Atrial Fibrillation is Associated with Increased Pacemaker Implantation Rates in the Placement of AoRTic Transcatheter Valve (PARTNER) Trial

Self-expanding and balloon-expandable valves in low risk TAVR patients

BACKGROUND

Recent randomized studies have broadened the indication of transcatheter aortic valve replacement (TAVR) to also include low-surgical-risk patients. However, the data on self-expanding (SE) and balloon-expandable (BE) valves in low-risk patients remain sparse.

METHODS

The current study is a post hoc analysis of combined data from both LRT 1.0 and 2.0 trials comparing BE and SE transcatheter heart valves.

RESULTS

A total of 294 patients received a BE valve, and 102 patients received an SE valve. The 30-day clinical outcomes were similar across both groups except for stroke (4.9% vs. 0.7%, p = 0.014) and permanent pacemaker implantation (17.8% vs. 5.8%, p < 0.001), which were higher in the SE cohort than the BE cohort. No difference was observed in terms of paravalvular leak (≥moderate) between the groups (0% vs. 1.5%, p = 0.577). SE patients had higher aortic valve area (1.92 ± 0.43 mm2 vs. 1.69 ± 0.45 mm2, p < 0.001) and lower mean gradient (8.93 ± 3.53 mmHg vs. 13.41 ± 4.73 mmHg, p < 0.001) than BE patients. In addition, the rate of subclinical leaflet thrombosis was significantly lower in SE patients (5.6% vs. 13.8%, p = 0.038).

CONCLUSION

In this non-randomized study assessing SE and BE valves in low-risk TAVR patients, SE valves are associated with better hemodynamics and lesser leaflet thrombosis, with increased rates of stroke and permanent pacemaker implantation at 30 days; however, this could be due to certain patient-dependent factors not fully evaluated in this study. The long-term implications of these outcomes on structural valve durability remain to be further investigated.

CLINICAL TRIAL REGISTRY

LRT 1.0: NCT02628899 LRT 2.0: NCT03557242.

Site-Level Variation and Predictors of Permanent Pacemaker Implantation Following TAVR in the Evolut Low-Risk Trial

We evaluated predictors of permanent pacemaker implantation (PPI) following self-expanding transcatheter aortic valve replacement (TAVR), examined site-to-site variability of PPI rates, and explored the relationship of implantation methods on the need for PPI. Despite the benefits of TAVR compared to surgical aortic valve replacement, increased PPI remains a limitation. A total of 699 patients without baseline PPI were included in the study. Clinical, echocardiographic, and procedural characteristics were compared in patient with and without new PPI. Clinical outcomes were assessed at 30 days and 1 year. Funnel plots were constructed to display site-to- site variability and identify outliers in PPI. Clinical outcomes were similar in patients with and without PPI. Predictors of a new PPI within 7 days included a baseline right bundle branch block (p < 0.001) and not using general anesthesia (p = 0.003). There was substantial site to site variability in the rate of PPI. Patients at sites with a lower PPI rate had shallower implantation depth at the non-coronary (p < 0.001) and the left coronary sinus (p < 0.001), and fewer patients with an implantation depth > 5 mm below the annulus (p = 0.004). In low-risk patients undergoing TAVR with Evolut valves, baseline conduction disorders and implant depth were important predictors of PPI. Implantation method may have contributed to this variability in PPI rates across clinical sites.

Predictors of high-degree atrioventricular block in patients with new-onset left bundle branch block following transcatheter aortic valve replacement

BACKGROUND

The development of new left bundle branch block (LBBB) is frequently seen post TAVR and is a known risk factor for progression to high degree AV block. The timing and likelihood of progression into complete heart block is variable and can develop after hospital discharge. We sought to determine predictors for the development of high degree AV block in patients who developed LBBB following TAVR.

METHODS

All patients between 2014 and 2019 underwent electrophysiology study after developing LBBB post TAVR. Data on these patients including baseline characteristics, echo parameters, EKG variables, HV interval, and the need for subsequent pacemaker implantation were extracted. A prolonged HV interval was defined as ≥ 65 ms. Clinically significant conduction abnormality was defined as development of high-degree AV block or clinically significant complete heart block.

RESULTS

Thirty-four patients were included in our study of which 10 (29.4%) developed clinically significant heart block, while 24 (70.6%) did not. The mean HV interval for patients with clinically significant heart block was 70.1 ms vs 57.8 ms for those who did not (p = 0.022). Pre-existing first-degree heart block prior to TAVR (p = 0.026), history of AFib (p = 0.05) in addition to STS score (p = 0.037) were predictors of development of high-degree AV block in our patient population.

CONCLUSIONS

In patients who develop LBBB following TAVR, HV interval, pre-existing first-degree heart block, and STS score predict progression to high-degree AV block. Performance of a routine electrophysiology study should be considered for high-risk patients who develop LBBB following TAVR.

Predicting Permanent Pacemaker Implantation following Trans-catheter Aortic Valve Replacement: A Contemporary Meta-Analysis of 981,168 patients

Background

Heart block requiring permanent pacemaker (PPM) implantation is a relatively frequent complication of transcatheter aortic valve replacement (TAVR).

