Impact of omitting the intravenous heparin bolus on outcomes of leadless pacemaker implantation.

BACKGROUND: Early guidance recommended a bolus of intravenous heparin at the beginning of leadless pacemaker (LP) implantation procedures. However, due to concern about bleeding complications, more recent practice has tended toward omitting the bolus and only running a continuous heparin infusion through the introducer sheath. The impact of omitting the heparin bolus on procedural outcomes is not clear. METHODS: We reviewed all Medtronic Micra LP implants at our institution from 9/2014 to 9/2022. The decision to bolus with heparin was at operator discretion. RESULTS: Among 621 LP implants, 326 received an intravenous heparin bolus, 243 did not, and 52 patients were excluded because heparin bolus status could not be confirmed. There was a trend toward more frequent omission of the heparin bolus with more recent implants. Median follow-up after LP implant was 14.3 (interquartile range [IQR]: 8.4-27.9) months. There was no difference between heparin bolus and no bolus groups in the number of device deployments/recaptures (1.42 ± 0.81 vs. 1.31 ± 0.66, p = .15). Implant-related adverse events were also similar between heparin bolus and no bolus groups: access-site hematoma requiring intervention (7 vs. 5, p = .99), pseudoaneurysm (1 vs. 1, p = .99), cardiac perforation (1 vs. 1, p = .99), intraprocedural device thrombus formation (2 vs. 4, p = .41), 30-day rehospitalization (21 vs. 15, p = .98), and 30-day all-cause mortality (16 vs. 14, p = .70). There was one additional nonfatal cardiac perforation in a patient who was excluded due to unknown heparin bolus status. Regarding device electrical parameters between heparin bolus and no bolus groups, there were no significant differences at the time of implant: pacing capture threshold 0.5 ± 0.4 vs. 0.5 ± 0.3, p = .10; pacing impedance 739.9 ± 226.4 vs. 719.1 ± 215.4, p = .52; R wave sensing 11.7 ± 5.7 vs. 12.0 ± 5.4, p = .34). Long-term device performance was also similar between groups. CONCLUSION: Omission of the systemic heparin bolus at the time of LP implantation appears safe in appropriately selected patients. Heparin bolus may still be considered in long cases requiring multiple device deployments or in patients at high risk for thrombotic complications.

Evaluation of the in vivo chemical reactivity of a novel copolymer insulation on cardiac leads in a single-center study.

BACKGROUND: Human in vivo data on the chemical stability of different transvenous lead materials, particularly OptimTM leads, are lacking. OBJECTIVES: The purpose of this study was to determine the chemical reactivity of insulation materials by analyzing the molar mass of extracted pacing and defibrillator leads METHODS: We collected extracted leads at Emory University Hospitals and sent the leads with thermoplastic outer insulation material for molar mass analysis, a material characteristic that informs biostability. Leads were separated based on the chemical identity of the outer insulation material, and the molar mass was measured by an independent party. The extent of chemical reaction was compared across leads having different materials: poly(ether)urethane 55D, poly(ether)urethane 80A, and Optim. RESULTS: A total of 70 leads were extracted. The subset of extracted leads having outer insulation materials composed of PEU or Optim were analyzed for molar mass, where implant times ranged from 0.12 to 16.26 years. The rate of chemical degradation was compared by plotting the extent of reaction [Mn(t = 0)/Mn(t)] as a function of implant time. The Optim molar mass decreased to 40% of its initial value at 10 years of implant. No change in the molar mass of the PEU insulations could be resolved over the same 10-year implant time. CONCLUSION: Because the molar mass of a polymer is directly related to its mechanical integrity, the observed decrease in molar mass of Optim likely translates into premature insulation defects and is consistent with the observed increased rate of electrical malfunction/noise in this subset of cardiac leads.

Outcomes of tricuspid regurgitation after lead extraction.

