Outcomes of cardiac resynchronization therapy using left ventricular quadripolar leads

Efficacy and safety of novel left ventricular pacing leads: 1-year analysis of the NAVIGATOR trial

OBJECTIVES

Assess safety and performance of novel quadripolar preshaped left ventricular (LV) leads: NAVIGO 4LV 2D ('S shaped') and NAVIGO 4LV ARC ('U shaped').

METHODS

Patients indicated for cardiac resynchronisation therapy were enrolled in a multicentre, prospective, controlled study (NAVIGATOR, NCT03279484). Patients were implanted with either a NAVIGO 4LV 2D or ARC lead, and assessed at 10 weeks, 6, 12 and 24 months post-implant. Co-primary safety and performance endpoints were assessed at 10 weeks. Safety endpoint was the patients' rate free from lead-related complications. Performance endpoint was the rate of patients with successful lead performance, defined as LV pacing threshold ≤2.5 V at 0.5 ms on at least one pacing vector, and the absence of phrenic nerve stimulation at the final programmed configuration. Lead-related complications and electrical parameters were monitored throughout study.

RESULTS

A NAVIGO 4LV lead was successfully implanted in 211 out of 217 patients (97.2%). The safety endpoint was met, with 100% and 96.1% of patients free from complications for NAVIGO 4LV 2D and ARC, respectively. The performance endpoint was met with 98.1% and 98.9% of patients with a successful lead performance for NAVIGO 4LV 2D and ARC, respectively. Over 12 months, the global complication-free rate for both leads was 97.1% (95% CI: 93.71% to 98.70%), with a mean pacing capture threshold of 1.23 V±0.73 V and a mean impedance of 951 Ω±300.1 Ω.

CONCLUSION

A high implantation success rate and low complication rate was reported for the novel NAVIGO 4LV 2D and ARC leads, along with successful performance up to 12 months.

Bipolar versus quadripolar left ventricular leads for cardiac resynchronization therapy: evidence to date

INTRODUCTION

In cardiac resynchronization therapy (CRT) devices, transvenous left ventricular (LV) leads are more prone to instability, high pacing thresholds, and phrenic nerve stimulation (PNS) that may necessitate lead revision, replacement in a suboptimal position, or deactivation of the lead. To overcome some of these challenges, quadripolar (QP) LV leads have been developed and accounted for over 90% of implanted LV leads 5 years after they were introduced.

AREAS COVERED

This review provides an overview of the current evidence of implanting QP leads in CRT as compared with traditional bipolar (BP) leads including details about feasibility, safety and lead performance, clinical outcome and cost-effectiveness.

EXPERT OPINION

Based on the current literature, implantation with a QP lead decreases revision rates but does not affect any clinical outcomes including mortality, hospitalization, symptoms, or echocardiographic parameters. Feasibility and stability do not differ between QP and BP leads. A QP lead should be preferred as first choice over a BP lead due to lower rates of PNS and lower pacing thresholds leading to less frequent lead revisions and battery replacements. In addition, this strategy may be cost saving despite a higher price of QP leads.

Six months clinical outcome comparison between quadripolar and bipolar left ventricular leads in cardiac resynchronization therapy: A prospective, non-randomized, single-centre observational study

Background and objectives

Quadripolar left ventricular (LV) leads in cardiac resynchronization therapy (CRT) offer multi-vector pacing with different pacing configurations and hence enabling LV pacing at most suitable site with better lead stability. We aim to compare the outcomes between quadripolar and bipolar LV lead in patients receiving CRT.

Methods

In this prospective, non-randomized, single-center observational study, we enrolled 93 patients receiving CRT with bipolar (BiP) (n = 31) and quadripolar (Quad) (n = 62) LV lead between August 2016 to August 2019. Patients were followed for six months, and outcomes were compared with respect to CRT response (defined as ≥5% absolute increase in left ventricle ejection fraction), electrocardiographic, echocardiographic parameters, NYHA functional class improvement, and incidence of LV lead-related complication.

