In a recent retrospective cohort study published in the Journal of American Medical Association conducted on patients with atrial fibrillation (AF) undergoing cardiac surgery, surgical left atrial appendage occlusion (S-LAAO) as compared with no surgical left atrial appendage occlusion (no S-LAAO) was significantly associated with lower risk of readmission for thromboembolism.
Dr. J. Matthew Brennan, the principal investigator and the interventional cardiologist at Duke University adds “The study adds substantial weight of evidence to the growing body of evidence which says that obliteration of the Left Atrial Appendage can lower stroke risk in patients.”
The study looked at patients older than 65 years with AF who have undergone cardiac surgery (whether the surgery was associated with S-LAOO or not) in the Society of Thoracic Surgeons Adult Cardiac Surgery Database. The patients have undergone the procedures during the years of 2011-2012 and were followed up till the end of 2014 for the occurrence of readmission for thromboembolism or hemorrhagic stroke. All-cause mortality and a composite end point of hemorrhagic stroke, thromboembolism, and all-cause mortality were also included in the follow-up.
“By far, this is the largest study that adds to the weight of the evidence to say that closure of the left atrial appendage is beneficial in patients undergoing open heart surgery who have AF”
– Dr. Matthew Brennan
After adjusting for the possible confounders, it was found that S-LAAO was associated with significant reduction in the rate of thromboembolism, all-cause mortality, and the composite end point but not the rate of the occurrence of hemorrhagic stroke.
The authors claim that the study is the largest to assess the long term outcomes of S-LAAO. Dr. Brennan comments on the results of the study saying ”If it were me, my family or my patient, I would certainly be requesting that they have their appendage closed. Prior to our study, there was still a fair bit of residual questioning in the community about whether or not the closing of the atrial appendage was worth it. However, our study says it pretty strongly, unless there’s a clear reason not to do it”
Highlighting the strengths of the study, he says, “By far, this is the largest study that adds to the weight of the evidence to say that closure of the left atrial appendage is beneficial in patients undergoing open heart surgery who have AF” and “patients who cannot take anticoagulants after their heart surgery are expected to benefit the most.”
In the publications, the authors acknowledge some limitations such as the absence of randomization, not including the method of performing S-LAOO, and the age of the patients being older than 65 years.
The authors also point out that the “discharge anticoagulation” variable was determined based on whether the patient had an anticoagulant prescription on discharge but the compliance to the medication could not be assessed.
Dr. Brennan comments “Since it is a non-randomized trial, we can’t say it is definitely the cause, but multiple studies really suggest that closure of the left atrial appendage is beneficial in patients undergoing open heart surgery who have atrial fibrillation.”
He also says “We don’t know how the appendages were closed, whether they were closed with a clamp or by sewing over the appendage and if it even makes a difference. Future research is required to figure it out.”