Based on prior knowledge, we know that chronic heart failure (CHF) is a condition in which the heart muscle becomes weak and is unable to pump blood effectively. Myocardial infarction (MI), also known as a heart attack, refers to the damage to the heart muscle caused by a lack of blood supply. Therefore, there is a potential relationship between MI complications and the development of CHF.

To analyze the relationship between the feature "STENOK_AN" (exertional angina pectoris in the anamnesis) and the task of determining if the patient shows chronic heart failure (CHF), we can hypothesize that patients who reported experiencing exertional angina pectoris more recently might have a higher likelihood of developing CHF.

Based on this hypothesis, we can create a dictionary with the possible values of feature STENOK_AN for each target class:

```json
{
    "no": ["never", "more than 5 years ago", "4-5 years ago"],
    "yes": ["during the last year", "one year ago", "two years ago", "three years ago"]
}
```

Please note that this dictionary includes the values of the feature that are likely to have a clear relationship with the target class. Values that are hard to predict or have a weak relationship are not included in this dictionary.