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.

A randomized phase III trial comparing trabectedin to best supportive care in patients with pre-treated soft tissue sarcoma: T-SAR, a French Sarcoma Group trial

BACKGROUND

The French Sarcoma Group assessed the efficacy, safety, and quality of life (QoL) of trabectedin versus best supportive care (BSC) in patients with advanced soft tissue sarcoma (STS).

PATIENTS AND METHODS

This randomized, multicenter, open-label, phase III study included adults with STS who progressed after 1-3 prior treatment lines. Patients were randomized (1 : 1) to receive trabectedin 1.5 mg/m² every 3 weeks or BSC, stratified into L-STS (liposarcoma/leiomyosarcoma) and non-L-STS groups (other histotypes). Patients from the BSC arm were allowed to cross over to trabectedin at progression. The primary efficacy endpoint was progression-free survival (PFS) confirmed by blinded central review and analyzed in the intention-to-treat population.

RESULTS

Between 26 January 2015 and 5 November 2015, 103 heavily pre-treated patients (60.2% with L-STS) from 16 French centers were allocated to receive trabectedin (n = 52) or BSC (n = 51). Median PFS was 3.1 months [95% confidence interval (CI) 1.8-5.9 months] in the trabectedin arm versus 1.5 months (0.9-2.6 months) in the BSC arm (hazard ratio = 0.39, 95% CI 0.24-0.64, P < 0.001) with benefits observed across almost all analyzed subgroups, but particularly in patients with L-STS (5.1 versus 1.4 months, P = 0.0001). Seven patients (13.7%) in the trabectedin arm (all with L-STS) achieved a partial response, while no objective responses were observed in the BSC arm (P = 0.004). The most common grade 3/4 adverse events were neutropenia (44.2% of patients), leukopenia (34.6%), and transaminase increase (32.7%). Health-related 30-item core European Organization for the Research and Treatment of Cancer Quality-of-Life Questionnaire evidenced no statistical differences between the arms for any domain and at any time point. After progression, 91.8% of patients crossed over from BSC to trabectedin.

CONCLUSION

Trabectedin demonstrates superior disease control to BSC without impairing QoL in patients with recurrent STS of multiple histologies, with greater impact in patients with L-STS.

Leadless pacing with Micra TPS: A comparison between right ventricular outflow tract, mid-septal, and apical implant sites

BACKGROUND

With its steerable transcatheter delivery system, the Micra can be deployed in nonapical positions within the right ventricle, potentially allowing reduction of the paced QRS width. We sought to evaluate the safety and long-term performance of the right ventricular outflow tract (RVOT) pacing using the Micra transcatheter pacing system (TPS). We also compared the paced QRS between RVOT, mid-septal, and apical implant positions.

METHODS

All patients who underwent a Micra TPS implantation at the University Hospitals of Leuven were enrolled in this observational study. Right ventricular (RV) position of the device was assessed on per-procedural ventriculography. Paced QRS was analyzed and follow-up completed at 1 month and then every 6 months.

RESULTS

Among the 133 patients included (mean follow-up: 13 ± 11 months), 45 were implanted in the RVOT, 58 midseptally, and 30 at the apex. All implant procedures were successful and no pericardial effusion was encountered within the 30 days post-implant. Two major complications were reported with devices implanted at the apex. Pacing impedance was significantly higher in the RVOT compared to the mid-septal and apical position (P < .001). Pacing threshold and R-wave amplitude did not differ over time in either position. The median narrowest paced QRS duration was observed in the RVOT (142 ms) compared to mid-septal (159 ms; P < .001), and apical position (181 ms; P < .001).

CONCLUSION

Implantation of the Micra TPS in the RVOT is safe and feasible. Electrical performance over time was comparable to mid-septal and apical positions. The narrowest paced QRS complexes is achieved with RVOT pacing.