INTRODUCTION: Transvenous leads have been implicated in tricuspid valve (TV) dysfunction, but limited data are available regarding the effect of extracting leads across the TV on valve regurgitation. The aim of this study is to quantify tricuspid regurgitation (TR) before and after lead extraction and identify predictors of worsening TR. METHODS: We studied 321 patients who had echocardiographic data before and after lead extraction. TR was graded on a scale (0 = none/trivial, 1 = mild, 2 = moderate, 3 = severe). A change of >1 grade following extraction was considered significant. RESULTS: A total of 321 patients underwent extraction of a total of 338 leads across the TV (1.05 ± 0.31 leads across the TV per patient). There was no significant difference on average TR grade pre- and postextraction (1.18 ± 0.91 vs. 1.15 ± 0.87; p = 0.79). TR severity increased after extraction in 84 patients, but was classified as significantly worse (i.e., >1 grade change in severity) in only 8 patients (2.5%). Use of laser lead extraction was associated with a higher rate of worsening TR postextraction (44.0% vs. 31.6%, p = 0.04). CONCLUSION: In our single-center analysis, extraction of leads across the TV did not significantly affect the extent of TR in most patients. Laser lead extraction was associated with a higher rate of worsening TR after extraction.

Safety of multi-access site venous closure following catheter ablation of atrial fibrillation and flutter.

BACKGROUND: Following catheter ablation, vascular access management involves potential complications and prolonged recovery. Recently, suture-mediated closure (SMC) devices were approved for venous access procedures. The objective of this study is to evaluate the safety of a commercially available SMC for multiple access site venous closure by duplex ultrasound (DUS) in asymptomatic subjects with non-visible complications. METHODS: Thirty-six subjects (63 ± 10.7 years old, 12 female) were enrolled. Following catheter ablation for atrial fibrillation, all subjects had SMC of every venous access site. Subjects underwent DUS of femoral veins and arteries. DUS was performed at discharge, and again at 30 days. Subjects were evaluated for clinically apparent vascular complications. RESULTS: Mean procedure duration was 138.6 min, and the time to hemostasis was 3.1 min/access site and 9.5 min/subject. Median time to ambulation was 193.5 min, and median time to discharge was 5.95 h, with discharge as early as 2.4 h. A median of 2 sheaths/vein and a median of 2 SMC devices/vein were used. There were no major complications and a 16.7% (6/36) minor complication rate at discharge. All complications resolved at 30 days. The complication rate was not higher in patients with 2 SMC per access site as compared to the patients who just received 1 SMC per access site. CONCLUSIONS: This study demonstrates the safety of multi-access closure using SMC, following catheter ablation procedures, for closure of sites that use sheath sizes from ≤ 8F to ≥ 15F and for those that use 2 or more SMCs per access site.

Long-term performance of single-connector (DF4) implantable defibrillator leads.

AIMS: Single-connector (DF4) defibrillator leads have become the predominantly implanted transvenous implantable cardioverter-defibrillator lead. However, data on their long-term performance are derived predominantly from manufacturer product performance reports. METHODS AND RESULTS: We reviewed medical records in 5289 patients with DF4 leads between 2011 and 2023 to determine the frequency of lead-related abnormalities. We defined malfunction as any single or combination of electrical abnormalities requiring revision including a sudden increase (≥2×) in stimulation threshold, a discrete jump in high-voltage impedance, or sensing of non-physiologic intervals or noise. We documented time to failure, predictors of failure, and management strategies. Mean follow-up after implant was 4.15 ± 3.6 years (median = 3.63), with 37% of leads followed for >5 years. A total of 80 (1.5%) leads demonstrated electrical abnormalities requiring revision with an average time to failure of 4 ± 2.8 years (median = 3.5). Of the leads that malfunctioned, 62/80 (78%) were extracted and replaced with a new lead and in the other 18 cases, malfunctioned DF4 leads were abandoned, and a new lead implanted. In multivariable models, younger age at implant (OR 1.03 per year; P < 0.001) and the presence of Abbott/St. Jude leads increased the risk of malfunction. CONCLUSION: DF4 defibrillator leads demonstrate excellent longevity with >98.3% of leads followed for at least 5 years still functioning normally. Younger age at implant and lead manufacturer are associated with an increased risk of DF4 lead malfunction. The differences in lead survival between manufacturers require further investigation.

Prospective validation of a risk score to predict pacemaker implantation after transcatheter aortic valve replacement.

