University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
Heart Rhythm. 2013 Sep;10(9):1368-74. doi: 10.1016/j.hrthm.2013.07.007. Epub 2013 Jul 11.
Acute studies have suggested that left ventricular pacing (LVP) may have benefits over biventricular pacing (BVP). The adaptive cardiac resynchronization therapy (aCRT) algorithm provides LVP synchronized to produce fusion with the intrinsic activation when the intrinsic atrioventricular (AV) interval is normal. The randomized double-blind adaptive cardiac resynchronization therapy trial demonstrated noninferiority of the aCRT algorithm compared to echocardiography-optimized BVP (control).
To examine whether synchronized LVP (sLVP) resulted in better clinical outcomes.
First, stratification by percent sLVP (%sLVP) and multivariate Cox proportional hazards model was used to assess the relationship between %sLVP and clinical outcomes. Second, outcomes were compared between patients in the aCRT arm (n = 318) and control patients (n = 160) stratified by intrinsic AV interval at randomization.
In the aCRT arm, %sLVP ≥50% (n = 142) was independently associated with a decreased risk of death or heart failure hospitalization (hazard ratio 0.49; 95% confidence interval 0.28-0.85; P = .012) compared with %sLVP <50% (n = 172). A greater proportion of patients with %sLVP ≥50% improved in Packer's clinical composite score at 6-month (82% vs. 68%; P = .002) and 12-month (80% vs. 62%; P = .0006) follow-ups compared to controls. In the subgroup with normal AV (n = 241), there was a lower risk of death or heart failure hospitalization (hazard ratio 0.52; 95% confidence interval 0.27-0.98; P = .044) with the aCRT algorithm. A greater proportion of patients in the aCRT arm improved in the clinical composite score at 6-month (81% vs. 69%; P = .041) and 12-month (77% vs. 66%; P = .076) follow-ups compared to controls.
Higher %sLVP was independently associated with superior clinical outcomes. In patients with normal AV conduction, the aCRT algorithm provided mostly sLVP and demonstrated better clinical outcomes compared to echocardiography-optimized BVP.
急性研究表明，左心室起搏（LVP）可能比双心室起搏（BVP）更有优势。适应性心脏再同步治疗（aCRT）算法提供了与固有房室（AV）间隔正常时产生融合的 LVP 同步，以产生融合。随机双盲适应性心脏再同步治疗试验表明，aCRT 算法与超声心动图优化的 BVP（对照）相比不劣效。
研究同步 LVP（sLVP）是否能带来更好的临床结果。
首先，通过固有 AV 间隔的百分比（%sLVP）和多变量 Cox 比例风险模型进行分层，评估%sLVP 与临床结果之间的关系。其次，根据随机分组时的固有 AV 间隔，比较 aCRT 组（n = 318）和对照组（n = 160）患者的结果。
在 aCRT 组中，%sLVP ≥50%（n = 142）与较低的死亡或心力衰竭住院风险独立相关（风险比 0.49；95%置信区间 0.28-0.85；P =.012），与%sLVP <50%（n = 172）相比。与对照组相比，具有 %sLVP ≥50%的患者在 6 个月（82%对 68%；P =.002）和 12 个月（80%对 62%；P =.0006）随访时更有可能改善 Packer 的临床综合评分。在固有 AV 正常的亚组（n = 241）中，aCRT 算法降低了死亡或心力衰竭住院的风险（风险比 0.52；95%置信区间 0.27-0.98；P =.044）。与对照组相比，aCRT 组有更多的患者在 6 个月（81%对 69%；P =.041）和 12 个月（77%对 66%；P =.076）随访时改善了临床综合评分。
较高的%sLVP 与更好的临床结果独立相关。在固有 AV 传导正常的患者中，aCRT 算法主要提供 sLVP，并与超声心动图优化的 BVP 相比，提供更好的临床结果。
