Low-temperature electrocautery reduces lead-related complications: insights from the WRAP-IT study

Background

Patients with an existing cardiovascular implantable electronic device (CIED) often require a generator replacement or system upgrade/revision, during which some degree of dissection is usually necessary to free the existing lead(s). Commonly used techniques include blunt dissection, standard surgical electrocautery, or newer forms of electrocautery such as the low-temperature electrosurgical device (PlasmaBlade Soft Tissue Dissection Device) designed to minimize inadvertent thermal injury to leads.

Objective

Determine whether the dissection technique impacts the likelihood of developing a lead-related complication.

Methods

The WRAP-IT trial enrolled patients undergoing CIED replacement, upgrade, revision or de novo CRT-D implant. This analysis excluded patients undergoing a de novo procedure. All adverse events were adjudicated by an independent physician committee. Data were analyzed using Cox proportional hazard regression modeling, controlling for capsulectomies and lead dissections.

Results

5639 patients (mean [±SD] age: 70.6±12.7 years; 28.8% female) underwent a replacement/upgrade/revision. Electrocautery was used in 5203 (92.3%) patients and among these, low-temperature electrocautery was used in 1866 (35.9%) patients. Compared to standard electrocautery, low-temperature electrocautery was used more often when leads were dissected or mobilized (P<0.001) or when a partial or complete capsulectomy was performed (P<0.001). Use of low-temperature electrocautery was associated with a 31% reduction in lead-related complications (HR: 0.69, 95% CI: 0.49–0.98, P=0.037) (Figure).

Conclusion

The low-temperature electrosurgical device (PlasmaBlade) uses precise pulses of radiofrequency energy to dissect tissue with only minimal thermal damage. In this large cohort of replacement, revision, and upgrade procedures, use of low-temperature electrocautery led to significantly fewer lead-related complications.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic

P549CIED infection risk score validation using US health claims data

Funding Acknowledgements

This work was supported by Medtronic

Background/Introduction: The increasing number of cardiac implantable electronic device (CIED) infections has led to increased interest in the identification of patients who may benefit from additional infection prevention measures.

Purpose

The purpose of this evaluation was to validate the predictive value of the Prevention of Arrhythmia Device Infection Trial (PADIT) risk score to identify patients at increased risk of CIED infection using a U.S. health claims data set.

Methods

A retrospective analysis using the Optum® Clinformatics® claims database was conducted to create a dataset of index procedures which either did or did not result in an infection.  The study population included both commercial and Medicare Advantage patients aged ≥18 years with at least one record of a CIED procedure between January 2011 and September 2014.  Major CIED infections, defined as an infection associated with system removal, invasive procedure without system removal, or death attributable to infection, were identified through diagnosis and procedure codes.  The dataset was randomized (stratified by PADIT score, which included prior procedures, age, depressed renal function, immunocompromised, and procedure type) into a Development Dataset (60%) and a Validation dataset (40%).  A frailty model allowing multiple procedures per patient was fit using the Development Dataset, with PADIT score as the only predictor, excluding patients with prior infection. Prior CIED infection, which was not available in the original PADIT data, was examined for additional predictive value.

Results

The data extraction resulted in a dataset of 53,554 index procedures among 51,583 patients, with 30,950 patients randomized to the Development Dataset.  The distribution of procedures was pacemakers (52%), ICD (20%), CRT (12%), and Revision/Upgrade (16%), while prior procedures were none (62%), 1 (37%), and 2 (1%). Among patients with no history of prior CIED infection, the frailty model showed that a 1 unit increase in the PADIT score predicts higher infection risk (20%) in the U.S. claims data set (Table 1). Prior CIED infection was associated with strong additional predictive value (HR 4.77, p < 0.0001) after adjusting for PADIT score.

Conclusion

In the largest external validation of a CIED risk score, the PADIT risk score predicts increased CIED infection risk, identifying higher risk patients that can benefit from targeted interventions to reduce the risk of CIED infection. Prior CIED infection brings additional predictive value to the PADIT score.

