The Cardiac Resynchronization Therapy Efficacy Enhancement (CRTee) study has shown that the Medtronic EffectivCRT-during atrial fibrillation algorithm can improve therapy delivery in heart failure patients with atrial fibrillation. This first-of-its-kind data on the algorithm were presented at the 2016 European Society of Cardiology (ESC) Congress in Rome, Italy.
The new EffectivCRT-during atrial fibrillation feature is designed to automatically determine the effectiveness of each left ventricular pace, adjusting pacing rates during atrial fibrillation.
CRTee was a prospective, randomised, crossover study of 71 patients with paroxysmal, persistent or permanent atrial fibrillation. Sixty-six patients were randomised first to either an existing algorithm or the new EffectivCRT algorithm, with the desired outcome of a higher percent of effective cardiac resynchronisation therapy being delivered during atrial fibrillation.
Fifty-four patients completed both arms. The EffectivCRT group increased effective pacing during AF by 7%, from 81% to 88%, p<0.001. Heart rate increased by only three beats-per-minute, from 77 to 80, p<0.001. Patients with a low percent of pacing at baseline (less than or equal to 80%) received the greatest benefit (average absolute increase of 15% effective pacing).
“This technology brings us one step closer to understanding effective left ventricular pacing for atrial fibrillation patients receiving cardiac resynchronisation therapy, which has been difficult to manage in the past” says Suneet Mittal, director, Electrophysiology Laboratory, Arrhythmia Institute of the Valley Health System, Ridgewood, USA. “We can now optimise treatment to a larger patient base, including difficult-to-treat non-responders, to hopefully prevent patients from undergoing additional treatments and often invasive follow-on procedures.”
The EffectivCRT Diagnostic and EffectivCRT-during atrial fibrillation algorithm are available on the Claria MRI Quad CRT-D SureScan in Europe. The EffectivCRT features are investigational only in the USA, and the Claria CRT-D is not approved for sale in the territory.