a review on remote monitoring technology applied to implantable electronic cardiovascular devices

Original ResearchA Review on Remote Monitoring Technology Applied to ImplantableElectronic Cardiovascular Devices

Paulo Dias Costa, B.Sc.,1,2 Pedro Pereira Rodrigues, M.Sc.,1,3,4

Antonio Hipolito Reis, M.D.,2

and Altamiro Costa-Pereira, M.D., Ph.D.1,4

1Department of Biostatistics and Medical Informatics—Facultyof Medicine, University of Porto, Porto, Portugal.

2Service of Cardiology, Department of Medicine—Hospital deSanto Antonio, Centro Hospitalar do Porto, Porto, Portugal.

3Laboratory of Artificial Intelligence and Decision Support,University of Porto, Porto, Portugal.

4Center for Research in Health Technologies and InformationSystems, Faculty of Medicine, University of Porto, Porto, Portugal.

AbstractImplantable electronic cardiovascular devices (IECD) include a

broad spectrum of devices that have the ability to maintain rhythm,

provide cardiac resynchronization therapy, and/or prevent sudden

cardiac death. The incidence of bradyarrhythmias and other cardiac

problems led to a broader use of IECD, which turned traditional

follow-up into an extremely heavy burden for healthcare systems to

support. Our aim was to assess the impact of remote monitoring on

the follow-up of patients with IECD. We performed a review

through PubMed using a specific query. The paper selection process

included a three-step approach in which title, abstract, and cross-

references were analyzed. Studies were then selected using previ-

ously defined inclusion criteria and analyzed according to the

country of origin of the study, year, and journal of publication; type

of study; and main issues covered. Twenty articles were included in

this review. Eighty percent of the selected papers addressed clinical

issues, from which 94% referred clinical events identification,

clinical stability, time savings, or physician satisfaction as ad-

vantages, whereas 38% referred disadvantages that included both

legal and technical issues. Forty-five percent of the papers referred

patient issues, from which 89% presented advantages, focusing on

patient acceptance/satisfaction, and patient time-savings. The

main downsides were technical issues but patient privacy was also

addressed. All the papers dealing with economic issues (20%) re-

ferred both advantages and disadvantages equally. Remote moni-

toring is presently a safe technology, widely accepted by patients

and physicians, for its convenience, reassurance, and diagnostic

potential. This review summarizes the principles of remote IECD

monitoring presenting the current state-of-the-art. Patient safety

and device interaction, applicability of current technology, and

limitations of remote IECD monitoring are also addressed. The use

of remote monitor should consider the selection of patients, the type

of disease, and centers’ availability to receive, interpret and re-

spond to device alerts. Before remote IECD monitoring can be

routinely used, technical, procedure, and ethical/legal issues

should be addressed.

Key words: implantable electronic cardiovascular devices, remote

monitoring, artificial pacemaker, cardioverter-defibrillator

Introduction

Device therapy for bradyarrhythmias has been successfully

used in clinical practice for more than 50 years with ob-

jectively proved efficiency, in terms of mortality and

quality of life.1 More recently, other electronic devices

similar to a pacemaker have been introduced in routine clinical

practice for providing cardiac resynchronization therapy (CRT) and/

or preventing sudden cardiac death. These devices, CRT devices and

implantable cardioverter-defibrillators (ICD’s), have the ability to

restore normal cardiac activation sequence and/or to detect and treat

a malignant arrhythmia, by means of electrical therapy, respective-

ly.2 Implantable electronic cardiovascular devices (IECD) include

pacemakers, ICDs and CRTs, as well as loop recorders and implantable

hemodynamic monitors.3

Over the last few years, the development of IECD technology along

with the emergence of new techniques and technologies has tre-

mendously increased the density of analysis and interpretation al-

gorithms. This increased the complexity and duration of follow-up

procedures. The development of battery technology4 along with the

increased patients means that life expectancy has extended not only

the longevity of these devices but also the burden of follow-up

procedures, which became overwhelming in relation with the

extremely vast population currently in follow-up.5 Traditional

follow-up of IECD is still a very resource-consuming activity,

requiring a great deal of time and differentiated human and technical

resources. Traditional follow-up also carries the inconvenience of

prolonged follow-up intervals, in which the physician has no in-

formation about the patient or the device.6

Our aim was to perform a survey of all available remote monitors,

explaining their advantages and inconveniences, along with patient

interaction and compliance. In particular, our objective was to de-

termine whether remote monitoring technology is effective in pro-

viding accurate real-time information regarding device operation

and patient diagnosis/therapies between appointments, while main-

taining patient-safe standards and reducing the burden of follow-up

on the healthcare community.

