Follow-up of CRT-ICD: Implications for the use of remote follow-up systems. Data from the InSync ICD Italian registry

Background: Launch of remote follow-up systems in Europe is currently underway. However, there is insufficient understanding of postimplant practices with respect to device follow-up, reprogramming of device features, and postshock clinic visits. Methods: We analyzed device-stored data from patients implanted with biventricular defibrillators (CRT-ICD) to characterize the management of patients in current clinical practice and the potential impact of remote follow-up systems. Results: Two hundred and seventeen patients were identified, all with complete device-data for at least one year. Over a follow-up period of 570 ± 158 days, 1,959 device interrogations were performed. Of these, the majority (1,280, 65%) involved the reprogramming of device parameters. The mean time interval between interrogations was 70 ± 25 days. Overall, a marked reduction of interrogations requiring reprogramming was observed between the first six months of follow-up and subsequent periods (from 3.6 ± 1.8 to 1.1 ± 1.0 interrogations/six months). A mean of 6.0 ± 5.9 device parameters was reprogrammed during the first six months of follow-up, versus 4.4 ± 5.6 (P = 0.000) during the subsequent period. From multivariate analysis, a higher-than-median number of interrogations was found to be significantly associated with defibrillator shocks (OR:2.51; 95%CI:1.42-4.42). Following a shock, a total of 133 interrogations in 60 patients were performed with 80% of these occurring within five days of the shock, and 49% did not require device reprogramming. Conclusion: Six months after implant, reprogramming of device parameters is significantly less frequent, making the use of remote follow-up systems a practical alternative for patients and physicians. Moreover, a considerable portion of post-shock interrogations does not involve reprogramming and may therefore be performed remotely.