Repeat Catheter Ablation after Very Late Recurrence of Atrial Fibrillation after Pulmonary Vein Isolation.

BACKGROUND AND AIMS: Atrial fibrillation (AF) recurs in about one third of patients after catheter ablation (CA), mostly in the first year. Little is known about the electrophysiological findings and the effect of re-ablation in very late AF recurrences after more than one year. The aim of this study was to determine the characteristics and outcomes of the first repeat CA after very late recurrence of AF after index CA. METHODS: We analysed patients from a prospective Swiss registry that underwent a first repeat ablation procedure. Patients were stratified depending on the time to recurrence after index procedure: early recurrence (ER) for recurrences within the first year and late recurrence (LR) if the recurrence was later. The primary endpoint was freedom from AF in the first year after repeat ablation. RESULTS: Out of 1864 patients included in the registry, 426 patients undergoing a repeat ablation were included in the analysis (28% female, age 63 ± 9.8 years, 46% persistent AF). 291 patients (68%) were stratified in the ER group and 135 patients (32%) in the LR group. Pulmonary vein reconnections were a common finding in both groups, with 93% in the ER group compared to 86% in the LR group (p = 0.052). In the LR group, 40 of 135 patients (30%) had a recurrence of AF compared to 90 of 291 patients (31%) in the ER group (log rank p = 0.72). CONCLUSION: There was no association between the time to recurrence of AF after initial catheter ablation and the characteristics and outcomes of the repeat procedure.

Biomarkers to Predict Improvement of Left Ventricular Ejection Fraction after Atrial Fibrillation Ablation.

INTRODUCTION: Atrial fibrillation (AF) and heart failure (HF) frequently coexist. Prediction of left ventricular ejection fraction (LVEF) recovery after catheter ablation (CA) for AF remains difficult. OBJECTIVES: To evaluate the value of biomarkers, alone and in conjunction with the Antwerp score to predict LVEF recovery after CA for AF. METHODS: Patients undergoing CA for AF with depressed LVEF(<50%) were included. Plasma levels of 13 biomarkers were measured immediately prior to CA. Patients were categorized into "responders" and "non-responders" in similar fashion to the Antwerp score derivation and validation cohorts. The predictive power of the biomarkers alone and combined in outcome prediction was evaluated. RESULTS: 208 patients with depressed LVEF were included (median age 63 years, 19% female, median LAVI 42 ml/m2, median LVEF 43%). At a median follow-up time of 30 months, 161 (77%) were responders and 47 (23%) were non-responders. Of 13 biomarkers, four (ANG2, GDF15, FGF23 and MyBPC3) were significantly different between responders and non-responders (p ≤0.001) and combined could predict the endpoint with an AUC of 0.72 (95%CI 0.64-0.81) overall, 0.69 (95%CI 0.59-0.78) in HFmrEF and 0.88 (95%CI 0.77-0.98) in HFrEF. Only ANG2 and GDF15 remained significantly associated with LVEF recovery after adjustment for age, sex and Antwerp score and significantly improved the accuracy of the Antwerp score predictions (p<0.001). The AUC of the Antwerp score in the outcome prediction improved from 0.75 (95% CI 0.67-0.83) to 0.78 (95% CI 0.70-0.86) CONCLUSION: A biomarker panel (ANG2, GDF15) significantly improved the accuracy of the Antwerp Score.

Impact of implantation depth and calcium burden on infranodal conduction delay after transcatheter aortic valve replacement.

Background: Infranodal conduction disorders are common after transcatheter aortic valve replacement (TAVR). Risk factors are incompletely understood. Objective: The purpose of this study was to assess the impact of valve implantation depth and calcium burden of the device landing zone on infranodal conduction intraprocedure pre- and post-TAVR. Methods: In all patients undergoing TAVR between June 2020 and June 2021, the His-ventricle (HV) interval was measured pre- and post-valve deployment. The difference between the 2 measurements defined delta HV, whereas infranodal conduction delay was defined as HV interval >55 ms. Valve implantation depth was measured as the distance between the aortic annular plane and the ventricular prosthesis end. Calcium burden was quantified as the volume of calcium in 6 regions of interest: the non-, right, and left coronary cusps (NCC, RCC, and LCC, respectively) and the corresponding regions of the left ventricular outflow tract (LVOT) underlying each cusp (LVOTNCC, LVOTRCC, LVOTLCC, respectively). Results: Of 101 patients (mean age 81 ± 5.7 years; 47% women), 37 demonstrated infranodal conduction delay intraprocedure post-TAVR. Overall, mean implantation depth was 5 ± 3.1 mm, median calcium volume was 2080 mm3 [interquartile range 632-2400]. Delta HV showed no correlation with implantation depth or calcium burden (r = -0.08 and r = 0.12, respectively). However, LVOTNCC calcification was a significant predictor for infranodal conduction delay post-valve deployment in a multivariable logistic regression model (odds ratio 1.62 per 100-mm3 increase (95% confidence interval 1.06-2.69; P = .04). Conclusion: Assessment of LVOTNCC calcification may identify patients at risk for infranodal conduction delay after TAVR, whereas implantation depth did not predict infranodal conduction delay.