1042 TELEMEDICINE and e-HEALTH DECEMBER 2010 DOI: 10.1089/tmj .2010.0082

BackgroundRemote monitoring technology has been used since the 1970s,

mainly to overcome great distances between pacing centers and

distant population agglomerates.7 Since then, pacing and remote

monitoring technology have made quite a significant leap.

REMOTE TECHNOLOGY FUNDAMENTALSRemote technologies requirements include, depending on the

relative importance on the practical application, in general (1) low

battery power; (2) safety and reliability; (3) data rate; and (4) data

latency. Based on these requirements, the choice of standards and

regulations to fulfill these needs is necessary.8

RADIO SPECTRUM AVAILABILITYThere are several standards for short range devices. Of these, the

most popular in Europe are those of the European Telecommunica-

tions Standards Institute. Popular frequencies range from 434 to

868 MHz. Nonetheless, a Medical Implants Communication Services

(MICS) band exists worldwide, ranging from 402 to 405 MHz, being

shared only with meteorological aids and specifically designated for

implanted medical devices. MICS systems are classified as class 1

under European directives and, therefore, the frequency band is

available in all European Union member states without license. MICS

is a unique new technology that provides high-speed communica-

tions capability between individuals with implanted devices and

medical practitioners for the purpose of diagnosing and delivering

therapy to individuals with various illnesses. Some committees are

studying future requirements for spectrum up to 3 GHz for medical

applications.8,9

SPECTRUM CHOICEThe choice of any particular spectrum and system has to be made

within the ranges stated above. IECDs have their own particular

problems including large body loss and inefficient antenna. The

400 MHz region offers a good compromise in this respect8 with the

added ability of transmitting radio signals in the human body.9

ULTRA WIDE BANDThis technology has many claimed advantages including high data

rate and low interference potential. However, this technology is not

being implemented in e-health mainly due to its power consumption.

Nonetheless, it has been suggested that it may have some advantages

over ultrasound in terms of in-body imaging.8

SECURITYThis is an area of major importance and difficulty. Although it

was desirable that, from one standpoint, IECDs would be readily

interrogated by means of standard radio interface signal by health

professionals, it has the chance of being maliciously interfered or

even reprogrammed and, therefore, the need to adopt standards.8

Further, MICS users must cooperate in the selection and use of

channels to avoid interference with other MICS transmissions. The

MICS transmitter must incorporate a mechanism for monitoring

the channel or channels that the MICS devices intend to occupy. The

Listen Before Talk protocol instructs the receiver to scan all chan-

nels in the MICS band for other users or noise before establishing a

connection.9 Conventional IECD protocols include encrypted

transmission of data, and MICS additionally provides a restricted

network.9

Available SystemsBefore describing all available systems, we once again remember

that none of the systems allows remote reprogramming of IECDs, a

capability that will probably not be available in the foreseeable future

due to regulatory issues.10 All major device manufacturers have in-

troduced systems for remote patient monitoring that we will now

describe.

HOME MONITORING�

Biotronik (Biotronik GmbH, Berlin, Germany) was pioneer in IECD

remote monitoring technology with the introduction of Home

Monitoring in 2001. It transmits data on a daily basis, at fixed time

intervals, and on the occurrence of a clinically relevant event and is

available in all recently manufactured devices. A cell-phone-like

patient device sends encrypted data automatically via mobile phone

lines to a central database in Europe. On reception, the data are

processed and forwarded to the caregiver. The system rapidly

transmits clinically relevant, symptomatic, or asymptomatic events

regardless of patient location.11

CARELINK� NETWORKMedtronic (Medtronic Inc., Minneapolis, MN) CareLink Network is

available in the newest ICD and CRT and defibrillation (CRT-D) de-

vices as well as pacemakers. The CareLink� monitor collects and

stores information on the device using radio frequency telemetry and

transmits device and patient data via standard phone lines and cell

phones (since 2009) to a secure data repository for processing, stor-

age, and viewing. After a series of confirmations, the system executes

data transfer trough an Internet connection. CareLink is used for

routine IECD checks and automatically checks newer ICDs and CRT-Ds

wirelessly daily and notifies physicians when problems are de-

tected.11

LATITUDE�

Boston Scientifics system Latitude (Boston Scientific, St. Paul, MN)

