Evidence review

Clinical and technical evidence

Regulatory bodies

A search of the Medicines and Healthcare Products Regulatory Agency (MHRA) website revealed that no manufacturer Field Safety Notices or Medical Device Alerts for this device. No reports of adverse events were identified from a search of the US Food and Drug Administration (FDA) database: Manufacturer and User Device Facility Experience (MAUDE).

Clinical evidence

Three relevant studies are summarised in this briefing. No studies that prospectively evaluated the clinical effects of LATITUDE NXT compared with standard in-clinic monitoring were identified.

The study by de Ruvo (2016), summarised in table 1 and table 2, was a prospective non-randomised cohort study that compared 4 different remote monitoring systems to investigate how the frequency of remote monitoring data transmissions affected the early detection of clinical and device-related events. Patients with implantable cardiac devices (n=211) were monitored for 1 year using LATITUDE NXT (Boston Scientific; n=49), BIOTRONIK Home Monitoring (Biotronik; n=61), CareLink (Medtronic; n=65) and Merlin (St Jude Medical; n=36) systems. The BIOTRONIK system is designed for continuous daily monitoring and sent data daily; all the other systems are designed for periodic monitoring (up to daily, subject to configuration) and for the purposes of the study were configured to send data every 3 months. Event-free rates averaged 55% across the year and were similar for all systems (p=0.23). Daily data transmissions were independently associated with an increased probability of detecting an event compared with quarterly transmissions. The chance of detecting an event was reduced by 20% (p=0.036) for a 1‑month increase in the interval between data transmission.

A retrospective observational study, summarised in table 3 and table 4, used patient data from the Boston Scientific ALTITUDE registry to investigate the association between the use of remote patient monitoring of implantable cardioverter defibrillators and all-cause mortality and hospital re-admission following first-time implantation (Akar et al. 2015). The study linked the patient data to the American College of Cardiology National Cardiovascular Data Registry of Implantable Cardiac Devices to adjust for differences in clinical and non-clinical factors in patients who used and did not use remote monitoring. The study used a multivariate time-dependant Cox model, and observed that patients who used remote monitoring had a significantly lower risk of death (hazard ratio 0.67, 95% confidence interval 0.64 to 0.71, p<0.0001) and hospital re-admission (hazard ratio 0.82, 95% confidence interval 0.80 to 0.84, p<0.0001) compared with those who did not.

An earlier retrospective observational study, summarised in table 5 and table 6, used the ALTITUDE database to compare survival in 69,556 patients monitored remotely and 124,450 patients monitored in-clinic (Saxon et al. 2010). This study showed statistically significant improvements in survival for patients having remote monitoring using both implantable cardiac devices (hazard ratio 0.56) and cardiac resynchronisation therapy defibrillators (hazard ratio 0.45, p<0.0001) compared with in-clinic monitoring. The study was unable to account for any possible clinical characteristics that may have influenced the decision to use remote monitoring, limiting the interpretation of the observed results.

Recent and ongoing studies

No current or in-development trials on the effectiveness of the LATITUDE NXT Patient Management System for heart failure or atrial fibrillation patients with implanted cardiac devices were identified.

Costs and resource consequences

LATITUDE NXT could reduce the number of follow-up attendances at cardiac device clinics and their associated costs. There is the potential for cost savings from more timely identification and treatment of clinical events. The system is currently used by at least 21 NHS trusts.

The economic evidence identified consisted of 1 abstract that addressed how using the LATITUDE NXT system affected the costs of treatment (Stern et al. 2013). This analysis was an individual patient event-based simulation based on a multicentre prospective single-arm observational study that enrolled 889 patients each with a cardiac resynchronisation therapy defibrillator. The patients were monitored using the LATITUDE NXT system to assess the type and frequency of alert notifications, time from alert notification to medical intervention, type of medical intervention, and patient compliance with weight and blood pressure monitoring (RAPID-RF trial; Boehmer et al. 2014). A subset of 128 patients who had at least 1 alert for weight change, atrial tachycardia or cardiac device shock with a subsequent intervention was modelled. A control group was created by cloning each trial patient and simulating their response in the absence of remote monitoring to the conditions that triggered each alert in the trial. The model suggested that remote monitoring reduced the total cost per patient by $323 (around £223) over the year of the trial. Savings were mainly related to a reduction in the cost of hospital admissions, and partially offset by an increase in physician visits and telephone counselling. Costs were based on a US healthcare payer perspective and the modelled population included only those patients whose remote monitoring system had triggered an alert. As such, the reported outcomes may not be applicable to the NHS, or representative of the general population using the LATITUDE NXT system.

The following 2016/17 National Tariff Payment System costs for NHS cardiology outpatient attendances have been provided for information:

  • first attendance, single professional: £166

  • first attendance, multi-professional: £230

  • follow-up attendance, single professional: £96

  • follow-up attendance, multi-professional: £148

Current reimbursement across the NHS for remote follow-up varies according to local arrangements.

Strengths and limitations of the evidence

No studies were identified that evaluated the clinical effects of the LATITUDE NXT Patient Management System compared with standard in-clinic monitoring.

The de Ruvo (2016) study was not UK-based, and was a non-randomised prospective cohort study with a small sample size. It was done at a single site, had short follow-up, and may be subject to sampling bias from the variation in monitoring frequency between the devices. In addition, the study included information about event classification but no clear delineation between clinical and technical events. It is possible that many events fell into several categories and may have been double-counted.

The studies by Akar et al. (2015) and Saxon et al. (2010) were observational, retrospective, non-randomised post-market analyses of the Boston Scientific ALTITUDE database, not prospectively defined clinical trials. Although adjustments were made for a number of measured clinical factors in Akar et al. (2015), it is possible other unmeasured factors could introduce bias. The only data on the cost consequences of using the system were presented in abstract format. It is therefore not possible to fully assess the quality of the evidence.