Left ventricular three-dimensional quadripolar lead acute clinical study: the LILAC study

Single- and multi-site pacing strategies for optimal cardiac resynchronization therapy: impact on device longevity and therapy cost

BACKGROUND

Multiple left ventricular pacing strategies have been suggested for improving response to cardiac resynchronization therapy (CRT). However, these programming strategies may sometimes entail accepting configurations with high pacing threshold and accelerated battery drain. We assessed the feasibility of predefined pacing programming protocols, and we evaluated their impact on device longevity and their cost-impact.

METHODS

We estimated battery longevity in 167 CRT-D patients based on measured pacing parameters according to multiple alternative programming strategies: single-site pacing associated with lowest threshold, non-apical location, longest interventricular delay, and pacing from two electrodes. To determine the economic impact of each programming strategy, we applied the results of a model-based cost analysis using a 15-year time horizon.

RESULTS

Selecting the electrode with the lowest threshold resulted in a median device longevity of 11.5 years. Non-apical pacing and interventricular delay maximization were feasible in most patients and were obtained at the price of a few months of battery life. Device longevity of > 10 years was preserved in 87% of cases of non-apical pacing and in 77% on pacing at the longest interventricular delay. The mean reduction in battery life when the second electrode was activated was 1.5 years. Single-site pacing strategies increased the therapy cost by 4-6%, and multi-site pacing by 12-13%, in comparison with the lowest-cost scenario.

CONCLUSIONS

Modern CRT-D systems ensure effective pacing and allow multiple optimization strategies for maximizing service life or for enhancing effectiveness. Single- or multi-site pacing strategies can be implemented without compromising device service life and at an acceptable increase in therapy cost.

Clinical outcome of left ventricular multipoint pacing versus conventional biventricular pacing in cardiac resynchronization therapy: a systematic review and meta-analysis

Cardiac resynchronization therapy (CRT) is an effective treatment for selected patients with systolic heart failure. Unlike conventional biventricular pacing (BIP), the left ventricular multipoint pacing (MPP) can increase the number of left ventricular pacing sites via a quadripolar lead positioned in the coronary sinus. This synthetic study was conducted to integratively and quantitatively evaluate the clinical outcome of MPP in comparison with BIP. We systematically searched the databases of EMBASE, Ovid medline, and Cochrane Library through May 2018 for studies comparing the clinical outcome of MPP with BIP in the patients who accepted CRT. Hospitalization for reason of heart failure, left ventricular eject fraction (LVEF), CRT response, all-cause morbidity, and cardiovascular death rate was collected for meta-analysis. A total of 11 studies with 29,606 participants were included in this meta-analysis. Compared with BIP group, MPP decreased heart failure hospitalization (OR, 0.41; 95% CI, 0.33 to 0.50; P < 0.00001), improved LVEF (mean difference, 4.97; 95% CI, 3.11 to 6.83; P < 0.00001), increased CRT response (OR, 3.64; 95% CI, 1.68 to 7.87; P = 0.001), and decreased all-cause morbidity (OR, 0.41; 95% CI, 0.26-0.66; P = 0.0002) and cardiovascular death rate (OR, 0.21; 95% CI, 0.11-0.40; P < 0.00001). The published literature demonstrates that MPP was more effective than BIP in the heart failure patients who accepted cardiac resynchronization therapy.

Long-term electrical performance of Attain Performa quadripolar left ventricular leads with all steroid-eluting electrodes: Results from a large worldwide clinical trial

BACKGROUND

Steroid-eluting (SE) electrodes suppress local inflammation and lower pacing capture thresholds (PCT); however, their effectiveness on quadripolar left ventricular (LV) leads in the cardiac vein is not fully studied. We evaluated the effectiveness of SE on all four LV pacing electrodes in human subjects enrolled in the Medtronic Attain® Performa™ quadripolar LV lead study.

METHODS

A total of 1,097 subjects were included in this evaluation. At each follow-up visit (1, 3, 6, and 12 months), LV PCT and pacing impedance were measured using either manual or automated testing methods. Summary statistics for PCT and impedance values were obtained for implant and each scheduled follow-up visit for all lead models.

RESULTS

Average extended bipolar (LV electrode to right ventricular Coil) PCTs for the four LV SE pacing electrodes (LV1, LV2, LV3, and LV4) on the three shapes of the quadripolar LV leads were 1.06 ± 0.97 V, 1.38 ± 1.26 V, 1.51 ± 1.33 V, and 2.25 ± 1.63 V, respectively, at 0.5-ms pulse width. PCTs remained low and stable throughout the 12-month follow-up period.

CONCLUSION

This clinical trial demonstrated that SE on all LV pacing electrodes is associated with low and stable PCTs for all quadripolar LV lead electrodes, resulting in multiple viable vectors for LV pacing. The large number of available vectors facilitates basal pacing, avoidance of PNS, and potentially prolongs generator longevity due to lower PCTs.

Maximization of interventricular conduction time by means of quadripolar leads for cardiac resynchronization therapy

PURPOSE

Identifying the left ventricular (LV) site associated with the maximum spontaneous interventricular conduction time (right ventricle (RV)-to-LV interval) has proved to be an effective strategy for optimal LV pacing site selection in cardiac resynchronization therapy (CRT). The aim of our study was to determine whether quadripolar LV lead technology allows RV-to-LV interval maximization.

METHODS

We enrolled 108 patients undergoing implantation of a CRT system using an LV quadripolar lead and 114 patients who received a bipolar lead. On implantation, the RV-to-LV interval was measured for the dipole of the bipolar leads and for each electrode of the LV lead (tip, ring 2, ring 3, ring 4).

RESULTS

In the quadripolar group, the mean RV-to-LV interval ranged from 90 ± 33 ms (tip) to 94 ± 32 ms (R4) (p > 0.05 for all comparisons). In 55 (51%) patients, the RV-to-LV interval was > 80 ms at all electrodes, while in 27 (25%) patients, no electrodes were associated with an RV-to-LV interval > 80 ms. At least one LV pacing electrode was associated with an RV-to-LV interval > 80 ms in 62 (70%) patients with a short (36 mm) inter-electrode distance, and in 19 (95%, p = 0.022) of those with a long distance (50.5 mm). In the bipolar group, the mean RV-to-LV interval was 72 ± 37 ms (p < 0.001 versus quadripolar). The RV-to-LV interval was > 80 ms in 44 (39%) patients (p < 0.001 versus quadripolar leads with both short and long inter-electrode distance).

CONCLUSIONS

Quadripolar leads allow RV-to-LV interval maximization. An optimal RV-to-LV interval seems achievable in the majority of patients, especially if the leads present a long inter-electrode distance.