Michael Vinther

Aims: According to the European Society of Cardiology (ESC) guidelines, patients with a cardiac implantable electronic device (CIED) are considered at moderate risk of infective endocarditis (IE), irrespective of CIED type. However, comparative data across CIED types and IE risk groups are limited. We examined IE rates according to CIED type compared with moderate- and high-risk groups. Methods and results: Danish nationwide registries were used to identify patients with first-time CIED implantation and reference populations at moderate and high risk of IE (2000–2022), based on the ESC guidelines. The high-risk group included patients with a left-sided prosthetic valve. Patients with prior IE or left-sided prosthetic valve were excluded from the CIED group. The primary outcome was incident IE within 10 years. The study included 84 171 CIED recipients, 127 966 moderate-risk patients, and 23 505 high-risk patients. Pacemakers were the most common CIED type (74.9%), followed by implantable cardioverter-defibrillator (16.6%), cardiac resynchronization therapy device with defibrillator (CRT-D) (4.6%), and cardiac resynchronization therapy device without defibrillator (3.9%). Pacemaker recipients were the oldest (median 78.2 years) and most frail. The 10-year cumulative incidence of IE was lowest in pacemaker recipients (1.0% [95% confidence interval (CI): 0.9–1.1]) and highest in CRT-D recipients (2.2% [95% CI: 1.7–2.9]). In adjusted analyses, all CIED types were associated with higher IE rates than the moderate-risk group but lower than the high-risk group. Conclusion: In this nationwide cohort, IE risk differed across CIED types, highest in CRT-D and lowest in pacemaker recipients. All CIED types were associated with higher risk than moderate-risk patients but lower risk than high-risk patients, supporting the ESC classification. Cardiac resynchronization therapy device with defibrillator recipients may warrant further evaluation of preventive strategies.

Background: Glucagon-like peptide-1 receptor agonist (GLP-1RA) therapy is increasingly used, but the physiological effects in patients with heart failure and reduced ejection fraction (HFrEF) remain uncertain. Continuously collected data from implantable cardiac devices may enable evaluation of drug effects in a real-world setting. Methods: In a nationwide Danish retrospective matched cohort study, GLP-1RA initiators with implantable cardiac devices were matched 1:5 to unexposed device recipients by sex and age. Sensor data were assessed from 30 days before to 30 days after initiation. Primary outcomes were changes in heart rate and thoracic impedance. Analyses were adjusted for baseline sensor value, BMI category, hypertension, and type 2 diabetes. Prespecified subgroup analyses were performed in patients with HFrEF. Results: In 666 patients (111 GLP-1RA initiators, 555 matched controls), semaglutide was used in 95% of initiators. Compared with controls, GLP-1RA initiation was associated with higher night heart rate (adjusted difference 2.12 bpm; 95% CI, 1.38–2.87), higher daily heart rate (1.46 bpm; 95% CI, 0.65–2.06), and higher thoracic impedance (0.66 Ω; 95% CI, 0.17–1.15) (all P < .01). S1 amplitude decreased (−0.09 mG; 95% CI, −0.14 to −0.04; P < .01). Heart rate increases followed a stepwise pattern across semaglutide dose levels, with an average increase of 2.5 bpm per dose escalation. Findings were directionally consistent in patients with HFrEF (GLP-1RA n = 80), with no evidence of effect modification. Conclusion: GLP-1RA initiation was associated with measurable changes in device-derived physiology. Larger studies are needed to evaluate clinical implications, including in HFrEF.

Aims: Cardiac implantable electronic device (CIED)-related infective endocarditis (IE) is associated with morbidity and mortality. Current guidelines recommend complete CIED extraction; however, the optimal timing for reimplantation remains uncertain. We aimed to evaluate CIED reimplantation rates, and outcomes in patients with non-surgically treated IE who underwent CIED extraction. Methods and results: We included all Danish residents ≥18 years diagnosed with first-time IE (2010–2021), with a pre-existing CIED, who underwent CIED extraction without concurrent valve surgery. Data were obtained from Danish nationwide registries. The primary variable of interest was CIED reimplantation within 90 days after extraction. Reimplantation rates were described, and reimplantation status was used to stratify patients for analysis of secondary outcomes, including recurrent IE-related bacteraemia and all-cause mortality within 6 months. Among 661 patients with CIED extraction due to IE, 396 (59.9%) underwent reimplantation within 3 months, with a median of 29 days (IQR:19–42 days). There was no significant difference in the 6 month cumulative incidence of recurrent bacteraemia with IE (2.5% [95% CI:0.95–5.5] vs. 1.8% [95% CI:0.8–3.6] P = 0.55) or mortality (11.2% [95% CI:7.0–16.4] vs. 7.0% [95% CI:4.7–10.0]; P = 0.11) between non-reimplanted and reimplanted patients. Conclusion: In IE patients who underwent CIED extraction, 60% of patients were reimplanted within 3 months with substantial variation in timing. No significant differences in outcomes were found by reimplantation status.

