Prognostic Effects of Vasomotor Reactivity during Targeted Temperature Management in Post-Cardiac Arrest Patients: A Retrospective Observational Study

Abstract

Early and precise neurological prognostication without self-fulfilling prophecy is challenging in post-cardiac arrest syndrome (PCAS), particularly during the targeted temperature management (TTM) period. This study aimed to investigate the feasibility of vasomotor reactivity (VMR) using transcranial Doppler (TCD) to determine whether final outcomes of patients with comatose PCAS are predicted. This study included patients who had out-of-hospital cardiac arrest in a tertiary referral hospital over 4 years. The eligible criteria included age ≥18 years, successful return of spontaneous circulation, TTM application, and bedside TCD examination within 72 h. Baseline demographics and multimodal prognostic parameters, including imaging findings, electrophysiological studies, and TCD-VMR parameters, were assessed. The final outcome parameter was cerebral performance category scale (CPC) at 1 month. Potential determinants were compared between good (CPC 1-2) and poor (CPC 3-5) outcome groups. The good outcome group (n = 41) (vs. poor (n = 117)) showed a higher VMR value (54.4% ± 33.0% vs. 25.1% ± 35.8%, p < 0.001). The addition of VMR to conventional prognostic parameters significantly improved the prediction power of good outcomes. This study suggests that TCD-VMR is a useful tool at the bedside to evaluate outcomes of patients with comatose PCAS during the TTM.

Keywords: doppler; out-of-hospital cardiac arrest; prognosis; targeted temperature management; transcranial; ultrasonography; vasomotor reactivity.

Figure 1

Flow chart. CPC, cerebral performance category; DOA, death on arrival; ECMO, extracorporeal membrane oxygenation; OHCA, out-of-hospital cardiac arrest; ROSC, return of spontaneous circulation; TCD, transcranial Doppler; TTM, targeted temperature management.

Figure 2

Methods of vasomotor reactivity test using transcranial Doppler (TCD-VMR). (A) Temporary hemodynamic change during TCD-VMR test by breath-holding maneuver. (B) Representative cases of preserved or impaired vasomotor reactivity in patients with post-cardiac arrest syndrome.

Figure 3

Receiver operating characteristic curve compared by adding vasomotor reactivity parameters to the traditional imaging study. ASPECTS-b, bilateral Alberta stroke program early computed tomography score; GWR, gray-to-white matter ratio; VMR, vasomotor reactivity.