Page 30 - Read Online

Page 12 of 19 Khokhar et al. Mini-invasive Surg 2022;6:2 https://dx.doi.org/10.20517/2574-1225.2021.97

devices such as the Emblok device, which incorporates a radiopaque 4 Fr guiding pigtail catheter in the
[114]
device system, mitigates the need for an additional access .
Generally, the use of CEPDs during TAVR has not been shown to reduce the incidence of in-hospital
stroke [112,113,115,116] . In contrast, data regarding the impact of CEPDs on MRI-defined lesion volume are
conflicting [117-119] ; however, a recent updated meta-analysis did not find any significant difference associated
[115]
with CEPD use on MRI lesion volume or number of new ischemic lesions . Further definitive answers
regarding the effectiveness of CEPDs for stroke reduction are expected with the results of the PROTECTED
TAVR (Stroke Protection With Sentinel During Transcatheter Aortic Valve Replacement) trial (NCT:
04149535) enrolling 3000 patients randomized 1:1 to TAVR with or without the Sentinel protection device.

Even with a CEPD deployed, a significant burden of silent cerebral events can still occur, which highlights
the importance of caution during wire, catheter, and delivery system exchanges and manipulations. Heparin
administration to reduce peri-procedural thrombosis should be activated clotting time guided, aiming
between 250 and 300 s. In high-bleeding-risk patients who develop intra-procedural or early post-operative
acute ischemic stroke, where a filling defect of a large intra-cranial vessel is identified, mechanical
thrombectomy can be performed [120,121] .

Late cerebrovascular events: 24 h to 30 days
Late cerebrovascular events (CVE) mainly arise from cardio-embolic sources, with atrial fibrillation (AF)
being the commonest cause . Patients with AF undergoing TAVR usually have multiple co-morbidities
[122]
[123]
with associated elevated thrombotic and bleeding risks, which requires specific attention . Heparin
reversal with protamine should be used cautiously and alternative methods to achieve hemostasis are
preferred. In certain cases, simultaneous implantation of a left atrial appendage occluder device during
TAVR has been performed and data from the WATCH-TAVR (NCT: 03173534) trial, which randomizes
patients to TAVR + medical therapy or TAVR + WATCHMAN device, are expected to provide further
insights. Current ESC/EACTS guidelines and other expert consensus recommend post-procedural oral
anticoagulation therapy alone or in combination with single anti-platelet agent depending on bleeding risk
profile [124,125] .

Finally, leaflet thrombosis or sub-clinical leaflet thrombosis is increasingly being recognized as a potential
[126]
source of late CVE, although reports are conflicting . Although routine post-TAVR anticoagulation
reduced the incidence of sub-clinical and leaflet thrombosis, this did not translate into a net clinical benefit
due to the increased bleeding risk . Taken together, these findings suggest that post-procedural
[127]
anticoagulation therapy should be limited to those patients with a pre-existing indication.

PACEMAKER IMPLANTATION
The incidence of permanent pacemaker implantation (PPI) remains significant in contemporary
cohorts . As TAVR expands towards lower-risk younger patients, a shorter hospital stay and earlier
[128]
discharge becomes more favorable. Given that the risk of developing high-grade atrio-ventricular block
requiring pacing is often unpredictable, individualized risk assessment is necessary to identify high-risk
[129]
electrical, anatomical, and procedural features . Patients with pre-existing conduction disease such as
right bundle branch block and prolonged PR-interval confer an elevated risk of requiring both early and late
PPI [130,131] . Increased calcium burden and distribution particularly in the DLZ and LVOT, as well as a deeper
implantation, are important procedural considerations, which are associated with elevated post-procedural
PPI rates [132,133] .