Diederichsen Søren Zöga, Haugan Ketil Jørgen, Køber Lars, Højberg Søren, Brandes Axel, Kronborg Christian, Graff Claus, Holst Anders Gaarsdal, Nielsen Jonas Bille, Krieger Derk, Svendsen Jesper Hastrup
Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; Department of Cardiology, Zealand University Hospital, Roskilde, Denmark.
Am Heart J. 2017 May;187:122-132. doi: 10.1016/j.ahj.2017.02.017. Epub 2017 Feb 20.
Atrial fibrillation (AF) increases the rate of stroke 5-fold, and AF-related strokes have a poorer prognosis compared with non-AF-related strokes. Atrial fibrillation and stroke constitute an intensifying challenge, and health care organizations are calling for awareness on the topic. Previous studies have demonstrated that AF is often asymptomatic and consequently undiagnosed. The implantable loop recorder (ILR) allows for continuous, long-term electrocardiographic monitoring with daily transmission of arrhythmia information, potentially leading to improvement in AF detection and stroke prevention.
The LOOP study is an investigator-initiated, randomized controlled trial with 6,000 participants randomized 3:1 to a control group or to receive an ILR with continuous electrocardiographic monitoring. Participants are identified from Danish registries and are eligible for inclusion if 70years or older and previously diagnosed as having at least one of the following conditions: hypertension, diabetes mellitus, heart failure, or previous stroke. Exclusion criteria include history of AF and current oral anticoagulation treatment. When an AF episode lasting ≥6minutes is detected, oral anticoagulation will be initiated according to guidelines. Expected follow-up is 4years. The primary end point is time to stroke or systemic embolism, whereas secondary end points include time to AF diagnosis and death.
The LOOP study will evaluate health benefits and cost-effectiveness of ILR as a screening tool for AF to prevent stroke in patients at risk. Secondary objectives include identification of risk factors for the development of AF and characterization of arrhythmias in the population. The trial holds the potential to influence the future of stroke prevention.
心房颤动（AF）使中风发生率增加5倍，与非AF相关的中风相比，AF相关的中风预后更差。心房颤动和中风构成了日益严峻的挑战，医疗保健组织呼吁提高对该主题的认识。先前的研究表明，AF通常无症状，因此未被诊断出来。植入式环路记录器（ILR）可进行连续、长期的心电图监测，并每日传输心律失常信息，有可能改善AF的检测和中风预防。
LOOP研究是一项由研究者发起的随机对照试验，6000名参与者按3:1随机分为对照组或接受ILR进行连续心电图监测。参与者从丹麦登记处中识别，年龄在70岁及以上且先前被诊断患有以下至少一种疾病：高血压、糖尿病、心力衰竭或既往中风，则有资格纳入。排除标准包括AF病史和当前口服抗凝治疗。当检测到持续≥6分钟的AF发作时，将根据指南启动口服抗凝治疗。预期随访时间为4年。主要终点是中风或全身性栓塞的发生时间，次要终点包括AF诊断时间和死亡时间。
LOOP研究将评估ILR作为AF筛查工具预防高危患者中风的健康益处和成本效益。次要目标包括确定AF发生的危险因素以及人群中心律失常的特征。该试验有可能影响中风预防的未来。
