Based on prior knowledge, it is difficult to determine the relationship between the feature "GT_POST" and the presence of chronic heart failure. However, we can still analyze the relationship by examining the distribution of "GT_POST" values for each target class.

Here is the dictionary representing the relationship between the feature and target:

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

Since the feature "GT_POST" is categorical with two categories ('no' and 'yes'), we can see that for the target class "no", only the value 'no' is present. And for the target class "yes", only the value 'yes' is present. 

This analysis suggests that the presence of chronic heart failure is associated with the value 'yes' for the feature "GT_POST". However, it is important to note that this analysis does not provide any insights into causality or the strength of the relationship between the feature and target.