P4526Implant procedure and lead handling characteristics of a novel active fixation quadripolar lead: Results from the Attain Stability Quad clinical trial

Background

Dislodgements of left ventricular (LV) leads are still a challenging problem in cardiac resynchronization therapy (CRT). The Attain Stability Quad (ASQuad) MRI SureScan 4798 steroid-eluting, quadripolar LV lead has a side-helix to enable the lead to be actively fixated to the vessel wall. The uniquely designed active fixation can be advantageous in vessels that are wide or have short take-offs. Further, the helix easily elongates to allow for future extraction.

Purpose

To report on the handling, performance and safety of ASQuad LV lead in a large clinical study.

Methods

The ASQuad clinical study is a prospective clinical trial from 50 centers in 10 countries enrolling CRT candidates implanted with the ASQuad LV lead. Aside from evaluating safety and effectiveness of the LV lead, the trial specifically collected data on parameters related to lead stability during and post implant.

Results

Of 440 enrolled patients (74.8% male, average age 70±11 years) that underwent an implant attempt, 426 (96.8%) were successfully implanted. The helix was mostly affixed in the mid to basal lateral position (62%), followed by mid to basal posterior position (29%). The lead tip placement was most often mid lateral or mid posterior (77%), and in a vein with diameter greater than the pacing electrode diameter (>5.1 French) in the majority (60%) of procedures. Among all subjects (n=421) who underwent pacing capture thresholds (PCT) tests before and immediate after guide catheter slitting, 98% reported ≤1 V difference in PCT, and 86% were within 0.5 V. The interquartile range for the difference in PCT was −0.1 to 0.1 V. The mean PCT at implant for all subjects at the final selected LV pacing vector was 1.15±0.70 V at 0.5 ms pulse width. The average LV lead implant time was 16±21 minutes. Targeted pacing location was achieved in 97% of successful implants, and 98% of implanters reported good or fair stability after guidewire removal. The overall handling of the LV lead was rated as acceptable by implanters in 99% of cases. Three patients (0.7%) experienced LV lead dislodgement post implant, and these complications were resolved by repositioning of the lead (0 and 1-day post implant) in two and by lead replacement when noted at 90 days follow-up in one.

Conclusions

The ASQuad LV lead was implanted with a high rate of success and ability to achieve the targeted pacing location. Lead handling and stability following guidewire removal were rated as acceptable by nearly all implanters. The side-helix likely improved LV lead stability since 98% of the subjects had ≤1 V difference in PCT before and after catheter slitting during implant procedures, and by demonstrating a low post implant lead dislodgement rate.

Acknowledgement/Funding

Sponsored by Medtronic

P6546Canadian Registry of Electronic Device Outcomes (CREDO): remote monitoring outcomes in the abbott battery performance alert, a multicentre cohort

Background

Cardiac implantable electronic devices have been known to have lead and device malfunctions leading to advisories. Increased use of remote monitoring of devices has been suggested to allow the identification of abnormal device performance and allow early intervention. We sought to describe the outcomes of patients with and without remote monitoring of in devices in the Abbott Premature Battery Depletion advisory with data from a Canadian registry

Methods

Patients with an Abbott device subject to the Battery Performance Alert Advisory from nine ICD implanting centres in Canada were included in the registry. The use of remote monitoring was identified from baseline and followup data in the registry. The primary outcome was detection of premature battery depletion and all cause mortality.

Results

2679 patents were identified with a device subject to the advisory. Devices were implanted between 2010 and 2017. 1716 patients (64%) had remote monitoring at baseline with this increasing to 83.7% at followup at 12 months. Premature battery depletion occurred in 43 patients (1.6%). Discovery of premature battery depletion was detected by remote monitoring in 70% of patients. There were 492 deaths during the follow up. Mortality was higher in those without a remote monitor compared to those with a remote monitor at follow-up and remote monitor at baseline and follow-up (11.3%, 2.6% versus 6.1% respectively; p=0.0186). There were no deaths attributed to premature battery depletion

Conclusion

The use of remote monitoring in patients with ICD and CRT under advisory reliably detected device failure and was associated with a reduction in all-cause mortality.

