We assessed the value of positron emission tomography to predict long-term outcome in patients with diabetes and ischemic left ventricular (LV) dysfunction. Circumferential profiles of nitrogen-13 ammonia (NH3) and fluorine-18 fluorodeoxyglucose uptakes were obtained in 61 patients who had diabetes and ischemic LV dysfunction. Patient profiles were compared with those from a normal database. NH3 and fluorine-18 fluorodeoxyglucose defect sizes and extent of perfusion-metabolism mismatch (percentage of myocardium with fluorine-18 fluorodeoxyglucose uptake minus NH3 uptake >2 SD above the normal difference) were determined. Patients were followed every 6 months. Over a mean follow-up of 4.3 years, cardiac death occurred in 52% of patients who underwent revascularization and 61% of those who underwent medical therapy (p = 0.69). No clinical or imaging variables predicted cardiac death in patients who underwent revascularization. In those who received medical therapy, mismatch in <3% of the left ventricle (risk ratio 4.0, p = 0.01) was the only multivariate predictor of cardiac death. Revascularization improved survival of patients who had mismatch of <3% at 4 years (p = 0.003) and at 8 years (p = 0.012) of follow-up. Patients who had mismatch <3% and ejection fraction <30% had the greatest improvement in survival with revascularization compared with medical therapy (p <0.0001). Revascularization also improved 4-year survival of patients who had NH3 perfusion defects of <25% of the left ventricle (p = 0.02). In conclusion, mismatch identifies medically treated patients who have diabetes and LV dysfunction, who are at high risk for cardiac death. Intermediate- and long-term survival of patients who have diabetes and mismatch may be improved with revascularization, and those who have significant mismatch and severe LV dysfunction have the greatest benefit.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine