Prediction of death and nonfatal myocardial infarction in high-risk patients: a comparison between the Duke treadmill score, peak exercise radionuclide angiography, and SPECT perfusion imaging.

UNLABELLED: Radionuclide exercise testing provides prognostic information in patients with known or suspected coronary artery disease (CAD). The relative contribution of 3 noninvasive tests--the Duke treadmill score (DTS), first-pass radionuclide angiography with calculation of the ejection fraction (RNA-EF), and perfusion SPECT--has not been comparatively assessed in a high-risk population undergoing all 3 tests. METHODS: We identified 997 patients (75% male; median age, 60 y) who underwent exercise treadmill testing with RNA-EF and SPECT perfusion imaging as a single test. The relative prognostic power of each test was evaluated in both an unadjusted manner and after adjustment for differences in baseline characteristics using Cox proportional hazards models. RESULTS: During a median follow-up of 4.1 y, 175 patients experienced outcome events. Without adjustment for baseline patient characteristics, each of the modalities proved highly predictive of the composite endpoint of cardiovascular death or nonfatal myocardial infarction (MI) (DTS chi(2) = 18.9, P = 0.0001; RNA-EF chi(2) = 34, P = 0.0001; SPECT chi(2) = 11.5, P = 0.0007). In clinically risk-adjusted models, RNA-EF was the most powerful predictor of cardiovascular death compared with the DTS and SPECT (chi(2) = 40.5, 27.6, and 19.8, respectively). Conversely, exercise SPECT perfusion was a stronger predictor of nonfatal MI than the DTS or RNA-EF (chi(2) = 26.7, 15.7, and 16.7, respectively). CONCLUSION: The DTS, perfusion SPECT, and RNA-EF are each significant predictors of cardiovascular events in high-risk patients. The optimal risk stratification of patients for CAD may include all 3 modalities.

Duke Scholars

Author Lawrence Liao Medicine, Cardiology

Author Salvador Borges-Neto Radiology, Nuclear Medicine