is not fully available in Europe. The long-range transmissions take

place by standard telephone lines, generally weekly. A patient action

button blinks on the transmitter when the patient needs to initiate

patient-driven communications, for example, on detection of a

clinically relevant event. The Latitude system delivers event notifi-

cations at two levels: Red alert or ‘‘urgent event notifications’’

identify conditions that may pose a real threat to patient’s health and

yellow alerts or ‘‘configurable clinical event notifications’’ send the

physician timely additional information pertaining to patient or

device functions.11

REMOTE MONITORING APPLIED TO CARDIOVASCULAR DEVICES

ª M A R Y A N N L I E B E R T , I N C . . VOL. 16 NO. 10 . DECEMBER 2010 TELEMEDICINE and e-HEALTH 1043

MERLIN.NETTM

Again in the case of St. Jude Medical (St. Jude Medical, Sylmar,

CA) Merlin@Home�, only a wand-operated version is available

outside the United States and is available for almost all ICD and

CRT-D devices. The interrogated data are sent via standard telephone

lines to a central repository for data processing and storage. Mobility

of the system and early detection of asymptomatic events are limited.

On sensing a vibration alert, a patient can manually trigger the

Merlin@Home device to transmit a report.11 The main characteristics

of all systems are summarized in Table 1.

Patient SafetyIn their early studies, Hayes12 and Pinski13 reported susceptibility

of interference from wireless communication devices on IECDs,

namely by cellular telephones and antitheft devices.14 Nevertheless,

they concluded that the use of such technology was safe counting

that some precaution measures were taken (e.g., cellular phone in the

ipsilateral ear or rapid passing by the antitheft devices). More re-

cently, some authors15,16 reported interference between video-cap-

sule endoscopy and some IECDs. One of the studies (in VOO, unipolar

mode) showed significant interference in the recording when the

capsule was near the pacemaker but no change in pacemaker func-

tioning.15 The other study16 showed normal function in all ICDs but

one (Biotronik Belos ICD). Nonetheless, they recommend suspending

ICD therapies in conjunction with close monitoring.

Detected malfunctions include oversensing and under-

sensing, induction of asynchronous ventricular dysrhythmias,

and noise. Interference risk depends on several factors and in-

cludes (1) distance between IECD and source; (2) transmitter pow-

er; and (3) the device itself. These problems are related to direct

IECD malfunction and not to data transfer and programming/

interrogation.16

As described earlier,7–9 remote monitoring uses an encrypted and/

or specific bandwidth reserved to medical devices and, therefore, is

not prone to interference or tampering by conventional wireless

networks.

MethodsAs previously stated, our aim was to establish the effectiveness of

remote monitoring technology applied to device follow-up.

LITERATURE SEARCHWe performed a search in Medline reference database through

PubMed, regardless of the type of publication, using the following

query: artificial pacemaker [MeSH Terms] AND (ICD [MeSH Terms]

OR pacemaker [All Fields] OR ICD [All Fields] OR CRM device [All

Fields] OR cardioverter-defibrillator [All Fields] OR defibrillator

[All Fields] OR implantable cardiovascular devices [All Fields]) AND

remote monitoring [All Fields].

Table 1. Current Commercially Available Patient Management Systems (2008)

HOME MONITORING CARELINK NETWORK LATITUDE MERLIN.NET

FDA approval 2001 2005 2006 2007

Patient device Home monitor Conexus Latitude communicator Merlin@Home

Characteristics Portable/simple Stationary/simple Stationary/interactive Stationary/voice interactive

Home telemetry MICS MICS/wand Wand Wand

Patient trigger Call back light Audio Audio Vibration

Transmission Daily follow-up/event messages

(automatic)

Scheduled follow-up/event

messages (automatic)

Scheduled follow-up/event

messages (automatic)

Scheduled follow-up/patient

initiated (automatic)

