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

OBJECTIVE: Despite 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.
METHODS: A 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.
RESULTS: The 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.
CONCLUSIONS: Dobutamine 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.