Background: In cardiac resynchronization therapy (CRT) targeting the optimal LV pacing site is decisive for therapy effectiveness. The aim of the study is to compare the clinical response of CRT in a group of pts whose LV lead was optimized vs a group of pts with a conventional procedure. Optimization consists in the selection of the best position through systematic screening of all the available pacing sites pursuing both the maximum electrical delay (Q-LV) and the highest response in LV dP/dtmax.
Methods: A group of 56 pts (OPT group) was optimized at implant, by means of a systematical screening of LV electrical delay and LV dP/dtmax in all available tributary veins of the coronary sinus and was compared with a group of 54 pts implanted with the conventional standard CRT procedure in the previous years and used as control group (CONV group).
Results: The response to CRT was evaluated as remodeling (variations in LVESVi) and clinical status (NYHA class and Packer HF clinical composite score). At 12 months follow up (mean FU 305±98 days), 44 pts (79%) vs 30 (56%) had a ?LVESVi?15% (p=0.014), 45 (80%) vs 33 (61%) improved NYHA?1 class (p=0.036), 41 (73%) vs 29 (54%) responded as Packer HF index (p=0.047), in OPT group vs CONV group respectively. In OPT group, pts with longer Q-LVmax (higher than median value of 133 ms) responded to CRT in 86% (?LVESVi?15%), 87% (?NYHA?1 class), and 83% (HF Packer index) of cases.
Conclusions: The acute optimization of LV pacing site, by means of a systematical screening of LV electrical delay and LV dP/dtmax, resulted in a significant higher rate of responder to CRT compared to the conventional non-optimized group. In our experience, longer Q-LVmax may predict a further benefit.