Patients on vitamin K treatment: is switching to direct-acting oral anticoagulation cost-effective? A target trial on a prospective cohort.

AIMS: Direct-acting oral anticoagulants (DOACs) have, to a substantial degree, replaced vitamin K antagonists (VKA) as treatments for stroke prevention in atrial fibrillation (AF) patients. However, evidence on the real-world causal effects of switching patients from VKA to DOAC is lacking. We aimed to assess the empirical incremental cost-effectiveness of switching patients to DOAC compared with maintaining VKA treatment. METHODS: The target trial approach was applied to the prospective observational Swiss-AF cohort, which enrolled 2415 AF patients from 2014 to 2017. Clinical data, healthcare resource utilisation and EQ-5D-based utilities representing quality of life were collected in yearly follow-ups. Health insurance claims were available for 1024 patients (42.4%). Overall survival, quality-of-life, costs from the Swiss statutory health insurance perspective and cost-effectiveness were estimated by emulating a target trial in which patients were randomly assigned to switch to DOAC or maintain VKA treatment. RESULTS: 228 patients switching from VKA to DOAC compared with 563 patients maintaining VKA treatment had no overall survival advantage over a 5-year observation period (HR 0.99, 95% CI 0.45, 1.55). The estimated gain in quality-adjusted life years (QALYs) was 0.003 over the 5-year period at an incremental costs of CHF 23 033 (€ 20 940). The estimated incremental cost-effectiveness ratio was CHF 425 852 (€ 387 138) per QALY gained. CONCLUSIONS: Applying a causal inference method to real-world data, we could not demonstrate switching to DOACs to be cost-effective for AF patients with at least 1 year of VKA treatment. Our estimates align with results from a previous randomised trial.

Reducing the burden of inconclusive smart device single-lead ECG tracings via a novel artificial intelligence algorithm.

Background: Multiple smart devices capable of automatically detecting atrial fibrillation (AF) based on single-lead electrocardiograms (SL-ECG) are presently available. The rate of inconclusive tracings by manufacturers' algorithms is currently too high to be clinically useful. Method: This is a prospective, observational study enrolling patients presenting to a cardiology service at a tertiary referral center. We assessed the clinical value of applying a smart device artificial intelligence (AI)-based algorithm for detecting AF from 4 commercially available smart devices (AliveCor KardiaMobile, Apple Watch 6, Fitbit Sense, and Samsung Galaxy Watch3). Patients underwent a nearly simultaneous 12-lead ECG and 4 smart device SL-ECGs. The novel AI algorithm (PulseAI, Belfast, United Kingdom) was compared with each manufacturer's algorithm. Results: We enrolled 206 patients (31% female, median age 64 years). AF was present in 60 patients (29%). Sensitivity and specificity for the detection of AF by the novel AI algorithm vs manufacturer algorithm were 88% vs 81% (P = .34) and 97% vs 77% (P < .001) for the AliveCor KardiaMobile, 86% vs 81% (P = .45) and 95% vs 83% (P < .001) for the Apple Watch 6, 91% vs 67% (P < .01) and 94% vs 82% (P < .001) for the Fitbit Sense, and 86% vs 82% (P = .63) and 94% vs 80% (P < .001) for the Samsung Galaxy Watch3, respectively. In addition, the proportion of SL-ECGs with an inconclusive diagnosis (1.2%) was significantly lower for all smart devices using the AI-based algorithm compared to manufacturer's algorithms (14%-17%), P < .001. Conclusion: A novel AI algorithm reduced the rate of inconclusive SL-ECG diagnosis massively while maintaining sensitivity and improving the specificity compared to the manufacturers' algorithms.

Left atrial posterior wall isolation using pulsed-field ablation: procedural characteristics, safety, and mid-term outcomes.

