RELATION OF REGIONAL FUNCTION, PERFUSION, AND METABOLISM IN PATIENTS WITH ADVANCED CORONARY-ARTERY DISEASE UNDERGOING SURGICAL REVASCULARIZATION

Background Imaging of myocardial glucose metabolism using [F-18]fluoro deoxyglucose (FDG) with positron emission tomography (PET) has been pr oposed for identification of tissue viability in patients with advance d coronary artery disease. This study was designed to evaluate the pre dictive value of flow and metabolic imaging for functional recovery af ter revascularization in myocardial segments of varying degrees of dys function. Methods and Results Thirty-seven patients (mean age, 59+/-11 years) with coronary artery disease and impaired left ventricular fun ction (ejection fraction, 34+/-10%) were studied with PET using FDG an d [N-13]ammonia before surgical coronary revascularization (3+/-1 graf ts per patient). Tissue was scintigraphically characterized as normal, nonviable (concordant reduction of perfusion and FDG uptake), viable without discordance of perfusion and metabolism (mildly reduced perfus ion and metabolism), or ischemically compromised (mismatch of reduced perfusion and maintained FDG uptake). Functional outcome was assessed by serial radionuclide ventriculography before and at 13+/-13 weeks (m edian interval of 8 weeks) after coronary revascularization. Preoperat ively impaired regional wall motion improved significantly in ischemic ally compromised (mismatch) revascularized segments but not in nonviab le myocardium or in viable myocardium without discordance of perfusion and metabolism. The negative predictive value of PET for functional r ecovery was 86%, whereas the positive predictive value in revasculariz ed regions ranged from 48% to 86%, depending on severity of baseline w all motion abnormalities. Conclusions PET identifies metabolically act ive tissue, which benefits from revascularization. Although the negati ve predictive value of PET for recovery was high, functional improveme nt of viable but ischemically compromised tissue was less frequent tha n previously reported. The predictive value of PET was highest in left ventricular segments with severe dysfunction and a mismatch or reduce d perfusion but preserved metabolism. Integration of PET, angiographic , and functional data is necessary for the optimal selection of patien ts with advanced coronary artery disease and impaired left ventricular function for revascularization.