From Population Health Research Institute, Hamilton, ON, Canada (J.S.H., J.W., D.L., H.D., K.S., S.R.M., S.J.C.); McMaster University, Hamilton, ON, Canada (J.S.H., J.W., D.L., H.D., W.F.M., S.R.M., A.S.P., S.J.C.); Amphia Ziekenhuis, Breda, the Netherlands (M.A.); WCN-Dutch Network for Cardiovascular Research (M.A.); University of Toronto, ON, Canada (A.H., A.V.); University of Western Ontario, London, Canada (P.L.-S.); University of Ottawa Heart Institute, ON, Canada (D.H.B.); Nij Smellinghe Hospital, Drachten, the Netherlands (J.J.d.G.); Ikazia Ziekenhuis, Rotterdam, the Netherlands (M.F.); Institut Universitaire de Cardiologie et de Pneumologie de Québec, QC, Canada (F.P.); University of Alberta, Edmonton, Canada (W.B.); University of Calgary, AB, Canada (M.D.H.); St. Jude Medical, Sylmar, CA (M.C.); Slingeland Ziekenhuis, Doetinchem, the Netherlands (F.S.); and Cambridge Cardiac Care Centre, ON, Canada (A.S.P.).
Circulation. 2017 Oct 3;136(14):1276-1283. doi: 10.1161/CIRCULATIONAHA.117.028845. Epub 2017 Aug 4.
Long-term continuous electrocardiographic monitoring shows a substantial prevalence of asymptomatic, subclinical atrial fibrillation (SCAF) in patients with pacemakers and patients with cryptogenic stroke. Whether SCAF is also common in other patients without these conditions is unknown.
We implanted subcutaneous electrocardiographic monitors (St. Jude CONFIRM-AF) in patients ≥65 years of age attending cardiovascular or neurology outpatient clinics if they had no history of atrial fibrillation but had any of the following: CHADS-VASc score of ≥2, sleep apnea, or body mass index >30 kg/m. Eligibility also required either left atrial enlargement (≥4.4 cm or volume ≥58 mL) or increased (≥290 pg/mL) serum NT-proBNP (N-terminal pro-B-type natriuretic peptide). Patients were monitored for SCAF lasting ≥5 minutes.
Two hundred fifty-six patients were followed up for 16.3±3.8 months. Baseline age was 74±6 years; mean CHADS-VASc score was 4.1±1.4; left atrial diameter averaged 4.7±0.8 cm; and 48% had a prior stroke, transient ischemic attack, or systemic embolism. SCAF ≥5 minutes was detected in 90 patients (detection rate, 34.4%/y; 95% confidence interval [CI], 27.7-42.3). Baseline predictors of SCAF were increased age (hazard ratio [HR] per decade, 1.55; 95% CI, 1.11-2.15), left atrial dimension (HR per centimeter diameter, 1.43; 95% CI, 1.09-1.86), and blood pressure (HR per 10 mm Hg, 0.87; 95% CI, 0.78-0.98), but not prior stroke. The rate of occurrence of SCAF in those with a history of stroke, systemic embolism, or transient ischemic attack was 39.4%/y versus 30.3%/y without (=0.32). The cumulative SCAF detection rate was higher (51.9%/y) in those with left atrial volume above the median value of 73.5 mL.
SCAF is frequently detected by continuous electrocardiographic monitoring in older patients without a history of atrial fibrillation who are attending outpatient cardiology and neurology clinics. Its clinical significance is unclear.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT01694394.
长期连续心电图监测显示，在起搏器患者和隐源性卒中患者中，无症状、亚临床心房颤动（SCAF）的发生率相当高。在没有这些情况的其他患者中，SCAF 是否也很常见尚不清楚。
我们为年龄≥65 岁、无房颤病史但有以下任何一种情况的患者植入皮下心电图监测仪（圣犹达 CONFIRM-AF）：CHADS-VASc 评分≥2 分、睡眠呼吸暂停或体重指数>30kg/m。入选标准还需要左心房扩大（≥4.4cm 或容积≥58ml）或升高（≥290pg/ml）的血清 NT-proBNP（氨基末端 B 型利钠肽前体）。患者接受持续≥5 分钟的 SCAF 监测。
256 例患者随访 16.3±3.8 个月。基线年龄为 74±6 岁；平均 CHADS-VASc 评分为 4.1±1.4；左心房直径平均为 4.7±0.8cm；48%有既往卒中、短暂性脑缺血发作或全身性栓塞。90 例患者（检出率为 34.4%/y；95%置信区间[CI]，27.7-42.3）检测到持续≥5 分钟的 SCAF。SCAF 的基线预测因素包括年龄增加（每 10 年的风险比[HR]，1.55；95%CI，1.11-2.15）、左心房直径（每厘米直径的 HR，1.43；95%CI，1.09-1.86）和血压（每 10mmHg 的 HR，0.87；95%CI，0.78-0.98），但与既往卒中无关。有卒中、全身性栓塞或短暂性脑缺血发作史患者的 SCAF 发生率为 39.4%/y，无卒中史患者为 30.3%/y（=0.32）。左心房容积高于 73.5ml 中位数的患者累积 SCAF 检出率较高（51.9%/y）。
在无房颤病史、正在接受心内科和神经内科门诊治疗的老年患者中，通过连续心电图监测常可检测到 SCAF。其临床意义尚不清楚。