BACKGROUND: Non-pulmonary vein (PV) ablation targets such as posterior wall isolation (PWI) have been tested in patients with persistent atrial fibrillation (AF). Pulsed-field ablation (PFA) offers a novel ablation technology possibly able to overcome the obstacles of incomplete PWI and concerns of damage to adjacent structures compared to thermal energy sources. Our aim was to assess procedural characteristics, safety, and mid-term outcomes of patients undergoing PWI using PFA in a clinical setting. METHODS: Patients undergoing PFA-PVI with PWI were included. First-pass isolation was controlled using a multipolar mapping catheter. RESULTS: One hundred consecutive patients were included (median age 69 [IQR 63-75] years, 33 females (33%), left atrial size 43 [IQR 39-47] mm, paroxysmal AF 24%). Median procedure time was 66 (IQR 59-77) min, and fluoroscopy time was 11 (8-14) min. PWI using PFA was achieved in 100% of patients with a median of 19 applications (IQR 14-26). There were no major complications. Overall, in 15 patients (15%), recurrent AF/AT was noted during a median follow-up of 144 (94-279) days. CONCLUSIONS: PWI using PFA appears safe and results in high acute isolation rates and high arrhythmia survival during mid-term follow-up. Further randomized trials are essential and warranted.

Omega-3 Fatty Acids and Markers of Thrombosis in Patients with Atrial Fibrillation.

Omega-3 fatty acids (n-3 FAs) are associated with a lower risk of ischemic stroke in patients with atrial fibrillation (AF). Antithrombotic mechanisms may in part explain this observation. Therefore, we examined the association of n-3 FAs with D-dimer and beta-thromboglobulin (BTG), markers for activated coagulation and platelets, respectively. The n-3 FAs eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and alpha-linolenic acid (ALA) were determined via gas chromatography in the whole blood of 2373 patients with AF from the Swiss Atrial Fibrillation cohort study (ClinicalTrials.gov Identifier: NCT02105844). In a cross-sectional analysis, we examined the association of total n-3 FAs (EPA + DHA + DPA + ALA) and the association of individual fatty acids with D-dimer in patients with detectable D-dimer values (n = 1096) as well as with BTG (n = 2371) using multiple linear regression models adjusted for confounders. Median D-dimer and BTG levels were 0.340 ug/mL and 448 ng/mL, respectively. Higher total n-3 FAs correlated with lower D-dimer levels (coefficient 0.94, 95% confidence interval (Cl) 0.90-0.98, p = 0.004) and lower BTG levels (coefficient 0.97, Cl 0.95-0.99, p = 0.003). Likewise, the individual n-3 FAs EPA, DHA, DPA and ALA showed an inverse association with D-dimer. Higher levels of DHA, DPA and ALA correlated with lower BTG levels, whereas EPA showed a positive association with BTG. In patients with AF, higher levels of n-3 FAs were associated with lower levels of D-dimer and BTG, markers for activated coagulation and platelets, respectively. These findings suggest that n-3 FAs may exert antithrombotic properties in patients with AF.

Durability of pulmonary vein isolation for atrial fibrillation: a meta-analysis and systematic review.

AIMS: Pulmonary vein isolation (PVI) plays a central role in the interventional treatment of atrial fibrillation (AF). Uncertainties remain about the durability of ablation lesions from different energy sources. We aimed to systematically review the durability of ablation lesions associated with various PVI-techniques using different energy sources for the treatment of AF. METHODS AND RESULTS: Structured systematic database search for articles published between January 2010 and January 2023 reporting PVI-lesion durability as evaluated in the overall cohort through repeat invasive remapping during follow-up. Studies evaluating only a proportion of the initial cohort in redo procedures were excluded. A total of 19 studies investigating 1050 patients (mean age 60 years, 31% women, time to remap 2-7 months) were included. In a pooled analysis, 99.7% of the PVs and 99.4% of patients were successfully ablated at baseline and 75.5% of the PVs remained isolated and 51% of the patients had all PVs persistently isolated at follow-up across all energy sources. In a pooled analysis of the percentages of PVs durably isolated during follow-up, the estimates of RFA were the lowest of all energy sources at 71% (95% CI 69-73, 11 studies), but comparable with cryoballoon (79%, 95%CI 74-83, 3 studies). Higher durability percentages were reported in PVs ablated with laser-balloon (84%, 95%CI 78-89, one study) and PFA (87%, 95%CI 84-90, 2 studies). CONCLUSION: We observed no significant difference in the durability of the ablation lesions of the four evaluated energies after adjusting for procedural and baseline populational characteristics.

