Impact of early exercise radionuclide cineangiography on long-term prognosis after CABG

Background. The immediate benefits of coronary artery bypass grafting might be only transient. This prospective study examined the capability of exercise radionuclide cineangiography done shortly after coronary artery bypass grafting to predict outcome and long-term prognosis. Methods. Results of exercise radionuclide cineangiography at 5.5 ± 0.7 months (range, 4 to 8 months) postoperatively were correlated with mortality, major surgical and nonsurgical cardiac events, and cardiac event-free survival in 100 consecutive patients who underwent coronary artery bypass grafting. Stepwise logistic regression analysis was used to evaluate the incremental value of radionuclide cineangiography beyond the commonly used variables. Results. Left ventricular ejection fraction at rest was normal (≤0.45) in 72 patients and increased on exercise in 58. The exercise radionuclide variables that correlated with future cardiac events were change and fractional change in heart rate, ST segment changes, anginal pain and congestive heart symptoms during exercise, rest ejection fraction, and change and fractional changes in ejection fraction. Predictors of event- free survival were exercise heart rate, rest ejection fraction, and change and fractional change in ejection fraction during exercise. Logistic regression analysis revealed that change in ejection fraction was an independent predictor of cardiac death and surgical interventions, whereas resting ejection fraction was a predictor of nonsurgical cardiac events. Conclusions. Postoperative exercise radionuclide cineangiography carried out soon after coronary artery by-pass grafting had definite independent prognostic value and should be performed routinely to help decide treatment protocol.