Ambulatory AV synchronous pacing over time using a leadless ventricular pacemaker: Primary results from the AccelAV study
BACKGROUND:Prior studies demonstrated that accelerometer-based mechanically-timed AV synchrony (AVS) is feasible using a leadless ventricular pacemaker. OBJECTIVE:This study reports on the performance of a leadless ventricular pacemaker with accelerometer-based algorithms that provide AVS pacing. METHODS:AccelAV was a prospective single-arm study to characterize AVS in patients implanted with a Micra AV, which uses the device accelerometer to mechanically detect atrial contractions and promote VDD pacing. The primary objective was to characterize resting AVS at 1-month in patients with complete AV block (AVB) and normal sinus function. RESULTS:A total of 152 patients (age 77Â±11 years, 48% female) from 20 centers were enrolled and implanted with a leadless pacemaker. Among patients with normal sinus function and complete AVB (n=54), mean resting AVS was 85.4% at 1-month, while ambulatory AVS was 74.8%. In the subset of patients (n=20) with programming optimization, mean ambulatory AVS was 82.6%, representing a 10.5% improvement (P<0.001). Quality of life as measured by the EQ-5D-3L improved significantly from pre-implant to 3 months (P=0.031). In 37 patients with AVB at both 1-month and 3-months, mean AVS during rest did not differ (86.1% vs 84.1%, P=0.43). There were no upgrades to dual-chamber devices or CRT through 3 months. CONCLUSION/CONCLUSIONS:Accelerometer-based mechanical atrial sensing provided by a leadless pacemaker implanted in the right ventricle significantly improves quality of life in a select cohort of patients with AV block and normal sinus function. AVS remained stable through 3 months and there were no system upgrades to dual-chamber pacemakers.
Correlation between AV synchrony and device collected AM-VP sequence counter in atrioventricular synchronous leadless pacemakers: A real-world assessment
INTRODUCTION/BACKGROUND:Micra atrioventricularÂ (AV) provides leadless atrioventricular synchronous pacing by sensing atrial contraction (A4 signal). Real-world operation and reliability of AV synchrony (AVS) assessment using device data have not been described. The purposes of this study were to (1) assess the correlation between AVS and atrial mechanical sensed-ventricular pacingÂ (AM-VP) percentages in patients with permanent high-degree AV block and (2) report on the real-world effectiveness of Micra AV. METHODS:The correlation between ECG-determined AVS in-clinic and device-collected %AM-VP was assessed using data from 40 patients with high-degree AV block enrolled in the Micra Atrial tRacking using a Ventricular AccELerometerÂ (MARVEL) 2 study. A retrospective analysis to assess continuously-sampled %AM-VP since last session, device programming, and electrical parameters was performed using Micra AV transmissions from the Medtronic CareLink database. Patients with transmissions â‰¥180 days postimplant were included. RESULTS:at 28 weeks. In patients with %VPÂ >90% (nâ€‰=â€‰1662), the median %AM-VP was 74.7%. For the full cohort, median %VP was 65.6% and median projected battery longevity was 10.5 years. CONCLUSION/CONCLUSIONS:In patients with a high pacing burden, %AM-VP provides a reasonable estimation of AVS. The first large real-world analysis of Micra AV patients with >90% VP showed stable atrial sensing over time with a median %AM-VP, a correlate of AVS, of 74.7%.
