A recent study presented at the annual meeting of the Heart Rhythm Society suggests an association of the use of remote monitoring for implantable cardioverter defibrillators (ICDs) and lower rates of mortality and rehospitalization.

In the PREDICT-RM study, researchers from Yale used registry data from the National Cardiovascular Data Registry (NCDR) and the Boston Scientific Altitude Registry in conjunction with mortality information from the Social Security database and hospitalization information from Medicare. Using a retrospective cohort of patients with first-time ICD or CRT-D devices implanted between 2006 and 2010, they compared mortality and rehospitalization rates between patients using remote monitoring versus those that were not in a total population of nearly 40,000 patients.

The researchers reported lower rates of mortality and rehospitalization over three years in patients enrolled in remote monitoring programs. In thinking about the implications of these findings, it is important to consider both whether there is a plausible mechanism that could explain the association as well as whether there are confounders present. To the latter point in particular, one important consideration is a problem that is fairly common in mobile health – access.

At the outset, it’s important to note that these findings were presented in an abstract format but have yet to be published in a peer review journal. With that in mind, the researchers reported a lower 3-year mortality in patients utilizing remote monitoring that was statistically significant (HR=0.67; 95% CI, 0.64-0.7) even when controlling for factors like age, gender, ischemic vs. nonischemic disease, and more. Similarly they identified a lower risk of rehospitalization when looking at the subset of Medicare patients for whom that data was available (HR=0.81; 95% CI, 0.79-0.83).

There are some important confounders to consider. Systems like Medtronic’s CareLink or Boston Scientific’s Latitude require several things of patients. For one, they require a phone line. Having spent several years in East Baltimore now, I can attest to the fact that there are patients who would not qualify for remote monitoring, either because of difficulty paying the phone bill or lack of a stable home.

Second, they require a certain level of health literacy to manage at home and the prospect of doing that could certainly be a deterrent for some patients to sign up. Third, there is certainly a cost associated with this service and one has to wonder whether insurance type plays a role in who enrolls in remote monitoring. All this to say that perhaps the patients enrolling in remote monitoring are fundamentally different in some critical way than those who don’t.

There are also conceivable ways that a mortality benefit could perhaps be achieved. Perhaps, for example, the use of remote monitoring leads to a consistent reduction in inappropriate shocks or in device malfunctions that would prevent appropriate shocks. Alternatively, maybe by catching inappropriate device activity earlier, there are less iatrogenic complications or effects on the heart or maybe there is some other mechanism at play here that has yet to be identified.

Source: Healio Cardiology