★ Effectiveness of insertable cardiac monitors for atrial fibrillation

atrial fibrillation increases the risk accident Ischemic stroke in patients with other risk factors for stroke. Previous ischemic strokes also increase the risk of recurrent stroke. If atrial fibrillation occurs after a stroke, patients usually begin oral anticoagulant treatment (AKO). In this case, it is one of the most effective treatments recommended by the guidelines.

Atrial fibrillation: only one in two patients have symptoms

Atrial fibrillation usually begins with infrequent, asymptomatic, and brief episodes. However, it can also present with increased heart rate, increased heart rate, feelings of restlessness, and difficulty breathing. Often occurring, asymptomatic atrial fibrillation may go undetected by standard monitoring methods. However, insertable cardiac monitors (ICMs) have a higher detection rate.

One study examined the effectiveness of ICM.

The multicenter randomized trial of Stroke of Known Cause and Underlying Atrial Fibrillation (STROKE AF) was published in 2021. 1). Standard follow-up included, for example: B. 12-lead electrocardiography, Holter monitoring and telemetry. ICM detected atrial fibrillation in 12.1% of cases, while standard monitoring detected atrial fibrillation in only 1.8% of patients.

Patients are observed for three years.

The study initially followed patients for just one year after their stroke. To learn more about the long-term occurrence of atrial fibrillation and the effectiveness of implantable cardiac monitors (ICMs), data from these patients three years after stroke were published (2). The study included 492 patients over 60 years of age or 50 to 59 years of age with at least one additional risk factor for stroke. Atrial fibrillation was defined as an episode of irregular heart rhythm without detectable P waves lasting more than 30 seconds.

The three-year incidence of atrial fibrillation was 21.7% in the ICM group compared with 2.4% in the control group. Atrial fibrillation detection rates in the ICM group increased throughout the study: 2.6% at 1 month, 7.9% at 6 months, 12.5% ​​at 12 months, and 18.5% at 2 months. of the year. In the majority of patients (88% in the ICM group), atrial fibrillation was asymptomatic.

The average duration of the longest episode of atrial fibrillation per patient was 176 minutes. In addition, 31 of 46 patients had at least one episode that lasted more than an hour. In the implantable cardiac monitor (ICM) group, both patients with and without atrial fibrillation were more likely to receive oral anticoagulation (OAC) therapy compared with the control group (24% vs. 8%).

The incidence of first recurrent ischemic and/or hemorrhagic stroke was similar in the ICM group compared with the control group. In the ICM group, three of 31 patients had atrial fibrillation measured before stroke; only one of these three was receiving OCP therapy at the time. Of the 31 control patients, none were found to have atrial fibrillation before the sleep attack, which was also likely due to measurement methods.

Conclusion

The study’s findings suggest that the risk of atrial fibrillation may increase even years after a stroke. They also highlight the superiority of implantable cardiac monitors (ICMs) over conventional standard measurement methods, despite numerous intermittent recordings. The burden of atrial fibrillation, measured by the daily cumulative duration of atrial fibrillation, increased during follow-up in many patients. In addition, data show that in patients with left atrial enlargement, heart failure Obesity or prolonged QRS duration are considered to be at high risk for atrial fibrillation.

Source: Gelber