Efficacy and safety of pulmonary vein isolation with pulsed field ablation vs. novel cryoballoon ablation system for atrial fibrillation.

AIMS: Pulsed-field ablation (PFA) has emerged as a novel treatment technology for patients with atrial fibrillation (AF). Cryoballoon (CB) is the most frequently used single shot technology. A direct comparison to a novel CB system is lacking. We aimed to compare pulmonary vein isolation (PVI) using PFA vs. a novel CB system regarding efficiency, safety, myocardial injury, and outcomes. METHODS AND RESULTS: One hundred and eighty-one consecutive patients underwent PVI and were included (age 64 ± 9.7 years, ejection fraction 0.58 ± 0.09, left atrial size 40 ± 6.4 mm, paroxysmal AF 64%). 106 patients (59%) underwent PFA (FARAPULSE, Boston Scientific) and 75 patients (41%) underwent CB ablation (PolarX, Boston Scientific). The median procedure time, left atrial dwell time and fluoroscopic time were similar between the PFA and the CB group with 55 [interquartile range (IQR) 43-64] min vs. 58 (IQR 48-69) min (P < 0.087), 38 (30-49) min vs. 37 (31-48) min, (P = 0.871), and 11 (IQR 9.3-14) min vs. 11 (IQR 8.7-16) min, (P < 0.81), respectively. Three procedural complications were observed in the PFA group (two tamponades, one temporary ST elevation) and three complications in the CB group (3× reversible phrenic nerve palsies). During the median follow-up of 404 days (IQR 208-560), AF recurrence was similar in the PFA group and the CB group with 24 vs. 30%, P = 0.406. CONCLUSION: Procedural characteristics were very similar between PFA and CB in regard to procedure duration fluoroscopy time and complications. Atrial fibrillation free survival did not differ between the PFA and CB groups.

Longitudinal Changes in Health-Related Quality of Life in Patients With Atrial Fibrillation.

Background Optimizing health-related quality of life (HRQoL) is an important aim of atrial fibrillation (AF) treatment. Little is known about patients' long-term HRQoL trajectories and the impact of patient and disease characteristics. The aim of this study was to describe HRQoL trajectories in an observational AF study population and in clusters of patients with similar patient and disease characteristics. Methods and Results We used 5-year follow-up data from the Swiss-Atrial Fibrillation prospective cohort, which enrolled 2415 patients with prevalent AF from 2014 to 2017. HRQoL data, collected yearly, comprised EuroQoL-5 dimension utilities and EuroQoL visual analog scale scores. Patient clusters with similar characteristics at enrollment were identified using hierarchical clustering. HRQoL trajectories were analyzed descriptively and with inverse probability-weighted regressions. Effects of postbaseline clinical events were additionally assessed using time-shifted event variables. Among 2412 (99.9%) patients with available baseline HRQoL, 3 clusters of patients with AF were identified, which we characterized as follows: "cardiovascular dominated," "isolated symptomatic," and "severely morbid without cardiovascular disease." Utilities and EuroQoL visual analog scale scores remained stable over time for the full population and the clusters; isolated symptomatic patients showed higher levels of HRQoL. Utilities were reduced after occurrences of stroke, hospitalization for heart failure, and bleeding, by -0.12 (95% CI, -0.18 to -0.06), -0.10 (95% CI, -0.13 to -0.08), and -0.06 (95% CI, -0.08 to -0.04), respectively, on a 0 to 1 utility scale. Utility of surviving patients returned to preevent levels 4 years after heart failure hospitalization; 3 years after bleeding; and 1 year after stroke. Conclusions In patients with prevalent AF, HRQoL was stable over time, irrespective of baseline patient characteristics. Clinical events of hospitalization for heart failure, stroke, and bleeding had only a temporary effect on HRQoL.

Comparison of the PolarX and the Arctic Front cryoballoon for pulmonary vein isolation in patients with symptomatic paroxysmal atrial fibrillation (COMPARE CRYO) - Study protocol for a randomized controlled trial.

