicated that HIR can predict HT accurately (area under the curve = 0.81; 95% CI, 0.738–0.882; P < 0.001) and predict PH (area under the curve = 0.801; 95% CI, 0.727–0.875; P < 0.001).

CONCLUSIONS:

Upon admission, hypoperfusion intensity ratio, an imaging parameter, predicted hemorrhagic transformation after reperfusion therapy in this patient population. ABBREVIATIONS: HT = hemorrhagic transformation; HIR = hypoperfusion intensity ratio; LVO = left vessel occlusion; EVT = endovascular thrombectomy; AIS = arterial ischemic stroke; OTP = onset-to-puncture; HI = hemorrhagic infarction; PH = parenchymal hematoma