In simple words: The patient's heart failure symptoms have significantly worsened since the last evaluation.

Symptoms demonstrated clinically important deterioration since last assessment (HF).

Example 1: A patient with a history of heart failure presents to the clinic with increased shortness of breath, leg swelling, and fatigue, indicating a worsening of their condition since their last visit., A patient being monitored remotely for heart failure transmits data showing a significant increase in weight, decreased exercise tolerance, and worsening cough, suggesting a decline in their heart function., A patient hospitalized for heart failure exacerbation experiences a sudden increase in fluid retention, decreased oxygen saturation, and chest pain, signaling a further deterioration in their cardiac status.

Documentation should include detailed descriptions of the patient's symptoms, objective findings on physical examination, and any relevant diagnostic test results (e.g., echocardiogram, BNP levels), clearly demonstrating the change in clinical status compared to the previous assessment.