Abstract Funding Acknowledgements Type of funding sources: None. OnBehalf Netherlands Heart Registration Background It is important to gain more insight into cardiogenic shock (CS), as currently little is known on how to improve outcomes. The aim of this study was to assess the incidence, clinical outcome and predictors for mortality of CS in acute coronary syndrome (ACS) patients treated by percutaneous coronary intervention (PCI). Methods The Netherlands Heart Registration (NHR) is a nationwide registry on all cardiac interventions. We used NHR data of ACS patients treated with PCI between 2015 and 2019. CS was defined as shock present at admission. Cox regression analysis was used to calculate hazard ratios (HR) with 95% confidence intervals (CI). Results Among 75,407 ACS patients treated with PCI, 3,028 patients (4.1%) were identified with CS. The incidences of CS were respectively; 4.3%, 3.9%, 3.5% and 4.3% per year. Median follow-up duration was 9 months (IQR 0-26) for patients with CS and 22 months (IQR 12-36) for patients without CS. Thirty-day mortality was 36% for patient with CS and 3% for patients without CS (p < 0.001). Factors independently associated with mortality in CS were: age (HR 1.02, 95%CI 1.02-1.03), estimated glomerular filtration rate (eGFR) (HR 0.98, 95%CI 0.98-0.99), diabetes mellitus (DM) (HR 1.25, 95%CI 1.08-1.45), multivessel disease (HR 1.22, 95%CI 1.06-1.39), prior myocardial infarction (MI) (HR 1.24, 95%CI 1.06-1.45) and out-of-hospital cardiac arrest (OHCA) (HR 1.71, 95%CI 1.50-1.94) (Table 1). Conclusion In this Dutch nationwide registry-based study of ACS patients treated by PCI, the incidence of CS was 4.1% over the 4-year study period. Predictors for mortality in CS were higher age, renal insufficiency, presence of DM, multivessel disease, prior MI and OHCA. Multivariable Cox regression analysisHR95% CIp-valueAge (years)1.021.02-1.03<0.001MaleNSDiabetes mellitus1.251.08-1.45<0.01Multivessel disease1.221.06-1.39<0.01CTONSPrior ...