Cardiovascular Surgery Risk Assessment in the "Real World": ArgenSCORE Adjusted by Center

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Abstract

Background: The ArgenSCORE I was developed in 1999 on a population with 8% mortality. The ArgenSCORE II emerged after re calibrating the original model in 2007 on a validation population with 4% mortality. Using the CONAREC XVI registry, we evaluated the hypothesis that the ArgenSCORE II could better predict the risk of in-hospital mortality in centers with low mortality, whereas the ArgenSCORE I could better predict mortality in centers with high mortality.

Methods: A total of 2548 patients from 44 centers of the prospective and multicenter cardiac surgery CONAREC XVI registry, were
analyzed. Mean observed mortality (OM) and mean expected mortality (EM) were estimated applying both versions of the ArgenS
CORE. The OM/EM ratio was calculated in each center for both models and the Z test was used to evaluate significant differences.

Results: In-hospital mortality was 7.69% for the entire registry. In 75% of the centers (33/44) mortality was >6%. In centers with mortality <6%, the OM/EM ratio was close to 1 after applying the ArgenSCORE II, without significant differences. In centers with mortality > 6%, the ArgenSCORE II significantly underestimated the risk. On the contrary, when the ArgenSCORE I was applied in these centers, the OM/EM ratio was close to 1, without significant differences.

Conclusions: The recalibrated ArgenSCORE II is recommended in centers with mortality < 6%, while in those with mortality > 6% the original ArgenSCORE I has better performance.