Outcomes and atrial substrate analysis in patients with HIV undergoing atrial fibrillation ablation
INTRODUCTION/BACKGROUND:Patients with HIV infection have increased risk of atrial fibrillation, but the pathophysiologic mechanisms and the utility of catheter ablation in this population are not well-studied. We aimed to characterize outcomes of atrial fibrillation ablation and left atrial substrate in patients with HIV. METHODS:The study was a retrospective propensity score-matched analysis of patients with and without HIV undergoing atrial fibrillation ablation. A search was performed in the electronic medical record for all patients with HIV who received initial atrial fibrillation ablation from 2011 to 2020. After calculating propensity scores for HIV, matching was performed with patients without HIV by using nearest-neighbor matching without replacement in a 1:2 ratio. The primary outcome was freedom from atrial arrhythmia and secondary outcomes were freedom from atrial fibrillation, freedom from atrial tachycardia, and freedom from repeat ablation, compared by log-rank analysis. The procedures of patients with HIV who underwent repeat ablation at our institution were further analyzed for etiology of recurrence. To further characterize the left atrial substrate, a subsequent case-control analysis was then performed for a set of randomly chosen 10 patients with HIV matched with 10 without HIV to compare minimum and maximum voltage at nine pre-specified regions of the left atrium. RESULTS:Twenty-seven patients with HIV were identified. All were prescribed antiretroviral therapy at time of ablation. These patients were matched with 54 patients without HIV by propensity score. 86.4% of patients with HIV and 76.9% of controls were free of atrial fibrillation or atrial tachycardia at 1 year (p = .509). Log-rank analysis showed no difference in freedom from atrial arrhythmia (p value .971), atrial fibrillation (p-value .346), atrial tachycardia (p value .306), or repeat ablation (p value .401) after initial atrial fibrillation ablation in patients with HIV compared to patients without HIV. In patients with HIV with recurrent atrial fibrillation, the majority had pulmonary vein reconnection (67%). There were no significant differences in minimum or maximum voltage at any of the nine left atrial regions between the matched patients with and without HIV. CONCLUSIONS:Ablation to treat atrial fibrillation in patients with HIV, but without overt AIDS is frequently successful therapy. The majority of patients with recurrence of atrial fibrillation had pulmonary vein reconnection, suggesting infrequent nonpulmonary vein substrate. In this population, the left atrial voltage in patients with HIV is similar to that of patients without HIV. These findings suggest that the pulmonary veins remain a critical component to the initiation and maintenance of atrial fibrillation in patients with HIV.
Sex differences in outcomes of transvenous lead extraction: insights from National Readmission Database
BACKGROUND:With the growing use of implantable cardiac devices, the need for transvenous lead extraction has increased, which translates to increased procedural volumes. Sex differences in lead extraction outcomes are not well studied. OBJECTIVE:The present study aims at evaluating the impact of sex on outcomes of lead extraction. METHODS:We identified 71,754 patients who presented between 2016 and 2019 and underwent transvenous lead extraction. Their clinical data were retrospectively accrued from the National Readmission Database (NRD) using the corresponding diagnosis codes. We compared clinical outcomes between male and female patients. Odds ratios (ORs) for the primary and secondary outcomes were calculated, and multivariable regression analysis was utilized to adjust for confounding variables. RESULTS:Compared to male patients, female patients had higher in-hospital complications including pneumothorax (OR 1.26, 95% CI (1.07-1.4), P < 0.01), hemopericardium (OR 1.39, 95% CI (1.02-1.88), P = 0.036), injury to superior vena cava and innominate vein requiring repair (OR 1.88, 95% CI (1.14-3.1), P = 0.014; OR 3.4, 95% CI (1.8-6.5), P < 0.01), need for blood transfusion (OR 1.28, 95% CI (1.18-1.38), P < 0.01), and pericardiocentesis (OR 1.6, 95% CI (1.3-2), P < 0.01). Thirty-day readmission was also significantly higher in female patients (OR 1.09, 95% CI (1.02-1.17), P < 0.01). There was no significant difference regarding in-hospital mortality (OR 0.99, 95% CI (0.87-1.14), P = 0.95). CONCLUSION/CONCLUSIONS:In female patients, lead extraction is associated with worse clinical outcomes and higher 30-day readmission rate.
