Main Organiser

Julius Centre University of Malaya

Co-organiser

Department of Social and Preventive Medicine, Faculty of Medicine, University of Malay

Supported by

University of Malaya

AUSSCORE II IN PREDICTING 30-DAY MORTALITY OF ISOLATED CABG PATIENTS

Author

Huq, Molla

Institution

Monash University

Abstract

Objectives: To update Australian pre-operative risk model (AusScore) and developing algorithm to identify high risk patients for 30-day mortality (died within 30 days of surgery) following isolated coronary artery bypass grafting (CABG) in Australia.

Methods: Data were collected from 20 Australian hospitals between 2001 and 2010. Logistic regression and bootstrapping were used to update AusScore risk model. The discrimination (ROC) and calibration (H-L p-value) of the model were evaluated using bootstrap 100-folds validation. Risk algorithm was derived to classify patients as low, moderate and high risk cohorts. A 30-day mortality risk prediction calculator was developed.

Results: From 2001 to 2010 21295 patients had isolated coronary artery bypass grafting (CABG) in 20 hospitals in Australia. The average age was 65±10.4 years and 77.8% were male. 11 variables including age, ejection fraction estimate, New York Heart Association (NYHA) class, pre-operative dialysis or GFR less than 60mL/min/1.732, urgency of procedures and previous cardiac surgery were identified as key risk factors. The discrimination and calibration of the model were very good (ROC: 0.081; H-L p-value: 0.393). The observed versus predicted 30-day mortality in the low, moderate and high risk groups were respectively 0.5% versus 0.6%, 1.7% versus 1.7% and 10.0% versus 9.4%.

Conclusion: The model (risk calculator) would be an important tool for cardiac surgeons for validating clinical decision for isolated CABG surgery and taking strategy to improve 30-day mortality. Also this would be a useful day-to-day tool for surgeons to inform patients and their families the associated risk of 30-day mortality after isolated CABG.