Impact of Baseline Collateral Status Assessed on Perfusion Scans on Patient Outcomes in Acute Ischemic Stroke: A Meta-analysis and Systematic Review
Divya Nayar1, Suryansh Bajaj1, Ajay Malhotra2
1University of Arkansas for Medical Sciences, 2Yale School of Medicine, New Haven, CT
Objective:

Ischemic stroke is one of the leading causes of global morbidity and healthcare burden.The aim of our study is to assess the impact of baseline collateral status assessed on perfusion imaging studies on patient outcomes.

Background:
Baseline collateral assessment plays a crucial role in the prognostication of patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO). Previous studies have had mixed results on whether it serves as a good prognostic marker. 
Design/Methods:
Original research articles published from 2015 to 2023 that met the following inclusion criteria were included: (a) patients with LVOAIS; (b) CTP and/or MRP were performed on arrival; (c) collateral status was assessed on CTP and/or MRP or CTA/MRA derived from the perfusion studies.
Results:
27 studies were included in the analysis having a total of 4,513 patients. The mean baseline NIHSS  ranged from 7.9 t o18.5 and the mean ASPECTS ranged from 7-10. A total of 18 studies including a total of 2,666 patients reported the data on functional independence at 3 months. Good collaterals were significantly correlated with functional independence (OR: 2.18, 95%CI: 1.71-2.78, p<0.01). 6 studies with a total of 491 patients reported the data on patient mortality. Good collaterals were significantly associated with a lower risk of patient mortality (OR: 0.49, 95%CI: 0.24-0.99, p=0.03). 13 studies with a total of 1,827 patients reported the data on successful recanalization. Good collaterals were significantly associated with a higher occurrence of successful recanalization (OR: 1.10, 95%CI: 1.00-1.21, p=0.025). 5 studies including a total of 363 patients reported the data on the incidence of sICH/HT occurring as a complication.
Conclusions:
Good baseline collateral status is associated with more than twofold higher likelihood of having good functional status at 90 days, a 50% lesser risk of having patient mortality and 10% higher likelihood of having successful recanalization.
10.1212/WNL.0000000000206669