Villa Emmanuel, Clerici Alberto, Messina Antonio, Testa Luca, Bedogni Francesco, Moneta Andrea, Donatelli Francesco, Troise Giovanni
Poliambulanza Foundation Hospital, Brescia, Italy. Electonic correspondence:
Sant'Ambrogio Clinical Institute-University of Milan, Milan, Italy.
J Heart Valve Dis. 2016 Nov;25(6):663-671.
The use of transcatheter aortic valve implantation (TAVI) following the introduction of Nitinol autoexpandable devices has spread rapidly during recent years. In addition, cardiac surgery has been revolutionized due to the use of Nitinol-based sutureless prostheses for aortic valve replacement (AVR). During the same period, however, permanent pacemaker (PPM) implantation has emerged as a frequent complication. The study aim was to identify the risk factors of PPM following the implantation of a Nitinol self-expanding prosthesis (for AVR or TAVI).
A study group was created between two institutions experienced in the use of nitinol devices, and a pool of 336 patients (56.6% CoreValve - Medtronic; 43.4% Perceval - Sorin) was available for a retrospective analysis. Pre-procedural clinical and electrocardiography (ECG) variables and postprocedural ECG variables were compared between the PPM group and control patients who had not received a PPM during their index hospitalization.
A PPM was required in 12.8% of patients (TAVI 17.5% versus AVR 6.8%, p = 0.007). PPM patients had a higher logistical EuroSCORE (median 20.77% versus 15.59%, p = 0.015), a lower use of statins (18.6% versus 34.2%, p = 0.04), a pre-procedural longer QRS interval (median 117 ms versus 98 ms, p = 0.002), and a higher incidence of conduction disturbances (29.3% versus 16.8%, p = 0.034), with a prevalence of right bundle branch block. At the first postprocedural ECG, non-stimulated PPM patients had a longer QRS interval (median 150 ms versus 113 ms, p<0.001) and a longer QTc interval (487.3 ± 46 ms versus 510.8 ± 53.8 ms, p = 0.005). Prevalent intra-ventricular conduction disorders in both groups included left bundle branch block. AVR patients received a PPM later than the TAVI group (median 6 days versus 3 days, p = 0.01). TAVI was an independent predictor of PPM at logistic regression analysis (OR 3.18; 95% CI 1.19-8.48, p = 0.021), but the significance disappeared after incorporating post-procedural ECG variables.
Nitinol technology is a ground-breaking option for aortic valve procedures. However, the radial forces of the self-expandable mechanism may be implicated in the increased need for PPM, mostly in cases of TAVI compared to AVR, that most likely are due to displacement of the stent provoked by in situ calcium clusters. Given the clinical and economic impact of PPM, new parameters are required to understand the stent/tissue interaction and to help with device selection.
近年来，自膨式镍钛诺装置应用于经导管主动脉瓣植入术（TAVI）后，该技术迅速普及。此外，基于镍钛诺的无缝合人工瓣膜用于主动脉瓣置换术（AVR），给心脏外科手术带来了变革。然而，在此期间，永久起搏器（PPM）植入已成为常见并发症。本研究旨在确定植入镍钛诺自膨式人工瓣膜（用于AVR或TAVI）后发生PPM的危险因素。
在两家使用镍钛诺装置经验丰富的机构中设立一个研究组，纳入336例患者（56.6%使用美敦力CoreValve；43.4%使用索林Perceval）进行回顾性分析。比较PPM组与在首次住院期间未接受PPM的对照患者术前的临床和心电图（ECG）变量以及术后ECG变量。
12.8%的患者需要植入PPM（TAVI组为17.5%，AVR组为6.8%，p = 0.007）。PPM患者的逻辑欧洲心脏手术风险评估系统（EuroSCORE）更高（中位数20.77%对15.59%，p = 0.015），他汀类药物使用率更低（18.6%对34.2%，p = 0.04），术前QRS间期更长（中位数117 ms对98 ms，p = 0.002），传导障碍发生率更高（29.3%对16.8%，p = 0.034），以右束支传导阻滞为主。在术后首次ECG检查时，未受刺激的PPM患者QRS间期更长（中位数150 ms对113 ms，p<0.001），QTc间期更长（487.3±46 ms对510.8±53.8 ms，p = 0.005）。两组常见的室内传导障碍包括左束支传导阻滞。AVR患者植入PPM的时间晚于TAVI组（中位数6天对3天，p = 0.01）。在逻辑回归分析中，TAVI是PPM的独立预测因素（比值比3.18；95%置信区间1.19 - 8.48，p = 0.021），但纳入术后ECG变量后，该显著性消失。
镍钛诺技术是主动脉瓣手术的开创性选择。然而，自膨式装置的径向力可能与PPM需求增加有关，与AVR相比，TAVI患者更为常见，这很可能是由于原位钙簇导致支架移位所致。鉴于PPM对临床和经济的影响，需要新的参数来了解支架/组织相互作用并辅助器械选择。