Persistent atrial fibrillation ablation: the ongoing search for the perfect wave [Editorial]
Development and validation of a risk score for predicting pericardial effusion in patients undergoing leadless pacemaker implantation: experience with the Micra transcatheter pacemaker
AIMS/OBJECTIVE:There is limited information on what clinical factors are associated with the development of pericardial effusion after leadless pacemaker implantation. We sought to determine predictors of and to develop a risk score for pericardial effusion in patients undergoing Micra leadless pacemaker implantation attempt. METHODS AND RESULTS/RESULTS:Patients (n = 2817) undergoing implant attempt from the Micra global trials were analysed. Characteristics were compared between patients with and without pericardial effusion (including cardiac perforation and tamponade). A risk score for pericardial effusion was developed from 18 pre-procedural clinical variables using lasso logistic regression. Internal validation and future prediction performance were estimated using bootstrap resampling. The scoring system was also externally validated using data from the Micra Acute Performance European and Middle East (MAP EMEA) registry. There were 32 patients with a pericardial effusion [1.1%, 95% confidence interval (CI): 0.8-1.6%]. Following lasso logistic regression, 11 of 18 variables remained in the model from which point values were assigned. The C-index was 0.79 (95% CI: 0.71-0.88). Patient risk score profile ranged from -4 (lowest risk) to 5 (highest risk) with 71.8% patients considered low risk (risk score â‰¤0), 16.6% considered medium risk (risk score = 1), and 11.7% considered high risk (risk score â‰¥2) for effusion. The median C-index following bootstrap validation was 0.73 (interquartile range: 0.70-0.75). The C-index based on 9 pericardial effusions from the 928 patients in the MAP EMEA registry was 0.68 (95% CI: 0.52-0.83). The pericardial effusion rate increased significantly with additional Micra deployments in medium-risk (P = 0.034) and high-risk (P < 0.001) patients. CONCLUSION/CONCLUSIONS:The overall rate of pericardial effusion following Micra implantation attempt is 1.1% and has decreased over time. The risk of pericardial effusion after Micra implant attempt can be predicted using pre-procedural clinical characteristics with reasonable discrimination. CLINICAL TRIAL REGISTRATION/BACKGROUND:The Micra Post-Approval Registry (ClinicalTrials.gov identifier: NCT02536118), Micra Continued Access Study (ClinicalTrials.gov identifier: NCT02488681), and Micra Transcatheter Pacing Study (ClinicalTrials.gov identifier: NCT02004873).
Urgent catheter ablation for treatment refractory symptomatic atrial fibrillation: Health care utilization and outcomes
The Marvel of Leadless Technology [Editorial]
Subcutaneous Versus Transvenous Implantable Defibrillator in Patients with Hypertrophic Cardiomyopathy
BACKGROUND:Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiomyopathy. Implantable Cardioverter Defibrillator (ICD) is important for prevention of sudden cardiac death (SCD) in patients at high risk. In recent years the subcutaneous ICD (S-ICD) has emerged as a viable alternative to the transvenous ICD (TV-ICD). The S-ICD does not require intravascular access, but cannot provide antitachycardia pacing therapy (ATP). OBJECTIVE:To assess the real world incidence of ICD therapy in patients with HCM implanted with TV-ICD versus S-ICD. METHODS:We compared the incidence of ATP and shock therapies between all HCM patients with S-ICD and TV-ICD enrolled in the Boston Scientific ALTITUDE database. Cumulative Kaplan Meier incidence was used to compare therapy free survival and Cox proportional hazard ratios were calculated. We performed an unmatched as well as propensity match analysis. RESULTS:We included 2047 patients with TV-ICD and 626 patients with S-ICD followed for an average of 1650.5Â±1038.5 and 933.4Â±550.6 days, respectively. Patients with HCM and TV-ICD had significantly higher rate of device therapy as compared to those with S-ICD (32.7 vs. 14.5 therapies /100 patient year; p<0.001), driven by a high incidence of ATP therapy in the TV-ICD group which accounted for more than 67% of therapies delivered. Shock incidence was similar between groups, both in the general and in the matched cohorts. CONCLUSIONS:Patients with HCM and S-ICD had significantly lower therapy rate than patients with TV-ICD without difference in shock therapy, suggesting potentially unnecessary ATP therapy. Empiric ATP programing in patients with HCM may be unbeneficial.
Symphony to Leadless pacing - An Ode to Joy [Editorial]
Ludwig van Beethoven's 9th Symphony is regarded by many musicologists as one of the finest works in the history of music. It is notable for several reasons, particularly being the first example of a composer using voices, with words sung by a chorus and vocal soloist in the final movement. This article is protected by copyright. All rights reserved.