Results

At the end of six months follow up, CRT with quadripolar lead was associated with better response rate as compared to bipolar pacing (85.48% vs 64.51%; p = 0.03), lesser heart failure (HF) hospitalization events (1.5 vs 2; p = 0.04) and better improvement in HF symptoms (patients with ≥1 NYHA improvement 87.09% vs 67.74%; p = 0.04). There were fewer deaths per 100 patient-year (6.45 vs 9.37; p = 0.04) and more narrowing of QRS duration (Δ12.56 ± 3.11 ms vs Δ7.29 ± 1.87 ms; p = 0.04) with quadripolar lead use. Lead related complications were significantly more with the use of bipolar lead (74.19% vs 41.94%; p = 0.02).

Conclusions

Our prospective, non-randomized, single-center observational study reveals that patients receiving CRT with quadripolar leads have a better response to therapy, lesser heart failure hospitalizations, lower all-cause mortality, and fewer lead-related complications, proving its superiority over the bipolar lead.

Clinical outcomes after implantation of quadripolar compared to bipolar left ventricular leads in patients undergoing cardiac resynchronization therapy: a systematic review and meta-analysis

Aims

Some retrospective and prospective studies in heart failure patients with indication for cardiac resynchronization therapy (CRT) suggest better clinical outcomes for quadripolar (QP) left ventricular (LV) leads over bipolar (BP) leads. Although, lead failure remains an important safety concern, when using these more complex, novel electrodes. To evaluate safety and efficacy outcomes for QP vs. BP LV leads in patients receiving CRT.

Methods and results

We performed a comprehensive literature search through 2018 in PubMed, Cochrane Library, and Google Scholar databases to identify studies comparing patients with QP and BP LV CRT leads. A total of 12 studies were selected for analysis comprising 31 403 patients (QP lead: 22 429 patients; BP lead: 8974 patients). Eight studies examined the effects of CRT on survival. In these studies, use of QP electrodes was associated with significantly better survival compared to patients with BP LV leads (OR 0.61, 95% CI 0.50–0.76; P < 0.01). Clinical improval measured in New York Heart Association functional class (OR 0.59, 95% CI 0.34–1.01; P = 0.05) and hospitalization rates (OR 0.67, 95% CI 0.55–0.83; P < 0.01) were also improved in patients receiving QP leads. Lead malfunctions defined as LV lead failure resulting in lead deactivation (OR 0.57, 95% CI 0.34–0.98; P = 0.04) or LV lead dislodgement requiring LV lead replacement/repositioning (OR 0.48; 95% CI 0.31–0.75; P < 0.01) were more often encountered among patients with BP leads compared to patients with QP leads.

Conclusion

Our meta-analysis suggests distinct benefits of QP over BP electrodes in patients undergoing CRT.

Current developments in cardiac rhythm management devices

Endocardial pacing has experienced a tremendous evolution since the 1960s. A lot of challenges associated with pacemaker and ICD devices have already been successfully targeted. However, a relevant number of problems have not been solved to date. Not all patients with accepted indication for biventricular pacing have benefited from cardiac resynchronisation therapy (CRT) despite extensive efforts to reduce the rate of non-responders. Current strategies to optimize lead position, multipolar left-ventricular (LV) pacing leads, new strategies to gain access to the left-ventricle (atrial transseptal or ventricular transseptal access) or alternative right-ventricular (septal, His bundle pacing) pacing sites, and "leadless" LV pacing have the potential to increase response to device-based heart-failure treatment. The opportunity of pacemaker and ICD remote monitoring led to relevant improvements in therapy management by timely detection of events requiring medical or invasive interventions (e.g., external cardioversion of atrial fibrillation, increasing effective biventricular pacing, catheter ablation of ventricular tachycardias, or changes in heart-failure medication). Two completely endocardial leadless "all-in-one" pacemaker systems recently became available. Besides these innovations, new "synergistic" therapy concepts combining catheter ablation and device therapy proved to affect clinical endpoints (e.g., ATAAC study and CASTLE-AF study).