INTRODUCTION: Single-shot devices are increasingly used for pulmonary vein isolation (PVI) in atrial fibrillation (AF). The Arctic Front cryoballoon (Medtronic) is the most frequently used single-shot technology. A recently developed novel cryoballoon has been introduced (PolarX, Boston Scientific) with the aim to address limitations of the Arctic Front system. METHODS: COMPARE CRYO is a multicentre, randomized, controlled trial with blinded endpoint adjudication by an independent clinical events committee. A total of 200 patients with paroxysmal AF undergoing their first PVI are randomized 1:1 between PolarX cryoballoon ablation and Arctic Front cryoballoon ablation. Continuous monitoring during follow-up is performed using an implantable cardiac monitor (ICM) in all patients. The primary endpoint is time to first recurrence of any atrial tachyarrhythmia (AF, atrial flutter, and/or atrial tachycardia) ≥ 120 s between days 91 and 365 post ablation as detected on the (ICM). Procedural safety is assessed by a composite of cardiac tamponade, persistent phrenic nerve palsy >24 h, vascular complications requiring intervention, stroke/transient ischemic attack, atrioesophageal fistula or death occurring during or up to 30 days after the procedure. Key secondary endpoints include (1) procedure and fluoroscopy times, (2) AF burden, (3) proportion of patients with recurrence in the blanking period, (4) proportion of patients undergoing repeat ablation, and (5) quality of life changes at 12 months compared to baseline. CONCLUSION: COMPARE CRYO will compare the efficacy and safety of the novel PolarX cryoballoon and the standard-of-practice Arctic Front cryoballoon for first PVI performed in patients with symptomatic paroxysmal AF. TRIAL REGISTRATION: (ClinicalTrials.gov ID: NCT04704986).

Accuracy in detecting atrial fibrillation in single-lead ECGs: an online survey comparing the influence of clinical expertise and smart devices.

BACKGROUND: Manual interpretation of single-lead ECGs (SL-ECGs) is often required to confirm a diagnosis of atrial fibrillation. However accuracy in detecting atrial fibrillation via SL-ECGs may vary according to clinical expertise and choice of smart device. AIMS: To compare the accuracy of cardiologists, internal medicine residents and medical students in detecting atrial fibrillation via SL-ECGs from five different smart devices (Apple Watch, Fitbit Sense, KardiaMobile, Samsung Galaxy Watch, Withings ScanWatch). Participants were also asked to assess the quality and readability of SL-ECGs. METHODS: In this prospective study (BaselWearableStudy, NCT04809922), electronic invitations to participate in an online survey were sent to physicians at major Swiss hospitals and to medical students at Swiss universities. Participants were asked to classify up to 50 SL-ECGs (from ten patients and five devices) into three categories: sinus rhythm, atrial fibrillation or inconclusive. This classification was compared to the diagnosis via a near-simultaneous 12-lead ECG recording interpreted by two independent cardiologists. In addition, participants were asked their preference of each manufacturer's SL-ECG. RESULTS: Overall, 450 participants interpreted 10,865 SL-ECGs. Sensitivity and specificity for the detection of atrial fibrillation via SL-ECG were 72% and 92% for cardiologists, 68% and 86% for internal medicine residents, 54% and 65% for medical students in year 4-6 and 44% and 58% for medical students in year 1-3; p <0.001. Participants who stated prior experience in interpreting SL-ECGs demonstrated a sensitivity and specificity of 63% and 81% compared to a sensitivity and specificity of 54% and 67% for participants with no prior experience in interpreting SL-ECGs (p <0.001). Of all participants, 107 interpreted all 50 SL-ECGs. Diagnostic accuracy for the first five interpreted SL-ECGs was 60% (IQR 40-80%) and diagnostic accuracy for the last five interpreted SL-ECGs was 80% (IQR 60-90%); p <0.001. No significant difference in the accuracy of atrial fibrillation detection was seen between the five smart devices; p = 0.33. SL-ECGs from the Apple Watch were considered as having the best quality and readability by 203 (45%) and 226 (50%) participants, respectively. CONCLUSION: SL-ECGs can be challenging to interpret. Accuracy in correctly identifying atrial fibrillation depends on clinical expertise, while the choice of smart device seems to have no impact.

Real-World Cost-Effectiveness of Pulmonary Vein Isolation for Atrial Fibrillation: A Target Trial Approach.

