Mortality prediction in adult cardiac surgery patients: comparison of two risk stratification models

W K Au1, M P Sun, K T Lam

  • 1Division of Cardiothoracic Surgery, The Grantham Hospital, Aberdeen, Hong Kong. auwkt@ha.org.hk

Insights

The EuroSCORE model demonstrated better accuracy than the Parsonnet model in predicting mortality for adult cardiac surgery patients in Hong Kong. This study suggests EuroSCORE can be a baseline for developing local risk prediction models.

Area of Science:

  • Cardiology
  • Thoracic Surgery
  • Health Services Research

Background:

  • Risk stratification is crucial for assessing cardiac surgical care quality.
  • EuroSCORE and Parsonnet are commonly used models for predicting mortality in cardiac surgery.
  • Local validation of these models is essential due to demographic and geographic variations.

Purpose of the Study:

  • To compare the predictive accuracy of the EuroSCORE and Parsonnet models in a Hong Kong adult cardiac surgery population.
  • To evaluate the performance of these risk models in quantifying mortality risk.
  • To assess the suitability of EuroSCORE as a baseline for a local risk model.

Main Methods:

  • Prospective study conducted at a regional hospital in Hong Kong from November 1999 to July 2005.
  • Inclusion of adult patients undergoing coronary artery bypass graft (CABG) and heart valve surgery.
  • Statistical analysis included observed vs. expected mortality, Hosmer-Lemeshow goodness-of-fit, and receiver operating characteristic (ROC) curves.

Main Results:

  • Observed mortality rates were 2.9% for CABG and 4.8% for valve surgery.
  • EuroSCORE predicted mortality rates of 4.0% (CABG) and 5.2% (valve), while Parsonnet predicted 5.9% (CABG) and 7.3% (valve).
  • EuroSCORE showed better calibration and discrimination than Parsonnet, with ROC areas of 0.76 (CABG) and 0.77 (valve) compared to Parsonnet's 0.74 (CABG) and 0.79 (valve).

Conclusions:

  • The EuroSCORE model performed well in predicting mortality for local adult cardiac surgery patients, demonstrating good calibration and discrimination.
  • Both models tended to overpredict mortality.
  • EuroSCORE serves as a valuable baseline for developing a region-specific risk prediction model for cardiac surgery in Hong Kong.
Abstract