Abstract: Background – Left-sided congestive heart failure (CHF) secondary to myxomatous mitral valve disease (MMVD) is associated with significant morbidity and mortality in the canine patient. Left atrial decompression (LAD) has been used to treat severely affected dogs who are failing standard medical therapy for a variety of reasons. No data has been published regarding the long term outcome of dogs who have undergone LAD.
Hypothesis/Objectives – The objective of our study was to determine incidence of atrial septal defect closure, frequency of right-sided congestive heart failure, frequency of hospitalizations after LAD, and survival times.
Animals – 111 client-owned dogs who were afflicted with ACVIM stage B2 (late), C or D MMVD and underwent LAD.
Methods – Retrospective cohort study enrolling patients with MMVD who had LAD performed between October 2018 and September 2021. Primary outcome variable was time to cardiac-related death or euthanasia. Secondary variables were time to right-sided CHF, atrial septal defect closure, and number of hospitalizations for CHF post-LAD.
Results – Closure of the iatrogenic atrial septal defect occurred in 22 dogs (20%). Iatrogenic atrial septal defect closure occurred most commonly in defects that were located caudally to the fossa ovalis. Forty dogs (36%) developed right-sided CHF as a sequela to the LAD, which occurred between 1 and 800 days post-operatively. 25/111 (22.5%) patients had hospitalizations within their lifetime post-LAD as a result of cardiac disease. Median survival time post-LAD was 379 days with a range of 1-1282 days.
Conclusions and clinical importance – Left atrial decompression was associated with a satisfactory survival time, given the severity of disease in the patient population. Right-sided congestive heart failure is common after the procedure, though onset is variable. Closure of the iatrogenic atrial septal defect is uncommon, and incidence can be minimized by ensuring transseptal puncture occurs within the fossa ovalis.
Learning Objectives:
Upon completion, participant will be able to define cases that might benefit from a left atrial decompression procedure.
Upon completion, participant will be able to anticipate possible complications that might occur follow left atrial decompression.
Upon completion, participant will be able to discuss the pros/cons of a left atrial decompression procedure with a pet owner.
