PREDICTION OF LONG-TERM SURVIVAL BY PREOPERATIVE EXERCISE TESTING IN PATIENTS WITH DEPRESSED EJECTION FRACTION UNDERGOING MYOCARDIAL REVASCULARIZATION

Ejection fraction is a major determinant of morbidity and mortality fo r patients with ischemic heart disease, Patients with an ejection frac tion of 0.40 or less are generally recognized as having a poorer progn osis than; those patients with an ejection fraction of 0.50 or better and remain a heterogeneous group, It would be useful if patients with a favorable surgical prognosis could be identified preoperatively, Fif ty-five patients who underwent coronary artery bypass grafting and had an ejection fraction less than 0.40 (mean of 0.23 +/- 0.07 standard d eviation) were studied by catheter measurement of pulmonary arterial p ressure and radionuclide left ventriculography, Heart rate, systemic b lood pressure, pulmonary artery pressures, cardiac output, and ejectio n fraction were measured, at rest, after nitroglycerin was given intra venously and with supine bicycle exercise, Forty-seven patients who ha d follow-up longer than 4 years were divided into two groups according to their life status (alive or dead) 4 years after operation, Measure d variables of exercise stress tests and clinical characteristics were entered into factor analysis to obtain a cardiac function factor scor e for predicting the life status after 4 years, The cardiac function f actor score was highly loaded by stroke index (rest, nitroglycerin), c ardiac index (exercise), systemic vascular resistance index (exercise) , and history of congestive heart failure, The cardiac function factor provided a predictive value superior to that of any individual variab le, By dividing the patients into two groups by cardiac function facto r score, the actuarial 5-year survival was 72% versus 17% for good and poor prognosis; groups, respectively (p < 0.0001). Preoperative exerc ise stress testing data integrated by factor analysis provide a predic tive tool for patients with a low ejection fraction.