Clinical impact of right ventricular pacing burden in patients with post-transcatheter aortic valve replacement permanent pacemaker implantation.

AIMS: Patients who undergo permanent pacemaker (PPM) implantation after transcatheter aortic valve replacement (TAVR) have a worse outcome. The aim of this study was to identify risk factors of worse outcomes in patients with post-TAVR PPM implantation. METHODS AND RESULTS: This is a single-centre, retrospective study of consecutive patients who underwent post-TAVR PPM implantation from 11 March 2011 to 9 November 2019. Clinical outcomes were evaluated by landmark analysis with cut-off at 1 year after the PPM implantation. Of the 1389 patients underwent TAVR during the study duration and a total of 110 patients were included in the final analysis. Right ventricular pacing burden (RVPB) ≥ 30% at 1 year was associated with a higher likelihood of heart failure (HF) readmission [adjusted hazard ratio (aHR): 6.333; 95% confidence interval [CI]: 1.417-28.311; P = 0.016] and composite endpoint of overall death and/or HF (aHR: 2.453; 95% CI: 1.040-5.786; P = 0.040). The RVPB ≥30% at 1 year was associated with higher atrial fibrillation burden (24.1 ± 40.6% vs. 1.2 ± 5.3%; P = 0.013) and a decrease in left ventricular ejection fraction (-5.0 ± 9.8% vs. + 1.1 ± 7.9%; P = 0.005). The predicting factors of the RVPB ≥30% at 1 year were the presence of RVPB ≥40% at 1 month and the valve implantation depth measured from non-coronary cusp ≥4.0 mm (aHR: 57.808; 95% CI: 12.489-267.584; P < 0.001 and aHR: 6.817; 95% CI: 1.829-25.402; P = 0.004). CONCLUSIONS: The RVPB ≥30% at 1 year was associated with worse outcomes. Clinical benefit of minimal RV pacing algorithms and biventricular pacing needs to be investigated.

Risk Stratification of New Persistent Left Bundle Branch Block After Transcatheter Aortic Valve Implantation.

Previous studies reported that new-onset persistent left bundle branch block (NOP-LBBB) was related to worse outcomes after transcatheter aortic valve implantation (TAVI). However, these results can be confounded by the presence of permanent pacemaker (PPM) implantation before and after TAVI. Long-term outcomes and the risk stratification of NOP-LBBB not having PPM implantation before and after TAVI have not been fully investigated. This is an international, multicenter, retrospective study of patients who underwent TAVI from July 31, 2007, to May 8, 2020. A total of 2,240 patients were included, and 17.5% of patients developed NOP-LBBB. NOP-LBBB was associated with cardiac mortality (adjusted hazard ratio [aHR] 1.419, 95% confidence interval [CI] 1.014 to 1.985, p = 0.041) and the composite outcomes of cardiac mortality and/or heart failure readmission (aHR 1.313, 95% CI 1.027 to 1.678, p = 0.030). Patients who developed NOP-LBBB with pre-TAVI left ventricular ejection fraction (LVEF) <40% were significantly associated with cardiac mortality (aHR 2.049, 95% CI 1.039 to 4.041, p = 0.038), heart failure (aHR 3.990, 95% CI 2.362 to 6.741, p <0.001), and the composite outcome (aHR 2.729, 95% CI 1.703 to 4.374, p <0.001). Although NOP-LBBB with pre-TAVI LVEF >40% had a significant decrease in LVEF 6 to 12 months after TAVI (-1.8 ± 9.7% vs +0.6 ± 8.1%, p = 0.003), NOP-LBBB with pre-TAVI LVEF <40% had a significant increase in LVEF 6 to 12 months after TAVI (+9.7 ± 13.6% vs +13.0 ± 11.7%, p = 0.157). In conclusion, patients with NOP-LBBB without pre-TAVI and post-TAVI PPM developed significantly worse long-term outcomes, especially in patients with pre-TAVI LVEF <40%. Further prospective investigation should be undertaken.

Risk Prediction Model for Cardiac Implantable Electronic Device Implantation After Transcatheter Aortic Valve Replacement.

