Time to return of spontaneous circulation and associations with early neurological outcome at hospital discharge after out-of-hospital cardiac arrest

Clinical Research in Cardiology https://doi.org/10.1007/s00392-026-02940-4 ORIGINAL PAPER Time to return of spontaneous circulation and associations with early neurological outcome at hospital discharge after out‑of‑hospital cardiac arrest Ulrik Rose1 · Marie Wulf1,2 · Morten Steen Kvistholm Jensen1,2 · Emma Riis Meyer1 · John Bro‑Jeppesen1,2 Received: 26 January 2026 / Accepted: 6 May 2026 © The Author(s) 2026 Abstract Aim To assess the impact of time to return of spontaneous circulation (ROSC) on early in-hospital neurological function and long-term survival in survivors after out-of-hospital cardiac arrest (OHCA). Methods This retrospective cohort study included survivors of OHCA admitted to the cardiology ward at Aarhus University Hospital. Patients were included from June 2020 to February 2024 and data were collected through review of medical records. Primary outcome was neurological function, and patients were stratified by modified Rankin Scale (mRS) at hospital discharge: good neurological outcome (mRS 0–2) and poor neurological outcome (mRS 3–6). Secondary outcomes were cognitive function assessed with Montreal Cognitive Assessment (MoCA) at hospital discharge and 180-day survival. Results In total, 321 patients were included, of which 232 (72%) had good neurological outcome and 89 (28%) had poor neurological outcome. Every 5-min increase in time to ROSC was associated with decreased odds of good neurological outcome (OR 0.88, 95% CI 0.81–0.95, p < 0.0001). This association remained significant after adjusting for age and primary rhythm (ORadjusted 0.86, 95% CI 0.78–0.95, p = 0.004). Patients with good neurological outcome had significantly higher MoCA scores (median 23 vs. 18, p < 0.001). In-hospital mortality was 6% and time to ROSC was not significantly associated with 180-day mortality. Conclusion In initial OHCA survivors transferred to the cardiology ward, increased time to ROSC was independently associated with decreased odds of good neurological function at hospital discharge, even after adjusting for age and primary rhythm. The majority of patients had good neurological function at hospital discharge. In this population time to ROSC was not associated with mortality. Ulrik Rose and Marie Wulf contributed equally to this work and share first authorship. * John Bro‑Jeppesen Marie Wulf 1 Department of Cardiology, Aarhus University Hospital, Palle Juul‑Jensens Boulevard 99, 8200 Aarhus N Aarhus, Denmark 2 Department of Clinical Medicine, Aarhus University, Aarhus, Denmark Vol.:(0123456789) Clinical Research in Cardiology Graphical Abstract Figure created by the authors using Microsoft PowerPoint. Keywords Out-of-hospital cardiac arrest · Neurological function · Outcome · Cardiopulmonary resuscitation · MRS · MoCA · ROSC · Neurological recovery Introduction In 2023, the incidence of out-of-hospital cardiac arrest (OHCA) in Denmark was approximately 4,500 cases, corresponding to 78 cases of OHCA per 100,000 inhabitants [1]. Improved management of OHCA and growing public awareness has contributed to a four-fold increase in 30-day survival rate reaching 14.4%, compared to two decades before [1]. As survival rates improve, there is an emergent need for a better understanding of the neurological outcome among OHCA survivors. Neurological impairment is among the most common complications following OHCA [2] and one of the most critical factors influencing neurological outcome is the duration of global cerebral ischemia, closely related to time to return of spontaneous circulation (ROSC) [3, 4]. Despite its central role in pathophysiology, the association between time to ROSC and early in-hospital neurological function remains inadequately explored. Several OHCA studies have reported neurological status on survivors [5] but only a limited number have specifically examined its association with the duration of time to ROSC and neurological function during hospital admission and at hospital discharge. A systematic review [6] suggests that shorter time to ROSC is associated with better neurological outcomes at discharge, but findings are inconsistent and largely based on small or single-center cohorts. Consequently, more evidence is needed to clarify how the duration of time to ROSC impacts early neurological recovery. This study aims to investigate the association between time to ROSC and temporal changes in early neurological function assessed at cardiology ward admission and hospital discharge in survivors after OHCA. Materials and methods Study area and population This study cohort consists of adult patients, aged ≥ 18 years, admitted to Department of Cardiology, Aarhus University Clinical Research in Cardiology Hospital (AUH) after successful or ongoing resuscitation for OHCA with a presumed cardiac cause in the period between May 2020 and February 2024. In this study, patients were defined as initial OHCA survivors, if surviving to admission to the cardiology ward. Patients were included at the time of transfer from the ICU or coronary care unit to the cardiology ward. The cardiology ward functions as a monitored stepdown unit where patients are hemodynamically stable and no longer require invasive ventilation or continuous vasoactive support. Patients who had in-hospital cardiac arrest, died during transportation, in the ICU or during initial treatment in the coronary care unit were excluded. Department of Cardiology, AUH is a tertiary referral center for cardiology and receives OHCA patients with unknown or presumed cardiac cause of cardiac arrest from the central region of Denmark with a population of 1.373.799 people [7]. Facilities such as transvenous pacing, coronary interventions, extracorporeal membrane oxygenation, right and left ventricular assist devices and targeted temperature management (TTM) were available 24/7 as part of a high-volume cardiac arrest center. Post-cardiac arrest care followed contemporary guidelines in regard to intensive care monitoring including TTM where the strategy changed on august 1 st 2022 to maintain normothermia. Acute coronary angiography was performed in all patients with ST-elevation in primary electrocardiogram or hemodynamic unstable, whereas a delayed coronary strategy was applied in other patients. Patients were typically transferred directly to the cardiology ward after stabilization or after completion of the post-resuscitation care in the ICU. Data collection This study is a retrospective cohort study with patients transferred to the cardiology ward from coronary unit or intensive care unit (ICU) at AUH after initial care of OHCA. Patient data were prospectively included in an observational registry as part of a clinical quality project. The registry was approved by department and hospital administrations with a waiver of informed consent according to Danish legislation and aggregated data can be reported without further approvals by hospital staff. The retrospective data were obtained (...truncated)