Objective

The purpose of this study was to perform a contemporary meta-analysis to provide an updated assessment of clinically useful predictors of PPM implantation post-TAVR.

Methods

Medline and EMBASE searches were performed to include all studies reporting PPM post-TAVR between 2015 and 2020. Pertinent data were extracted from the studies for further analysis. RevMan was used to create forest plots and calculate risk ratios (RRs).

Results

We evaluated 41 variables from 239 studies with a total of 981,168 patients. From this cohort, 17.4% received a PPM following TAVR. Strong predictors for PPM implant were right bundle branch block (RBBB) (RR 3.12; P <.001) and bifascicular block (RR 2.40; P = .002). Intermediate factors were chronic kidney disease (CKD) (RR 1.53; P <.0001) and first-degree atrioventricular block (FDAVB) (RR 1.44; P <.001). Weak factors (RR 1–1.50; P <.05) were male gender, age ≥80 years, body mass index ≥25, diabetes mellitus (DM), atrial fibrillation (AF), and left anterior fascicular block (LAFB). These factors along with increased left ventricular outflow tract (LVOT) area (>435 mm²) and/or aortic annulus diameter (>24.4 mm) were incorporated to propose a new scoring system to stratify patients into high- and low-risk groups.

Conclusion

Male gender, age ≥80 years, FDAVB, RBBB, AF, DM, CKD, Medtronic CoreValve, transfemoral TAVR, increased LVOT, and aortic annulus diameter were significant predictors of post-TAVR PPM implantation. Preprocedural assessment should consider these factors to guide clinical decision-making before TAVR. Validation of our scoring system is warranted.

The conjunction conundrum in Transcatheter Aortic Valve Implantation

A continuous discussion regarding the predictors for permanent pacemaker implantation (PPI) following transcatheter aortic valve implantation (TAVI) is ongoing, especially in the era of low and medium risk patients. The aim of this article is to review the data so far regarding the pathophysiology, risk factors, and the indications for permanent pacemaker implantation after TAVI. The factors that contribute to rhythm abnormalities post TAVI can be divided into pre-existing conduction abnormalities, patient-related anatomical factors, and peri-procedural technical factors. The latter components are potentially modifiable, and this is where attention should be directed, particularly now that in an era of TAVI expansion towards lower-risk patients.

Liver transplantation and atrial fibrillation: A meta-analysis

AIM

To assess prevalence of pre-existing atrial fibrillation (AF) and/or incidence of AF following liver transplantation, and the trends of patient's outcomes overtime; to evaluate impact of pre-existing AF and post-operative AF on patient outcomes following liver transplantation.

METHODS

A literature search was conducted utilizing MEDLINE, EMBASE and Cochrane Database from inception through March 2018. We included studies that reported: (1) prevalence of pre-existing AF or incidence of AF following liver transplantation; or (2) outcomes of liver transplant recipients with AF. Effect estimates from the individual study were extracted and combined utilizing random-effect, generic inverse variance method of DerSimonian and Laird. The protocol for this meta-analysis is registered with PROSPERO (International Prospective Register of Systematic Reviews, No. CRD42018093644).

RESULTS

Twelve observational studies with a total of 38586 liver transplant patients were enrolled. Overall, the pooled estimated prevalence of pre-existing AF in patients undergoing liver transplantation was 5.4% (95%CI: 4.9%-5.9%) and pooled estimated incidence of AF following liver transplantation was 8.5% (95%CI: 5.2%-13.6%). Meta-regression analyses were performed and showed no significant correlations between year of study and either prevalence of pre-existing AF (P = 0.08) or post-operative AF after liver transplantation (P = 0.54). The pooled OR of mortality among liver transplant recipients with pre-existing AF was 2.34 (2 studies; 95%CI: 1.10-5.00). In addition, pre-existing AF is associated with postoperative cardiovascular complications among liver transplant recipients (3 studies; OR: 5.15, 95%CI: 2.67-9.92, I 2 = 64%). With limited studies, two studies suggested significant association between new-onset AF and poor clinical outcomes including mortality, cerebrovascular events, post-transplant acute kidney injury, and increased risk of graft failure among liver transplant recipients (P < 0.05).

CONCLUSION

The overall estimated prevalence of pre-existing AF and incidence of AF following liver transplantation are 5.4% and 8.5%, respectively. Incidence of AF following liver transplant does not seem to decrease overtime. Pre-existing AF and new-onset AF are potentially associated with poor clinical outcomes post liver transplantation.

Revisiting Atrial Fibrillation in the Transcatheter Aortic Valve Replacement Era

Atrial fibrillation (AF) is a known complication of many cardiac procedures, including those undergoing surgical aortic valve replacement (SAVR). In the transcatheter aortic valve replacement (TAVR) era, AF has been noted not only to be present in these patients but also associated with morbidity and mortality. In this article, we first outline the significance of AF in general and then more specifically in patients undergoing cardiac surgery. We then compare and contrast specific clinical issues related to AF in patients with aortic stenosis undergoing aortic valve replacement, traditionally with SAVR, but now increasingly more common with TAVR.