Cardiac surgical patients are not the same. But who knows that: the patient, the cardiologist or the surgeon?

Nowadays, outcome measures get published following risk adjustment; mortality rates are adjusted for risks to give a picture of the performance of a surgeon or a unit. The risk factors associated with in-hospital death are likely to reflect concurrent disease-specific variables. Factors associated with increased resource utilisation (as measured by length of stay) reflect serious co-morbid illness. The various models are effective at predicting population behaviour, but not necessarily suited for predicting individual outcomes. Further work needs to be done both to explain the differences in risk factors seen between the various risk stratification models and to determine which models are best suited in clinical practice. This document reviews the current evidence and risk stratification tools currently employed in cardiac surgery practice.