Evaluation of Short-Term Pacing Effect to Predict Long-Term Response to Cardiac Resynchronization Therapy: The TRAJECTORIES Study

Cardiac resynchronization therapy (CRT) is an effective treatment for chronic symptomatic systolic heart failure with cardiac dyssynchrony, but about 1/3 of patients do not respond favorably to the therapy. We hypothesized that acute modifications of the coronary sinus (CS) pacing cathode movements induced by biventricular pacing may be related to resynchronization process and consequently may carry predictive power on CRT response. A method for the 3D reconstruction of CS lead's pacing cathode trajectory (3DTJ) throughout a cardiac cycle showed that trajectory's geometry suddenly changed in responders (R) upon starting of biventricular pacing, becoming less eccentric and more multi-directional. Our multicenter observational study aimed at evaluating the clinical value of 3DTJ. Out of 119 patients enrolled, 50 have ended follow-up and have been analyzed. Concordance between 3DTJ metrics and response was 82% overall (41/50), 91% in R (31/34), 62% in NR (10/16). The proposed 3DTJ metric showed high sensitivity (91%) with specificity=62%; PPV=84%, NPV=77%. From our data, 3DTJ seems a promising tool to acutely predict CS pacing site-specific response to CRT. Its investigational use as an intra-operatory, real-time guidance for selecting LV pacing sites may open new opportunities for CRT patients' selection and therapy delivery.