Pacemaker Dependency after Cardiac Surgery: A Systematic Review of Current Evidence

Background
Severe postoperative conduction disturbances requiring permanent pacemaker implantation frequently occur following cardiac surgery. Little is known about the long-term pacing requirements and risk factors for pacemaker dependency in this population.
Methods
We performed a systematic review of the literature addressing rates and predictors of pacemaker dependency in patients requiring permanent pacemaker implantation after cardiac surgery. Using a comprehensive search of the Medline, Web of Science and EMBASE databases, studies were selected for review based on predetermined inclusion and exclusion criteria.
Results
A total of 8 studies addressing the endpoint of pacemaker-dependency were identified, while 3 studies were found that addressed the recovery of atrioventricular (AV) conduction endpoint. There were 10 unique studies with a total of 780 patients. Mean follow-up ranged from 6–72 months. Pacemaker dependency rates ranged from 32%-91% and recovery of AV conduction ranged from 16%-42%. There was significant heterogeneity with respect to the definition of pacemaker dependency. Several patient and procedure-specific variables were found to be independently associated with pacemaker dependency, but these were not consistent between studies.
Conclusions
Pacemaker dependency following cardiac surgery occurs with variable frequency. While individual studies have identified various perioperative risk factors for pacemaker dependency and non-resolution of AV conduction disease, results have been inconsistent. Well-conducted studies using a uniform definition of pacemaker dependency might identify patients who will benefit most from early permanent pacemaker implantation after cardiac surgery.

背景
心脏外科术后常出现严重的术后传导障碍，需行永久起搏器植入术（permanent pacemaker implantation）。目前针对该人群的长期起搏需求及起搏器依赖的危险因素，相关研究仍较为匮乏。
方法
本研究针对心脏外科术后需行永久起搏器植入术的患者，就其起搏器依赖（pacemaker dependency）发生率及预测因素开展系统综述。通过对Medline、Web of Science及EMBASE数据库进行全面检索，依据预先设定的纳入与排除标准筛选待综述的研究。
结果
本研究共筛选出针对起搏器依赖结局的研究8项，针对房室传导（atrioventricular (AV) conduction）恢复结局的研究3项，共计10项独立研究，纳入患者共780例。平均随访时长范围为6~72个月。起搏器依赖发生率介于32%~91%之间，房室传导恢复率介于16%~42%之间。不同研究对起搏器依赖的定义存在显著异质性。多项患者自身及手术相关特异性变量被证实与起搏器依赖独立相关，但各研究间的结果并不一致。
结论
心脏外科术后起搏器依赖的发生频率存在较大差异。尽管单项研究已明确了多种与起搏器依赖及房室传导疾病未缓解相关的围手术期危险因素，但各研究结果并不一致。采用统一的起搏器依赖定义开展高质量研究，或可识别出心脏外科术后最需早期行永久起搏器植入术获益的患者群体。