Long-range telemetry GSM/GPRS/landline GSM/landline Landline Landline

Information of events Fax/e-mail/SMS E-mail/SMS Fax/phone Fax/e-mail/SMS

Early detection <24 h (all events) <24 h (all events) <24 h (all events) Not available

Data storage Long term Long term Long term Long term

Interface with EMR HL7 HL7/some EMR HL7 HL7/some EMR

Data presentation Event-based Event-based Traffic light-based Event-based guidance

Cognitive interpretation Physician Raytel partnership Raytel partnership Mednet/raytel partnership

Impact on battery longevity Low High High Not available

FDA, U.S. Food and Drug Administration; MICS, medical implants communication services; GSM, global system for mobile communication; GPRS, general packet radio

service; SMS, short message service; EMR, electronic medical records; HL7, health level interface standard.

Note: Adapted from Jung et al.11

COSTA ET AL.

1044 TELEMEDICINE and e-HEALTH DECEMBER 2010

SELECTION PROCESSThe query was performed on December 28, 2008, initially re-

turning 24 papers for analysis. The analysis was performed by a

single investigator in three steps. The first step was done by trying to

relate the title and the object of the study choosing those articles that

were related with our subject. In the next step, we analyzed the ab-

stract of all the selected articles and excluded those that were not

adequate to our purpose. The last step consisted in performing a

cross-linked examination by selecting articles related with those

previously selected in step two.

SELECTION CRITERIASelection criteria were defined before the query and included (1)

study addresses remote monitoring technology, particularly applied

to IECD; (2) description of study design; (3) statistical analysis of

results; and (4) study includes both results and discussion on different

issues.

STUDY VARIABLESThe study variables used for analyzing the papers were country of

origin of the study (first author), year and journal of publication, type

of study, and main issues covered:

. Patient issues: all nonclinic issues that can be perceived by the

patient or have impact on their daily routine;. Clinical issues: all issues related to diagnosis, follow-up, and

treatment that involve staff or routine clinical management,

including legal and ethical aspects of clinical practice;. Economic impact issues: all the issues that imply costs for the

patient, the staff, healthcare providers, or healthcare systems.

For better understanding, the entire selection process is described

in Figure 1.

ResultsAfter applying all of the above criteria, we selected 20 articles on

which we based our review.10,11,17–34 A first overview on the selected

papers allowed us to place them in terms of type, time, and location

while exploring the issues each of them covers.

After a brief analysis, we observed that 30% of the articles were

originated from the United States and 25% were originated from

Italy. If analyzed all together, European countries were responsible

for 70% of the publications. Regarding the field of expertise of the

journal, we observed that the vast majority (95%) was published in

Cardiology related journals, with only one paper appearing in a

Medical Informatics journal.19 More than half (55%) of the articles

were published in 2008 and 2009, as use of these technologies have

increased. The main topics included patient, clinical, and economic

impact issues. Articles include 45% nonrandomized clinical trials,

25% reviews, and two (10%) major ongoing trials, emphasizing the

current interest in this subject. Table 2 summarizes the characteristics

of selected papers.

PATIENT AND CLINICAL ISSUESThe main findings regarding patient and clinical issues are sum-

marized in Tables 3 and 4. Eight of nine patient issues papers pre-

sented advantages with 75% focused on patient acceptance/

satisfaction. Patient time savings were mentioned in four of eight

papers. The main downsides were technical issues in three of four

papers. Ninety-four percent of physician issues papers presented

advantages, focusing on clinical events identification (67%), clinical

stability of patients (40%), time savings (33%), and physician satis-

faction (33%). Six papers referred to disadvantages for physicians,

including legal and technical issues (50%).

The study by Lazarus et al.17 reported that remote monitoring in

devices at risk detects as promptly as currently possible the small

number of device failures, eliminates the need of unnecessary re-

placements, and provides patients with the highest level of reassur-

ance and comfort. In the study by Res et al.,18 a high or very high

satisfaction was claimed by 97% of patients and a small number of

patients, who believe they have experienced a shock, but have not

had one, can be reassured in case they have not had a malignant

tachyarrhythmia. Asymptomatic ventricular dysrhythmias can also

be traced and followed, and patients can be seen for treatment to

improve patient compliance.

