Telemedical Interventional Monitoring in Heart Failure (TIM-HF), a randomized, controlled intervention trial investigating the impact of telemedicine on mortality in ambulatory patients with heart failure: study design

Remote patient management (telemonitoring) may help to detect early signs of cardiac decompensation, allowing optimization of and adherence to treatments in chronic heart failure (CHF). Two meta-analyses have suggested that telemedicine in CHF can reduce mortality by 30-35%. The aim of the TIM-HF study was to investigate the impact of telemedical management on mortality in ambulatory CHF patients. CHF patients [New York Heart Association (NYHA) II/III, left ventricular ejection fraction (LVEF) < 35%] with a history of cardiac decompensation with hospitalization in the past or therapy with intravenous diuretics in the prior 24 months (no decompensation required if LVEF < 25%) were randomized 1:1 to an intervention group of daily remote device monitoring (electrocardiogram, blood pressure, body weight) coupled with medical telephone support or to usual care led by the patients' local physician. In the intervention group, 24/7 physician-led medical support was provided by two central telemedical centres. A clinical event committee blinded to treatment allocation assessed cause of death and reason for hospitalization. The primary endpoint was total mortality. The first secondary endpoint was a composite of cardiovascular mortality or hospitalization due to heart failure. Other secondary endpoints included cardiovascular mortality, all-cause and cause-specific hospitalizations (all time to first event) as well as days lost due to heart failure hospitalization or cardiovascular death (in % of follow-up time), and changes in quality of life and NYHA class. Overall, 710 CHF patients were recruited. The mean follow-up was 21.5 +/- 7.2 months, with a minimum of 12 months. The study will provide important prospective outcome data on the impact of telemedical management in patients with CHF.