Cardiology Division, Department of Medicine, University of Rochester Medical Center, Rochester, New York, USA.
Heart Rhythm. 2013 Aug;10(8):1136-43. doi: 10.1016/j.hrthm.2013.04.013. Epub 2013 May 25.
The optimal atrioventricular pacing delay (AVD) in cardiac resynchronization therapy (CRT) remains to be determined.
To determine whether programming CRT devices to short AVD (S-AVD) will improve clinical response secondary to greater reductions in dyssynchrony.
The study population comprised 1235 patients with left bundle branch block enrolled in Multicenter Automatic Defibrillator Implantation Trial in Cardiac Resynchronization Therapy (MADIT-CRT). We assessed the relationship between AVD and outcomes. Patients programmed to S-AVD (median value of <120 ms; n = 337) vs long AVD (L-AVD; ≥120 ms; n = 390) were assessed for the end points of heart failure (HF) or death, death alone, and echocardiographic response to the CRT at 1-year follow-up. Outcomes were also compared to the left bundle branch block implantable cardioverter-defibrillator-only group (n = 508).
Multivariate analysis showed that patients programmed to S-AVD experienced a significant 33% (hazard ratio [HR] 0.67; 95% confidence interval [CI] 0.44-0.85; P = .037) reduction in the risk of HF or death and a 47% (HR 0.53; 95% CI 0.29-0.94; P = .031) reduction in death alone as compared with those programmed to L-AVD. Patients with CRT-programmed S-AVD and L-AVD experienced 63% (HR 0.37; 95% CI 0.26-0.53; P < .001) and 46% (HR 0.54; 95% CI 0.31-0.96; P < .001) reduction, respectively, in the risk of HF or death compared to patients with implantable cardioverter-defibrillator alone. At 1 year of follow-up, S-AVD vs L-AVD was associated with a greater reduction in left ventricular end-systolic volume (34.2% vs 30.8%; P = .002) along with a significantly greater improvement in dyssynchrony (22.3% vs 9.4%; P = .036).
Our findings indicate that in MADIT-CRT programming, the CRT AVD <120 ms was associated with a greater clinical and echocardiographic response to CRT.
心脏再同步治疗（CRT）的最佳房室（AV）起搏延迟（AVD）仍有待确定。
确定将 CRT 设备编程为短 AVD（S-AVD）是否会因更大程度地减少不同步而改善临床反应。
研究人群包括 1235 名患有左束支传导阻滞的患者，他们参加了多中心自动除颤器植入治疗心脏再同步治疗试验（MADIT-CRT）。我们评估了 AVD 与结局之间的关系。将 AVD 编程为 S-AVD（中位数<120ms；n=337）与长 AVD（L-AVD；≥120ms；n=390）的患者在 1 年随访时评估心力衰竭（HF）或死亡、单独死亡以及 CRT 的超声心动图反应的终点。还将结局与左束支传导阻滞植入式心脏复律除颤器仅组（n=508）进行比较。
多变量分析显示，与 L-AVD 相比，S-AVD 程控患者 HF 或死亡风险降低 33%（风险比[HR]0.67；95%置信区间[CI]0.44-0.85；P=0.037），单独死亡风险降低 47%（HR 0.53；95% CI 0.29-0.94；P=0.031）。S-AVD 和 L-AVD 程控 CRT 的患者 HF 或死亡风险分别降低 63%（HR 0.37；95% CI 0.26-0.53；P<.001）和 46%（HR 0.54；95% CI 0.31-0.96；P<.001），与单独植入式心脏复律除颤器患者相比。在 1 年随访时，S-AVD 与 L-AVD 相比，左心室收缩末期容积减少 34.2%（P=0.002），不同步改善更为显著（22.3% vs 9.4%；P=0.036）。
我们的研究结果表明，在 MADIT-CRT 编程中，CRT AVD<120ms 与 CRT 的更大临床和超声心动图反应相关。
