Usefulness of dobutamine radionuclide ventriculography for prediction of left ventricular function improvement after coronary artery bypass grafting for ischemic cardiomyopathy

Ventricular function may improve after coronary artery bypass grafting (CAB G) in patients with ischemic cardiomyopathy depending on the amount of cont ractile myocardial reserve, Based on the studies using dobutamine echocardi ography to predict regional wall improvement after revascularization, we in vestigated the benefit of low-dose dobutamine radionuclide ventriculography for assessing functional contractile reserve in this population. The study group included 56 patients with ischemic cardiomyopathy (mean left ventric ular [LV] ejection fraction [EF] of 23 +/- 5%) and multivessel disease, who were referred for viability assessment. All underwent radionuclide ventric ulography before and during infusion of 5 and 10 mu g/kg/min of dobutamine, An increase in global LVEF from rest to dobutamine wets calculated, and 10 % was considered the cutoff value to predict ventricular improvement alter CABG. Of the 35 patients who underwent CABG 1 month later, 29 were availabl e for repeated radionuclide ventriculography after 12 +/- 5 months. Of thes e, 15 showed improvement (Delta LVEF greater than or equal to 5%, mean 10 /- 5%) and 14 did not (Delta LVEF <5%, mean -1 +/- 3%), The increase in EF with dobutamine had the highest univariate predictive value of all paramete rs evaluated. The sensitivity, specificity, and positive and negative predi ctive values of dobutamine radionuclide ventriculography were 67%, 93%, 91% , and 72%, respectively. We conclude that dobutamine radionuclide ventricul ography is a useful method to assess contractile reserve and predict ventri cular functional improvement alter CABG in patients with ischemic cardiomyo pathy, (C)1999 by Excerpta Medica, Inc.