Cardiomyopathy, Dilated/diagnostic imaging; Contrast Media/administration & dosage; Echocardiography, Doppler, Color; Gadolinium DTPA/administration & dosage; Magnetic Resonance Imaging; Myocardial Contraction; Ventricular Function, Left; Aged; Biomechanical Phenomena; Cardiomyopathy, Dilated/mortality; Cardiomyopathy, Dilated/physiopathology; Cardiomyopathy, Dilated/therapy; Chi-Square Distribution; Disease-Free Survival; Female; Heart Failure/mortality; Heart Failure/physiopathology; Heart Failure/therapy; Heart-Assist Devices; Humans; Kaplan-Meier Estimate; Longitudinal Studies; Male; Middle Aged; Multivariate Analysis; Observer Variation; Patient Readmission; Predictive Value of Tests; Proportional Hazards Models; Reproducibility of Results; Retrospective Studies; Risk Assessment; Risk Factors; Stress, Mechanical; Stroke Volume; Ventricular Remodeling