Based on prior knowledge and analysis, we can determine the relationship between the feature "MP_TP_POST" and the task of whether the patient shows chronic heart failure.

Since "MP_TP_POST" represents the presence or absence of paroxysms of atrial fibrillation at the time of admission or prehospital stage, it is not directly related to chronic heart failure. However, it is possible that patients with paroxysms of atrial fibrillation at the time of admission or prehospital stage may have a higher likelihood of experiencing chronic heart failure.

To analyze the relationship between "MP_TP_POST" and chronic heart failure, we need access to the myocardial infarction complications data for the patient, specifically the target variable indicating the presence or absence of chronic heart failure.

Here is a dictionary providing the possible values of "MP_TP_POST" for each target class:

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

Note: Since we don't have detailed information on the presence or absence of chronic heart failure for each value of "MP_TP_POST," we assume that the target class "no" indicates the absence of chronic heart failure, while the target class "yes" indicates the presence of chronic heart failure. In the "yes" class, patients may have "MP_TP_POST" categorized as both "no" and "yes" cases.