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.