Figure 4. Mirror period for the evaluation of days of heart failure hospitalization. The figure is describing the method to assess the number of days of hospitalization before/after BAV. Patients 1 and 2 died before 1-year post BAV, thus the time period used to record the number of days of HF hospitalization was less than 1 year in these patients. Patient 3 survived more than 1 year, thus the entire year before BAV was used to collect number of days of HF hospitalization.