Mechanical thrombectomy in patients with acute ischemic stroke and ASPECTS ≤6: a meta-analysis

It is uncertain whether mechanical thrombectomy (MT) increases the probability of a good outcome (modified Rankin Scale (mRS) 0-2) in patients with Alberta Stroke Program Early CT Score (ASPECTS) 0-6.

To assess the impact of MT in patients with pretreatment ASPECTS 0-6.

According to PRISMA guidelines, we performed a systematic search of three databases for series of patients with ASPECTS 0-6 treated by MT. Random-effects meta-analysis was used to pool the following: rate of mRS 0-2 at 3 months follow-up, symptomatic intracranial hemorrhage (sICH), and mortality rates.

We included 17 studies and 1378 patients with ASPECTS 0-6 (1194 MT, 184 medical management). The rate of mRS 0-2 was 30.1% and 3.2% after MT and medical management, respectively. MT gave higher odds of mRS 0-2 (OR 4.76, p=0.01). Patients with ASPECTS 6 and 5 had comparable rates of good outcome (37.7% and 33.3%, respectively). Overall, the rate of mRS 0-2 was 17.1% in patients with ASPECTS 0-4: 22.1% and 13.9% of patients with ASPECTS 4 and 0-3 were functionally independent, respectively. Successful recanalization (Thrombolysis in Cerebral Infarction grade 2b-3) gave higher odds of mRS 0-2 than unsuccessful reperfusion (OR 5.2, p=0.001). The MT group tended to have lower odds of sICH compared with the controls (OR 0.48, p=0.06). Patients aged <70 years had higher rates of mRS 0-2 than those aged >70 years (40.3% vs 16.2%).

Patients with ASPECTS 0-6may benefit from MT. Successful reperfusion increases the probability of 3-month functional independence without increasing the risk of sICH. Patients with ASPECTS 5 and 6 have comparable outcomes. MT can still enable approximately one in four patients with ASPECTS 4 to be independent, whereas only 14% of subjects with ASPECTS 0-3 regain a good functional outcome.