INTRODUCTION: The need for pacemaker is a common complication after transcatheter aortic valve replacement (TAVR). We previously described the Emory Risk Score (ERS) to predict the need for new pacemaker implant (PPM) after TAVR. Metrics included in the score are a history of syncope, pre-existing RBBB, QRS duration ≥140 ms, and prosthesis oversizing ≥16%. To prospectively validate the previously described risk score. METHODS: We prospectively evaluated all patients without pre-existing pacemakers, ICD, or pre-existing indications for pacing undergoing TAVR with the Edwards SAPIEN 3 prosthesis at our institution from March 2019 to December 2020 (n = 661). Patients were scored prospectively; however, results were blinded from clinical decision-making. The primary endpoint was PPM at 30 days after TAVR. Performance of the ERS was evaluated using logistic regression, a calibration curve to prior performance, and receiver operating characteristic (ROC) analysis. RESULTS: A total of 48 patients (7.3%) had PPM after TAVR. A higher ERS predicted an increased likelihood of PPM (OR 2.61, 95% CI: 2.05-3.25 per point, p < 0.001). There was good correlation between observed and expected values on the calibration curve (slope = 1.04, calibration at large = 0.001). The area under the ROC curve was 0.81 (95% CI [0.74-0.88], p < 0.001). CONCLUSIONS: The ERS prospectively predicted the need for PPM in a serial, real-world cohort of patients undergoing TAVR with a balloon-expandable prosthesis, confirming findings previously described in retrospective cohorts. Notably, the prospective performance of the score was comparable with that of the initial cohorts. The risk score could serve as a framework for preprocedural risk stratification for PPM after TAVR.

Outcomes of leadless pacemaker implantation after cardiac surgery and transcatheter structural valve interventions.

INTRODUCTION: Permanent pacing indications are common after cardiac surgery and transcatheter structural valve interventions. Leadless pacemakers (LPs) have emerged as a useful alternative to transvenous pacemakers. However, current commercially available LPs are unable to provide atrial pacing or cardiac resynchronization and relatively little is known about LP outcomes after cardiac surgery and transcatheter valve interventions. METHODS: This retrospective study included patients who received a Micra VR (MicraTM MC1VR01) or Micra AV (MicraTM MC1AVR1) (Medtronic) leadless pacemaker following cardiac surgery or transcatheter structural valve intervention between September 2014 and September 2022. Device performance and clinical outcomes, including ventricular pacing burden, ejection fraction, and need for conversion to transvenous pacing systems, were evaluated during follow-up. RESULTS: A total of 78 patients were included, of whom 40 received a Micra VR LP implant, and 38 received a Micra AV LP implant. The mean age of the cohort was 65.9 ± 17.9 years, and 48.1% were females. The follow-up duration for the entire cohort was 1.3 ± 1.1 years: 1.6 ± 1.3 years for the Micra VR group and 0.8 ± 0.5 years for the Micra AV group. Among the cohort, 50 patients had undergone cardiac surgery and 28 underwent transcatheter structural valve interventions. Device electrical performance was excellent during follow-up, with a small but clinically insignificant increase in ventricular pacing threshold and a slight decrease in pacing impedance. The mean right ventricle pacing (RVP) burden significantly decreased over time in the entire cohort (74.3% ± 37.2% postprocedure vs. 47.7% ± 40.6% at last follow-up, p < .001), and left ventricle ejection fraction (LVEF) showed a modest but significant downward trend during follow-up (55.0% ± 10.6% vs. 51.5% ± 11.2% p < .001). Patients with Micra VR implants had significantly reduced LVEF during follow-up (54.1% ± 11.9% vs. 48.8% ± 11.9%, p = .003), whereas LVEF appeared stable in the Micra AV group during follow-up (56.1% ± 9.0% vs. 54.6% ± 9.7%, p = .06). Six patients (7.7%) required conversion to transvenous pacing systems, four who required cardiac resynchronization for drop in LVEF with high RVP burden and two who required dual-chamber pacemakers for symptomatic sinus node dysfunction. CONCLUSION: Leadless pacemakers provide a useful alternative to transvenous pacemakers in appropriately selected patients after cardiac surgery and transcatheter structural valve interventions. Device performance is excellent over medium-term follow-up. However, a significant minority of patients require conversion to transvenous pacing systems for cardiac resynchronization or atrial pacing support, demonstrating the need for close electrophysiologic follow-up in this cohort.

