Automatic adjustment of stimulation output in resynchronization therapy: impact and effectiveness in clinical practice

BACKGROUND: Algorithms for automatic pacing output adjustment have been implemented in pacemakers and implantable defibrillators (ICD) and recently in cardiac resynchronization therapy defibrillators (CRT-D). We assessed the impact and effectiveness of these automatic features. METHOD AND RESULTS: We prospectively enrolled patients successfully implanted with the following Medtronic CRT-Ds: Concerto with automatic left ventricular (LV) output management algorithm, Consulta automatic management of atrial, right ventricular (RV) and LV voltage, and Sentry (only manual voltage adjustments). Patients with complete device data available for at least 12 months were included in the analysis. We analysed data from 739 patients (360 Sentry, 335 Concerto, 44 Consulta). During the first 6 months, the LV pacing amplitude underwent more frequent adjustments in Concerto (63%, P< 0.001) and Consulta (64%, P= 0.047) patients than in Sentry (48%). Similarly, RV and atrial amplitude at 6 months differed from the pre-discharge value more frequently in Consulta (61 and 50%, respectively) than in Sentry patients (33 and 28%, both P< 0.01). The LV pulse amplitude for Concerto and the voltages in the three chambers of Consulta were significantly lower than the corresponding values programmed in Sentry at 6 and 12 months. The proportion of CRT-D interrogations involving manual reprogramming was 97 ± 8% for Sentry, 79 ± 20% for Concerto, and 56 ± 16% for Consulta (all P< 0.001). CONCLUSIONS: Algorithms for the automatic management of the pacing output reduced pacing output in comparison with the standard manual management approach, with potential optimization of battery longevity. Moreover, they reduced the need to manually reprogram CRT-Ds, suggesting the possibility to simplify CRT-D management and facilitate remote monitoring.