Prediction of 14-year outcomes in patients with a limited exercise capacity: Utility of dobutamine myocardial perfusion imaging in a high-risk population

Abstract

ObjectiveDespite multiple studies on the diagnostic and prognostic use of dobutamine myocardial perfusion imaging (MPI), information on its long-term prognostic value is scarce. The aim of this study was to assess the value of this technique for the prediction of very long-term outcome. MethodsA total of 721 patients with limited exercise capacity underwent dobutamine MPI for the evaluation of suspected or known coronary artery disease. 719 of 721 patients attended follow-up (99.7%). Twenty-eight patients who underwent early coronary revascularization were excluded from analysis. Endpoints were all-cause mortality, cardiac death, nonfatal infarction, and coronary revascularization. Kaplan-Meier survival curves were constructed, and univariate and multivariate analyses were performed to identify predictors of long-term outcome. ResultsThe mean age of patients was 60 ± 11 years, and 61% were male. Myocardial perfusion abnormalities were present in 381 patients (55%) and included fixed defects in 190 patients (27%) and reversible defects in 191 patients (28%). During a median follow-up time of 14 years (range 0-16), 295 deaths occurred (43%), of which 158 were cardiac deaths (23%). Nonfatal myocardial infarction occurred in 35 (5%), and late coronary revascularization was performed on 133 patients (19%). An abnormal dobutamine MPI provided significant prognostic information for prediction of cardiac death, hard cardiac events, and MACE, after adjustment for significant clinical variables and stress test variables. ConclusionsDobutamine MPI provides incremental prognostic information for the prediction of cardiovascular outcomes in patients with limited exercise capacity. The long-term prognosis of patients with limited exercise capacity who have an abnormal dobutamine MPI is significantly worse than those with a normal MPI.