Prediction of early and delayed postoperative deaths after coronary artery bypass surgery alone in Italy. Multivariate predictions based on Cox and logistic models and a chart based on the accelerated failure time model.
BACKGROUND
The aim of the multicenter OP-RISK (OPerative RISK) study was to investigate the early (28 days) and delayed (365 days) death rates following coronary artery bypass grafting (CABG) among patients representing a nationwide distribution [Centers in Northern (2), Central (1) and Southern (1) Italy] and further to define the multivariate risk factors for the early and delayed mortality after CABG.


METHODS
Data were collected from 1126 patients undergoing CABG alone. Data were analyzed using Cox and logistic regression models, to accurately assess the major factors influencing survival over time after CABG. Having defined the significant factors, we constructed a chart of the absolute early risk of mortality using the accelerated failure time model.


RESULTS
Using the Cox proportional hazards model and logistic regression we have demonstrated that age, preoperative ejection fraction and heart rate, and the duration of aortic cross-clamping are multivariate risk factors in the short and long term. The role of one arterial conduit was also assessed.


CONCLUSIONS
The OP-RISK study produced relevant information for risk assessment and control in CABG and the results may form the basis for the objective quality assurance and accreditation of cardiac surgical institutions in Italy. Incidentally, Cox model appeared more adequate than logistic model for the assessment of the major factors influencing survival over time after CABG. The risk factors so assessed were used to construct a chart for practical predictive purposes.
Puddu
Paolo Emilio
PE
Department of Cardiac Surgery, La Sapienza University of Rome, Italy. puddu.pe@iol.it
Brancaccio
Gianluca
G
Leacche
Marzia
M
Monti
Francesco
F
Lanti
Mariapaola
M
Menotti
Alessandro
A
Gaudio
Carlo
C
Papalia
Ugo
U
Marino
Benedetto
B
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001026:Coronary Artery Bypass / Q000401:mortality*; D006339:Heart Rate; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008875:Middle Aged; D015233:Models, Statistical; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors