Cardiology Section, Veterans Affairs Eastern Colorado Health System, Denver2Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora.
Population Health Research Institute, Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada.
JAMA Cardiol. 2017 Mar 1;2(3):324-331. doi: 10.1001/jamacardio.2016.5167.
Subclinical atrial fibrillation (AF) is associated with an increased risk for stroke.
Subclinical AF is asymptomatic, short in duration, and usually detected with long-term, continuous monitoring. Most prior studies have explored its consequences using cardiovascular implantable electronic devices (CIEDs). Although current prevalence estimates are derived from study populations with prior CIEDs, 3 trials will assess the time to a first AF diagnosis among patients receiving a CIED for purposes of AF detection. Stroke risk estimates are currently limited to patients with a prior CIED and vary widely, ranging from a hazard ratio of 0.87 (95% CI, 0.58-1.31) to 9.40 (95% CI, 1.80-47.00). Stroke risk pathogenesis may include factors that are proximately causal, upstream risk activators, and risk markers. The treatment of subclinical AF may be a useful stroke prevention strategy; however, no direct evidence of benefit from oral anticoagulation exists in this population. Two ongoing trials will assess the risk and benefit of non-vitamin K oral anticoagulants among patients at high risk for stroke with a previously placed implantable CIED, but without a prior diagnosis of clinical AF. If clinical benefit is proven, then the cost-effectiveness of screening for and the treatment of subclinical AF will require additional study.
At present, no evidence suggests that implanting a CIED to detect AF or initiating oral anticoagulation therapy among those in whom AF is detected is beneficial. Ongoing and future studies will identify people at high risk for developing subclinical AF and will evaluate the efficacy, safety, and economic value of oral anticoagulation therapy in this population.
无症状性心房颤动（AF）与中风风险增加相关。
无症状性 AF 是无症状的，持续时间短，通常通过长期、连续监测来检测。大多数先前的研究都使用心血管植入式电子设备（CIEDs）来探索其后果。尽管目前的流行率估计值是从先前使用过 CIED 的研究人群中得出的，但 3 项试验将评估在因 AF 检测而接受 CIED 的患者中首次 AF 诊断的时间。目前，中风风险估计仅限于先前有 CIED 的患者，并且差异很大，范围从危险比 0.87（95%CI，0.58-1.31）到 9.40（95%CI，1.80-47.00）。中风风险发病机制可能包括直接因果关系、上游风险激活剂和风险标志物的因素。无症状性 AF 的治疗可能是一种有用的中风预防策略；然而，在这一人群中，口服抗凝剂并没有直接获益的证据。两项正在进行的试验将评估在先前放置的植入式 CIED 且无临床 AF 既往诊断的高危中风患者中，非维生素 K 口服抗凝剂的风险和获益。如果临床获益得到证实，那么筛查和治疗无症状性 AF 的成本效益将需要进一步研究。
目前，没有证据表明植入 CIED 以检测 AF 或在检测到 AF 的患者中开始口服抗凝治疗有益。正在进行和未来的研究将确定有发生无症状性 AF 高风险的人群，并评估在该人群中口服抗凝治疗的疗效、安全性和经济价值。
