Wireless Single-Lead ECG Monitoring to Detect New-Onset Postoperative Atrial Fibrillation in Patients After Major Noncardiac Surgery: A Prospective Observational Study

Abstract

BACKGROUND: New-onset postoperative atrial fibrillation (POAF) is associated with several cardiovascular complications and higher mortality. Several pathophysiological processes such as hypoxia can trigger POAF, but these are sparsely elucidated, and POAF is often asymptomatic. In patients undergoing major gastrointestinal cancer surgery, we aimed to describe the frequency of POAF as automatically estimated and detected via wireless repeated sampling monitoring and secondarily to describe the association between preceding vital sign deviations and POAF. METHOD: Patients ≥60 years of age undergoing major gastrointestinal cancer surgery were continuously monitored for up to 4 days postoperatively. Electrocardiograms were obtained every minute throughout the monitoring period. Clinical staff were blinded to all measurements. As for the primary outcome, POAF was defined as 30 consecutive minutes or more detected by a purpose-built computerized algorithm and validated by cardiologists. The primary exposure variable was any episode of peripheral oxygen saturation (Spo 2 ) <85% for >5 consecutive minutes before POAF. RESULTS: A total of 30,145 hours of monitoring was performed in 398 patients, with a median of 92 hours per patient (interquartile range [IQR], 54-96). POAF was detected in 26 patients (6.5%; 95% confidence interval [CI], 4.5-9.4) compared with 14 (3.5%; 95% CI, 1.94-5.83) discovered by clinical staff in the monitoring period. POAF was followed by 9.4 days hospitalization (IQR, 6.5-16) versus 6.5 days (IQR, 2.5-11) in patients without POAF. Preceding episodes of Spo 2 <85% for >5 minutes (OR, 1.02; 95% CI, 0.24-4.00; P = .98) or other vital sign deviations were not significantly associated with POAF. CONCLUSIONS: New-onset POAF occurred in 6.5% (95% CI, 4.5-9.4) of patients after major gastrointestinal cancer surgery, and 1 in 3 cases was not detected by the clinical staff (35%; 95% CI, 17-56). POAF was not preceded by vital sign deviations. (Anesth Analg 2022;135:100-9) KEY POINTS• Questions: Can new-onset postoperative atrial fibrillation (POAF) after major abdominal surgery be detected in the surgical wards by continuous wearable monitoring, and is POAF preceded by deviating vital signs? • Findings: A high detection rate of POAF (6.5%, 95% confidence interval [CI], 4.5-9.4) was found using wireless monitoring with repeated sampling, and no significant associations were found between POAF and preceding deviating vital signs. • Meaning: Wireless repeated sampling monitoring can detect POAF outside routine monitoring in surgical wards, and these events do not seem to be preceded by vital sign derangement.

Frequency and risk factors of atrial fibrillation after acute abdominal surgery: A prospective cohort study

“…The authors are unaware of other studies that have utilized continuous cardiac rhythm monitoring in the acute abdominal surgery setting. A recent paper has utilized continuous single‐lead cardiac rhythm monitoring after major elective abdominal cancer surgery in patients older than 60 years 35 . In line with the present study, monitoring resulted in additional identification of cases of POAF 35 .…”

“…A recent paper has utilized continuous single-lead cardiac rhythm monitoring after major elective abdominal cancer surgery in patients older than 60 years. 35 In line with the present study, monitoring resulted in additional identification of cases of POAF. 35 It remains uncertain whether these additional diagnoses of asymptomatic POAF after abdominal surgery are associated with an increased risk of complications.…”

“…35 In line with the present study, monitoring resulted in additional identification of cases of POAF. 35 It remains uncertain whether these additional diagnoses of asymptomatic POAF after abdominal surgery are associated with an increased risk of complications. Nevertheless, device-detected asymptomatic AF diagnosed in the general population is associated with an increased risk of thromboembolic events and death close to that of symptomatic AF.…”

Remote monitoring of cancer patients with suspected Covid-19 using wearable sensors and regular mobile data networks; results of the RECAP feasibility study (NCT04397705)

“…The Isansys sensors used in this study have previously been evaluated in the inpatient paediatric setting, in general hospital wards and following major gastrointestinal surgery (10)(11)(12). A number of studies are ongoing, although none in a home based, ambulatory population.…”

The future of postoperative vital sign monitoring in general wards: improving patient safety through continuous artificial intelligence-enabled alert formation and reduction

“…Using CVSM may also allow for detection of otherwise overlooked complications such as asymptomatic atrial fibrillation were CVSM detected new onset atrial fibrillation after major abdominal surgery, whereof one-third was undetected by clinical staff, with potential for preventive antithrombotic measures [14], and future systems will also potentially allow for continuous ST-segment analyses to detect risk for cardiac injury [15,16]. The case of atrial fibrillation also supports that development of CVSM systems must consider any preexisting conditions as to reduce alerts caused by an abnormal but chronic condition, whilst identifying new important deviations in the same patient.…”