Validation of four different risk stratification systems in patients undergoing off-pump coronary artery bypass surgery: a UK multicentre analysis of 2223 patients

• Published in: Heart (British Cardiac Society) Vol. 89; no. 4; pp. 432 - 435
• Main Authors: Al-Ruzzeh, S, Asimakopoulos, G, Ambler, G, Omar, R, Hasan, R, Fabri, B, El-Gamel, A, DeSouza, A, Zamvar, V, Griffin, S, Keenan, D, Trivedi, U, Pullan, M, Cale, A, Cowen, M, Taylor, K, Amrani, M
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Cardiovascular Society 01.04.2003; BMJ; BMJ Publishing Group Ltd; BMJ Publishing Group LTD; Copyright 2003 by Heart
• Subjects: ACC/AHA; American College of Cardiology/American Heart Association; Biological and medical sciences; CABG; Calibration; Cardiology; Colleges & universities; Coronary artery bypass; Coronary Artery Bypass - methods; Coronary Artery Bypass - mortality; coronary artery bypass graft surgery; Coronary Disease - mortality; Coronary Disease - surgery; Coronary vessels; Data collection; Evaluation; Female; Heart; Heart attacks; Heart surgery; Hospitals; Humans; Interventional Cardiology and Surgery; Male; Medical sciences; Methods; Middle Aged; Mortality; off-pump coronary artery bypass surgery; OPCAB; Physicians; Prospective Studies; receiver operating characteristic curve; Risk Assessment - methods; Risk Factors; Risk factors (Health); risk stratification; ROC; ROC Curve; SCTS; Sensitivity and Specificity; Society of Cardiothoracic Surgeons of Great Britain and Ireland; Statistical analysis; Statistics; Surgery; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Surgical outcomes; United Kingdom - epidemiology; Veins & arteries; United Kingdom; Europe; United Kingdom > UK; Ireland; Cardiopulmonary bypass; Human; Prognosis; Treatment; Aortocoronary; Bypass; Surgery; Risk analysis
• ISSN: 1355-6037; 1468-201X
• DOI: 10.1136/heart.89.4.432

Background: Various risk stratification systems have been developed in coronary artery bypass graft surgery (CABG), based mainly on patients undergoing procedures with cardiopulmonary bypass. Objective: To assess the validity and applicability of the Parsonnet score, the EuroSCORE, the American College of Cardiology/American Heart Association (ACC/AHA) system, and the UK CABG Bayes model in patients undergoing off-pump coronary artery bypass surgery (OPCAB) in the UK. Methods: Data on 2223 patients who underwent OPCAB in eight cardiac surgical centres were collected. Predicted mortality risk scores were calculated using the four systems and compared with observed mortality. Calibration was assessed by the Hosmer–Lemeshow (HL) test. Discrimination was assessed using the receiver operating characteristic (ROC) curve area. Results: 30 of 2223 patients (1.3%) died in hospital. For the Parsonnet score the HL test was significant (p < 0.001) and the receiver operating characteristic curve (ROC) area was 0.74. For the EuroSCORE the HL test was also significant (p = 0.008) and the ROC area was 0.75. For the ACC/AHA system the HL test was non-significant (p = 0.7) and the ROC area was 0.75. For the UK CABG Bayes model the HL test was also non-significant (p = 0.3) and the ROC area was 0.81. Conclusions: The UK CABG Bayes model is reasonably well calibrated and provides good discrimination when applied to OPCAB patients in the UK. Among the other three systems, the ACC/AHA system is well calibrated but its discrimination power was less than for the UK CABG Bayes model. These data suggest that the UK CABG Bayes model could be an appropriate risk stratification system to use for patients undergoing OPCAB in the UK.