Permanent Pacing After Transcatheter Aortic Valve Implantation: Incidence, Predictors and Evolution of Left Ventricular Function

Abstract Background: Transcatheter aortic valve implantation (TAVI) is a well-established procedure; however, atrioventricular block requiring permanent pacemaker implantation (PPI) is a common complication. Objectives: To determine the incidence, predictors and clinical outcomes of PPI after TAVI, focusing on how PPI affects left ventricular ejection fraction (LVEF) after TAVI. Methods: The Brazilian Multicenter TAVI Registry included 819 patients submitted to TAVI due to severe aortic stenosis from 22 centers from January/2008 to January/2015. After exclusions, the predictors of PPI were assessed in 670 patients by use of multivariate regression. Analysis of the ROC curve was used to measure the ability of the predictors; p < 0.05 was the significance level adopted. Results: Within 30 days from TAVI, 135 patients (20.1%) required PPI. Those patients were older (82.5 vs. 81.1 years; p = 0.047) and mainly of the male sex (59.3% vs 45%; p = 0.003). Hospital length of stay was longer in patients submitted to PPI (mean = 15.7 ± 25.7 vs. 11.8 ± 22.9 days; p < 0.001), but PPI affected neither all-cause death (26.7% vs. 25.6%; p = 0.80) nor cardiovascular death (14.1% vs. 14.8%; p = 0.84). By use of multivariate analysis, the previous presence of right bundle-branch block (RBBB) (OR, 6.19; 3.56-10.75; p ≤ 0.001), the use of CoreValve® prosthesis (OR, 3.16; 1.74-5.72; p ≤ 0.001) and baseline transaortic gradient > 50 mm Hg (OR, 1.86; 1.08-3.2; p = 0.025) were predictors of PPI. The estimated risk of PPI ranged from 4%, when none of those predictors was present, to 63%, in the presence of all of them. The model showed good ability to predict the need for PPI: 0.69 (95%CI: 0.64 - 0.74) in the ROC curve. The substudy of 287 echocardiograms during the 1-year follow-up showed worse LVEF course in patients submitted to PPI (p = 0.01). Conclusion: BRD prévio, gradiente aórtico médio > 50 mmHg e CoreValve® são preditores independentes de implante de MPD pós-TAVI. Ocorreu implante de MPD em aproximadamente 20% dos casos de TAVI, o que prolongou a internação hospitalar, mas não afetou a mortalidade. O implante de MPD afetou negativamente a FEVE pós-TAVI.

**背景**：经导管主动脉瓣植入术（Transcatheter Aortic Valve Implantation, TAVI）是一项成熟的临床术式，但术后并发需行永久性心脏起搏器植入术（Permanent Pacemaker Implantation, PPI）的房室传导阻滞是其常见并发症。**研究目的**：明确TAVI术后PPI的发生率、危险因素及临床结局，重点探讨PPI对TAVI术后左心室射血分数（Left Ventricular Ejection Fraction, LVEF）的影响。**研究方法**：巴西多中心TAVI注册研究纳入了2008年1月至2015年1月期间，来自22个医学中心的819例因重度主动脉瓣狭窄接受TAVI治疗的患者。排除不符合入组标准的病例后，对剩余670例患者采用多因素回归分析评估PPI的危险因素，并通过受试者工作特征（ROC）曲线衡量各危险因素的预测效能，检验水准设定为p<0.05。**研究结果**：TAVI术后30天内，共有135例患者（占比20.1%）需接受PPI治疗。与未行PPI的患者相比，该组患者年龄更大（82.5岁 vs 81.1岁；p=0.047），男性占比更高（59.3% vs 45%；p=0.003）。行PPI治疗的患者住院时长更长（平均住院时长15.7±25.7天 vs 11.8±22.9天；p<0.001），但PPI并未对全因死亡率（26.7% vs 25.6%；p=0.80）或心血管死亡率（14.1% vs 14.8%；p=0.84）产生显著影响。经多因素回归分析显示，既往合并右束支传导阻滞（Right Bundle-Branch Block, RBBB）（比值比OR=6.19，95%置信区间CI:3.56~10.75；p≤0.001）、使用CoreValve®人工瓣膜（OR=3.16，95%CI:1.74~5.72；p≤0.001）以及基础状态下跨主动脉瓣压力阶差>50mmHg（OR=1.86，95%CI:1.08~3.2；p=0.025）是TAVI术后需行PPI的独立危险因素。PPI的发生风险可从无上述危险因素时的4%，升至同时存在全部三项危险因素时的63%。该预测模型的ROC曲线下面积为0.69（95%CI:0.64~0.74），提示具备较好的PPI发生风险预测能力。对287例患者1年随访期间的超声心动图结果进行亚组分析显示，接受PPI治疗的患者术后LVEF变化趋势更差（p=0.01）。**结论**：既往右束支传导阻滞、基础跨主动脉瓣平均压力阶差>50mmHg以及使用CoreValve®人工瓣膜均为TAVI术后永久性起搏器植入术的独立危险因素。约20%的TAVI患者术后需行永久性起搏器植入术，该操作可延长患者住院时长，但不会对患者死亡率产生影响。永久性起搏器植入术会对TAVI术后左心室射血分数产生负面影响。