Comparison of risk prediction models in infarct-related cardiogenic shock

Aims: Several prediction models have been developed to allow accurate risk assessment and provide better treatment guidance in patients with infarct-related cardiogenic shock (CS). However, comparative data between these models are still scarce. The objective of the study is to externally validate different risk prediction models in infarct-related CS and compare their predictive value in the early clinical course. Methods and results: The Simplified Acute Physiology Score (SAPS) II Score, the CardShock score, the IABP-SHOCK II score, and the Society for Cardiovascular Angiography and Intervention (SCAI) classification were each externally validated in a total of 1055 patients with infarct-related CS enrolled into the randomized CULPRIT-SHOCK trial or the corresponding registry. The primary outcome was 30-day all-cause mortality. Discriminative power was assessed by comparing the area under the curves (AUC) in case of continuous scores. In direct comparison of the continuous scores in a total of 161 patients, the IABP-SHOCK II score revealed best discrimination [area under the curve (AUC = 0.74)], followed by the CardShock score (AUC = 0.69) and the SAPS II score, giving only moderate discrimination (AUC = 0.63). All of the three scores revealed acceptable calibration by Hosmer-Lemeshow test. The SCAI classification as a categorical predictive model displayed good prognostic assessment for the highest risk group (Stage E) but showed poor discrimination between Stages C and D with respect to short-term-mortality. Conclusion: Based on the present findings, the IABP-SHOCK II score appears to be the most suitable of the examined models for immediate risk prediction in infarct-related CS. Prospective evaluation of the models, further modification, or even development of new scores might be necessary to reach higher levels of discrimination.