Impact of the left ventricular lead position for long-term prognosis after cardiac resynchronization therapy in heart failure patients

Abstract

Background: An important determinant of successful cardiac resynchronization therapy for heart failure is the position of the left ventricular (LV) pacing lead. The aim of this study was to analyze the impact of the LV lead position on outcome in patients with cardiac resynchronization therapy (CRT). Objective; We assessed the relationship between anatomic LV lead position and long-term mortality and morbidity in CRT patients. Methods: The location of the LV lead was assessed by means of coronary venograms and chest x-rays recorded at the time of device implantation. The LV lead location was classified along the short axis into an anterior, lateral, or posterior position and along the long axis into a basal, midventricular, or apical region. Echocardiographic reduction of LV end-systolic volume, increase of LV ejection fraction and clinical outcomes were evaluated with respect to the LV lead position. Results: Totally 91 patients implanted with CRT from July 2004 to July 2011 were included in this analysis, and median follow-up period was 34 months. The LV lead was placed in the LV apex in 3 (3%) patients, in the midventricular position in 64 (70%), in the basal position in 19 (21%), in the anterior position in 8 (9%), in the lateral position in 75 (82%), and in the posterior position in 1 (1%) patients. The lateral lead location compared with leads located in the nonlateral position was associated with a significantly decreased risk for death (hazard ratio (HR)=0.347; 95% confidence interval (CI), 0.165 to 0.727; P=0.014). The midventriculer lead position was also associated with a decreased risk for death (HR=0.441; 95% CI, 0.226 to 0.862; P=0.002). Survival salvage analysis showed that cumulative hazards were significantly lower in those with lateral lead position (log-rank P=0.003), and mid ventricular lead position (log-rank P=0.014). Cox multivariate analysis showed lateral LV lead position was an independent positive factor of mortality (HR=0.346; 95% CI, 0.146 to 0.820; P=0.016). All 3 patients that a LV lead was placed in the LV apex were dead with heart failure. There was no significant difference in echocardiographic results among the positions of the LV lead. Conclusion: CRT with the lateral and the midventricular LV lead positions are associated with decreased risk of death in comparison with other LV lead positions.