Association between Venous Transit and Functional Outcomes Post Thrombectomy in Patients with Acute Basilar Artery Occlusion

Prolonged venous transit (PVT) is an imaging marker that assesses venous outflow on perfusion imaging time to maximum (T_max) maps. PVT presence (PVT+) is associated with 90-day mortality and poor functional recovery in patients with anterior circulation acute ischemic stroke caused by large vessel occlusion who underwent endovascular thrombectomy (EVT). PVT absence (PVT-) correlates with excellent outcomes. We determined the association between PVT and functional outcomes post EVT in patients with acute basilar artery occlusion (BAO).

In this retrospective study, we included patients from 9 academic medical centers. We selected patients who had prethrombectomy CT or MR perfusion imaging and assessment of 90-day mRS. PVT+ in the posterior circulation was defined as a T_max ≥10 seconds delay in the torcula, left transverse sinus, and/or right transverse sinus. PVT- was defined as the absence of this marker. The primary outcome was excellent functional outcome at 90 days as defined by an mRS 0-1.

Ninety-seven patients with acute BAO were scored for PVT. Fifty-eight patients (60%) had PVT+ and 39 (40%) had PVT-. PVT- patients were younger (median age 60 years [interquartile range {IQR} 50-70] versus 68 years [IQR 62-79] in PVT+; P = .01), more likely to present with a wake-up stroke (44% versus 16% in PVT+; P = .04), and more likely to have excellent functional outcomes (44% versus 22% in PVT+; P = .03). In an adjusted multivariable regression analysis, lower presentation NIHSS was associated with excellent functional outcomes (OR: 0.89; 95% CI, 0.82-0.96; P = .002). There was also a significant interaction between age and PVT, whereas older patients with PVT+ experienced worse outcomes (P = .04).

In patients with acute BAO who underwent EVT, lower presentation NIHSS was associated with excellent 90-day functional outcomes, and PVT+ was associated with worse outcomes in older patients.