Masella et al.,19 using a remote monitoring system in an Italian

population, reported 23 unscheduled contacts by patients, with only

2 requiring clinic visits. The remote monitoring system used in this

study was judged very easy to use by 96% of patients, and 78% of

patients preferred remote monitoring rather than a clinic appoint-

ment.19 Similar results (98%) were observed by Schoenfeld et al.20

Marzegalli et al.21 reported that patients found that remote moni-

toring saved time (travel and appointment) and decreased their costs.

Two major trials to determine clinical outcomes of prolonged re-

mote monitoring and potential benefits to clinic staff are expected to

be completed in the end of 2009.22,23

A retrospective analysis by Heidbuchel et al.24 concluded that

during the vast majority of scheduled visits, no relevant or device-

related problems were detected in 78.2% of patients, and 90% of

patients required no medical treatment or device programming. TheFig. 1. Schematic description of paper selection.



clinical and device-related problems detected in 21.8% of patients

could have been recognized and treated by a general practitioner or

referring cardiologist, or in a scheduled traditional follow-up.

However, unscheduled appointments were much more frequent than

scheduled ones (80.6% vs. 21.7%; p< 0.001) and in 45.7% of un-

scheduled appointments device reprogramming or hospitalization

was required. These results indicate that remote monitoring can di-

agnose the vast majority (99.5%) of arrhythmias and device-related

problems.

Two large studies of CRT-D devices demonstrate that remote

monitoring can alert the clinician to fluid accumulation in the

lungs.25,26 This allows clinicians to call the patient to adjust therapy

and decrease need for admissions for congestive heart failure, a direct

benefit to both the patient and the healthcare system.

Case reports have highlighted the benefits of early detection of

malfunctions and arrhythmias using remote monitoring, particularly

lead insulation or fracture, anomalous impedance risings, battery

depletion, and arrhythmias.27,28

ECONOMIC IMPACTThe main economic advantage of remote monitoring cited was

decreased follow-up costs. Reimbursement issues were considered

the main disadvantage.

Fauchier et al.29 concluded that since recommended follow-up in-

tervals range from 3 to 6 months, remote monitoring can save up to two

visits per year. In terms of savings, this represents a net saving of $948

per patient. Also, regarding transportation, the mean reduction in cost

over a 5 year period was $2,722, with savings beginning at 26 months.

Table 2. General Characteristics of Selected Papers

PATIENT ISSUES CLINICAL ISSUES ECONOMIC IMPACT N

Number of studies 9 (45%) 16 (80%) 4 (20%) —

10,17–21,24,30,32 10,11,17–20,22–28,31,32,34 11,29,30,33 20 (100%)

Country of publication

United States 10,20,32 10,20,22,23,32 33 6 (30%)

Germany — 11,28 11 2 (10%)

France 17 17 29 2 (10%)

Netherlands 18 18,31 — 2(10%)

Italy 19,21 19,25,26,34 — 5 (25%)

Belgium 24 24 — 1 (5%)

Czech Republic — 27 — 1 (5%)

Finland 30 — 30 1 (5%)

Year of publication

2004 20 20,28 — 2 (10%)

2005 32 32 29 2 (10%)

2006 10,18 10,18 — 2 (10%)

2007 17 17,22,25 — 3 (15%)

2008 19,21,24,30 11,19,23,24,27,31,34 11,30,33 10 (50%)

2009 — 26 — 1 (5%)

Type of study

RCT (design) 22,23 2 (10%)

NRCT 17,19,21,24,30,32 17,19,24,26,32,34 29,30 9 (45%)

Review 18,20 11,18,20,25,31 11 5 (25%)

Case report — 27,28 — 2 (10%)

Other 10 10 33 2 (10%)

RCT, randomized clinical trial; NRCT, nonrandomized clinical trial.

COSTA ET AL.

1046 TELEMEDICINE and e-HEALTH DECE MBER 2010

Similarly, Raatikainen et al.30 concluded that the replacement of

traditional follow-up by remote monitoring reduced the direct costs

of ICD follow-up to the healthcare providers by 155e and for patients

by 22e. When compared with traditional follow-up, remote moni-

toring reduced the costs in the studied population from 38.048e to

23.534e (38%). Obviously, these figures have to be put in perspective,

regarding the type of IECD (ICD, CRT, or conventional pacemakers),

the cost of transportation and distance, the cost of appointments, the

inconvenience of unscheduled appointments, and several other fac-

tors. Nevertheless, we can infer that a substantial saving per patient is

attained by the use of remote monitoring.