Aims: In the largest nationwide study of Danish patients undergoing transcatheter aortic valve implantation, we examined the clinical impact of pre-existing right bundle branch block – a known risk factor for permanent pacemaker implantation – on outcomes including pacemaker implantation, heart failure, and all-cause mortality. Methods and results: We included first-time transcatheter aortic valve implantation patients in Denmark from 2008 to 2021. Patients were stratified by baseline right bundle branch block status using the digital Danish Nationwide Electrocardiogram Cohort. The study outcomes were new pacemaker implantation, heart failure, and all-cause mortality at 30, 90, and 365 days. A composite of the study outcomes was also assessed. A total of 4900 patients were included, of whom 438 (9%) had baseline right bundle branch block. Mean age was 81 years, 55% were male. At 90 days, the overall pacemaker implantation incidence was 9%, but markedly higher in the right bundle branch block group: 28.3% vs. 7.1% [hazard ratio (HR) 4.61, 95% confidence interval (CI) 3.60–5.91]. Right bundle branch block was not associated with higher rates of heart failure (10.1% vs. 8.3%; HR 1.23, 95% CI 0.86–1.77) or death (3.7% vs. 3.6%; HR 1.08, 95% CI 0.64–1.82). The findings were consistent at 1 year. Conclusion: In this comprehensive nationwide cohort, right bundle branch block strongly predicted pacemaker implantation after transcatheter aortic valve implantation but importantly, not heart failure or all-cause mortality. The neutral association with heart failure and mortality should be explored further.

Aims: A typical left bundle branch block (LBBB) contraction pattern prior to cardiac resynchronization therapy (CRT) has been demonstrated to be highly associated with response beyond QRS morphology and duration. This study investigates whether septal deformation type and lateral wall strain amplitude may be of particular importance for long-term outcome after CRT implantation. Methods: From two centres, 208 CRT candidates with LBBB, New York Heart Association functional class II–IV, left ventricular ejection fraction ≤35%, and QRS duration ≥ 120 ms underwent echocardiography before CRT-defibrillator (CRT-D) implantation. Results: Four septal contraction patterns were identified: 36 patients (17%) had double-peaked systolic pattern (LBBB-1), 51 (25%) had early pre-ejection peak shortening followed by systolic stretch (LBBB-2), 43 (21%) had shortening with one systolic peak inside 70% of the ejection phase (LBBB-3), and 78 (38%) had normal septal peak timing outside early 70% of ejection phase (LBBB-4). The primary outcome (freedom from death, implantation of a left ventricular assist device, and heart transplantation) occurred in 48 patients during a median follow-up of 4 years (interquartile range 3.25–4). The most favourable outcome was associated with LBBB-1 and LBBB-2, which had one-seventh the risk of the primary outcome compared to LBBB-4 (HR: 0.14 [95% confidence interval: 0.06–0.34]; P < 0.001). Patients in the lowest tertile of lateral wall strain (>−7.4%) were at high risk of an event compared to the other patients (HR: 2.57 [1.46–4.55]; P = 0.001). Conclusion: The long-term clinical benefit of CRT-D in patients with LBBB pre-implantation varies. Subtypes of septal contraction patterns and, to a lesser degree, lateral function are important determinants of outcome in patients with CRT-D.

