HRS 2014: Remote Monitoring of Cardiac Devices: Hard Evidence for the Digital Transformation of Medicine

John Mandrola


May 13, 2014

The Heart Rhythm Society 2014 Scientific Sessions began with a triumphant celebration of all that is digital. Medical practice will grow more connected and more social, said the futurists.

Yet, even I, an early adopter, left the coronation wondering about hard evidence. Is there any? Is there any signal that the digital revolution improves real outcomes? Is this hype or hope? Can technology actually help us live longer or better?

The answer is yes.

Let me tell you about remote monitoring of patients with cardiac internal electronic devices (CIEDs), such as pacemakers, implantable cardiac defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. There were remarkable data presented at this meeting that convincingly show that patients who use this mode of monitoring, rather than just traditional in-office device checks, are more likely to be alive. A mortality benefit from digital medicine!

First, let's review plausibility and background:

Plausibility: Modern-day cardiac devices do much more than just sense, pace, and shock the heart. The sensors and wireless connectivity in these devices provide troves of data to caregivers—about the person and the device. Although some thinkers have valid concerns about the overmonitoring of human life, it is clear that CIEDs can transmit very useful (actionable) data.

Background: Dr Leslie Saxon (University of Southern California, Los Angeles) and coworkers did the first mega-cohort study with remote monitoring of patients with ICDs and CRT-D devices[1]. They compared patients followed on remote monitoring and those with in-clinic-only visits for five years. They found that patients on remote monitoring had a relative risk reduction of 50%. Although this was a strong signal, the groups were nonrandomized, there was limited knowledge of the clinical characteristics of the patients, and the remote monitoring came from just one manufacturer. These limitations and the possibility of confounding variables and selection bias prevent making a causative link.

The New Data

Dr Suneet Mittal (Valley Hospital Heart & Vascular Institute, New York, NY) presented data from a cohort study in which they used the St Jude Medical database (Merlin) to analyze mortality rates in patients with and without remote monitoring. In a late-breaking clinical trial[2] and a featured poster[3] presentation, his group showed convincingly that patients on remote monitoring had lower mortality rates, regardless of type of device, including pacemakers. The relationship was strengthened when they looked at the degree of adherence. The more patients used remote monitoring, the more likely they were to be alive.

As reported by Steve Stiles on heartwire , two key findings of their analyses addressed preconceived ideas about remote monitoring. It has been thought that the association of lower mortality and remote monitoring was due to selection bias (eg, wealthier, healthier patients choose to monitor remotely, whereas sicker patients don't). When Dr Mittal's group looked for these differences in patient characteristics, they found none. However, they did note counterintuitive geographic relationships. The use of remote monitoring was lowest in major urban areas, such as Southern Florida, New York, and Los Angeles.

Other Data Presented

Science, especially these days, is best when backed by confirmatory evidence.

In the third late-breaking clinical-trial session, Dr Joseph Akar (Yale University, New Haven, CT) presented another analysis of remote monitoring and its effects on mortality[4]. This group of researchers used data from the Boston Scientific database (Altitude registry). Their results were similar: remote monitoring, in all subgroups, was associated with lower mortality compared with standard in-office follow-up. On a Kaplan-Meier graph, the curves separated early. Although clinical characteristics of the patients in this nonrandomized sample were generally similar, there were a few notable differences. The remote-monitoring group had a higher percentage of patients with CRT devices, white patients, and those admitted for elective implants.

These findings are not specific to the US. A group of Italian investigators also reported, in a poster session, that remote monitoring resulted in reduced morality and cardiovascular-related hospital admissions[5].


I welcome these findings because such data favorably affect both sides of the benefit/risk ratio of cardiac devices. Every decision in medicine is a gamble, and CIEDs are surely that. On one side are the benefits (bradycardia support, sudden death prevention, relief of heart failure symptoms, etc), and on the other side are the risks (inappropriate shocks, hardware failure, changing mode of death without extending meaningful life, etc).

Consider one obvious way remote monitoring affects the risk side of the CIED gamble: early detection of hardware failure, a subject that this meeting offered many abstracts on. (Think Fidelis and Riata). On the benefit side, early detection of asymptomatic AF may help prevent a disabling stroke, while early detection of ventricular arrhythmia may indicate the onset of ischemia and possibility of revascularization. And it's not just objective Xs and Os. There is also the possibility that remote monitoring enhances patient engagement with their care, creating a "healthy-adherer effect." (See this poster on how remote monitoring induced behavior change in patients[6].)

When medicine is done well, doctors partner with patients, and together, they make the best gamble for each patient. Remote monitoring is a simple tool that decreases risk and increases benefit of cardiac devices. These data argue it’s not extra,or just for convenience.

Here is a brand of digital medicine and patient monitoring that we should actively promote to all patients receiving cardiac devices.



Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.