Timing of device reimplantation and reinfection rates following cardiac implantable electronic device infection: a systematic review and meta-analysis

Update on Cardiovascular Implantable Electronic Device Infections and Their Prevention, Diagnosis, and Management: A Scientific Statement From the American Heart Association: Endorsed by the International Society for Cardiovascular Infectious Diseases

The American Heart Association sponsored the first iteration of a scientific statement that addressed all aspects of cardiovascular implantable electronic device infection in 2010. Major advances in the prevention, diagnosis, and management of these infections have occurred since then, necessitating a scientific statement update. An 11-member writing group was identified and included recognized experts in cardiology and infectious diseases, with a career focus on cardiovascular infections. The group initially met in October 2022 to develop a scientific statement that was drafted with front-line clinicians in mind and focused on providing updated clinical information to enhance outcomes of patients with cardiovascular implantable electronic device infection. The current scientific statement highlights recent advances in prevention, diagnosis, and management, and how they may be incorporated in the complex care of patients with cardiovascular implantable electronic device infection.

Lead Extraction-Indications, Procedure, and Future Directions

Cardiac implantable electronic device (CIED) implantation has steadily increased in the United States owing to increased life expectancy, better access to health care, and the adoption of updated guidelines. Transvenous lead extraction (TLE) is an invasive technique for the removal of CIED devices, and the most common indications include device infections, lead failures, and venous occlusion. Although in-hospital and procedure-related deaths for patients undergoing TLE are low, the long-term mortality remains high with 10-year survival reported close to 50% after TLE. This is likely demonstrative of the increased burden of comorbidities with aging. There are guidelines provided by various professional societies, including the Heart Rhythm Society, regarding indications for lead extraction and management of these patients. In this paper, we will review the indications for CIED extraction, procedural considerations, and management of these patients based upon the latest guidelines.

Timing and mid-term outcomes of using leadless pacemakers as replacement for infected cardiac implantable electronic devices

BACKGROUND

Cardiac implantable electronic device (CIED) infections have a high morbidity and mortality and are an indication of device extraction. As a replacement, leadless pacemakers (LPs) may be preferable due to a low infection risk, but mid-term data on reinfections is lacking. Moreover, early LP reimplantation in pacemaker-dependent patients would circumvent the need for temporary pacemakers.

METHODS

We included all patients with LP implantation as a replacement for an infected CIED, between January 2013 and December 2021. The occurrence of reinfection was assessed during standard follow-up visits.

RESULTS

Twenty-nine patients (mean age 81 ± 9 years) were included, of which 21 (73%) had a pocket infection, 7 (24%) endocarditis, and 1 (3%) a systemic infection without endocarditis. All LP implantations were successful. LPs were implanted before extraction (n = 4, 13%), simultaneously with extraction (n = 5, 17%) and after extraction (n = 20, 70%). No reinfection occurred during the follow-up of median 32 months (IQR 13-66 months). Repeat blood cultures obtained in 9 (30%) patients and transthoracic echocardiography in all 7 patients with pacemaker endocarditis were negative for reinfection. In a subset of 6 LPs extracted during follow-up due to early battery depletion, prophylactically after the battery advisory or due to non-capture (median 36 months (range 0-67 months) post-implantation), histopathologic examination of tissues around the LPs showed no signs of infection.

CONCLUSIONS

After replacing infected CIEDs for an LP, no reinfections occurred in over 2.5 years follow-up. These results confirm that in case of CIED infection, the LP is an appealing replacement device. LP implantation before CIED extraction is feasible.