Reimbursement issues are a complex matter by themselves and

will not be addressed in more depth, with the risk of getting out of

scope. Nevertheless, some residual problems still subside, namely

regarding the relatively slow progress in confirming clinical benefit,

the lack of reliable cost-benefit data11 on remote monitoring, and the

different reimbursement schemes among healthcare systems, with some

countries stressing the need of new models of reimbursement.29,30,33

The information contained in the analyzed papers and regarding

economic impact is summarized on Table 5.

DiscussionMore than three decades have transpired since the inception of

transtelephonic pacemaker monitoring. This modality has proved

useful for tracking the function of early pacemakers, particularly

when both lead and pulse generators longevities were highly un-

predictable. Further, until relatively recently, the complexity of new

devices outpaced the capabilities of transtelephonic monitoring.

Remote monitoring of implanted ICDs is, in contrast to pacers, a

relatively recent development.11,31,32

The demographic increase in mean

age of populations along with the

incremental cost of the provision of

healthcare has a severe impact on

health and, therefore, leads to increas-

ing requirements of technological ap-

plications to reduce costs as well as

improving healthcare. Although these

applications have a widely recognized

value, they cannot entirely replace

human contact, namely in traditional

follow-up and, thus, need to be com-

plementary with each other. We have to

keep in mind that remote monitoring

technologies are not an instrument to

replace traditional follow-up (that

should always be scheduled according

to international guidelines5) but rather

a technology that helps healthcare

professionals to monitor and act on

changes in cardiovascular status of the

patient or the device between scheduled

follow-up. The majority of ICD recipi-

ents are routinely followed from 3 to 6 months.5 Additionally, a

substantial number of patients require additional nonscheduled visits

due to arrhythmic events or system-related complications. The

challenge is to be able to avoid routine follow-up visits such as

integrity check and/or confirmation that no arrhythmic events or

IECD-related issues occurred.31

These systems, while enormously reducing the economic impact

of unscheduled follow-up sessions (and the inherent cost of a

possible admission and treatment), still have some problems re-

garding healthcare provider’s reimbursement.11,29,30,33 Also, re-

motely reprogramming IECDs have additional caveats, both

technical and ethical, that need to be addressed before widespread

implementation will be possible.32–34 This is of particular impor-

tance, as remote monitoring is particularly vulnerable in this field

mainly because the law-making process tends to be outpaced by

technology development and also because of national/European

differences. Additionally, different proprietary technologies for

remote monitoring could pose a major obstacle to data integration,

making it an important premise. Also, the scarce resources of

clinical guidelines may pose a problem to remote monitoring im-

plementation. These issues should be seriously addressed before

remote monitoring can be routinely used and firmly established in

clinical practice.11,25,32–34 Nevertheless, we have to consider that

the economic impact regarding cost estimates and savings must

consider multiple factors, multiple different devices, device costs,

and longevity of different devices. Moreover, issues regarding

reimbursement must be further clarified to show differences in

systems in different countries and must be the subject of future

research. Fully automated remote monitoring capabilities will

probably be included in all upcoming IECDs. Useful new sensors are

Table 3. Patient Issues Regarding Remote Monitoring and Its Main Determinants

ADVANTAGES (N¼ 8) DISADVANTAGES (N¼ 4)

Patient issues (n¼ 9) Patient convenience Technical issues

Reduce patient inconvenience10 Failure to properly handle the system18

Patient acceptance/satisfaction Difficulty in antenna positioning20

Easy/very easy to use10,19–21,30 Transmission problems21

High acceptance18,19,21 Other issues

High/very high level of satisfaction18,21,30 Patient privacy32

Patient reassurance Remote technology: manufacturer specific32

Patient reassurance17,24

Patient calmness19

Time saving

Overall time savings18

Saving in traveling time19,21,30

Saving in waiting time19,21,30



also expected to soon become available. The evolution of IECD

toward patient monitoring may shift the emphasis from a device-

oriented to a patient-oriented monitoring, allowing a new broader

multidisciplinary approach. That will probably change the follow-

up routines, allowing clinicians to intervene more rapidly,

improving clinical outcomes and reducing costs.

