Division of Cardiology, University of California, San Francisco, San Francisco.
Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco.
JAMA Cardiol. 2022 Feb 1;7(2):167-174. doi: 10.1001/jamacardio.2021.5010.
Atrial fibrillation (AF) is the most common arrhythmia. Although patients have reported that various exposures determine when and if an AF event will occur, a prospective evaluation of patient-selected triggers has not been conducted, and the utility of characterizing presumed AF-related triggers for individual patients remains unknown.
To test the hypothesis that n-of-1 trials of self-selected AF triggers would enhance AF-related quality of life.
DESIGN, SETTING, AND PARTICIPANTS: A randomized clinical trial lasting a minimum of 10 weeks tested a smartphone mobile application used by symptomatic patients with paroxysmal AF who owned a smartphone and were interested in testing a presumed AF trigger. Participants were screened between December 22, 2018, and March 29, 2020.
n-of-1 Participants received instructions to expose or avoid self-selected triggers in random 1-week blocks for 6 weeks, and the probability their trigger influenced AF risk was then communicated. Controls monitored their AF over the same time period.
AF was assessed daily by self-report and using a smartphone-based electrocardiogram recording device. The primary outcome comparing n-of-1 and control groups was the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) score at 10 weeks. All participants could subsequently opt for additional trigger testing.
Of 446 participants who initiated (mean [SD] age, 58 [14] years; 289 men [58%]; 461 White [92%]), 320 (72%) completed all study activities. Self-selected triggers included caffeine (n = 53), alcohol (n = 43), reduced sleep (n = 31), exercise (n = 30), lying on left side (n = 17), dehydration (n = 10), large meals (n = 7), cold food or drink (n = 5), specific diets (n = 6), and other customized triggers (n = 4). No significant differences in AFEQT scores were observed between the n-of-1 vs AF monitoring-only groups. In the 4-week postintervention follow-up period, significantly fewer daily AF episodes were reported after trigger testing compared with controls over the same time period (adjusted relative risk, 0.60; 95% CI, 0.43- 0.83; P < .001). In a meta-analysis of the individualized trials, only exposure to alcohol was associated with significantly heightened risks of AF events.
n-of-1 Testing of AF triggers did not improve AF-associated quality of life but was associated with a reduction in AF events. Acute exposure to alcohol increased AF risk, with no evidence that other exposures, including caffeine, more commonly triggered AF.
ClinicalTrials.gov Identifier: NCT03323099.
心房颤动（AF）是最常见的心律失常。尽管患者报告说，各种暴露决定了 AF 事件何时以及是否会发生，但尚未对患者选择的触发因素进行前瞻性评估，并且对于个体患者，描述假定的与 AF 相关的触发因素的效用仍然未知。
检验 n-of-1 试验自我选择的 AF 触发因素是否会提高与 AF 相关的生活质量的假设。
设计、设置和参与者：一项持续至少 10 周的随机临床试验测试了一款智能手机移动应用程序，该程序适用于患有阵发性 AF 且拥有智能手机并对测试假定的 AF 触发因素感兴趣的有症状患者。参与者于 2018 年 12 月 22 日至 2020 年 3 月 29 日期间进行筛选。
n-of-1 参与者在 6 周内以随机 1 周块的方式接受暴露或避免自我选择的触发因素的指导，然后告知他们触发因素对 AF 风险的影响概率。对照组在同一时间段内监测他们的 AF。
通过自我报告和使用基于智能手机的心电图记录设备每天评估 AF。比较 n-of-1 组和对照组的主要结局是 10 周时的心房颤动对生活质量的影响（AFEQT）评分。所有参与者随后都可以选择进行额外的触发因素测试。
在 446 名开始参与（平均[SD]年龄，58[14]岁；289 名男性[58%]；461 名白人[92%]）的参与者中，320 名（72%）完成了所有研究活动。自我选择的触发因素包括咖啡因（n=53）、酒精（n=43）、睡眠减少（n=31）、运动（n=30）、左侧卧位（n=17）、脱水（n=10）、大餐（n=7）、冷食或冷饮（n=5）、特定饮食（n=6）和其他定制的触发因素（n=4）。在 AFEQT 评分方面，n-of-1 组与仅接受 AF 监测组之间没有显著差异。在干预后 4 周的随访期间，与同期对照组相比，触发测试后报告的每日 AF 发作明显减少（调整后的相对风险，0.60；95%CI，0.43-0.83；P<.001）。在个体化试验的荟萃分析中，仅暴露于酒精与 AF 事件风险显著升高相关。
AF 触发因素的 n-of-1 测试并未改善与 AF 相关的生活质量，但与 AF 事件的减少相关。急性暴露于酒精会增加 AF 风险，没有证据表明其他暴露因素（包括咖啡因）更常引发 AF。
ClinicalTrials.gov 标识符：NCT03323099。
