Prognostic Value of Resting and Submaximal Exercise Radionuclide Ventriculography After Acute Myocardial Infarction in High-Risk Patients With Single and Multivessel Disease PASCAL NICOD, MD, JAMES R. CORBETT, MD, BRIAN G. FIRTH, MD, DPhil, SAMUEL E. LEWIS, MD, ROBERT E. RUDE, MD, ROBERT HUXLEY, MD, and JAMES T. WILLERSON, MD In patients who survive the acute phase of myo- cardial infarction, those with multivessel coronary artery disease generally have a worse prognosis than those with single-vessel disease. However, some patients with slgnlflcant multlvessel stenoses have a good prognosis, whereas some with a slg- nificant single-vessel stenosis have a poor progno- sis. Thus, although definition of coronary anatomy may be helpful, it is a not a fail-safe prognosttcator. In this retrospective analysis, the association of abnormalities at rest and during submaximal exer- cise testing with radionuclide ventrlculography after acute myocardial infarction with major cardiac complications (death, recurrent infarction, severe angina or congestive heart failure) in the ensuing 6 months was assessed in patients with single and multivessel disease. Coronary angiography and submaximal exercise testing with radlonuclide ventriculography were performed within 3 months of each other in 42 patients. Eleven of the 16 pa- tients with single-vessel coronary stenosis had major cardiac complications. The subsequent course of these 16 patients was correctly predicted by left ventricular ejection fraction (LVEF) 10.40 in 6 patients, by LVEF <OS5 in 7 patients, by failure of LVEF to increase by 0.05 units in 13 patients, and by an increase in left ventrtcular end-systolic volume index (LVESVI) durlng exercise >5 % above baseline in 11 patients. Of the 26 patients with multlvessel coronary artery disease, 24 had major cardiac complications. The subsequent course of these 26 patients was correctly predicted in 13 by LVEF 50.40, in 20 by LVEF <0.55, in 25 by a failure of LVEF to increase by 0.05 units during exercise, and in 20 by an increase in LVESVI by >5 % during exercise. Thus, submaximal exercise testlng with radionuclide ventrlculography may provide valuable prognostic information concerning the occurrence of major cardiac events after myocardial infarction not only in patients with multlvessel dtsease, but also in those with single-vessel disease. Exercise-ln- duced abnormalities of left ventricular function may have greater prognostic importance than the de- llneatlon of coronary arterial anatomy or the as- sessment of residual left ventricular function at rest. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONML After the acute phase of myocardial infarction (M I), certain patients remain at risk of developing serious late complications. Recent attempts to identify those pa- tients at risk of late complications have utilized a variety of techniques: Some attempt to quantitate the amount of irreversibly damaged myocardium (for example, se- From the Departments of Internal Medicine (Cardiology Division) and Radiology (Nuclear Medicine Division), the University of Texas Health Science Center at Dallas and Parkland Memo&l Hospital, Dallas, Texas. This work was supported by lschemic SCOR Grant HL-17669 of the National Institutes of Health, Bethesda, Maryland and the Harry S. Moss Heart Fund, Dallas, Texas. Manuscript received January 91993; revised manuscript received April 11, 1983, accepted April 12, 1983. Address for reprints: Brian G. Firth, MD, DPhil, lschemic Heart Center, Room L5-134. University of Texas Health Science Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75235. rial creatine kinase determinations and imaging with technetium stannous pyrophosphate or thallium), whereas others assess residual myocardial function (radionuclide ventriculography or echocardiogra- phy).l-13 Still other techniques attempt to assess the amount of viable myocardium at risk of further damage. Specifically, submaximal exercise testing has been re- ported to be useful in the detection of patients at risk of developing further complications after infarction, and the simultaneous use of radionuclide techniques seems to improve both the sensitivity and specificity of exer- cise testing in detecting high-risk patients.1P22 Alter- natively, coronary angiography allows the recognition of patients with significant single or multivessel coro- nary arterial stenoses after MI; the presence of single- vessel disease is generally associated with a better