Safety of same-day discharge after lead extraction procedures.

BACKGROUND: Same-day discharge (SDD) after cardiovascular procedures is rapidly gaining ground. OBJECTIVE: We sought to evaluate the safety of SDD after transvenous lead extraction (TLE). METHODS: We performed a retrospective chart review of patients who underwent elective TLE between January 2020 and October 2021 at our institution. The primary outcome was SDD, and major procedural complications and readmissions within 30 days of the procedure were secondary outcomes. RESULTS: In this analysis of 111 patients who underwent elective TLE, 80 patients (72%) were discharged on the same day (SDD group) while 31 patients (28%) stayed overnight (overnight group). Lead malfunction was the most common indication for TLE in both groups. Patients in the overnight group were more likely to have a lead dwell time of ≤10 years than those in the SDD group (38.7% vs 20% of all leads in each group; P = .042), have laser sheaths used for extraction and a higher number of leads extracted. No major complications were reported in both groups. In a multivariate analysis, lower body mass index and the use of laser sheath during TLE were predictors of overnight stay. Patients who underwent a procedure using advanced extraction techniques were 3.5 times more likely to stay overnight (95% confidence interval 1.27-9.78; P = .016). CONCLUSION: In appropriately selected patients undergoing elective lead extraction, SDD is feasible and safe. Higher body mass index, fewer extracted leads, shorter lead dwell times (<10 years), and less frequent use of laser-powered extraction sheaths were associated with an increased likelihood of SDD.

Novel use of an irrigated ablation catheter to monitor real-time hemodynamics during ablation.

INTRODUCTION: Hemodynamic decompensation during catheter ablation occurs due to prolonged procedure time and irrigant delivery directly into the cardiac chambers. Real-time hemodynamic monitoring of patients undergoing catheter ablation procedures may identify patients at risk of decompensation; we set out to assess the feasibility of a novel, real-time, intracardiac pressure monitoring system using a standard irrigated ablation catheter. METHODS: We studied 13 consecutive who underwent pressure measurement of the left atrium (LA) and left ventricle (LV) via transeptal access with a Swan Ganz (SG) catheter followed by two commercially available irrigated ablation catheters. Pressure waveform data was extracted to compare LA peak pressure, LV peak systolic pressure, LV end-diastolic pressure, and waveform analysis. RESULTS: Comparison between the SG and ablation catheters (AblA; AblB) demonstrated that LV systolic pressure (0.61-16.8 mmHg; 1.32-18.2 mmHg), and LV end-diastolic pressure (-3.4 to 2.8 mmHg; -3.0 to 3.35 mmHg) were well correlated and had accepted repeatability. Ablation waveforms demonstrated an 89.9 ± 6.4% correlation compared to SG waveforms. CONCLUSION: Pressure measurements derived from an irrigated ablation catheter are accurate and reliable when compared to an SG catheter. Further studies are needed to determine how real-time pressure monitoring can improve outcomes during ablation procedures.

The Feasibility and Safety of Flecainide Use Among Patients With Varying Degrees of Coronary Disease.

BACKGROUND: Class IC antiarrhythmic agents are effective for treating atrial tachyarrhythmias, but their use is restricted in patients with coronary artery disease (CAD). Data on the safety of the use of IC agents in patients with CAD in the absence of recent acute coronary syndromes are lacking. OBJECTIVES: This study sought to evaluate the safety and feasibility of treatment with IC agents in patients with varying degrees of CAD in a large serial, real-world cohort. METHODS: We retrospectively identified all patients at our institution from January 2005 to February 2021 on a IC agent (n = 3,445) and those on sotalol or dofetilide (n = 2,216) as controls, excluding those with a prior history of ventricular tachycardia, implantable cardioverter-defibrillator placement, or nonrevascularized myocardial infarction. Baseline clinical characteristics included degree of CAD (categorized as none, nonobstructive, or obstructive), other comorbid illness, and medication use. Clinical outcomes, including survival, were ascertained. We performed Cox regression analysis to evaluate the effect of IC use on event-free survival across varying degrees of CAD. RESULTS: After adjustment for baseline characteristics, there was an independent association between IC use and improved mortality. However, there was an interaction between IC use and degree of CAD (compared to sotalol) demonstrating poorer event-free survival among those with obstructive coronary disease (HR: 3.80; 95% CI: 1.67-8.67; P = 0.002). CONCLUSIONS: Among select patients with nonobstructive CAD and without a history of ventricular tachycardia, IC agents are not associated with increased mortality. Therefore, these agents may be an option for some patients in whom they are frequently restricted. Further prospective studies are warranted.

