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 ¡À 10 years; 28.3 % female; NYHA class 3.2 ¡À 0.3; LVEF (29 ¡À 6 % ); QRS width 146 ¡À 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 ¡À 0.9V); LV wave amplitude (15 ¡À 8 mV); LV impedance (874 ¡À 215 Ohms); median procedure time (skin to skin), 55 min. [45?0] and median of procedure fluoroscopy time, 11 min. [6.2?9]. 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 ¡À 6 vs. 30.2 ¡À 8 % ; p = 0.02), LVEDD (72.4 ¡À 11 vs. 66 ¡À 11 mm; p = 0.01), LVESD (62 ¡À 12 vs. 56 ¡À 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.