What is the "Optimal" follow-up schedule for ICD patients?

Background In the absence of comparative studies, recommended routine follow-up (FU) intervals for implantable cardioverter defibrillator (ICD) patients range from 1 to 6 months; most patients are followed at 3 month intervals. Methods Six hundred and eighteen ICD patients were routinely seen 4 weeks after implant and then every 3 months. Unplanned visits (UPV) were either patient initiated or due to manufacturer recalls. FU visits included patient history/ examination, ICD interrogation, pacing/sensing threshold and pacing/shock impedance. Chest X-rays were performed every 6 months. To validate FU interval recommendations, a comparative analysis on the detection of complications was performed, relying either on the information of every, or of every other FU visit, i.e., on 3 or 6 month intervals. Results During 3.3 +/- 2.8 years, 137 complications occurred in 110 patients (17%). However, identification of only 34% was dependent on the FU schedule, since the mode of detection was ICD interrogation in 38 and history/ physical examination in nine patients. The remainder was diagnosed by UPV in 47, manufacturer recall in seven, accidental discovery during device replacement in two, and routine X-ray in 34 patients. Complication free survival at 2 years was 86.4% for patients implanted before 1999, and 89.2% thereafter (P = 0.003). Regarding 6 rather than 3 month FU intervals, a theoretical maximum delay of 3 months in the detection of potentially life-threatening complications would have occurred in 1.7% of all. patients. For those implanted after 1999, this related to only 0.9%. Conclusions ICD-retated complications detected during routine FU visits are relatively rare, particularly with newer generation ICD systems. Thus, 6 month FU intervals appear to be safe. With new developments such as patient alert features and telemedicat data transmission, FU intervals in ICD clinics might even be further extended. (c) 2005 The European Society of Cardiology. Published by Elsevier Ltd. All rights reserved.