Long Term Follow-Up of Stereotactic Body Radiation Therapy for Refractory Ventricular Tachycardia in Advanced Heart Failure Patients.

Background: Initial studies of stereotactic body radiation therapy (SBRT) for refractory ventricular tachycardia (VT) have demonstrated impressive efficacy. Follow-up analyses have found mixed results and the role of SBRT for refractory VT remains unclear. We performed palliative, cardiac radio ablation in patients with ventricular tachycardia refractory to ablation and medical management. Methods: Arrhythmogenic regions were targeted by combining computed tomography imaging with electrophysiologic mapping with collaboration from a radiation oncologist, electrophysiologist and cardiac imaging specialist. Patients were treated with a single fraction 25 Gy. Total durations of VT, the quantity of antitachycardia pacing (ATP) and shocks before and after treatment as recorded by implantable cardioverter-defibrillators (ICDs) were analyzed. Follow-up extended until most recent device interrogation unless transplant, death or repeat ablation occurred sooner. Results: Fourteen patients (age 50-78, four females) were treated and had an average of two prior ablations. Nine had ACC/AHA Stage D heart failure and three had left ventricular assist devices (LVAD). Two patients died shortly after SBRT, one received a prompt heart transplant and another had significant VT durations in the following months that were inaccurately recorded by their device. Ten of the 14 patients remained with adequate data post SBRT for analysis with an average follow-up duration of 216 days. Seven of those 10 patients had a decrease in VT post SBRT. Comparing the 90 days before treatment to cumulative follow-up, patients had a 59% reduction in VT, 39% reduction in ATP and a 60% reduction in shocks. Four patients received repeat ablation following SBRT. Pneumonitis was the only complication, occurring in four of the fourteen patients. Conclusion: SBRT may have value in advanced heart failure patients with refractory VT acutely but the utility over long-term follow-up appears modest. Prospective randomized data is needed to better clarify the role of SBRT in managing refractory VT.

Same-Day Versus Next-Day Discharge Strategies for Left Atrial Ablation Procedures: A Parallel, Intra-Institutional Comparison of Safety and Feasibility.

BACKGROUND: Head-to-head comparative data for the postoperative care of patients undergoing left atrial ablation procedures are lacking. OBJECTIVE: We sought to investigate complication and readmission rates between patients undergoing same-day (SD) or next-day (ND) discharges for ablative procedures in the left atrium, primarily atrial fibrillation (AF). METHODS: Two electrophysiology centers simultaneously perform left atrial ablations with differing discharge strategies. We identified all patients who underwent left atrial ablation from August 2017 to August 2019 (n = 409) undergoing either SD (n = 210) or ND (n = 199) discharge protocols. We analyzed any clinical events that resulted in procedural abortion, extended hospitalization, or readmission within 72 hours. RESULTS: The primary endpoint of complication and readmission rate was similar between SD and ND discharge (14.3% vs 12.6%, p = 0.665). Rates of complications categorized as major (2.4% vs 3.0%, p = 0. 776) and minor (11.9% vs 9.5%, p = 0.524) were also similar.Multivariable regression modeling revealed no significant correlation between discharge strategy and complication/readmission occurrence (OR 1.565 [0.754 - 3.248], p = 0.23), but a positive association of hypertension and procedure duration (OR 3.428 [1.436 - 8.184], p = 0.006) and (OR 1.01 [1 - 1.019], p = 0.046) respectively. CONCLUSIONS: Left atrial ablation complication and readmission rates were similar between SD and ND discharge practices. Hypertension and procedural duration were associated with increased complication rates irrespective of discharge strategy. These data, which represent the first side-by-side comparison of discharge strategy, suggests same-day discharge is safe and feasible for left atrial ablation procedures.

