OBJECTIVE To assess psychometric properties of a questionnaire covering treatment satisfaction and disease-specific knowledge among patients discharged after treatment for acute coronary syndrome. METHODS Comparative scaling of the questionnaire using latent class analysis (LCA) and exploratory factor analysis (EFA) in a consecutive sample of 2015 patients. RESULTS LCA revealed four qualitatively differing patterns of patients' knowledge and five distinct patterns of treatment satisfaction. EFA for patients' knowledge identified four uncorrelated "dimensions". Patient satisfaction was scored in a two-factor solution despite proven heterogeneity of persons. CONCLUSIONS LCA was helpful to identify classes of patients that cannot be scaled according to a latent trait model. PRACTICE IMPLICATIONS Specific patterns of insufficient disease-specific knowledge and satisfaction requiring specific interventions became visible.