Cleveland Clinic Foundation, Cleveland, OH (N.V.).
Saint Thomas Research Institute, Nashville, TN (J.B.).
Circ Arrhythm Electrophysiol. 2020 Nov;13(11):e008680. doi: 10.1161/CIRCEP.120.008680. Epub 2020 Oct 7.
Left ventricular (LV) epicardial pacing results in slowly propagating paced wavefronts. We postulated that this effect might limit cardiac resynchronization therapy efficacy in patients with LV enlargement using conventional biventricular pacing with single-site LV pacing, but be mitigated by LV stimulation from 2 widely spaced sites using MultiPoint pacing with wide anatomic separation (MPP-AS: ≥30 mm). We tested this hypothesis in the multicenter randomized MPP investigational device exemption trial.
Following implant, quadripolar biventricular single-site pacing was activated in all patients (n=506). From 3 to 9 months postimplant, among patients with available baseline LV end-diastolic volume (LVEDV) measures, 188 received biventricular single-site pacing and 43 received MPP-AS. Patients were dichotomized by median baseline LVEDV indexed to height (LVEDVI). Outcomes were measured by the clinical composite score (primary efficacy end point), quality of life, LV structural remodeling (↑EF >5% and ↓ESV 10%) and heart failure event/cardiovascular death.
LVEDVI was 1.1 mL/cm. Baseline characteristics differed in patients with LVEDVI versus LVEDVI. Among patients with LVEDVI, biventricular single-site pacing was less efficacious compared to patients with LVEDVI (clinical composite score, 65% versus 79%). In contrast, MPP-AS programming generated greater clinical composite score response (92% versus 65%, =0.023) and improved quality of life (-31.0±29.7 versus -15.7±22.1, =0.038) versus biventricular single-site pacing in patients with LVEDVI. Reverse remodeling trended better with MPP-AS programming. In patients with LVEDVI, heart failure event rate increased following the 3-month randomization point with biventricular single-site pacing (0.0150±0.1725 in LVEDVI -0.0190±0.0808 in LVEDVI , =0.012), but no heart failure event occurred in patients with MPP-AS programming between 3 and 9 months in LVEDVI. All measured outcomes did not differ in patients receiving MPP-AS and biventricular single-site pacing with LVEDVI.
Conventional biventricular single-site pacing, even with a quadripolar lead, has reduced efficacy in patients with LV enlargement. However, the greatest response rate in patients with larger hearts was observed when programmed to MPP-AS pacing.
左心室（LV）心外膜起搏导致起搏波阵面缓慢传播。我们推测，在使用传统的双心室起搏进行单部位 LV 起搏治疗 LV 扩大的患者中，这种效应可能会限制心脏再同步治疗的效果，但可以通过使用多点起搏（MPP-AS：≥30mm）从 2 个广泛分离的部位进行 LV 刺激来减轻。我们在多中心随机 MPP 研究性设备豁免试验中检验了这一假设。
植入后，所有患者（n=506）均激活了四极双心室单部位起搏。在植入后 3 至 9 个月期间，在有基线 LV 舒张末期容积（LVEDV）测量值的患者中，188 例接受了双心室单部位起搏，43 例接受了 MPP-AS。根据 LVEDV 与身高的比值（LVEDVI），患者分为中位数基线 LVEDVI。主要终点为临床综合评分（主要疗效终点）、生活质量、LV 结构重塑（EF 增加≥5%和 ESV 减少≥10%）和心力衰竭事件/心血管死亡。
LVEDVI 为 1.1ml/cm。LVEDVI 和 LVEDVI 患者的基线特征不同。在 LVEDVI 患者中，与 LVEDVI 患者相比，双心室单部位起搏的疗效较差（临床综合评分，65%对 79%）。相比之下，MPP-AS 编程在 LVEDVI 患者中产生了更大的临床综合评分反应（92%对 65%，=0.023），并改善了生活质量（-31.0±29.7 对-15.7±22.1，=0.038），而双心室单部位起搏。在 LVEDVI 患者中，MPP-AS 编程的逆重构趋势更好。在 LVEDVI 患者中，双心室单部位起搏在 3 个月随机分组后心力衰竭事件率增加（LVEDVI 为 0.0150±0.1725，LVEDVI 为 0.0190±0.0808，=0.012），但在 LVEDVI 患者中，在 3 至 9 个月期间，接受 MPP-AS 编程的患者未发生心力衰竭事件。在接受 MPP-AS 和 LVEDVI 双心室单部位起搏的患者中，所有测量的结果均无差异。
即使使用四极导线，传统的双心室单部位起搏在 LV 扩大的患者中也疗效降低。然而，在心脏较大的患者中，观察到最大的反应率是在进行 MPP-AS 起搏时。
