Evolution of ventricular and valve function in patients with right ventricular pacing - A randomized controlled trial comparing leadless and conventional pacing.

BACKGROUND: Leadless pacemakers (PMs) were recently introduced to overcome lead-related complications. They showed high safety and efficacy profiles. Prospective studies assessing long-term safety on cardiac structures are still missing. OBJECTIVE: The purpose of this study was to compare the mechanical impact of Micra with conventional PM on heart function. METHODS: We conducted a non-inferiority trial in patients with an indication for single chamber ventricular pacing. Patients were 1:1 randomized to undergo implantation of either Micra or conventional monochamber ventricular pacemaker (PM). Patients underwent echocardiography at baseline, 6 and 12 months after implantation. Analysis included left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and valve function. N-terminal-pro hormone B-type natriuretic peptide (NT-pro-BNP) levels were measured at baseline and 12 months. RESULTS: Fifty-one patients (27 in Micra group and 24 in conventional group) were included. Baseline characteristics were similar for both groups. At 12 months, (1) the left ventricular function as assessed by LVEF and GLS worsened similarly in both groups (∆LVEF -10 ± 7.3% and ∆GLS +5.7 ± 6.4 in Micra group vs. -13.4 ± 9.9% and +5.2 ± 3.2 in conventional group) (p = 0.218 and 0.778, respectively), (2) the severity of tricuspid valve regurgitation was significantly lower with Micra than conventional pacing (p = 0.009) and (3) median NT-pro-BNP was lower in Micra group (970 pg/dL in Micra group versus 1394 pg/dL in conventional group, p = 0.041). CONCLUSION: Micra is non inferior to conventional PMs concerning the evolution of left ventricular function at 12-month follow-up. Our data suggest that Micra has a comparable mechanical impact on the ventricular systolic function but resulted in less valvular dysfunction.

Bacteraemia after leadless pacemaker implantation.

BACKGROUND: Transvenous 3 permanent pacemaker-related infection is a severe condition associated with significant morbidity and mortality. Leadless pacemakers may be more resistant to bacterial seeding during bloodstream infection because of its small surface area and encapsulation in the right ventricle. This study reports the incidence and outcomes of bacteraemia in patients implanted with a Micra leadless pacemaker. We present 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) findings obtained in a subgroup of patients. METHODS: We report a retrospective cohort study of 155 patients who underwent a Micra TPS implant procedure at the University Hospitals of Leuven between July 2015 and July 2019. We identified the patients who developed an episode of bacteraemia, proved by ≥2 positive blood cultures. RESULTS: Of the 155 patients, 15 patients presented an episode of bacteraemia at a median of 226 days (range: 3-1129) days after the implant procedure. Gram-positive species accounted for 73.3% (n = 11) of the bacteraemia including Staphylococcus (n = 5), Enterococcus (n = 3), and Streptococcus (n = 3). The source of infection was identified in nine patients (60%) including endocarditis in four patients, urinary tract in three patients, and skin in two patients. 18 F-FDG PET/CT imaging performed in six patients did not show sign of infection around the leadless pacemaker. Bacteraemia was resolved in all patients after adequate antibiotherapy. Four patients died early during follow up. For all other patients, there were no recurrence of systemic infection during a median follow up of 263 days (range: 15-1134). CONCLUSION: In our small cohort, no leadless pacemaker endocarditis was observed among patients with bacteraemia.

Determinants of the difficulty of leadless pacemaker implantation.

BACKGROUND: The Micra Transcatheter Pacing System is implanted directly in the right ventricle (RV) through the femoral vein using a steerable transcatheter delivery system. The present study was done to identify determinants of difficult leadless pacemaker implant procedures including operator, patient, and RV anatomical characteristics. METHODS: All patients who underwent a Micra implant from July 2015 to December 2018 at our center were analyzed. From an RV angiogram acquired during implantation, RV geometry including systolic and diastolic volumes and ejection fraction was characterized. The presence of septomarginal trabeculation was noted. RESULTS: One hundred twenty-six patients (mean age: 79 ± 11 years old, mostly male: 77%) were enrolled. Mean Micra RV implant procedure time was 24 ± 23 min, with 1.7 ± 1.3 deployments of the device. No significant change in implant procedure time was observed after the first 30 implants. Eleven patients had a prominent septal component of the septomarginal trabeculation in the RV. Univariate analysis showed that the procedure time was positively correlated with the presence of a prominent septal component of the septomarginal trabeculation (P < .001) or an episode of heart failure (P = .02) and negatively correlated with the number of procedures performed by the operator (P < .001). After multivariable analysis, only the presence of a prominent septal component of the septomarginal trabeculation (P < .001) and the number of procedures performed by the operator (P < .001) were associated with the implant procedure time. CONCLUSIONS: In our experience, implant procedure time of a Micra leadless pacemaker depended on the presence of a prominent septal component of the septomarginal trabeculation and operator experience.

