Cardiopulmonary Resuscitation Without Aortic Valve Compression Increases the Chances of Return of Spontaneous Circulation in Out-of-Hospital Cardiac Arrest: A Prospective Observational Cohort Study

OBJECTIVES: Following current cardiopulmonary resuscitation (CPR) guidelines, which recommend chest compressions at "the center of the chest," similar to 50% of patients experiencing out-of-hospital cardiac arrest (OHCA) undergo aortic valve (AV) compression, obstructing blood flow. We used resuscitative transesophageal echocardiography (TEE) to elucidate the impact of uncompressed vs. compressed AV on outcomes of adult patients experiencing OHCA. DESIGN: Prospective observational cohort study. SETTING: Single center. PATIENTS: This study included adult OHCA patients undergoing resuscitative TEE in the emergency department. Patients were categorized into AV uncompressed or AV compressed groups based on TEE findings. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was sustained return of spontaneous circulation (ROSC). The secondary outcomes included end-tidal co2 (Etco2) during CPR, any ROSC, survival to ICU and hospital discharge, post-resuscitation withdrawal, and favorable neurologic outcomes at discharge. Additional analyses on intra-arrest arterial blood pressure (ABP) were also conducted. The sample size was pre-estimated at 37 patients/group. From October 2020 to January 2023, 76 patients were enrolled, 39 and 37 in the AV uncompressed and AV compressed groups, respectively. Intergroup baseline characteristics were similar. Compared with the AV compressed group, the AV uncompressed group had a higher probability of sustained ROSC (53.8% vs. 24.3%; adjusted odds ratio [aOR], 4.72; p = 0.010), any ROSC (56.4% vs. 32.4%; aOR, 3.30; p = 0.033), and survival to ICU (33.3% vs. 8.1%; aOR, 6.74; p = 0.010), and recorded higher initial diastolic ABP (33.4 vs. 11.5 mm Hg; p = 0.002) and a larger proportion achieving diastolic ABP greater than 20 mm Hg during CPR (93.8% vs. 33.3%; p < 0.001). The Et-co2, post-resuscitation withdrawal, and survival to discharge revealed no significant intergroup differences. No patients were discharged with favorable neurologic outcomes. Uncompressed AV seemed critical for sustained ROSC across all subgroups. CONCLUSIONS: Absence of AV compression during OHCA resuscitation is associated with an increased chance of ROSC and survival to ICU. However, its effect on long-term outcomes remains unclear.