Telemedicine in heart failure: Pre-specified and exploratory subgroup analyses from the TIM-HF trial

Background Meta-analyses have suggested that remote telemedical management (RTM) positively affects clinical outcomes in chronic HF patients. The results of two recent randomised RTM trials do not corroborate these results. We aim to report prospectively defined and exploratory subgroup analyses for the TIM-HF trial and to identify a patient profile that could potentially benefit from RTM for further investigation in randomised clinical trials. Methods In TIM-HF, 710 stable chronic HF patients, in NYHA class II or III with a history of HF decompensation within 2years previously or a LVEF≤25% were randomly assigned (1:1) to RTM or usual care. The primary outcome was total death and secondary outcomes included days lost due to death or HF hospitalisation and a composite of cardiovascular death and HF hospitalisation. Twelve subgroups were prospectively defined and patient profiling was investigated for the subgroup with a prior history of HF decompensation, an LVEF≥25% and a PHQ-9 score<10. Results The subgroup treatment effects were significant for total mortality for the PHQ-9 subgroup only (p for interaction<0.027). For the outcome ‘number of days lost due to hospitalisation for HF or death’, the subgroup treatment effects were significant (p for interaction<0.05) for patients with a prior HF decompensation or an ICD implant or a PHQ score of <10 and for the patient-profiling subgroup. Conclusions Telemedicine management may not be appropriate for all HF patients. Future research needs to investigate which HF population may benefit from this intervention.