Shockable rhythm as an independent prognostic factor in patients with non-ST elevation undergoing percutaneous coronary intervention after out-of-hospital cardiac arrest: a registry-based cohort study

BACKGROUND: Although the timing and indications for coronary angiography (CAG) after out-of-hospital cardiac arrest (OHCA) have been widely studied, the characteristics associated with favorable outcomes in patients with non-ST-elevation (non-STE) undergoing percutaneous coronary intervention (PCI) remain unclear. METHODS: This retrospective cohort study used a citywide, prospectively collected OHCA registry in Daegu, Korea (2018-2022), which included adult patients with non-STE after OHCA who underwent both CAG and PCI. Given the limited number of outcome events relative to the covariates, Firth's penalized logistic regression identified factors independently associated with survival to hospital discharge and favorable neurological outcomes (cerebral performance category 1-2). RESULTS: Of the 5,026 patients treated by Emergency Medical Services for OHCA, 371 underwent CAG; 258 (69.5%) had no ST elevation on the initial electrocardiogram, and 105 (40.7%) underwent PCI and formed the study cohort. Sixty-nine patients (65.7%) survived to discharge, and 55 (52.4%) had favorable neurological outcomes. Initial shockable rhythm (adjusted odds ratio [aOR], 5.38; 95% confidence interval [CI], 1.77-18.02), prehospital return of spontaneous circulation (ROSC) (aOR, 10.30; 95% CI, 3.62-33.06), and shorter scene time interval (aOR, 0.88 per minute; 95% CI, 0.79-0.98) were independently associated with survival. Initial shockable rhythm (aOR, 11.02; 95% CI, 3.39-43.00) and prehospital ROSC (aOR, 11.69; 95% CI, 3.69-45.03) were independently associated with favorable neurological outcomes. CONCLUSION: Among patients with non-STE after OHCA who underwent CAG and PCI, initial shockable rhythm and prehospital ROSC were independently associated with survival and neurological outcomes, whereas shorter scene time interval was independently associated with only survival. Because the cohort was restricted to patients who survived to undergo PCI, these findings reflect prognostic stratification within an already treated group and cannot infer the benefits of CAG or PCI. Therefore, prospective confirmation is warranted.