Outcomes Of Manifest Right Free Wall Accessory Pathway Ablation: Data From A Single Center.

BACKGROUND: Right free wall (RFW) accessory pathways (AP) typically present anatomical challenges to ablation leading to high rates of procedural failure and recovery of AP conduction. METHODS: Patients with a diagnosis of Wolff-Parkinson-White Syndrome (WPW) and a manifest RFW AP undergoing an electrophysiology study (EPS) or an ablation at our center between 01/01/2008 and 08/01/2019 were identified from our databases using diagnosis codes and manual chart review. RESULTS: Twenty-one patients with manifest RFW AP underwent EPS, all of which were targeted for ablation. Single procedure success rate was 19 / 21 (90.5%). Of the 19 successful cases, 4 (17.4%) patients were found to have recurrent right free wall pathway conduction at follow-up and each underwent a successful 2nd procedure (9.5%). Fluoroscopic and 3D electroanatomic mapping software was used in all cases to guide ablation. A 4 mm or 8 mm non-irrigated radiofrequency (RF) ablation catheter was used in 76% of cases while an 8 mm cryo-catheter was used in one case. More than one type of ablation catheter was used in four cases (16%). A steerable sheath was used in 68% of cases. CONCLUSIONS: In a tertiary center, RFW AP ablation has high acute success (>90%) but approximately 21% of patients with initially successful ablation required a 2nd procedure for recurrence of pathway conduction. A combination of a large tip ablation catheter and a steerable sheath were used in most cases.

Prospective evaluation of health status, quality of life and clinical outcomes following implantable defibrillator generator exchange.

BACKGROUND: Little is known about health status and quality of life (QoL) after implantable cardioverter-defibrillator (ICD) generator exchange (GE). METHODS: We prospectively followed patients undergoing first-time ICD GE. Serial assessments of health status were performed by administering the 36-Item Short Form Survey (SF-36). RESULTS: Mean age was 67.5 ± 14.3 years, left ventricle ejection fraction (LVEF) was 36.5% ± 15.0% and over 40% of the cohort had improved LVEF to > 35% at the time of GE. SF-36 scores were significantly worse in physical/general health domains compared to domains of emotional/social well-being ( P < 0.001 for each comparison). Physical health scores were significantly worse among those with medical comorbidities including diabetes, chronic obstructive pulmonary disease and atrial fibrillation. Mean follow-up was 1.6 ± 0.5 years after GE. Overall SF-36 scores remained stable across all domains during follow-up. Survival at 3 years post-GE was estimated at 80%. Five patients died during follow-up and most deaths were adjudicated as non-arrhythmic in origin. Four patients experienced appropriate ICD shocks after GE, three of whom had LVEF which remains impaired LVEF (i.e., < 35%) at the time of GE. CONCLUSION: Patients undergoing ICD GE have significantly worse physical health compared to emotional/social well-being, which is associated with the presence of medical comorbidities. In terms of clinical outcomes, the incidence of appropriate shocks after GE among those with improvement in LVEF is very low, and most deaths post-procedure appear to be non-arrhythmic in origin. These data represent an attempt to more fully characterize the spectrum of QoL and clinical outcomes after GE.

Ablation of manifest septal accessory pathways: a single-center experience.

BACKGROUND: Ablation of septal accessory pathways (SAPs) is associated with an increased risk of heart block. Data on outcomes of SAP ablation in adults are limited. OBJECTIVES: To describe outcomes of SAP ablation in our center. METHODS: Patients with Wolff-Parkinson-White syndrome (WPW) undergoing an EP study at our center between January 2008 and August 2019 were identified from our institutional database. Location of the pathway was noted as anteroseptal (AS), midseptal (MS), or posteroseptal (PS). Outcomes of the ablation including success, complication rates, and recurrences were also recorded. RESULTS: Thirty-three patients with SAP underwent 35 EP studies: AS (n = 13), MS (n = 5), and PS (n = 15). Thirty pathways were targeted for ablation, two of which required a 2nd procedure resulting in 32 attempts at ablation in 30 patients. In the remaining 3 patients, SAP did not have malignant features and were not targeted for ablation. Single-procedure success rate was 28/30 (93.33%): 9/10 AS, 5/5 MS, and 14/15 PS ablations. One AS pathway was successfully ablated during a 2nd procedure. Two complications were observed: 1 pericardial effusion in a patient who underwent epicardial mapping and ablation of both PS and right free wall APs. Additionally, transient 2:1 AV block occurred during an MS pathway ablation that recovered during follow-up and did not require permanent pacing procedure. CONCLUSION: In this single-center experience, ablation of manifest SAP was associated with high success rates and low complication rates. No instances of permanent heart block requiring pacing occurred.

