Based on prior knowledge, there is a known association between diabetes mellitus and chronic heart failure. Diabetes mellitus is considered to be a risk factor for the development of heart failure. Therefore, it is expected that patients with a history of diabetes mellitus (endocr_01 = 'yes') are more likely to show chronic heart failure.

Here is the dictionary describing the relationship between the feature "endocr_01" and the target variable "chronic heart failure":

```json
{
	"no": ["no"],
	"yes": ["yes"]
}
```

Explanation:
- For patients without chronic heart failure (target class "no"), the possible values of the feature "endocr_01" are ['no'].
- For patients with chronic heart failure (target class "yes"), the possible values of the feature "endocr_01" are ['yes'].

Note: It is assumed that there are no missing or unknown values for the feature "endocr_01".