Is it feasible to outsource the remote monitoring of implantable cardiac defibrillators in a large tertiary hospital?

AIM: To provide a detailed description of the workflow at our telecardiology centre and to analyse the workload of real-world remote monitoring with the aim to assess the feasibility to outsource this service. METHODS: A retrospective analysis was conducted on the telecardiology service provided at the University Hospitals of Leuven by extracting patient demographic data, general time usage and detailed information about the type of remote contacts. 10,869 contacts in 948 patients have been included. A 2-week prospective study was conducted on the same service by documenting and monitoring every action performed by specialised nurses when analysing and solving remote monitoring transmissions. 337 contacts in 262 patients were collected during this period. RESULTS: Both analyses indicated similar numbers of events and interventions. Unplanned transmissions were more challenging and required more interventions than planned transmissions. Relatively little time (retrospective median: 1.83 min; prospective median: 1.56 min, per event) was spent on incoming non-actionable 'normal' transmissions (retrospective: 46%; prospective: 40% of all events). Retrospectively 54% and prospectively 60% of transmissions showed abnormalities and were responsible for most of the time expended. Disease-related issues were the most frequent cause for these 'abnormal' alerts. Contacting patients and physicians were key interventions undertaken. Interaction initiated by patients mainly involved the installation process (42%) and bedside monitoring problems (32%). CONCLUSION: External data centres could deal with 40% of the transmissions, but the decline in workload would be negligible for the in-hospital remote monitoring team, because very little time is spent dealing with the many 'non-event' transmissions whereas most of the time is spent solving clinical problems. Providing sufficient resources and optimising communication protocols is necessary to aid in managing the workload of the remote monitoring team.Implications for practiceContacting patients and physicians are key interventions for specialist nurses in remote monitoring centres.Detailed timing confirmed that most time was spent on relevant disease-related clinical problems.Despite dealing with ∼40% of transmissions, outsourcing to external data centres would decrease the workload only by 15-25%.Patient initiated contacts with questions concerning remote monitoring form a high burden and should be countered by scaling the service and creating communication protocols.

Leadless pacemaker for patients following cardiac valve intervention.

BACKGROUND: Permanent pacing is common after valve intervention. The presence of a conventional pacemaker in this population is recognized as a risk factor for infectious events. Therefore, a leadless pacing system could be the preferred strategy when permanent pacing is required after valve intervention. AIM: To report periprocedural outcomes and follow-up of patients undergoing implantation of a leadless pacing system after valve intervention. METHODS: Patients with previous valve intervention at the time of attempted implantation of a leadless pacemaker (Micra™, Medtronic, Minneapolis, MN, USA) were included, and were compared with a control group (patients also implanted with Micra™ without valve intervention). RESULTS: Among a total of 170 Micra™ implantation procedures, 54 patients (31.8%) had a history of valve intervention: 28 after aortic valve replacement; 10 after mitral valve replacement; one after single tricuspid valvuloplasty; and 15 after multiple valve surgery. Median age of the patients was 82.5 (77.0-86.0) years and 53.7% were male. Patients with previous valve intervention had a higher incidence of arterial hypertension (P=0.014) and ischaemic heart disease (P=0.040). The primary indications for permanent pacing after valve intervention were high-degree atrioventricular block (59.3%) and atrial fibrillation with bradycardia (27.8%). Micra™ was successfully implanted in all patients (n=170) without any procedure-related major complications. During a median follow-up of 12 months, electrical performance was excellent and similar in both groups. Also, a similar reduction in left ventricular ejection fraction was observed at 12 months in both groups, which was correlated with the percentage of right ventricular pacing. CONCLUSION: A leadless pacemaker is safe and efficient after valve intervention, and therefore represents an effective pacing option in patients after valve intervention.