Safety and Efficacy of a Single Procedure of Extraction and Reimplantation of Infected Cardiovascular Implantable Electronic Device (CIED) in Comparison with Deferral Timing: An Observational Retrospective Multicentric Study

(1) Background: Infections are among the most frequent and life-threatening complications of cardiovascular implantable electronic device (CIED) implantation. The aim of this study is to compare the outcome and safety of a single-procedure device extraction and contralateral implantation versus the standard-of-care (SoC) two-stage replacement for infected CIEDs. (2) Methods: We retrospectively included 66 patients with CIED infections who were treated at two Italian hospitals. Of the 66 patients enrolled in the study, 27 underwent a single procedure, whereas 39 received SoC treatment. All patients were followed up for 12 months after the procedure. (3) Results: Considering those lost to follow-up, there were no differences in the mortality rates between the two cohorts, with survival rates of 81.5% in the single-procedure group and 84.6% in the SoC group (p = 0.075). (4) Conclusions: Single-procedure reimplantation associated with an active antibiofilm therapy may be a feasible and effective therapeutic option in CIED-dependent and frail patients. Further studies are warranted to define the best treatment regimen and strategies to select patients suitable for the single-procedure reimplantation.

Long-term outcomes of non-systematic device reimplantation following lead extraction in selected patients

Following the removal of cardiovascular implantable electronic devices (CIEDs), reassessment of the need for a new device is vital. Some patients may have exhibited an improvement in rhythm or cardiac function and may thus no longer meet the guideline requirements for reimplantation. However, the long-term outcomes of non-systematic device reimplantation remain unknown. In the present study, it was hypothesized that the implantation of pacing systems in selected patients following lead extraction is safe. In order to confirm this hypothesis, a total of 854 patients (aged between 28 and 82 years) who underwent the removal of a CIED were enrolled in the present study and they were all reassessed to determine whether a new device following lead extraction was necessary. In order to determine which patients would undergo non-systematic device reimplantation, the standard guidelines, the criteria and the wishes of the patient were all taken into consideration. Patients remained device-free unless an adverse clinical event occurred that required reimplantation. The primary study endpoint was the rate of sudden death or reimplantation. Between January, 2014 and December, 2019, 854 consecutive patients underwent pacing system extraction, of whom 210 patients (24.6%) underwent non-systematic device reimplantation following careful reassessment (the non-reimplantation group). Among the 210 patients, 162 (77.1%) were fitted with pacemakers, 26 (12.4%) underwent cardiac resynchronization therapy or cardiac resynchronization therapy-defibrillator and 22 (10.5%) were implanted with a cardioverter-defibrillator. During a mean follow-up period of 40.4 months, 86 patients reached the primary endpoint of the study, including 54 out of 210 patients (25.7%) who experienced an adverse clinical event that required reimplantation and 32 out of 210 patients (15.2%) who experienced sudden death. Reimplantation of a new device was not required in ~25% of the patients. On the whole, the present study demonstrates that following pacing system removal, non-systematic device reimplantation associated with close surveillance is safe for selected patients.

Evaluation of Anti-Tumor Effects of Whole-Body Low-Dose Irradiation in Metastatic Mouse Models

Low-dose irradiation (LDI) has recently been shown to have various beneficial effects on human health, such as on cellular metabolic activities, DNA repair, antioxidant activity, homeostasis potency, and immune activation. Although studies on the immunogenic effects of LDI are rapidly accumulating, clinical trials for cancer treatment are considered premature owing to the lack of available preclinical results and protocols. Here, we aim to investigate anti-tumor and anti-metastatic effects of whole-body LDI in several tumor-bearing mouse models. Mice were exposed to single or fractionated whole-body LDI prior to tumor transplantation, and tumor growth and metastatic potential were determined, along with analysis of immune cell populations and expression of epithelial-mesenchymal transition (EMT) markers. Whole-body fractionated-LDI decreased tumor development and lung metastasis not only by infiltration of CD4⁺, CD8⁺ T-cells, and dendritic cells (DCs) but also by attenuating EMT. Moreover, a combination of whole-body LDI with localized high-dose radiation therapy reduced the non-irradiated abscopal tumor growth and increased infiltration of effector T cells and DCs. Therefore, whole-body LDI in combination with high-dose radiation therapy could be a potential therapeutic strategy for treating cancer.