Ref : Tu JV et al. Multicenter validation of a risk index for mortality, intensive care unit stay, and overall hospital length of stay after cardiac surgery. Circulation. 1995;91:677-84
Urgency of Surgery
Urgent : surgery required within the same hospital admission (eg, unstable angina stabilized with maximal medical therapy).Emergency : any surgery that is required within 24 hours at the time of referral (eg, postcatheterization "crash", unstable angina with hemodynamic instability).
Ejection Fraction :
Assessed by angiography or echocardiography.
Type of Surgery
Complex = multivalve or valve plus CABG.