OBJECTIVES: The aim of this study was to develop and validate a risk prediction model for high-grade atrioventricular block requiring cardiac implantable electronic device (CIED) implantation after transcatheter aortic valve replacement (TAVR). BACKGROUND: High-grade atrioventricular block requiring CIED remains a significant sequelae following TAVR. Although several pre-operative characteristics have been associated with the risk of post-operative CIED implantation, an accurate and validated risk prediction model is not established yet. METHODS: This was a single center, retrospective study of consecutive patients who underwent TAVR from March 10, 2011, to October 8, 2018. This cohort sample was randomly divided into a derivation cohort (group A) and a validation cohort (group B). A scoring system for risk prediction of post-TAVR CIED implantation was devised using logistic regression estimates in group A and the calibration and validation were done in group B. RESULTS: A total of 1,071 patients underwent TAVR during the study period. After excluding pre-existing CIED, a total of 888 cases were analyzed (group A: 507 and group B: 381). Independent predictive variables were as follows: self-expanding valve (1 point), hypertension (1 point), pre-existing first-degree atrioventricular block (1 point), and right bundle branch block (2 points). The resulting score was calculated from the total points. The internal validation in group B showed an ideal linear relationship in calibration plot (R2 = 0.933) and a good predictive accuracy (area under the curve: 0.693; 95% confidence interval: 0.627 to 0.759). CONCLUSIONS: This prediction model accurately predicts post-operative risk of CIED implantation with simple pre-operative parameters.

Impact of Right Ventricular Pacing in Patients Who Underwent Implantation of Permanent Pacemaker After Transcatheter Aortic Valve Implantation.

Atrioventricular conduction disturbances requiring implantation of permanent pacemaker (PPM) are a common complication following transcatheter aortic valve implantation (TAVI). Previous registry data are conflicting but suggestive of an increased risk in heart failure admissions in the post-TAVI PPM cohort. Given the expanding use of TAVI, the present study evaluates the effects of chronic right ventricular pacing (RV pacing) in post-TAVI patients. This is a single-center study of 672 patients who underwent TAVI from 2011 to 2017 of which 146 underwent PPM. Follow-up 1-year post-TAVI outcome data were available for 55 patients and were analyzed retrospectively. Patients who underwent PPM were more likely to have heart failure admissions (17.1% vs 10.1%; hazard ratio [HR] 1.70; 95% confidence interval [CI] 1.10 to 2.64; p 0.019) and a trend toward increased mortality (21.9% vs 15.4%; HR 1.42; 95% CI 0.99 to 2.05; p 0.062). At 1-year follow-up, 30 of 55 (54.5%) patients demonstrated >40% RV pacing. Compared with patients who had <40% RV pacing, those with >40% RV pacing were more likely to have heart failure admissions (8% vs 40%; HR 5.0; 95% CI 1.23 to 20.27; p 0.007) and demonstrated a trend toward increased mortality (12% vs 33.3%; HR 2.78; 95% CI 0.86 to 9.00; p 0.064). This is suggestive that the post-TAVI PPM cohort is particularly sensitive to chronic RV pacing.

Atrial fibrillation ablation using remote magnetic navigation and the risk of atrial-esophageal fistula: international multicenter experience.

PURPOSE: Remote magnetic navigation (RMN) has been used in various electrophysiological procedures, including atrial fibrillation (AF) ablation. Atrial-esophageal fistula (AEF) is one of most disastrous complications of AF ablation. We aimed to evaluate the incidence of AEF during AF ablation using RMN in comparison to manual ablation. METHODS: We conducted the first international survey among RMN operators for assessment of the prevalence of AEF and procedural parameters affecting the risk. Data from parallel survey of AEF among Canadian interventional electrophysiologists (CIE) using only manual catheters served as control. RESULTS: Fifteen RMN operators (who performed 3637 procedures) and 25 manual CIE operators (7016 procedures) responded to the survey. RMN operators were more experienced than CIE operators (16.3 ± 8.3 vs. 9.2 ± 5.4 practice years in electrophysiology, p = 0.007). The maximal energy output in the posterior wall was higher in the operator using RMN (33 ± 5 vs. 28.6 ± 4.9 W; p = 0.02). Other parameters including use of preprocedural images, irrigated catheter, pump flow rate, esophageal temperature monitoring, intracardiac echocardiography (ICE), and general anesthesia were similar. CIE operators administered proton-pump inhibitors postoperatively significantly more than RMN operators (76 vs. 35%, p = 0.01). AEF was reported in 5 of the 7016 patients in the control group (0.07%) but in none of the RMN group (p = 0.11). CONCLUSIONS: AEF is a rare complication and its evaluation necessitates large-scale studies. Although no AEF case with RMN was reported in this large study or previously on the literature, the rarity of this complication prevents firm conclusion about the risk.

