Abstract TMP90: The Harm Sign As A Trial Biomarker Of Reperfusion Injury: Frequency, Determinants, And Outcomes In EVT Patients With Successful Reperfusion

Introduction:With successful reperfusion (SR, mTICI 2b-3) now being achieved in the great preponderance of patients undergoing endovascular thrombectomy (EVT), prevention of blood-brain barrier disruption and reperfusion injury is an emerging therapeutic target. For trials of agents to reduce BBB injury, the hyperintense acute reperfusion marker (HARM) sign is a potentially useful physiologic biomarker. However, past studies of HARM have generally failed to disaggregate non-EVT patients, EVT patients without SR, and EVT patients with SR.Methods:In a prospectively maintained database, we analyzed consecutive patients with SR (mTICI 2b-3) after EVT for anterior circulation large vessel occlusion undergoing post-gadolinium MRI scans at 3-6h and 24h after thrombectomy.Results:Among 48 SR patients meeting study entry criteria, the HARM sign was present in 65%. Patients with HARM sign, compared to those without, did not differ in age or NIHSS, but were more often female (54% vs 10%), more often had history of hypertension (65% vs 47%), and had higher initial SBP (156 vs 144). Patients with HARM sign more often received IV TPA (39% vs 29%), had longer time from onset to achievement of SR (median 352 vs 264 mins), underwent more passes (2.5 vs 1.9), and less often had complete (mTICI 3) reperfusion (13% vs 41%). With regard to outcomes, HARM patients more often had radiologic hemorrhage (75% vs 24%), less often were ambulatory at discharge (23% vs 59%), had less functional independence (mRS 0-2) at 90d (33% vs 59%), and had higher in-hospital mortality (16% vs 0%).Conclusion:The HARM sign is present in two-thirds of EVT patients with successful reperfusion; is associated with higher blood pressure, IV lytic therapy, longer time to reperfusion, more procedure manipulations, and less than complete macro-reperfusion; and is strongly associated with hemorrhagic transformation and worse clinical outcomes. The HARM sign is a promising biomarker for use in trials of treatments to avert reperfusion injury.