RESUMO
OBJECTIVE: Noninvasive differentiation between ischemic cardiomyopathy (ICM) and nonischemic (NICM) cardiomyopathy is frequently difficult. The aim of this study was to analyze the value of stress test and stress-rest gated single-photon emission computed tomography (SPECT) criteria to differentiate between ICM and NICM. METHODS: Data pertaining to 145 consecutive patients (mean age: 63±11 years, 24 women) assessed by means of stress-rest gated SPECT with Tc-tetrofosmin, with left ventricular ejection fraction less than or equal to 40% (107 patients with ICM and 38 with NICM according to coronary angiography) and known coronary anatomy, were analyzed. RESULTS: Multivariate analyses of gated SPECT variables identified a summed stress score greater than 21 [odds ratio (OR) 7.67, 95% confidence interval (CI): 2.85-20.58)] and divergent pattern (OR 6.84, 95% CI: 1.83-25.5) as predictors of ICM, and analysis of exercise test variables disclosed metabolic equivalents less than or equal to 7.3 (OR 10.75, 95% CI: 3.64-31.81) and ST depression of at least 1 mm (OR 6.97, 95% CI: 1.42-34.3) as independent predictors of ICM. The exercise test variables had a significant additional predictive value of ICM over gated SPECT variables (P<0.001). CONCLUSION: Estimated functional capacity and ST depression improve the diagnostic value of stress-rest SPECT to differentiate between ICM and NICM.