An empirically based tool for analyzing mortality associated with congenital heart surgery

Area of Science:

• Cardiothoracic Surgery
• Pediatric Cardiology
• Health Services Research

Background:

• Congenital heart surgery outcomes analysis requires reliable risk estimation.
• Current risk systems are primarily based on subjective complexity or risk projections.
• An objective, empirically derived index is needed to assess in-hospital mortality risk.

Purpose of the Study:

• To develop an objective, empirically based index for estimating in-hospital mortality risk in congenital heart surgery.
• To create statistically derived risk categories for surgical procedures.
• To improve upon existing subjective risk assessment methods.

Main Methods:

• Utilized data from 77,294 operations from the EACTS and STS Congenital Heart Surgery Databases (2002-2007).
• Calculated procedure-specific mortality rates using a Bayesian model, assigning a numeric STS-EACTS score (0.1-5.0).
• Grouped procedures into 5 optimal risk categories and validated the model against existing methods (RACHS-1, Aristotle).

Main Results:

• Mortality rates varied from 0.3% to 29.8% across procedure types.
• The STS-EACTS score and categories showed good discrimination (C-indices 0.784 and 0.773) in validation.
• The STS-EACTS score demonstrated superior predictive accuracy compared to RACHS-1 and Aristotle scores, especially when including patient covariates.

Conclusions:

• The proposed STS-EACTS risk scores and categories offer high discrimination for predicting mortality.
• This objective system represents a significant improvement over existing consensus-based methods.
• These measures can facilitate objective comparison of mortality outcomes across institutions.