No studies have been published regarding factors related to difficult CRT implantation procedure and primary left ventricular (LV) lead implant failure.

The aim of this prospective study was twofold: (1) to evaluate the prevalence and predictive factors of prolonged CRT implantation procedure; (2) to identify the predictive factors of primary LV lead implantation failure.

Between November 2008 and September 2009, 106 pts underwent primo CRT implantation. Population characteristics were a mean age of 69 ± 10 years; 28.3% female; NYHA class 3.2 ± 0.3; LVEF (29 ± 6%); QRS width 146 ± 23 ms. Primo CRT implantation was obtained in 96/106 pts (90.5% primary success). A second procedure was successfully attempted in 6/10 pts with a second more experienced operator (5.7%). Among the remaining 4 pts, 1 pt required an epicardial LV lead implantation, and the implantation was not reattempted in the other 3 pts. The overall success rate of CRT implantation was 96.2% (102/106 pts). Procedure parameters were as follows: LV threshold (1.4 ± 0.9V); LV wave amplitude (15 ± 8mV); LV impedance (874 ± 215 Ohms); median procedure time (skin to skin), 55 min. [45–80] and median of procedure fluoroscopy time, 11 min. [6.2–29]. In 24 patients (22.6%), difficult procedures requiring 85 min of implantation duration occurred. By univariate analysis, predictive factors of difficult implantation were LV ejection fraction (25.6 ± 6 vs. 30.2 ± 8%; p = 0.02), LVEDD (72.4 ± 11 vs. 66 ± 11 mm; p = 0.01), LVESD (62 ± 12 vs. 56 ± 12 mm; p = 0.04) and the operator’s experience (very experienced operator vs. less experienced operator; p = 0.006). By multivariate analysis, only primary LV lead implantation failure, LVESD and operator’s experience were independently associated with difficult procedures. In this patient subset with primary LV lead implant failure (n = 10), the only independent predictive factor was the LVESV (p = 0.03).

In this study, the rate of difficult CRT device implantation procedures approached 25%. Both the degree of LV dysfunction and the operator’s experience were independent predictors of surgical difficulties.