Relationship between device-detected burden and duration of atrial fibrillation and risk of ischemic stroke.

BACKGROUND: Wider availability of continuous rhythm monitoring has made feasible the incorporation of metrics of atrial fibrillation (AF) burden and duration into the decision to initiate anticoagulation. However, the relationship between thresholds of burden and duration and underlying risk factors at which anticoagulation should be considered remains unclear. OBJECTIVE: The purpose of this study was to evaluate the relationships of these metrics with each other and the outcome of stroke/transient ischemic attack (TIA). METHODS: We identified patients with cardiovascular implantable electronic devices (CIEDs) with atrial leads who had at least 1 interrogation in 2016 demonstrating nonpermanent AF and were not receiving oral anticoagulation (OAC). We evaluated the relationship between burden (ie, percentage of time spent in AF), the longest single episode of AF, and risk factors (ie, CHA2DS2-VASc score) in predicting risk of stroke/TIA. RESULTS: The study included 384 patients with mean follow-up of 3.2 ± 0.8 years and incidence of stroke/TIA of 14.8% during follow-up (∼4.6% per year). The burden of AF and the duration of longest episode demonstrated a significant positive correlation to each other but not CHA2DS2-VASc score. Importantly, although the CHA2DS2-VASc score was predictive of stroke/TIA, neither burden nor duration was associated with stroke/TIA. CONCLUSION: Among patients with CIED-detected AF not receiving OAC, the amount of AF (measured by either burden or duration) does not seem to significantly impact stroke risk, whereas CHA2DS2-VASc score does. These data suggest that among patients with CIED-detected AF, once AF occurs, stroke risk seems to be predominantly driven by underlying risk factors.

Life cycle management of Micra transcatheter pacing system: Data from a high-volume center.

BACKGROUND: Data on the management of Micra transcatheter pacing system (TPS) at the time of an upgrade or during battery depletion is limited. OBJECTIVE: We sought to evaluate the management patterns of patients implanted with a Micra TPS during long-term follow-up. METHODS: We retrospectively identified patients who underwent Micra implantation from April 2014 to November 2019. We identified patients who underwent extraction (n = 11) or had an abandoned Micra (n = 12). RESULTS: We identified 302 patients who received a Micra during the period of the study. Mean age was 72.7 ± 15.4 years, 54.6% were men, and left ventricular ejection fraction was 51.9 ± 5.2%. Mean follow-up was 1105.5 ± 529.3 days. Procedural complications included pericardial tamponade (n = 1) treated with pericardiocentesis, significant rise in thresholds (n = 6) treated with reimplantation (n = 4), and major groin complications (n = 2). Indications for extraction included an upgrade to cardiac resynchronization therapy (CRT) device (n = 3), bridging after extraction of an infected transvenous system (n = 3), elevated thresholds (n = 3), and non-Micra-related bacteremia (n = 2). The median time from implantation to extraction was 78 days (interquartile range: 14-113 days), with the longest extraction occurring at 1442 days. All extractions were successful, with no procedural or long-term complications. Indications for abandonment included the need for CRT (n = 6), battery depletion (n = 2), increasing thresholds/failure to capture (n = 3), and pacemaker syndrome (n = 1). All procedures were successful, with no procedural or long-term complications. CONCLUSION: In this large single-center study, 6% of patients implanted with a Micra required a system modification during long-term follow-up, most commonly due to the requirement for CRT pacing. These patients were managed successfully with extraction or abandonment.