[Radiofrequency ablation of left premature ventricular complex from the papillary muscle]

BACKGROUND

Radiofrequency ablation for incessant and symptomatic premature ventricular complex (PVC) localized in a left papillary muscle is uncommon. 3D mapping and cardiac MRI may be useful to achieve ablation success.

CLINICAL CASE

A fifty-four-years-old man was referred for palpitations. His medical history included placement of a right coronary artery stent six years before and a normal ejection fraction (EF). The Holter monitoring under beta-blocker therapy (46% PVCs) and ECG showed monomorphic PVCs with a right bundle branch block, positive concordance with V5 transition and a superior axis, with no R/T phenomenon. During two separate electrophysiologic procedures (recurrence), a 3D mapping (Velocity, ST-Jude Medical™) system was used combined with an irrigated tip catheter. The earliest site of PVC activation documented with the mapping system was near the posterior papillary muscle. Pace mapping in this area showed nearly 90% concordance. After 2126 seconds of radiofrequency applications, there were no more PVC and no inducible arrhythmia. Post procedure cardiac MRI showed scar in the inferior-lateral area of the left ventricle including a section of the posterior papillary muscle. Scar included 50% of the thickness of the wall (previous 2005 myocardial infarction and radiofrequency lesions). Residual EF was 55%. At 2 months of follow-up, the patient was asymptomatic, with only 53 PVCs on 24-hour Holter monitoring. Patient was maintained under beta-blocker therapy for his coronary artery disease. At six-month follow-up, he is still asymptomatic.

CONCLUSION

This case report stresses the role of cardiac MRI and 3D cartography systems for successful treatment of papillary muscle PVCs associated with ischemic cardiomyopathy, which still represent a therapeutic challenge.

Intraoperative study of polarization and evoked response signals in different endocardial electrode designs

Some new generation pacemakers use an algorithm based on evoked response (ER) detection to verify beat-to-beat capture and to enable automatic adjustment of output. This is a prospective acute study of polarization signal (PS) and ER in nine currently available electrodes. Intraoperative testing of ventricular bipolar electrodes used the Autocapture (AC) algorithm. The intrinsic R wave, PS, ER, acceptance of AC function, and stimulation thresholds (STs) were obtained. Ventricular electrodes were categorized as follows: titanium nitride (TiN)-coated passive and active fixation, high impedance (HI), passive fixation (VP), iridium oxide-coated titanium (IROX) (VI), and platinum helix (PH) active fixation. Acute testing was performed in 217 patients with an average age of 74.26 years, 59.6% were men with primary pacing indication-SSS (46.3%). There were no significant differences found with respect to R wave and threshold between the various electrodes. PH active-fixation electrodes had significantly higher ER and PS than other groups including the TiN-coated active-fixation electrodes. TiN-coated electrodes (active and passive fixation) had significantly lower PS than other electrodes. As a result, TiN electrodes had a significantly higher functional rate of AC (91.7%), whereas PH had the lowest rate (0%). In conclusion, (1) polarization characteristics are significantly different for commercially available ventricular electrodes, (2) certain physical features at the tissue to electrode interface like TiN coating appears to be more important in determining PS than electrode tip size and fixation method, and (3) the current algorithm for AC requires electrodes that provide low polarization for satisfactory performance.

Circadian variation of paroxysmal atrial fibrillation. PA3 Investigators. Atrial Pacing Peri-ablation for Prevention of Atrial Fibrillation Trial

The circadian variation of paroxysmal atrial fibrillation (AF) was studied in 67 patients who received a dual-chamber pacemaker 3 months before a planned atrioventricular node ablation. A distinct circadian variation of AF was observed with 2 time peaks in initiation (1 in the early morning and 1 in the early evening hours), which was modulated by atrial pacing, the duration of AF, and the use of beta-adrenergic blocking agents.