Monocentric experience of leadless pacing with focus on challenging cases for conventional pacemaker

AIM

Leadless cardiac pacemaker has been developed to reduce complications related to cardiac pacing and is considered as an alternative to conventional pacemaker although safety and efficacy data in clinical practice are limited. The purpose of this study was to investigate the safety and efficacy profile of Micra Transcatheter Pacing System (TPS) used in daily clinical activity with a focus on challenging cases for conventional pacing.

METHODS

A total of 66 patients (46 men, 79.1 ± 9.7 years) having a Class I or II indication for ventricular pacing underwent a Micra TPS implant procedure. All patients were enrolled in a prospective registry. Follow-up visits were scheduled at discharge and after 1, 3, 6 and 12 months.

RESULTS

Primary indication for pacing was third degree atrioventricular block (30.3%), sinus node dysfunction (21.2%) or permanent atrial fibrillation with bradycardia (45.5%). The device was successfully implanted in 65 patients (98.5%). During follow-up of 10.4 ± 6.1 months (range 1-23 months), electrical measurements remained stable. Mean pacing capture threshold, pacing impedance and R-wave sensing were respectively 0.57 ± 0.32 V, 580 ± 103 Ohms, 10.62 ± 4.36 mV at the last follow-up. One major (loss of function) and three minor adverse events occurred. Pericardial effusion, dislodgement, device related infection or pacemaker syndrome were not observed. Micra TPS implantation was straightforward for patients with congenital or acquired cardiac and/or vascular abnormalities, previous tricuspid surgery and after heart transplantation.

CONCLUSION

Our experience confirms that implantation of Micra is safe and efficient in a real world population including patients who present a challenging condition for conventional pacing.

[A randomized controlled trial of metastases-directed treatment in patients with metastatic prostate cancer using stereotactic body irradiation: A GETUG-AFU trial]

The goal of treatment of metastatic prostate cancer remains palliation. The oligometastatic state could be the right time to intensify therapy by introducing metastases directed treatments. The aim of this trial was to evaluate the benefit of radiotherapy to all macroscopic metastatic sites and to the primary disease in patients with hormone sensitive oligometastatic prostate cancer.

Path integral approach to closed-form option pricing formulas with applications to stochastic volatility and interest rate models

We present a path integral method to derive closed-form solutions for option prices in a stochastic volatility model. The method is explained in detail for the pricing of a plain vanilla option. The flexibility of our approach is demonstrated by extending the realm of closed-form option price formulas to the case where both the volatility and interest rates are stochastic. This flexibility is promising for the treatment of exotic options. Our analytical formulas are tested with numerical Monte Carlo simulations.

Potential role of remote monitoring for scheduled and unscheduled evaluations of patients with an implantable defibrillator

AIMS

Follow-up of implantable cardioverter defibrillator (ICD) patients, with regular in-office visits every 3-6 months, puts a significant burden on specialized electrophysiology clinics. New technology allows for remote monitoring of device function. We wanted to investigate its potential reliability and to which extent its use can reduce in-office visits.

METHODS AND RESULTS

We retrospectively analysed data from 1739 prospectively coded ICD visits in a random set of 169 patients (followed between 2 month and 10.4 year in an academic centre). We defined (i) whether the visit was planned or not, (ii) what were the reasons for unplanned visits, (iii) whether any relevant finding was made, (iv) whether a remote monitoring system with the ability or not to detect pacing threshold would have been able to capture the problem, and (v) what actions were taken. The standard follow-up scheme consisted of in-office visits 1 month after implantation and then every 6 months, unless approaching battery depletion. From the 1739 visits, 1530 were performed according to clinical schedule (88%) and in 1197 of those (78.2%), no relevant finding was made. In 0.52% (n = 8) early post-implant pacing threshold increases would not have been detected by remote monitoring without the ability to determine thresholds (although two patients showed a high impedance). Moreover, in 6% of the planned visits, reprogramming would require a consecutive in-office visit (4%) or hospitalization (2%). Only 175 visits (9.6% of all) were conducted prior to the planned follow-up date due to patient symptoms [another 42 (2.4%) were due to planned surgery or safety warnings]. The proportion of relevant findings during unscheduled visits was significantly higher than during scheduled visits (80.6 vs. 21.8%; P < 0.0001) and a higher proportion of those was arrhythmia- and/or device-related (85.1 vs. 55.3%, P < 0.0001). Reprogramming was required more often (33.1 vs. 4%; P < 0.0001) and hospitalization rate was higher (18.3 vs. 2%; P < 0.0001), so that 51.4% of unscheduled visits would require in-office evaluation. Overall, remote follow-up would correctly exclude device function abnormalities or arrhythmic problems in 1402 (82.2%), identify an arrhythmic problem in 262 (15.3%), correctly identify a device-related problem in 35 (2.1%), but potentially miss an isolated pacing problem in 6 (0.46%). Clinical evaluation would diagnose a relevant clinical problem in the absence of any device interrogation abnormality in 170 patients (10%).

