Comparison of Automatic and Manual Threshold Testing in Patients with Permanent Pacemakers: Results from COMET Study

Background: Automaticity of cardiac devices is designed to reduce the burden on physicians while securing patient safety. The aim of this study is to elucidate accuracy of automatic adjustment algorithm of pacing output and effectiveness of this feature for time reduction during clinic visits. Methods and Results: Patients implanted with pacemakers capable of automatically adjusting the pacing output were enrolled. During their routine device follow-ups, pacing thresholds were compared between manual measurements and most recently recorded data in the device, which had been measured automatically at prespecified timing. Difference between -0: 25 and 0.5 volts were predefined as equivalent. Time required for conventional follow-up was also compared to device interrogation and data assessment. A total of 359 patients from 32 centers were enrolled. Calculated 95% confidence interval of difference in volts for atrium was (-0: 0625; 0) and the difference for ventricle was nonsignificant. These results met the equivalence criteria. Observed time to interrogate and assess device-stored pacing threshold was shorter by average of 3.3 minutes compared to manual method. Conclusions: The pacing threshold determined by the automatic measurement algorithm was accurate. Follow-up time was shorter when utilizing automaticity of pacemakers. The system is safe and time efficient.