Implantation Feasibility,Procedure‐Related Adverse Events and Lead Performance During 1‐Year Follow‐Up in Patients Undergoing Triple‐Site Cardiac Resynchronization Therapy: A Substudy of TRUST CRT Randomized Trial

Feasibility and Safety of Triple‐Site CRT . Introduction: This substudy was to assess implantation feasibility and long‐term safety of triple‐site resynchronization therapy (CRT) in a series of consecutive patients included in a randomized trial. Methods and results: One hundred consecutive patients enrolled into Triple‐Site Versus Standard Cardiac Resynchronization Therapy Randomized Trial were analyzed. Eligibility criteria included NYHA class III‐IV, sinus rhythm, QRS ≥ 120 milliseconds, left ventricular ejection fraction ≤35%, and significant mechanical dyssynchrony. Patients were randomized in a 1:1 ratio to conventional or triple‐site CRT with defibrillator–cardioverter. After 12 months of resynchronization 30% of patients with conventional resynchronization and 12.5% with triple‐site CRT were in NYHA functional class III or IV (P < 0.05). Implantation of triple‐site systems was significantly longer (median 125 minutes vs 96 minutes; P < 0.001), with higher fluoroscopic exposure, especially in patients with very enlarged left ventricle or pulmonary hypertension. Implantation success‐rate was similar in the triple‐site and conventional group (94% vs 98%; P = NS); however, additional techniques had to be used in a greater proportion of the triple‐site patients (33.3% vs 16%; P < 0.05). Long‐term lead performance tests revealed significantly higher pacing threshold and lower impedance in the triple‐site group. The 1‐year incidence of serious, CRT‐related adverse events was similar in triple‐site and conventional group (20.8% vs 30%; P = NS). Conclusions: Triple‐site CRT is associated with more pronounced functional improvement than standard resynchronization. This form of pacing is equally safe and feasible as the conventional CRT. However, triple‐site procedure is more time‐consuming, associated with higher radiation exposure and the need to use additional techniques. Triple‐site resynchronization is associated with less favorable electrical lead characteristics. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1228–1236, November 2012)