Does the Risk-Benefit Analysis Favor the Extraction of Failed, Sterile Pacemaker and Defibrillator Leads?

When pacing or defibrillator leads become redundant: Extract or abandon?

The 2017 Heart Rhythm Society expert consensus paper on lead management and extraction did not express a preference for either extracting or abandoning pacing or defibrillator leads that are dysfunctional or superfluous after an upgrade (hereafter referred to as redundant leads). However, no randomized or even nonrandomized trials show a better patient outcome with extraction. Many experienced centers currently advise patients to have redundant leads removed to prevent more complicated procedures after years of abandonment. According to the literature, however, not all abandoned leads need to be extracted as >90% will have an uneventful follow-up. As immediate extraction of redundant leads has a small but significant risk, this will generate more adverse events at the population level than when extraction is limited to the patients with future lead complications, even considering a higher extraction risk at that time. Lead extraction is also limited to specialized centers and often necessitates expensive tools, in contrast to abandoning leads, which can be safely performed by any experienced device specialist without additional cost.

Therapeutic Ultrasound in Cardiovascular Medicine

An advantage of therapeutic ultrasound (US) is the ability to cause controlled biological effects noninvasively. Depending on the magnitude and frequency of exposure parameters, US can interact in different ways with a variety of biological tissues. The development and clinical utility of therapeutic US techniques are now rapidly growing, especially with regard to the application of US pulses for cardiac pacing and the potential treatment of cardiovascular diseases. This review outlines the basic principles of US-based therapy in cardiology, including the acoustic properties of the cardiovascular tissue, and the use of US in therapeutic cardiovascular medicine.

Venous System Interventions for Device Implantation

Subclavian obstruction is common after lead implantation and the need to add or replace a lead is increasing. Subclavian venoplasty (SV) is a safe and effective option for venous occlusion. Peripheral venography overestimates the severity of the obstruction. A wire can usually be advanced into the central circulation for SV. Compared with dilators, SV improves the quality of venous access, providing unrestricted catheter manipulation for His bundle pacing and left ventricular lead implantation. SV preserves venous access and reduces lead burden. SV can easily be added to the implanting physicians lead management options.

The Negative Chronotropic Effect in Rat Heart Stimulated by Ultrasonic Pulses: Role of Sex and Age

OBJECTIVES

The goal of this study is to investigate the role of sex and age of the negative chronotropic effect after exposure of 3.5-MHz pulsed ultrasound (US) to the rat heart.

METHODS

Forty F344 rats were exposed transthoracically to ultrasonic pulses at a duty factor of approximately 1.0% at 2.0-MPa peak rarefactional pressure amplitude. The transthoracic ultrasonic bursts were delivered consecutively in five 10-s intervals, that is, 10 s of 6-Hz pulse repetition frequency (PRF), 10 s of 5-Hz PRF, 10 s of 4-Hz PRF, 10 s of 5-Hz PRF, and 10 s of 6-Hz, for a 50-s total exposure duration. The rats were divided into 8 groups (n = 5 each): US young male, control young male, US young female, control young female, US old male, control old male, US old female, and control old female.

RESULTS

Two-way ANOVA for repeated measures was used to compare heart rate, cardiac output, arterial pressure, and other hemodynamic values (baseline) before and after US stimulation. Sex versus age versus US interaction was detected for heart rate. Cardiac output showed an age effect, and ejection fraction showed age and US effects. The arterial pressure showed a sex effect. A negative chronotropic effect (∼30% decrease in heart rate) was observed for young female rats. An hypothesis is that the US effect is weight (menopause) dependent, because the young (premenopausal) female rats weighed approximately 40 to 60% less than other groups of rats.

CONCLUSIONS

It is likely that the ovarian hormones are responsible for different US-induced cardiac bioeffects in different ages and sexes.

Lead Extraction Considerations for the Referring Cardiologist

The population of patients with cardiac implantable electronic devices (CIEDs) continues to grow due to increasing indications in an aging population and breakthroughs in both the medical and the surgical care of patients with heart disease. As a result, there has been a growing need for device and lead extractions due to the growing population of patients with CIEDs and the subsequent need for system upgrades or revisions because of complications, infections, and lead advisory alerts.

Cardiac Implantable Electronic Device Infections: Added Complexity and Suboptimal Outcomes With Previously Abandoned Leads

OBJECTIVES

This study sought to assess the impact of previously abandoned leads on the clinical management of cardiac device infections, notably transvenous lead extraction and subsequent clinical course.

BACKGROUND

The population of patients with cardiac implantable electronic devices continues to grow with a disproportionate increase in device infections, which are invariably life threatening. A potentially complicating issue is the widely practiced strategy of device lead abandonment at the time of system revision, change, or upgrade, which is affecting an increasing number of patients.

