Discussions:
In our study of ~ 28000 pLAAC procedures, we found
significant gender-specific differences in outcomes during index
hospitalization as well as during subsequent readmissions. Specific
findings of our study include A) Women had higher overall complications
primarily driven by bleeding-related complications. i.e., 1.3-fold
increased risk of major bleeding, 1.8-fold higher risk for cardiac
tamponade, and 2-fold augmented risk of ischemic stroke. B) There was no
gender-specific difference in peri-procedural mortality, c) Women
remained at 20% and 13% higher risk for readmission at 30 and
180-days, respectively, d) High Charlson category, ESRD, anemia,
pulmonary hypertension, and chronic lung diseasease were significant
predictors of subsequent readmissions. Elective procedures were
associated with lower readmissions.
A study published by Freeman and his colleagues reported pLAAC device
utilization is gradually increasing since the approval of the WATCHMAN
device in 2015[13]. Additionally, the reported adverse event rates
were much lower than the pivotal PROTECT-AF and PREVAIL trial. In the
PROTECT-AF trial, subgroup analysis showed a reduction of primary
efficacy endpoint (composite of stroke, cardiovascular or unexplained
death, and systemic embolization) in men, but there was no difference in
women[9]. The PREVAIL trial, which evaluated device efficacy and
adverse events, did not report gender-specific analysis[8]. Our
comparative analysis reported higher peri-procedural complications rates
in women, which was primarily driven by hemorrhagic complications. The
study results align with the recently published National Cardiovascular
Data Registry (NCDR), Left atrial appendage occlusion (LAAO)
registry-based study by Daren et al.[10] Determining the causality
of this difference becomes more pressing as pLAAC devices are now being
compared to novel oral anticoagulants as a second-line treatment for AF
patients.[14]
Though our study can not determine the causality, few possible
explanations can be relatable. A quantitative study based on the Mayo
Clinic tissue registry showed the anatomical difference in LAA between
men and women.[15] In men, LAAs are wider and longer, while in
women, they are shorter, have more volume, and have a high orifice
location. [16, 17] This difference, along with older age, might be
associated with a frail LAA wall, contributing to higher pericardial
complications. Bleeding during index hospitalization might be related to
smaller and shorter common femoral artery size in women [18],
leading to difficult access, and a high prevalence of anemia may
exacerbate the situation. Resuarringly, though complications were higher
in women, there was no difference in mortality.
Our study showed women are at 20% and 13% higher risk for readmission
at 30 days and 6-months. Late clinical referral, advanced age, multiple
co-morbidity, higher bleeding risk, and more peri-procedural
complications might be associated with prolonged LOS and lead to more
readmissions in women. Since atrial fibrillation is associated with
higher thromboembolic and bleeding complications in women, we carried
out subgroup analysis to determine a cause-specific gender-based
difference of readmission[3]. It showed no difference between men
and women in both thromboembolic and bleeding-related readmissions,
suggesting equal efficacy in both groups.
Careful pre-procedural anatomical evaluation of LAA anatomy through
advanced imaging and intervening electively (vs. urgent), when feasible,
may help to reduce peri-procedural complications and in-term
readmissions. Appropriately managing the risk factors such as
peri-procedural pericardial complications can also play an essential
role in avoiding readmissions. Pre-procedural management of patients’
past conditions such as anemia, renal disease, valvular disease, and
chronic lung diseases through a systemic approach and incorporating
guidelines in routine practice might reduce the readmission burden in
this cohort. Postprocedural close follow-up and interval monitoring for
GI bleed and renal function should be encouraged.