Impact of coronary sinus lead position on biventricular pacing: mortality and echocardiographic evaluation during long-term follow-up.

Introduction: Biventricular pacing is an established treatment for congestive heart failure. Whether the anatomic location of the coronary sinus (CS) lead affects outcomes is unknown. The aim of this study was to evaluate the clinical response and mortality in patients who had transvenous CS leads placed in different anatomic branches for biventricular pacing.

Methods And Results: We evaluated 233 consecutive patients with New York Heart Association (NYHA) class III-IV heart failure and ejection fraction <35% who had successful placement of a transvenous left ventricular lead through a CS venous branch. Patients were divided into two groups based on anatomic lead position. Group 1 (n = 66) included leads in the anterior and anterolateral branches. Group 2 (n = 167) included leads in the lateral and posterolateral branches. Postimplant, functional capacity improved from an average 3.1 to 2.7 in group 1 (P = 0.001) and from 3.1 to 2.3 in group 2 (P = 0.001). Left ventricular ejection fraction (LVEF) measured by transthoracic echocardiography did not improve significantly in group 1 (pre-LVEF 18%, post-LVEF 20%; P = NS) but increased significantly from 19% to 27% in group 2 (P = 0.008). Despite the difference in ejection fraction response, the mortality in the two groups after a mean follow-up of 546 days was similar (13.6% group 1 vs 17.9% group 2).

Conclusion: Placement of the CS lead in the lateral and posterolateral branches is associated with significant improvement in functional capacity and greater improvement in left ventricular function compared with the anterior CS location. This improvement does not appear to influence mortality.