Kongebro Emilie Katrine, Diederichsen Søren Zöga, Xing Lucas Yixi, Haugan Ketil Jørgen, Graff Claus, Højberg Søren, Olesen Morten S, Krieger Derk, Brandes Axel, Køber Lars, Svendsen Jesper Hastrup
Department of Cardiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark.
Department of Cardiology, Zealand University Hospital Roskilde, Roskilde, Denmark.
TH Open. 2024 Jan 8;8(1):e19-e30. doi: 10.1055/a-2202-4296. eCollection 2024 Jan.
Atrial fibrillation (AF) prevalence is rising; however, data on the bleeding risks associated with the detection of subclinical AF are needed. Our objective was to determine the bleeding increment associated with implantable loop recorder (ILR) screening for subclinical AF and subsequent anticoagulation initiation compared with usual care. This post hoc study utilized LOOP trial data from 6,004 elderly patients with stroke risks randomized to either ILR ( = 1,503) or usual care ( = 4,503). The mean follow-up time was 64.5 months, and none were lost to follow-up. The primary exposure was the initiation of oral anticoagulation, and the main outcome was the risk of major bleeding events following initiation of oral anticoagulants (OACs), determined by time-dependent cox regression. Second, we investigated antithrombotic prescription patterns and major bleeding events after antiplatelet treatment and in subgroups. OAC was initiated in 1,019 participants with a mean age (years) of 78.8 (± 4.67) in control versus 77.0 (± 4.84) in ILR, < 0.0001. Altogether did 202 participants end or pause OAC treatment. Among AF patients (n = 910) had 40 (28%) completely ended OAC and 105 (72%) temporarily paused OAC during follow-up. Major bleeding events totaled 221 (3.7%). Forty-seven major bleeding events followed an OAC initiation in 1,019 participants (4.6%); 26 versus 21 events in the control and ILR groups, respectively. The hazard ratio (HR) for major bleeding after OAC initiation compared with before initiation was 2.08 (1.50-2.90) < 0.0001 overall, 2.81 (1.82-4.34) < 0.0001 for control and 1.32 (0.78-2.23) = 0.31 for the ILR group ( = 0.07 for interaction). Antiplatelet treatment resulted in an overall adjusted HR of 1.3 (0.96-1.75) = 0.09. For OAC users aged ≥75 years in the ILR group, the rate of major bleeding was 1.73 (0.92-2.96) compared with 0.84 (0.36-1.66) for an age <75 years, and the rate of the corresponding control subgroup aged ≥75 years was 2.20 (1.23-3.63) compared with 1.64 (0.82-2.93) for an age <75 years. The individual risk of major bleeding increased twofold after initiation of oral anticoagulation for all patients in this study. However, the patients screened for subclinical AF did not have a higher bleeding risk after initiation of anticoagulation compared with those in usual care. The LOOP study is registered at ClinicalTrials.gov, identifier: NCT020364 50.
心房颤动（AF）的患病率正在上升；然而，需要有关检测亚临床AF相关出血风险的数据。
我们的目标是确定与植入式环路记录器（ILR）筛查亚临床AF及随后启动抗凝治疗相比，与常规治疗相比的出血增量。
这项事后研究利用了LOOP试验的数据，该试验纳入了6004例有中风风险的老年患者，随机分为ILR组（n = 1503）或常规治疗组（n = 4503）。平均随访时间为64.5个月，无失访病例。主要暴露因素为口服抗凝药的启动，主要结局为口服抗凝药（OACs）启动后发生大出血事件的风险，通过时间依赖性Cox回归确定。其次，我们调查了抗栓治疗处方模式以及抗血小板治疗后及亚组中的大出血事件。
在对照组中，1019名参与者启动了OAC，平均年龄（岁）为78.8（±4.67），而ILR组为77.0（±4.84），P < 0.0001。共有202名参与者结束或暂停了OAC治疗。在AF患者（n = 910）中，40例（28%）在随访期间完全停止了OAC，105例（72%）暂时暂停了OAC。大出血事件共计221例（3.7%）。在1019名参与者中，47例大出血事件发生在启动OAC之后（4.6%）；对照组和ILR组分别为26例和21例。与启动OAC之前相比，启动OAC后大出血的风险比（HR）总体为2.08（1.50 - 2.90），P < 0.0001，对照组为2.81（1.82 - 4.34），P < 0.0001，ILR组为1.32（0.78 - 2.23），P = 0.31（交互作用P = 0.07）。抗血小板治疗导致的总体调整后HR为1.3（0.96 - 1.75），P = 0.09。在ILR组中，年龄≥75岁的OAC使用者大出血发生率为1.73（0.92 - 2.96），而年龄<75岁者为0.84（0.36 - 1.66），相应对照组年龄≥75岁亚组为2.20（1.23 - 3.63），年龄<75岁者为1.64（0.82 - 2.93）。
在本研究中，所有患者口服抗凝药启动后大出血的个体风险增加了两倍。然而，筛查亚临床AF的患者在启动抗凝治疗后与接受常规治疗的患者相比，出血风险并未更高。
LOOP研究已在ClinicalTrials.gov注册，标识符：NCT02036450。
