Abstract Background Mechanical cardiopulmonary resuscitation (mCPR) devices aim to improve outcomes after cardiac arrest by delivering consistent, high-quality chest compressions. The mechanisms underlying their clinical benefits remain unclear. Objectives To evaluate the association of mCPR with return of spontaneous circulation (ROSC) and survival to hospital discharge, and to explore the mediating role of CPR quality indicators. Methods In this multicenter retrospective study, adult cardiac arrest patients receiving mCPR or manual CPR between 2022 and 2024 were analyzed. Inverse probability of treatment weighting (IPTW) adjusted for confounding. Weighted logistic regression estimated adjusted odds ratios (aORs) for ROSC and survival. Causal mediation analysis assessed indirect effects via compression rate, compression depth, and no-flow time. Results Among 723 patients, mCPR was associated with increased odds of ROSC (aOR 2.46; 95% CI 1.50–4.03; p < 0.001) and survival (aOR 4.28; 95% CI 2.33–7.87; p < 0.001). Mediation analysis showed that improvements in CPR quality partially mediated these effects (all p < 0.001). Conclusions Mechanical CPR improves cardiac arrest outcomes partly by enhancing CPR process quality. These findings support wider implementation of mCPR devices and emphasize CPR quality as a key therapeutic target.
Qiao et al. (Wed,) studied this question.