Abstract 3524: Triventricular Pacing Significantly Improves Symptoms and Positive Remodelling Compared to Biventricular Pacing in Heart Failure Patients: A Randomised Crossover Trial
Background: Despite the effectiveness of cardiac resynchronisation therapy (CRT), a significant proportion of patients fail to respond to CRT. The use of alternative multi-site ventricular pacing strategies may improve patient symptoms and clinical outcome.
Methods: This was a single-centre, double-blind randomised cross-over trial of multisite pacing in 43 patients (35M, age 66.7±9.5 years) with standard (S) CRT indications. A TriVentricular (TriV) device was implanted with pacing leads in the right ventricular (RV) apex and two lateral branches of the coronary sinus (CS) [Group A; n=23]. When this was not impossible, or in patients with a pre-existing pacemaker, the third lead was positioned on the RV outflow tract (RVOT) [Group B; n=20]. Four pacing modes were programmed: SCRT, TriV, dual site (RV or CS) and single site (RVOT or CS) pacing, in randomised order, at 3 month intervals, with clinical and echocardiographic assessment at the end of each period. The primary end-point was 6 minute walk distance (6MW). Secondary end-points included Minnesota Living With Heart Failure questionnaire scores (MLHF), peak oxygen consumption (VO2max), LV function & dimensions.
Results: In the 37 patients who completed the assessments at 1 year, TriV pacing significantly improved 6MW (451±112m vs 425±119m for SCRT pacing; p=0.008) and MLHF score (32±19 vs 38±24 for SCRT pacing; p=0.036). TriV pacing resulted in significant improvement in VO2max compared to baseline; this was not seen with SCRT. TriV pacing produced significant improvements in LV end-diastolic volume and ejection fraction compared to SCRT. (See Table⇓). The proportion of patients improving by at least one NYHA class was 72% for SCRT pacing vs 83% for TriV pacing.
Conclusion: TriVentricular pacing significantly increased exercise capacity and improved patient symptoms and LV remodelling and appears to be superior to SCRT.