The findings were presented for the first time at the Heart Failure Congress 2014, held 17-20 May in Athens, Greece. The Congress is the main annual meeting of the Heart Failure Association of the European Society of Cardiology.
The prospective IN-TIME multicentre trial included 664 patients with chronic heart failure, class II or III New York Heart Association (NYHA) symptoms and left ventricular ejection fraction <35% who were receiving optimal medical therapy. Nearly two-thirds of patients (60%) received a cardiac resynchronisation defibrillator (CRT-D) while 40% received an implantable cardioverter defibrillator (ICD).
All of the implanted devices had a home telemonitoring capability. Patients were randomised in a 1:1 fashion to have the telemonitoring function switched on or off. For those patients who had the telemonitoring function switched on, data from their device was transmitted to a monitoring physician or clinic to enable early detection of arrhythmias or other complications. Patients with the telemonitoring switched off were followed up during visits to the clinic.
The findings of the overall study were presented at ESC Congress 2013. Briefly, the trial showed that telemonitoring reduced the proportion of patients with a worsened composite clinical score consisting of all cause mortality, overnight hospitalisation for worsened heart failure, change in NYHA class, and change in patient global self assessment from 27.2% to 18.9% (p=0.013) (primary outcome). Telemonitoring also reduced one-year mortality from 8.7% to 3.4% (p=0.004) (secondary outcome).
The current subanalysis of the IN-TIME trial, presented for the first time today, investigated whether home telemonitoring was equally effective in patients with a CRT-D and patients with an ICD.
Professor Gerhard Hindricks, principal investigator of the study, said: "We predefined this subanalysis because we wanted to know if our overall findings were the same in both device types. This would have an impact on the interpretation of the data and recommendations for treatment in these patient populations."
He continued: "The patient population receiving a CRT-D is quite different to the patient population receiving an ICD. Usually the patients with an indication for CRT implantation are at higher risk of worsening of heart failure during the natural course of the disease, and they profit more from defibrillator therapy with a cardiac resynchronisation function."
The researchers found that the relative risk of the primary outcome in the telemonitoring versus control group was similar in the ICD (0.61, p=0.06) and CRT-D (0.75, p=0.10) patients. The relative risk of the secondary outcome was also similar in both device groups (ICD: 0.38, p=0.15; CRT-D: 0.35, p=0.014).
Professor Hindricks said: "This subanalysis adds to the general finding of the IN-TIME trial. We now know that ICD patients and CRT-D patients benefit to an almost equivalent extent from home telemonitoring."
He concluded: "The take home message for clinicians is that if you have a patient with advanced heart failure and an ejection fraction less than 35% who is on optimal medical therapy, consider implantation of an ICD or CRT-D that is capable of home telemonitoring. Patients on both types of devices will benefit equally from home telemonitoring, with improved clinical outcomes including reduced mortality."