Prognostication of neurological outcome after cardiac arrest using wavelet phase coherence analysis of cerebral oxygen

The prognosis for cardiac arrest (CA) is associated with the degree of cerebral ischemia. We investigated the relationship between the wavelet coherence of cerebral oxyhemoglobin (HbO2) among different channels and outcomes after CA. Moreover, we aimed to develop a prognostication method after CA. Eighty-three post-resuscitation patients were included. The HbO2 data were collected during the post-resuscitation period (median day, 1) using functional near-infrared spectroscopy. The coherence between sections of prefrontal HbO2 oscillations in five frequency intervals (I, 0.6–2 Hz; II, 0.15–0.6 Hz; III, 0.05–0.15 Hz; IV, 0.02–0.05 Hz; and V, 0.0095–0.02 Hz) were analyzed. We evaluated the outcomes using cerebral performance category (CPC) scores (good outcome, CPC ≤ 2 and poor outcome, CPC ≥ 3) at 3 months after CA. Additionally, the predictive method was developed using the biomarker and coherence value after CA. Among the included patients, 19 patients (22.9%) had a good outcome. Poor outcome group had significantly lower phase coherence in the myogenic frequency interval III compared to good outcome group (0.36 ± 0.14 vs. 0.54 ± 0.18, P