ConclusionsAfter reviewing the issue of remote monitoring, we can conclude

that it is currently a major issue in Europe, reflected by the number of

studies produced in Europe, and probably because this issue has been

addressed in the United States for quite sometime and is currently

being used in clinical practice widely.

Also, based on our analysis, we can infer that remote monitor-

ing is presently a safe technology, widely accepted by the patients

for its convenience and reassurance. It has enormous potential for

the clinician, both for monitoring diseases and treatment and for

identifying potential harmful situations. This is of major importance,

as it can help the physician to perceive any changes of clinical status

of the patient or the device and act on it. Nevertheless, two major

trials are still pending for published conclusions and are expected to

further enlighten this subject.22,23

The fact that in our analysis economic impact disadvantages

match advantages may, in part, explain the delay in the im-

plementation of remote technology. Nevertheless, remote monitoring

has the ability to reduce the direct costs of follow-up, by reducing the

number of in-office visits, transportation costs, and staff-saving

costs.

However, a series of issues should be solved before remote mon-

itoring can be routinely used in Europe and include data integration

Table 4. Clinical Issues Regarding Remote Monitoring and Its Main Determinants


Clinical issues (n¼ 16) Clinical events Legal issues

Identification of number/type of episodes10,11,17,18,20,25,26,32 Need to establish legal responsibility for an immediate response11

Identification of number/type of delivered

therapies10,11,17,18,20,25,26,32Need to issue guidelines on remote monitoring11,25

Reduce inappropriate delivered therapy18 Need to inform patient on purpose, use, and limitations of remote

monitoring11

Silent arrhythmias discovery10,18,20,24–26,28,32 Patients’ privacy32

Assessment of antiarrhythmic drug

efficacy10,18,20,24–26,28Technical characteristics

Identifying abnormal device functions10,11,17,20,24–27,31,32 Does not allow remote reprogramming17,19,24

Patients’ clinical stability Most current remote systems do not allow determination of

pacing threshold24

Prediction of hospitalization10,26,31,32

Changes in patients’ clinical status11,17,26

Helping in the design of individualized follow-up11,31

Time savings

Overall time savings for physicians19,34

Follow-up clinic optimization17,19,23,24

Physician satisfaction

High physician satisfaction working with remote monitoring19

Assessing patient data20

Ability to provide comparable to in-office interrogation data20

Timely identification of clinically important

issues20,22,23,31

Reprogramming

Makes reprogramming less frequent34

Postshock interrogations can be done remotely34

COSTA ET AL.


of different proprietary technologies, the scarce resources of clinical

guidelines, and ethical and legal issues.

We can conclude that remote monitoring technology is effective in

providing accurate real-time information regarding device operation

and patient diagnosis/therapies between appointments while main-

taining patient-safe standards and reducing the burden of follow-up

on the healthcare community.

While we were writing this article, two important reviews were

published, further substantiating our conclusions.35,36 Nevertheless,

our work has a broader approach on remote monitoring technology,

therefore providing additional contributions on this subject.

Despite all these considerations, nowadays all major companies

have remote monitoring systems applied to IECDs, and several devices

are available for clinical use. The type of device should be carefully

selected depending on the patient, the type of disease, and the centers’

availability to receive, interpret, and respond to device alerts.

Authors’ ContributionsPaulo Dias Costa was responsible for the conception and design of

the paper and for drafting the article. Pedro Pereira Rodrigues was

responsible for drafting and critically revising the article. Antonio

Hipolito Reis and Altamiro Costa-Pereira were responsible for criti-

cally revising the manuscript.

Disclosure StatementNo competing financial interests exist.

R E F E R E N C E S

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3. Abraham WT. New approaches to monitoring heart failure before symptomsappear. Rev Cardiovasc Med 2006;7(Suppl 1):S33–S41.

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Table 5. Economic Impact of Remote Monitoring and Its Main Determinants


Economic impact (n¼ 4) Savings in follow-up Reimbursement issues

Overall reduction of follow-up costs29,30 Lack of reimbursement issues11,29

Time-saving tool11,30 Slow progress in confirming clinical benefit11

Resource-saving tool11 Lack of reliable cost-benefit data11

Transportation costs29,30 Requirement for new models of reimbursement33

Reduction of number of visits29 Reimbursement schemes different healthcare systems29,30,33

Staff costs reduction 29,33

Patient working days savings33



18. Res JC, Theuns DA, Jordaens L. The role of remote monitoring in the reductionof inappropriate implantable cardioverter defibrillator therapies. Clin ResCardiol 2006;95(Suppl 3):III17–III21.

