Worsening tricuspid regurgitation after ICD implantation is rather due to transvenous lead than natural progression

BACKGROUND

Transvenous implantable cardioverter-defibrillators (TV-ICDs) are associated with greater tricuspid regurgitation (TR) severity, which leads to increased mortality. The pathophysiology is assumed to be lead-related, hence, treatment includes lead extraction. However, TR may also naturally occur in the high-risk ICD population, or may be caused by right ventricular pacing. We sought to evaluate the effect of ICD type (with or without lead) and pacing percentage on post-implantation TR severity.

METHODS

In this retrospective cohort study, consecutive patients were included with a primary S-ICD or TV-ICD implantation between 2009 and 2019 and echocardiography studies ≤3 months before and ≤ 3 years post-implantation. The effect of ICD type on TR severity at follow-up was estimated adjusting for ventricular pacing percentage and potential confounders. The effect of ventricular pacing percentage on TR severity at follow-up was adjusted for potential confounders.

RESULTS

118 patients were included (mean age 52 ± 21): 31 (26%) with an S-ICD and 87 (74%) with a TV-ICD. Median 20 months post-implantation, worsening TR was found in 11/31 (34%) S-ICD patients and 45/87 (52%) TV-ICD patients (p = 0.15). Adjusted for age, atrial fibrillation, baseline TR and mitral regurgitation, ventricular pacing percentage, ICD dwelling time, BMI, hypertension and left ventricular ejection fraction, TV-ICDs were significantly associated with greater TR severity (OR 9.90, p = 0.002). Ventricular pacing percentage was very low, and not significantly associated with greater TR severity (OR 0.95, p = 0.066).

CONCLUSIONS

Our results suggest that greater TR severity in ICD patients is mainly caused by the transvenous lead, rather than natural progression in the ICD population.

Real-world long-term battery longevity of leadless pacemakers

Background

Leadless pacemakers (LPs) have proven safe on the mid-term. Long-term safety will largely depend on the need for replacements with a concomitant risk of complications. As replacements are mainly due to battery depletion, battery longevity is, in essence, an important determinant of long-term safety. Mean battery longevity of the most often implanted LP (Micra VR) predicted by the manufacturer is 12 years, but mid- and long-term data is lacking.

Purpose

We sought to determine the long-term battery longevity of this LP in a real-world cohort.

Methods

Consecutive patients with an LP implantation at our tertiary hospital from January 2014 to September 2021 were included in a prospective cohort. Baseline characteristics and electrical parameters during all yearly follow-up visits were assessed.

Results

105 patients (73 [70%] male, age at implantation 80±9 years) were included. Pacing indications were atrial fibrillation with slow conduction (34 [32%]), third degree AV block (35 [33%]), incomplete AV block (12 [11%]), sinus node disease (23 [22%]) and unexplained syncope (1 [1%]). At implantation, pacing threshold, impedance and R-wave amplitude were 0.76±0.64V at 0.24ms, 790±220Ω and 11.1±4.9mV, respectively, lower rate was programmed at 50–60/min in 88 (84%), <50/min in 8 (7.6%) and >60/min in 9 (8.6%) and rate-responsive pacing was programmed on in 51 (49%). Median follow-up was 25 months (range 2–88 months). Pacing percentage was 46% (IQR 12–98%) at year 0; 64% (10–99%) at year 5 and 91% (56–100%) at year 7.

No battery failures were seen during follow-up. At 3 years, expected battery longevity was >8 years (maximum value) in nearly all patients (49/50 [98%]) and at 5 years in the majority (16/18 [89%]) of patients; at 7 years, expected battery longevity ranged from 4.1 to >8 years (Figure). This implies an expected battery longevity of >13 years in the majority of patients. In two subjects, expected battery longevity was below the maximum value within 5 years after implantation. In the first, latest follow-up visit was after 3 years and expected battery longevity was 3.0 years. An increase in pacing percentage of +70 percent points was seen during follow-up and there was a relatively high pacing capture threshold (1.5V@0.4ms). In the second, the latest follow-up visit was at 6 years, and expected battery longevity was 1.9 years. This was caused by a large increase in pacing percentage (+80 percentage points) and lower rate of 70/min; pacing threshold was 0.5V@0.24ms. We did not see clear overall differences in expected battery longevity at 5 years, when the patients were stratified per quartile pacing percentage. Of 34 deaths during follow-up, 31 (91%) had expected battery longevity >8 years at the last follow-up visit.

Conclusions

These long-term real-world data suggest that the battery longevity of the Micra LP will exceed the expected battery longevity. Data from larger registries is necessary to confirm these results.

Funding Acknowledgement

Type of funding sources: None.

Leadless pacemakers as replacement for infected transvenous pacemakers: different strategies are feasible

Funding Acknowledgements

Type of funding sources: None.

Introduction

Pacemaker infections have a high morbidity and mortality and are an indication for extraction. For reimplantation, leadless pacemakers (LPs) may be preferable due to a low chance of infection. Even more, early LP reimplantation in pacemaker-dependent patients would circumvent the need for temporary pacemakers.

Methods

We included all patients with LP implantation before, simultaneously with, or after transvenous pacemaker extraction due to infection, between January 2013 and December 2021. Outcomes were assessed during standard follow-up visits.

Results

30 patients (mean age 81±8 years) were included, of which 19 (63%) had a pocket infection, 10 (33%) endocarditis and 1 (3%) a systemic infection without endocarditis (Table). LP implantation was successful in all and was performed before extraction in 2 patients (7%; 3 and 5 days before), simultaneously in 6 (20%) and after extraction in 22 (73%). There were 3 procedural complications: 2 femoral artery bleedings and one LP dislocation. Also, one patient with complete AV block and an initially stable escape rhythm had an in-hospital cardiac arrest due to asystole after transvenous pacemaker extraction, but before LP implantation. During follow-up of median 21 months (IQR 7-53 months), no reinfection occurred. Six Nanostims were extracted due to early battery depletion, prophylactically after the battery advisory, or due to non-capture (median 36 months [range 0-67 months] after implantation); histopathologic examination of tissues around the devices showed no signs of infection. Two Nanostims were abandoned after which another device was implanted. No further device revisions were necessary during follow-up.

Conclusions

In case of transvenous pacemaker infection, LP implantation before, simultaneously with or after extraction is safe and effective.

A comprehensive scoping review on transvenous temporary pacing therapy

Transvenous temporary cardiac pacing therapy (TV-TP) is widely used to treat life-threatening arrhythmias. Yet aggregated evidence on TV-TP is limited. We conducted a systematic scoping review to evaluate indications, access routes and complications of TV-TP, as well as permanent pacemaker therapy (PPM) following TV-TP. Clinical studies concerning TV-TP were identified in Ovid MEDLINE. Case studies and studies lacking complication rates were excluded. To assess complication incidence over time, differences in mean complication rates between 10-year intervals since the introduction of TV-TP were evaluated. We identified 1398 studies, of which 32 were included, effectively including 4546 patients. Indications varied considerably; however TV-TP was most commonly performed in atrioventricular block (62.7%). The preferred site of access was the femoral vein (47.2%). The mean complication rate was 36.7%, of which 10.2% were considered serious. The incidence of complications decreased significantly between 10-year interval groups, but remained high in the most recent time period (22.9%) (analysis of variance; p < 0.001). PPM was required in 64.2% of cases following TV-TP. Atrioventricular block was the primary indication for TV-TP; however indications varied widely. The femoral vein was the most frequent approach. Complications are common in patients undergoing TV-TP. Although a decrease has been observed since its introduction, the clinical burden remains significant. The majority of patients who underwent TV-TP required PPM therapy.