OBJECTIVES: Randomized controlled trials of pulmonary vein isolation (PVI) for treating atrial fibrillation (AF) have proven the procedure's efficacy. Studies assessing its empirical cost-effectiveness outside randomized trial settings are lacking. We aimed to evaluate the effectiveness and cost-effectiveness of PVI versus medical therapy for AF. METHODS: We followed a target trial approach using the Swiss-AF cohort, a prospective observational cohort study that enrolled patients with AF between 2014 and 2017. Resource utilization and cost information were collected through claims data. Quality of life was measured with EQ-5D-3L utilities. We estimated incremental cost-effectiveness ratios (ICERs) from the perspective of the Swiss statutory health insurance system. RESULTS: Patients undergoing PVI compared with medical therapy had a 5-year overall survival advantage with a hazard ratio of 0.75 (95% CI 0.46-1.21; P = .69) and a 19.8% SD improvement in quality of life (95% CI 15.5-22.9; P < .001), at an incremental cost of 29 604 Swiss francs (CHF) (95% CI 16 354-42 855; P < .001). The estimated ICER was CHF 158 612 per quality-adjusted life-year (QALY) gained within a 5-year time horizon. Assuming similar health effects and costs over 5 additional years changed the ICER to CHF 82 195 per QALY gained. Results were robust to the sensitivity analyses performed. CONCLUSIONS: Our results show that PVI might be a cost-effective intervention within the Swiss healthcare context in a 10-year time horizon, but unlikely to be so at 5 years, if a willingness-to-pay threshold of CHF 100 000 per QALY gained is assumed. Given data availability, we find target trial designs are a valuable tool for assessing the cost-effectiveness of healthcare interventions outside of randomized controlled trial settings.

Validation of a clinical model for predicting left versus right ventricular outflow tract origin of idiopathic ventricular arrhythmias.

BACKGROUND: Prediction of the chamber of origin in patients with outflow tract ventricular arrhythmias (OTVA) remains challenging. A clinical risk score based on age, sex and presence of hypertension was associated with a left ventricular outflow tract (LVOT) origin. We aimed to validate this clinical score to predict an LVOT origin in patients with OTVA. METHODS: In a two-center observational cohort study, unselected patients undergoing catheter ablation (CA) for OTVA were enrolled. All procedures were performed using an electroanatomical mapping system. Successful ablation was defined as a ≥80% reduction of the initial overall PVC burden after 3 months of follow-up. Patients with unsuccessful ablation were excluded from this analysis. RESULTS: We included 187 consecutive patients with successful CA of idiopathic OTVA. Mean age was 52 ± 15 years, 102 patients (55%) were female, and 74 (40%) suffered from hypertension. A LVOT origin was found in 64 patients (34%). A score incorporating age, sex and presence of hypertension reached 73% sensitivity and 67% specificity for a low (0-1) and high (2-3) score, to predict an LVOT origin. The combination of one ECG algorithm (V2 S/V3 R-index) with the clinical score resulted in a sensitivity and specificity of 81% and 70% for PVCs with R/S transition at V3 . CONCLUSION: The published clinical score yielded a lower sensitivity and specificity in our cohort. However, for PVCs with R/S transition at V3, the combination with an existing ECG algorithm can improve the predictability of LVOT origin.

Transvenous Lead Extraction during Cardiac Implantable Device Upgrade: Results from the Multicenter Swiss Lead Extraction Registry.

BACKGROUND: Device patients may require upgrade interventions from simpler to more complex cardiac implantable electronic devices. Prior to upgrading interventions, clinicians need to balance the risks and benefits of transvenous lead extraction (TLE), additional lead implantation or lead abandonment. However, evidence on procedural outcomes of TLE at the time of device upgrade is scarce. METHODS: This is a post hoc analysis of the investigator-initiated multicenter Swiss TLE registry. The objectives were to assess patient and procedural factors influencing TLE outcomes at the time of device upgrades. RESULTS: 941 patients were included, whereof 83 (8.8%) had TLE due to a device upgrade. Rotational mechanical sheaths were more often used in upgraded patients (59% vs. 42.7%, p = 0.015) and total median procedure time was longer in these patients (160 min vs. 105 min, p < 0.001). Clinical success rates of upgraded patients compared to those who received TLE due to other reasons were not different (97.6% vs. 93.0%, p = 0.569). Moreover, multivariable analysis showed that upgrade procedures were not associated with a greater risk for complications (HR 0.48, 95% confidence interval 0.14-1.57, p = 0.224; intraprocedural complication rate of upgraded patients 7.2% vs. 5.5%). Intraprocedural complications of upgraded patients were mostly associated with the implantation and not the extraction procedure (67% vs. 33% of complications). CONCLUSIONS: TLE during device upgrade is effective and does not attribute a disproportionate risk to the upgrade procedure.