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21. Marzegalli M, Lunati M, Landolina M, Perego GB, Ricci RP, Guenzati G, et al.Remote monitoring of CRT-ICD: The multicenter Italian CareLink evaluation-ease of use, acceptance, and organizational implications. Pacing ClinElectrophysiol 2008;31:1259–1264.

22. Varma N. Rationale and design of a prospective study of the efficacy of aremote monitoring system used in implantable cardioverter defibrillator follow-up: The Lumos-T Reduces Routine Office Device Follow-Up Study (TRUST) study.Am Heart J 2007;154:1029–1034.

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24. Heidbuchel H, Lioen P, Foulon S, Huybrechts W, Ector J, Willems R, et al.Potential role of remote monitoring for scheduled and unscheduled evaluationsof patients with an implantable defibrillator. Europace 2008;10:351–357.

25. Boriani G, Diemberger I, Martignani C, Biffi M, Valzania C, Bertini M, et al.Telecardiology and remote monitoring of implanted electrical devices: Thepotential for fresh clinical care perspectives. J Gen Intern Med 2008;23(Suppl 1):73–77.

26. Santini M, Ricci RP, Lunati M, Landolina M, Perego GB, Marzegalli M, et al.Remote monitoring of patients with biventricular defibrillators through theCareLink system improves clinical management of arrhythmias and heartfailure episodes. J Interv Card Electrophysiol 2009;24:53–61.

27. Neuzil P, Taborsky M, Holy F, Wallbrueck K. Early automatic remote detection ofcombined lead insulation defect and ICD damage. Europace 2008;10:556–557.

28. Wildau HJ. Wireless remote monitoring for patients with atrialtachyarrhythmias. J Electrocardiol 2004;37(Suppl 1):53–54.

29. Fauchier L, Sadoul N, Kouakam C, Briand F, Chauvin M, Babuty D, et al. Potentialcost savings by telemedicine-assisted long-term care of implantablecardioverter defibrillator recipients. Pacing Clin Electrophysiol 2005;28(Suppl1):S255–S259.

30. Raatikainen MJ, Uusimaa P, van Ginneken MM, Janssen JP, Linnaluoto M.Remote monitoring of implantable cardioverter defibrillator patients: A safe,time-saving, and cost-effective means for follow-up. Europace 2008;10:1145–1151.

31. Theuns DA, Jordaens LJ. Remote monitoring in implantable defibrillator therapy.Neth Heart J 2008;16:53–56.

32. Schoenfeld MH, Reynolds DW. Sophisticated remote implantable cardioverter-defibrillator follow-up: A status report. Pacing Clin Electrophysiol2005;28:235–240.

33. Wilkoff BL, Auricchio A, Brugada J, Cowie M, Ellenbogen KA, Gillis AM. HRS/EHRA Expert consensus on the monitoring of cardiovascular implantableelectronic devices (CIEDs): Description of techniques, indications,personnel, frequency and ethical considerations. Heart Rhythm 2008;5:907–925.

34. Lunati M, Gasparini M, Santini M, Landolina M, Perego GB, Pappone C, et al.Follow-up of CRT-ICD: Implications for the use of remote follow-up systems.Data from the InSync ICD Italian registry. Pacing Clin Electrophysiol2008;31:38–46.

35. Burri H, Senouf D. Remote monitoring and follow-up of pacemakers andimplantable cardioverter defibrillators. Europace 2009;11:701–709.

36. Kusumoto F, Goldschlager N. Remote monitoring of patients with implantedcardiac devices. Clin Cardiol 2010;33:10–17.

Address correspondence to:

Paulo Dias Costa, B.Sc.

Service of Cardiology

Department of Medicine—Hospital de Santo Antonio

Centro Hospitalar do Porto

Largo do Prof. Abel Salazar

Porto 4099-001

Portugal

E-mail: [email protected]

Received: May 25, 2010

Revised: July 20, 2010

Accepted: July 25, 2010

COSTA ET AL.


a review on remote monitoring technology applied to implantable electronic cardiovascular devices

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