Background: Current guidelines recommend complete removal of a cardiac implantable electronic device (CIED) in patients with infective endocarditis (IE), although these recommendations are largely based on expert opinion (level of evidence C). We aimed to examine outcomes stratified by CIED removal status in patients with IE. Methods: Using Danish nationwide registries (2010–2021), we identified patients aged ≥18 years with first-time IE, who were alive at discharge, managed without valve surgery and had a CIED. Patients who underwent CIED removal during IE admission were compared with those without removal. The study outcomes were IE readmission, recurrent bacteraemia (including IE with the same microbial aetiology) and all-cause mortality within 6 months after discharge. Results: The study population comprised 1040 patients with non-surgically managed IE and a CIED, and among these, 596 (57.3%) underwent CIED removal during admission. Patients who underwent removal were younger and less frail than those without removal. In the removal versus non-removal group, the 6-month cumulative incidences were 2.5% (95% CI 1.4% to 4.1%) vs 7.1% (95% CI 4.9% to 9.9%) for IE readmission (p value <0.001), 2.1% (95% CI 1.1% to 3.5%) vs 5.2% (95% CI 3.4% to 7.6%) for recurrent bacteraemia (p value=0.005) and 11.5% (95% CI 9.1% to 14.3%) vs 20.0% (95% CI 16.4% to 23.9%) for all-cause mortality (p value <0.001). In multivariable Cox regression models, CIED removal was associated with lower 6-month rates of IE readmission (HR 0.39 (95% CI 0.19 to 0.79)) and all-cause mortality (HR 0.70 (95% CI 0.49 to 0.996)), compared with no removal. Conclusions: In this nationwide study of patients with non-surgically managed IE and a CIED, CIED removal was associated with significantly lower 6-month rates of IE readmission, recurrent bacteraemia and mortality compared with no removal, supporting current guideline recommendations. However, randomised clinical trials are warranted to determine the most effective treatment strategy.

Aims: Individuals experiencing a sudden cardiac arrest with ventricular fibrillation and no identifiable cause are diagnosed with idiopathic ventricular fibrillations (IVFs). 2D speckle tracking echocardiography (2DSTE) has been able to detect differences between IVF patients and controls. However, the association between these differences and the risk of ventricular arrhythmias (VAs) remains unknown. This study aimed to investigate whether parameters derived from myocardial deformation analysis using 2DSTE are associated with the recurrence of VA in IVF patients. Methods and results: This single-centre, cross-sectional study enrolled IVF patients treated with an implantable cardioverter defibrillator. IVF patients were compared with healthy sex- and age-matched controls. Furthermore, IVF patients were categorized into two groups (IVF patients with or without recurrent VA) based on the recurrence of VA over a 5-year follow-up period. Left ventricular global longitudinal strain (LVGLS) and left ventricular mechanical dispersion (LVMD) were investigated using 2DSTE and compared across all groups. Fifty-six IVF patients, males 39 (69.9%), age 49 ± 15 years, and 55 controls were included. IVF patients showed significantly increased LVMD (35.78 ± 13.4 ms vs. 31.0 ± 9.8 ms; P = 0.03) and decreased LVGLS (−18.8% ± 3.0% vs. −20.5% ± 2.7%; P < 0.01) compared with controls. IVF patients with recurrent VA had significantly increased LVMD compared with IVF patients without recurrent VA (43.63 ± 13.63 vs. 33.16 ± 12.45; P = 0.02). Conclusion: IVF patients had an increased LVMD and decreased LVGLS compared with healthy controls. Increased LVMD was significantly associated with recurrent VA in IVF patients suggesting a potential clinical value in risk stratification of VA recurrency in IVF patients.

Aim To investigate whether a compressive dressing after pacemaker or implantable cardioverter defibrillator (ICD) implantation and replacement applied for three hours can prevent bleeding, hematomas and pain. Method The study was a quasi-experimental interventional study including patients scheduled for implantation or replacement of a pacemaker or an ICD. In alternating months patients either received a compressive dressing (intervention group) or no compressive dressing (control group). Patients were followed at the catheterization lab, for three hours on the ward and until the first outpatient control visit (after 1-3 months). Outcomes was: Bleeding graded as bleeding, oozing or pocket-hematomas. Hematomas were measured by degrees and size. Pain was rated in a numerical rank scale (NRS). Results A total of 242 elective patients were included (intervention group n=114, control group n=128). The intervention group did not show any significant difference in development of pocket-hematomas compared to the control (p=0.24). Pain score was low in both groups (intervention NRS=1.41 vs. control NRS 1.32). Furthermore, no significant difference in pocket hematomas at follow-up were observed (p=0.77). Conclusion Using a compressive dressing did not significantly reduce bleeding or pocket hematomas after pacemaker or ICD implantation or replacement. Furthermore, no significant difference related to pain was observed. This study shows that patients who are not considered to be at elevated risk for bleeding or pocket-hematomas do not seem to benefit from a compressive dressing. Keywords Pacemaker, Implantable Cardioverter Defibrillator, Prophylactic compression bandaging, Pocket-hematoma, Device, Compression tool.