Quebec Heart & Lung Institute, Laval University, Quebec City, Quebec, Canada.
J Am Coll Cardiol. 2012 Oct 30;60(18):1743-52. doi: 10.1016/j.jacc.2012.07.035. Epub 2012 Oct 3.
This study evaluated the predictive factors and prognostic value of new-onset persistent left bundle branch block (LBBB) in patients undergoing transcatheter aortic valve implantation (TAVI) with a balloon-expandable valve.
The predictors of persistent (vs. transient or absent) LBBB after TAVI with a balloon-expandable valve and its clinical consequences are unknown.
A total of 202 consecutive patients with no baseline ventricular conduction disturbances or previous permanent pacemaker implantation (PPI) who underwent TAVI with a balloon-expandable valve were included. Patients were on continuous electrocardiographic (ECG) monitoring during hospitalization and 12-lead ECG was performed daily until hospital discharge. No patient was lost at a median follow-up of 12 (range: 6 to 24) months, and ECG tracing was available in 97% of patients. The criteria for PPI were limited to the occurrence of high-degree atrioventricular block (AVB) or severe symptomatic bradycardia.
New-onset LBBB was observed in 61 patients (30.2%) after TAVI, and had resolved in 37.7% and 57.3% at hospital discharge and 6- to 12-month follow-up, respectively. Baseline QRS duration (p = 0.037) and ventricular depth of the prosthesis (p = 0.017) were independent predictors of persistent LBBB. Persistent LBBB at hospital discharge was associated with a decrease in left ventricular ejection fraction (p = 0.001) and poorer functional status (p = 0.034) at 1-year follow-up. Patients with persistent LBBB and no PPI at hospital discharge had a higher incidence of syncope (16.0% vs. 0.7%; p = 0.001) and complete AVB requiring PPI (20.0% vs. 0.7%; p < 0.001), but not of global mortality or cardiac mortality during the follow-up period (all, p > 0.20). New-onset LBBB was the only factor associated with PPI following TAVI (p < 0.001).
Up to 30% of patients with no prior conduction disturbances developed new LBBB following TAVI with a balloon-expandable valve, although it was transient in more than one third. Longer baseline QRS duration and a more ventricular positioning of the prosthesis were associated with a higher rate of persistent LBBB, which in turn determined higher risks for complete AVB and PPI, but not mortality, at 1-year follow-up.
本研究评估了经皮球囊扩张式主动脉瓣置换术（TAVI）后新发持续性左束支传导阻滞（LBBB）的预测因素及其预后价值。
经皮球囊扩张式 TAVI 后持续性（与一过性或无）LBBB 的预测因素及其临床后果尚不清楚。
共纳入 202 例基线无心室传导障碍或既往植入永久性起搏器（PPI）的连续患者，行经皮球囊扩张式 TAVI。患者在住院期间接受连续心电图（ECG）监测，在住院期间每天进行 12 导联心电图检查，直至出院。中位随访 12 个月（范围：6 至 24 个月）时无患者失访，97%的患者可获得心电图记录。PPI 的标准仅限于发生高度房室传导阻滞（AVB）或严重症状性心动过缓。
TAVI 后新发 LBBB 见于 61 例（30.2%）患者，出院时分别有 37.7%和 57.3%恢复正常，6 至 12 个月随访时分别有 60.3%和 82.7%恢复正常。基线 QRS 时限（p=0.037）和心室假体深度（p=0.017）是持续性 LBBB 的独立预测因素。出院时持续性 LBBB 与左心室射血分数降低（p=0.001）和 1 年随访时功能状态恶化（p=0.034）相关。出院时无 PPI 的持续性 LBBB 患者，晕厥发生率较高（16.0% vs. 0.7%；p=0.001）和需要 PPI 的完全性 AVB 发生率较高（20.0% vs. 0.7%；p<0.001），但随访期间全因死亡率或心源性死亡率无差异（均，p>0.20）。新发 LBBB 是 TAVI 后 PPI 的唯一相关因素（p<0.001）。
无先前传导障碍的患者中，多达 30%在经皮球囊扩张式 TAVI 后新发 LBBB，其中超过三分之一为一过性。基线 QRS 时限较长和心室假体位置更偏心室侧与持续性 LBBB 发生率较高相关，继而与 1 年随访时完全性 AVB 和 PPI 风险较高相关，但与死亡率无关。