Feasibility and safety of using an esophageal protective system to eliminate esophageal thermal injury: implications on atrial-esophageal fistula following AF ablation.

BACKGROUND: Ablation for atrial fibrillation (AF) requires energy delivery in close proximity to the esophagus (Eso) which has accounted for the LA-Eso fistula, a rare but life-threatening complication. PURPOSE: We evaluated an Eso cooling system to protect the Eso during RF ablation. METHODS AND RESULTS: An "in vitro" heart-Eso preparation was initially used to test a temperature-controlled fluid-circulating system (EPSac [esophageal protective system]-RossHart Technologies Inc.) and an expandable compliant Eso sac during cardiac RF delivery (4 mm tip, perpendicular to the heart, 15 g pressure) at 25, 35, and 45 W, 100 +/- 5 Omega for 30 seconds with the EPSac at 25, 15, 10, and 5 degrees C. All cardiac lesions were transmural. Eso thermal injury could only be avoided with the EPSac at 10 and 5 degrees C. The system was then tested in 6 closed chest dogs, each receiving 12 RFs (LA aiming at the Eso) for 30 seconds: without EPSac (control) at 35 W (1 dog); at 45 W with EPSac at 25 degrees C (1 dog), 10 degrees C (2 dogs), and 5 degrees C (2 dogs). The EPSac volume was intentionally increased to displace the Eso toward the LA (2 dogs 5 and 10 degrees C). Eso injured control and EPSac at 25 degrees C; Eso spared EPSac at 5 and 10 degrees C, without Eso displacement. Shallow external Eso injury noted when intentionally displacing the Eso toward the LA. CONCLUSIONS: The EPSac spares the Eso from collateral thermal injury. It requires circulating fluid at 5 or 10 degrees C and a compliant sac to avoid displacement of the Eso. Its safety and efficacy remain to be demonstrated in patients undergoing AF ablation.

A novel mesh electrode catheter for mapping and radiofrequency delivery at the left atrium-pulmonary vein junction: a single-catheter approach to pulmonary vein antrum isolation.

BACKGROUND: Electrical isolation of pulmonary veins (PV) by radiofrequency (RF) ablation is often performed in patients with atrial fibrillation (AF). Current catheter technology usually requires the use of a multielectrode catheter for mapping in addition to the ablation catheter. PURPOSE: We evaluated the feasibility and safety of using a single, expandable electrode catheter (MESH) to map and to electrically isolate the PV. METHODS AND RESULTS: Nineteen closed-chest mongrel dogs, weighing 23-35 kg, were studied under general anesthesia. Intracardiac echocardiography (ICE) was used to guide transseptal puncture and to assess PV dimensions and contact of the MESH with PV ostia. ICE and angiography of RSPV were obtained before and after ablation, and prior to sacrifice at 7-99 days. An 11.5 Fr steerable MESH was advanced and deployed at the ostium of the RSPV. Recordings were obtained via the 36 electrodes comprising the MESH. For circumferential ablation, RF current was delivered at a target temperature of 62-65 degrees C (4 thermocouples) and maximum power of 70-100 W for 180 to 300 seconds. Each animal received 1-4 RF applications. Entrance conduction block was obtained in 13/19 treated RSPVs. Pathological examination confirmed circumferential and transmural lesions in 13 of 19 RSPV. LA mural thrombus was present in 3 animals. There was no significant PV stenosis. CONCLUSION: Based on this canine model, a new expandable MESH catheter may safely be used for mapping and for PV antrum isolation. This approach may decrease procedure time without compromising success rate in patients undergoing AF ablation.