QRS duration predicts outcomes in cardiac arrest survivors undergoing therapeutic hypothermia

Background: Whether the electrocardiography (ECG) serial changes predict outcomes in cardiac arrest survivors undergoing therapeutic hypothermia remains unclear. Methods and results: This retrospective observational study enrolled 366 adult nontraumatic cardiac arrest survivors who underwent therapeutic hypothermia in a tertiary transfer center during 2006–2018. The ECG at return of spontaneous circulation (ROSC), during hypothermia and after rewarming were analyzed. 295 cardiac arrest survivors were included. Compared with the survivors, the non-survivors had longer QRS durations at the ROSC (118.33 ± 32.47 ms vs 106.88 ± 29.78 ms, p < 0.001) and after rewarming (99.26 ± 25.07 ms vs 93.03 ± 19.09 ms, p = 0.008). The enrolled patients were classified into 4 groups based on QRS duration at the ROSC and after rewarming, namely (1) narrow–narrow (narrow QRS at ROSC and narrow QRS after rewarming, n = 156), (2) narrow–wide (n = 29), (3) wide–narrow (n = 87), and (4) wide–wide (n = 23) group. The wide–wide group had the worst survival rates [odds ratio (OR) = 0.141, p = 0.001], followed by the narrow–wide group (OR 0.223, p = 0.003) and the wide–narrow group (OR 0.389, p = 0.003). Conclusions: In cardiac arrest survivors given therapeutic hypothermia, QRS durations at the ROSC, after rewarming and their changes may predict survival to hospital discharge.