Abstract Background Mortality in cardiogenic shock (CS) remains very high. Several risk scores have been purposed to early stratification, although the CS aetiology could influence in this prediction. Purpose The aim is to investigate in-hospital prognosis and mortality risk in CS patients depending on the CS aetiology comparing the prognostic accuracy of CardShock and IABP scores in a Mediterranean cohort. Method Shock CAT study was a multicentre, prospective, observational study conducted between December 2018 and December 2019 in eight public University hospitals in Catalonia (Spain), including CS patients due to acute coronary syndrome (ACS) and other aetiologies. Data on clinical presentation, biomarkers, management, including mechanical assistance support were analyzed comparing ACS and non-ACS patients. Cardshock and IABP score have been compared to assess 90-days mortality risk in both groups. Results A total of 382 CS patients were included, mean age was 65.3 (SD 13.9) years and 75.1% were men. Patient were classified in ACS (n=232, 60.7%) and non-ACS (n=150, 39.3%). In ACS group, 77.6% were STEMI, reperfussion in 84.7% of cases, all with primary angioplasty, 9% developed mechanical complications and 19.4% primary ventricular fibrillation. Main non-ACS aetiologies were severe heart failure (36.2%), malignant arrhythmias (22.1%), valve disease (8.0%) and myocarditis (7.4%). ACS group had less prevalence of women (17.7% vs 36%, p=0.001) and previous myocardial infarction (13.9% vs 24.8%, p=0.007). Mechanical assistance device was implanted more in ACS patients (43.1% vs 16.7%, p<0.001, mainly intraaortic balloon pump (35.6% vs 9.8%, p<0.001) and ECMO (10.7% vs 3%, p=0.01). Both shock risk scores were higher in ACS patients, Cardshock (4.5 vs 4.0, p=0.006) and IABP (2.4 vs 1.9, p=0.005). In-hospital mortality was higher in ACS (37.1 vs 26.7%, p=0.035) although this difference loss the significance at 90-days (40.9 vs 31.8%, p=0.074) and 6-months (45.2 vs 35.8%, p=0.176). Receiver-operating characteristic curves demonstrated that IABP shock score had superior prognostic power for predicting 90-days mortality when compared with Cardshock score in ACS patients (area under the curve -AUC- 0.74 vs 0.66) respectively, p=0.047, although both scores were similar in non-ACS (AUC 0.64 vs 0.62, p=0.693), Figures 1–2. Conclusions Cardiogenic shock due to ACS had higher in-hospital mortality than non-ACS CS, although this difference decreased at 90 days and 6 months. IABP score provided better 90-days mortality risk prediction than CardShock score in ACS patients, but both scores are similar in non-ACS cardiogenic shock. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2