Validation of the Greek Cardiovascular Diet Questionnaire 2 (CDQ-2) and Single-Center Cross-Sectional Insights into the Dietary Habits of Cardiovascular Patients

Background/Objectives: Dietary recommendations are an essential part of guidelines for the best management of chronic cardiovascular diseases. The present study aimed to validate the Greek version of Cardiovascular Diet Questionnaire 2 (CDQ-2) and to assess the dietary habits among cardiovascular patients. Methods: A single-center cross-sectional observational study was conducted. The study population was cardiovascular patients that were users of a private primary healthcare clinic. The data were collected between December 2024 and January 2025. The questionnaire was translated from French, back-translated, and reviewed by a committee of experts. The MEDAS was used as a gold standard. The psychometric measurements that were performed included reliability coefficients and Explanatory Factor Analysis (EFA). Results: The total sample comprised 90 individuals. The Cronbach’s α was 0.97. A bivariate Pearson’s correlation established that there was a strong, statistically significant linear relationship between the CDQ-2 and MEDAS scores, with r(90) = 0.962 and p < 0.001. Cardiovascular patients seemed to have suboptimal dietary patterns, as indicated by the relatively low mean CDQ-2 score of 2.9 (SD = 17.2), along with a mean MEDAS score of 8 (SD = 5.2), where younger individuals (p < 0.001), males (p = 0.042), single/divorced/widowed individuals (p < 0.001), individuals with lower physical activity (p = 0.001), and active smokers (p = 0.022) demonstrated significantly poorer adherence to the optimal cardiovascular dietary status. Conclusions: The survey indicated that CDQ-2 was a valid and reliable scale to use in cardiovascular patients in Greece. Also, the patients were characterized by suboptimal dietary habits, indicating the need for personalized interventions to improve their dietary habits.