Comparison and Validation of Diagnostic Criteria of Malignant Middle Cerebral Artery Infarction

Objectives Malignant middle cerebral artery infarction (mMCAi) is a critical condition. Decompressive hemicraniectomy (DHC) improves survival after mMCAi, but its surgical indications vary across studies. We aimed to compare and validate diagnostic criteria of mMCAi. Methods In this prospective cohort study, we recruited patients with acute ischemic stroke in the MCA territory. Based on eight diagnostic criteria of mMCAi reported in randomized trials of DHC, we examined their agreement in diagnosing mMCAi by these criteria and explored their prognostic value on 3‐month death. In patients meeting any of these criteria, we investigated the association of DHC with functional outcomes (assessed by modified Rankin scale, mRS). We proposed an operational definition of mMCAi. Results We included 1290 patients with MCA infarction (mean age 68.2 years, 58.2% men), with an incidence of mMCAi ranging from 4.4% to 20.9%. All criteria but HeADDFIRST reached substantial to almost perfect agreement with each other in diagnosing mMCAi (Cohen′s kappa ranging from 0.64 to 0.92). Three‐month death rates of patients with mMCAi ranged from 42.3% to 73.2%, with hazard ratios of death ranging from 3.79 to 5.65. DHC improved the overall distribution of mRS scores and reduced the risk of death at 3 months in patients who met any criteria of DESTINY, HAMLET, DESTINY II, or HeADDFIRST. Patients who met either HAMLET or DESTINY II criteria had comparable incidence (around 12%, Cohen′s kappa 0.92) and 3‐month case fatality (around 60%). Based on these two criteria, we proposed an operational definition for mMCAi, which identified 14.0% of patients with mMCAi who benefited from DHC on reducing 3‐month death (OR 0.35, 95% CI 0.12–0.97) and improving mRS distribution (common OR 2.62, 95% CI 1.02–6.71). Conclusion Patients with MCA infarction who met HAMLET or DESTINY II criteria had a relatively high incidence and case fatality, and both benefited from DHC. Trial Registration: ClinicalTrials.gov identifier: NCT03222024