The association between the extent and degree of perfusion–metabolism mismatch and improvement in perfusion and left ventricular ejection fraction (LVEF) after revascularization was assessed. The secondary aim was to identify the best precoronary artery bypass graft surgery (pre-CABG) PET parameter, if any, to predict the improvement in the perfusion and LVEF after CABG.
Methods and results
Overal, 31 patients (mean age: 58+8.3 years) with ischemic left ventricle dysfunction underwent NH3 and 18F-FDG PET for the assessment of myocardial viability. CABG was performed in these patients and after a mean interval of 3 months, NH3 PET was repeated. The percentages of viable myocardium (VM), hibernating myocardium, degree of mismatch, and LVEF in pre-CABG PET were calculated. These were compared, the median [INCREMENT]LVEF and percent increase in perfusion being 5 (interquartile range: 3–9) and 78.7 (interquartile range: 51.3–100), respectively. No significant association was observed between the severity or extent of perfusion defect/mismatch and improvement in perfusion or LVEF after CABG. Patients with at least 65% VM predicted a 5-unit increase in LVEF at 88.9% sensitivity (P=0.1).
There was no significant relation between the severity and extent of perfusion–metabolism mismatch with improvement in perfusion and LVEF after CABG. After CABG for ischemic left ventricle dysfunction, VM shows a tendency toward better improvement in LVEF.