```json
{
	"no": ["no"],
	"yes": ["yes"]
}
```
Based on the given feature description and task, the feature "GEPAR_S_n" represents the use of anticoagulants in the ICU. In this case, there are two possible categories: "yes" and "no".

For the task of determining whether the myocardial infarction complications data shows chronic heart failure, the feature "GEPAR_S_n" doesn't provide explicit information about chronic heart failure. It solely indicates whether anticoagulants were used in the ICU for the patient.

As a result, it is not possible to analyze the relationship between this feature and the presence of chronic heart failure using the given information. Therefore, the dictionary consists only of the available values of the feature without any specific analysis.