Introduction: Cardiac resynchronisation is an effective therapy in patients with heart failure with reduced ejection fraction (EF). A novel active fixation coronary sinus (CS) lead, Attain Stability, has been released in a bipolar and quadripolar configuration, with the hypothesis it will improve targeted lead positioning and stability independent of vessel anatomy. We sought to compare implant procedure parameters and electromechanical stability of the active fixation lead with passive fixation CS leads.
Methods: Retrospective study involving six major UK cardiac centres. Patients who received active fixation leads were compared with passive fixation lead recipients in a 1:2 ratio. The primary outcome was total lead displacements (combined macro-/micro-displacements, defined as displacements requiring repositioning procedures, or an increase in threshold ≥0.5 volts or pulse width ≥0.5 msec,or a change in pacing polarity). Multivariate analysis was performed to establish predictors of the primary outcome, assessing fixation mechanism (active or passive), number of poles (quadripolar or bipolar), contributing centre and follow-up duration.
Results: 761 patients were included (253 with active fixation leads, 508 with passive fixation leads), of which 736 had pacing follow-up data. There were no group differences in the baseline characteristics with respect to age, gender, EF, NYHA class, and co-morbidities (P>0.05 for all). The primary endpoint rate was 31% (75/241) in the active and 43% (214/495) in the passive fixation group (p=0.002). 6 patients (2.5%) in the active group and 14 patients (2.8%) in the passive group required CS lead repositioning procedures (p=0.981). In the multivariable analysis, active leads were associated with a significant reduction in lead displacements, odds ratio 0.62 (95% CI 0.43–0.9), p=0.012. For the whole, 761 patient, cohort there were differences in favour of passive compared with active leads in procedure duration, 120 [96–149] minutes versus 127 [105–155] minutes (p=0.008), and fluoroscopy time, 17 [11–26] minutes versus 18.5 [13–27] minutes (p=0.0022). The median follow-up duration was similar (active versus passive): 31 [17–47] weeks versus 34 [16–71] weeks, (p=0.052). Complication rates were no different: 2/253 (0.8%) active versus 12/508 (2.4%) passive (p=0.22).
Conclusion: In this large, multi-centre study, active fixation Attain Stability CS leads demonstrated superior electromechanical stability compared with passive fixation leads, with minimal increases in implant procedure and fluoroscopy times and no differences in complication rates.
Also included in the model: contributing hospital, which was significant.