CONCLUSION

ICD remote monitoring can potentially diagnose >99.5% of arrhythmia- or device-related problems if combined with clinical follow-up by the local general practitioner and/or referring cardiologist. It may provide a way to significantly reduce in-office follow-up visits that are a burden for both hospitals and patients.

Ablation of Focally Induced Atrial Fibrillation:. Selective or Extensive?

INTRODUCTION

Focally induced atrial fibrillation (AF) often is due to ectopic activity in the pulmonary veins (PV). Although initial approaches were aimed at ablating only the ectopic foci, more extensive ablation approaches have evolved that isolate all PVs empirically and/or create circumferential ablation lines in the left atrium (LA). These techniques last longer and may be associated with more risks. We retrospectively evaluated the outcome and risks of ablation for focally induced AF in a single-center patient population.

METHODS AND RESULTS

We report on 47 patients (32 men and 15 women; age 47 +/- 10 years) in whom 52 ablations were performed. In 19 patients (22 sessions), ablation was directed at the site(s) of overt ectopic activity ("selective" group), whereas in 28 patients (30 sessions) without sufficient ectopy to determine the culprit PV a mean of 3.5 PVs were empirically targeted for bidirectional disconnection from the LA ("extensive" group). On a preprocedural Holter recording, the "selective" group had significantly more isolated atrial ectopy (3,276 +/- 2,933 vs 620 +/- 937 beats/24 hours) and runs of atrial tachycardia (330 +/- 202 vs 53 +/- 87 runs/24 hours) than the "extensive" group (P < 0.01 for both). Only 11% had persistent AF before ablation. Acute procedural success was 81% (elimination of all ectopy) and 83%, respectively (bidirectional and fully circumferential isolation of all targeted PVs). Procedure and fluoroscopy times were significantly shorter in the "selective" group. There were no major complications, but 7 minor complications and 2 acute PV stenoses > 50% in the 30 "extensive" procedures were observed. Mean follow-up was 8.4 +/- 8.5 months (median 6.9). Kaplan-Meier analysis, excluding recurrences during only the first month ("delayed cure"), showed AF recurrence in 45% after 6 months and in 55% after 1 year. Outcome was not dependent on ablation approach ("selective" or "extensive") nor was time to first AF (22 +/- 64 days and 30 +/- 69 days). AF recurrence tended to be higher in patients with larger LA (P = 0.08), underlying heart disease or hypertension (P = 0.08), and those "extensive" patients in whom not all 4 PVs were targeted (P = 0.07).

CONCLUSION

Trigger-directed ablation for focally induced AF is associated with a relatively high recurrence rate during follow-up. Apart from recurrence of the ectopic trigger, this may point to underlying structural changes in the atrial substrate not addressed by the ablation. Prospective evaluation of the risk-to-benefit profile of any technique (selective, extensive, including linear lines) is required.

Density of a gas of spin-polarized fermions in a magnetic field

For a fermion gas with equally spaced energy levels that is subjected to a magnetic field, the particle density is calculated. The derivation is based on the path integral approach for identical particles, in combination with the inversion techniques for the generating function of the static response functions. Explicit results are presented for the ground state density as a function of the magnetic field with a number of particles ranging from 1 to 45.