METHODS

The study assessed the impact of previously abandoned leads in a prospectively maintained registry of consecutive patients undergoing percutaneous extraction of infected cardiac devices at the Cleveland Clinic between August 1996 and September 2012. The primary clinical endpoint was complete procedural and clinical success defined as the successful removal of the device and all lead material from the vascular space, in the absence of a major complication.

RESULTS

Of 1,386 patients with infected cardiac devices, 323 (23.3%) had previously abandoned leads. Failure to achieve the primary endpoint occurred more frequently in patients with abandoned leads (13.0% vs. 3.7%; p < 0.0001). This was primarily due to retention of lead material (11.5% vs. 2.9%; p < 0.0001), which was associated with poor clinical outcomes including higher rates of 1-month mortality (7.4% vs. 3.5% in those without lead remnants). Lead extraction procedures in patients with previously abandoned leads were longer (p < 0.0001), with longer fluoroscopy times (p < 0.0001), and more likely to require specialized extraction tools (94.4% vs. 81.8%; p < 0.0001) or adjunctive rescue femoral workstations (14.9% vs. 2.9%; p < 0.0001). Procedural complications occurred more frequently in patients with previously abandoned leads (11.5% vs. 5.6%; p = 0.0003), which was true for both major (3.7% vs. 1.4%; p = 0.009) and minor complications (7.7% vs. 4.4%; p = 0.02).

CONCLUSIONS

Previously abandoned leads complicate the management of cardiac device infections, leading to worse clinical outcomes.

Managing patients with advisory defibrillator leads: what can we learn from published data?

Defibrillator lead advisories stir a lot of emotions, both with patients and physicians, and this may influence lead management. We reviewed the literature for a more evidence-based approach to this issue.

From the complications of two of the current advisory leads, the Medtronic Sprint Fidelis and St. Jude Riata leads, and the consequences of possible interventions, we can conclude that a restrained approach to premature replacement is appropriate. It may be opportune to replace the leads during a scheduled generator replacement in case of a higher electrical failure rate, in order to prevent future premature interventions.

We found no support to extract non-functional advisory leads. In contrast, extraction is often more demanding than anticipated, and the risk substantially exceeds that of simply abandoning the leads.

Ultrasound-induced heart rate decrease: role of the vagus nerve

The goal of this study is to investigate the role of the vagus nerve (VN) in the ultrasound (US)-induced negative chronotropic effect (deceased heart rate). One of the functions of the VN is to mediate lowering of the heart rate. A previous study showed a decrease of ~20% in the heart rate but the mechanism of the effect was not investigated. Sprague Dawley rats (n = 20) were exposed transthoracically to ultrasonic pulses at an approximate duty factor of 1% with sequentially 2.0, 2.5, and 3.0 MPa peak rarefactional pressure amplitudes (PRPAs). The ultrasonic exposure parameters herein were chosen to match those of the previous study to have confidence that an ultrasound-induced negative chronotropic effect would occur. For each of the three PRPA sequences, the pulse repetition frequency (PRF) started slightly greater than the rat's heart rate and then was decreased sequentially in 1-Hz steps every 10 s (i.e., 6, 5, and 4 Hz for a total duration of 30 s). The experiments were organized in a standard (2 × 2) factorial design with VN (cut versus intact) as one factor and US (on versus off) as another factor. VN (intact/cut) and US (on/off) groups were divided into four groups each consisting of 5 animals: 1) VN intact-US off, 2) VN intact-US on, 3) VN cut-US off, and 4) VN cut-US on. Two-way analysis of variance for repeated measures was used to compare heart rate, cardiac output, systolic volume, ejection fraction, end-diastolic volume, end-systolic volume, respiratory rate, and arterial pressure before and after ultrasound stimulation. In this study, the heart rate decreased ~4% for the non-vagotomy and vagotomy groups. The ultrasound effect was significant for heart rate (p = 0.02) and cardiac output (p = 0.005) at 3 min post US exposure; the vagotomy effect was not significant. For heart rate, the Bonferroni test showed no differences between the four groups. The vagotomy group showed similar ultrasound-induced cardiac effects compared with the non-vagotomy group, suggesting that the vagus nerve is not influenced by the ultrasound exposure procedures. The US application caused a negative chronotropic effect of the rat heart without affecting the hemodynamic conditions. The results at this point are suggestive for an alternative cardiac pacing capability.

Extraction of Sterile Leads: Is it Beneficial?

Extraction of sterile leads remains a controversial area. The risks and benefits of abandoning a lead are largely unknown, whereas the risks of lead extraction are better studied. Lead management decisions need to be made on a patient-by-patient basis, with important input from the patient and family. This article presents several representative cases and reviews the major considerations in making the decision of whether or not to extract a sterile lead that has become either no longer needed or no longer functional.