BOSTON — Remote monitoring of implantable cardioverter defibrillators reduced the number of routine office visits and dramatically cut the delay from arrhythmia onset to physician exam, according to a new analysis of more than 1,400 patients.
“This is a landmark study. It shows you can reduce [routine] health care use but increase patient safety” by remote monitoring, Dr. Niraj Varma said at the Heart Rhythm Society's annual meeting. “There is a sense that we need remote monitoring for absolutely every” implanted cardiac device, said Dr. Varma, a cardiac electrophysiologist at the Cleveland Clinic, where he said every implanted defibrillator is now followed by remote monitoring at the clinic.
The findings came from the Lumos-T Safely Reduces Routine Office Device Follow-Up (TRUST) study, which tested the safety and efficacy of Biotronik Home Monitoring, a system that is built into the company's implantable cardioverter defibrillators (ICDs). Dr. Varma said that he has financial relationships with Biotronik, which sponsored the study, as well as with other cardiac device manufacturers.
TRUST tested remote monitoring in a “real-world” setting, with 85% of the patients monitored at community hospitals and 15% monitored at academic centers. The study was done at 105 locations in North America.
The fully automatic system, already on the U.S. market, requires no action by patients. Data are automatically transmitted by a device that sits by the patient's bed. The device is programmed to retrieve a day's worth of data at about 2 a.m. and transmit it to a central monitoring station at the patient's hospital.
The 972 patients randomized to remote monitoring received a bedside transmitter, and were scheduled for in-office monitoring at 3 and 15 months after implantation. The 471 controls did not transmit monitoring data, and were scheduled for the same two monitoring visits as well as office visits at 6, 9, and 12 months after ICD placement. The average age of the patients was 63 years, 72% were men, and 73% received their ICDs for arrhythmia prophylaxis. Their average left ventricular ejection fraction was 29%.
During the first year following placement, remote-monitoring patients had an average of 1.3 scheduled office visits and an average of 0.7 nonscheduled visits, for a total average of 2 office visits per year. The control patients averaged 3.0 scheduled office visits and 0.5 unscheduled office visits, for a total average of 3.5 office visits. Remote monitoring therefore resulted in an average cut of 1.5 office visits per patient per year, or a 43% reduction that was statistically significant for the study's primary outcome. Dr. Varma reported this finding last November at the annual meeting of the American Heart Association.
The study's primary safety measure was the combined incidence of death, stroke, or need for surgical intervention during the year of follow-up. This end point occurred in 9% of the remote-monitoring patients and in 9% of the control patients, showing that “remote monitoring is safe for ICD surveillance,” Dr. Varma said.
An important additional analysis looked at the average time elapsed between the onset of an arrhythmia and the patient's evaluation by a physician. In his November report, Dr. Varma presented a preliminary analysis based on mean times to patient evaluation. In the remote-monitoring group, the average delay ranged from 11 days for ventricular fibrillation episodes to 25 days for atrial fibrillation. In the control group, the delay interval ranged from 42 days for supraventricular tachycardias to 47 days for ventricular tachycardias and atrial fibrillations. Although remote monitoring cut the delay, the time seemed surprisingly long, Dr. Varma said. It turned out that a small number of outlier episodes substantially increased average delay times, he added.
In the new analysis reported at the Heart Rhythm Society meeting, the median time from all electrical events to physician visit was 3.3 days, compared with a median of 35 days with conventional ICD monitoring. Among patients with ventricular arrhythmias, the median interval from the episode to the exam was 1 day with remote monitoring, compared with a median delay of 30-35 days by conventional monitoring. With remote monitoring, the median delay to an exam after a supraventricular tachycardia was 2 days and 5 days after atrial fibrillation.
“The major power of remote monitoring is to speed up the detection of events. The time we show [in the new analysis] is very rapid,” Dr. Varma said in an interview.
Results reported by other researchers have documented that the number of arrhythmia events flagged by remote monitoring is manageably small and that the alerts are consistently clinically important, he added. The TRUST results support this, although Dr. Varma has not yet reported the data. “The system performs comprehensive surveillance without unnecessary notifications. The false positives and false negatives are very low.”