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


  • Identifier: NCT00814840.

  • This study was conducted for the Triple-Site Versus Standard Cardiac Resynchronization Therapy Study (TRUST CRT) investigators.

  • Study data have been accepted as oral presentation at the 18th World Congress on Cardiac Electrophysiology & Cardiac Techniques, Cardiostim 2012, Nice – France, June 13–16.

  • Drs. Lenarczyk and Kowalski received consultant fees from Medtronic and Biotronik. Dr. Sredniawa received consultant fees from Medtronic. Dr. Wozniak received consultant fees from Biotronik. Other authors: No disclosures.

Radosław Lenarczyk, M.D., Department of Cardiology, Congenital Heart Disease and Electrotherapy, Silesian Medical University, Silesian Center for Heart Disease, Skłodowskiej-Curie 9, 44–800 Zabrze, Poland. Fax: 0048 32 37 33 792; E-mail:


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)