Abstract
BACKGROUND: Killip-Kimball classification has been used for estimating death risk in patients suffering acute myocardial infarction (AMI). Killip-Kimball stage IV corresponds to cardiogenic shock. However, the Society for Cardiovascular Angiography and Interventions (SCAI) classification provides a more precise tool to classify patients according to shock severity. The aim of this study was to apply this classification to a cohort of Killip IV patients and to analyze the differences in death risk estimation between the two classifications. METHODS: A single-center retrospective cohort study of 100 consecutive patients hospitalized for "Killip IV AMI" between 2016 and 2023 was performed to reclassify patients according to SCAI stage. RESULTS: Distribution of patients according to SCAI stages was B=4%, C=53%, D=27%, E=16%. Thirty-day mortality increased progressively according to these stages (B=0%, C=11.88%, D=55.56%, E=87.50%; P<0.001). The exclusive use of Killip IV stage overestimated death risk compared to SCAI C (35% vs. 11.88%, P=0.002) and underestimated it compared to SCAI D and E stages (35% vs. 55.56% and 87.50%, P=0.03 and P<0.001, respectively). Age >69 years, creatinine >1.15 mg/dl and advanced SCAI stages (SCAI D and E) were independent predictors of 30-day mortality. Mechanical circulatory support use showed an almost significant benefit in advanced SCAI stages (D and E hazard ratio, 0.45; 95% confidence interval, 0.19-1.06; P=0.058). CONCLUSIONS: SCAI classification showed superior death risk estimation compared to Killip IV. Age, creatinine levels and advanced SCAI stages were independent predictors of 30-day mortality. Mechanical circulatory support could play a beneficial role in advanced SCAI stages.