In general, data from randomized trials suggest that there is really no benefit for longitudinal monitoring of device-based parameters for enhancing HF management, and this provides an important cautionary note that more data do not always equate to more information.

Looking for example at the results from DOT-HF (Diagnostic Outcome Trial in Heart Failure),^[12] which randomized HF patients to management with or without guidance from impedance data, the clinicians who had access to the impedance data were no better at keeping their patients alive, and actually were worse at keeping their patients out of the hospital, than the physicians who relied on traditional information.  This may have been because the impedance signal was overly sensitive, or perhaps because when impedance dropped in these HF patients, clinicians felt compelled to refer patients to the emergency department for evaluation, where they were frequently admitted.

The paradoxical increase in the rates of hospitalization in impedance-guided strategies suggests that perhaps this is not the signal that we need for monitoring HF patients.