Cambridge University Hospitals NHS Foundation Trust have increased capacity to insert implantable cardiac monitors to detect atrial fibrillation after cryptogenic ischaemic stroke by using the joint stroke / cardiology multidisciplinary team, which is working to identify suitable patients.
The practice described in this example is in line with the NICE diagnostics guidance 41 (DG41) on Implantable cardiac monitors to detect atrial fibrillation after cryptogenic stroke.
Authors: Dr Kayvan Khadjooi, Consultant in Stroke Medicine, Dr Anna Chousou, Clinical Research Fellow in Cardiology, Dr V Vassiliou, Honorary Consultant in Cardiology, Dr Peter Pugh, Consultant in Cardiology.
Aims and objectives
- To improve the care of patients with ischaemic stroke with not yet identified cause.
- To increase the number of eligible patients receiving long-term cardiac monitoring (Reveal LINQ) following an ischaemic stroke
- To reduce the risk of recurrent ischaemic strokes by identifying the cause and initiating appropriate secondary prevention (anticoagulation in case of atrial fibrillation or AF)
- To increase the capacity to insert implantable cardiac monitors by using Reveal LINQ which can be inserted outside a cardiac catheter laboratory by a trained technician (not necessarily a cardiologist)
Reasons for implementing your project
Implantable cardiac monitors (Medtronic Reveal devices) have been inserted at Cambridge University Hospitals in some patients following ischaemic stroke since 2009. There has been an increased awareness about the importance of identifying whether AF is the cause of cryptogenic stroke which is why the stroke and cardiology departments aimed to improve screening for AF in patients with ischaemic stroke.
The development in the technology to the Reveal LINQ devices which can be inserted outside of a cardiac catheter laboratory by non-medical staff has provided an opportunity to increase capacity in the department for inserting these devices. This has allowed more eligible patients to have access to this technology.
How did you implement the project
There is a strong ethos in the stroke department about the importance of identifying the cause of ischaemic stroke, as undiagnosed AF is a strong risk factor for recurrent strokes which can have very high morbidity and mortality. Training sessions and professional development within the department improved awareness.
The stroke department has had a close working relationship with the cardiology department. When the service was first established, regular multidisciplinary team meetings were scheduled to discuss eligible patients and agree on referral. As the care pathway has become well established referral for eligible patients to cardiology is made via email following an MDT discussion either face to face or via email between stroke and cardiology.
In the beginning, Reveal devices were offered to patients under 55 years of age following ischaemic stroke when thorough investigations, identified no cause for stroke and there was a clinical suspicion of a cardiac arrhythmia as the cause. Now, Reveal devices are offered to more patients, regardless of age, when clinical suspicion of cardiac arrhythmias as the cause of stroke is high. Patients should have 24-48 hour inpatient cardiac monitoring in the hyperacute stroke unit, and/or 24 hour outpatient cardiac monitoring before being eligible for Reveal LINQ.
Implantation is done by a cardiology consultant, cardiology registrar or trained technician. A cardiology nurse is currently being trained to increase capacity. The cardiology department implants Reveal LINQ in the cardiac catheter laboratory or outside the lab if needed. It takes approximately 10 minutes to insert and patients can generally go home within 2 hours.
The cardiology team monitor the devices remotely for at least 6 months and up to 3 years, when usually battery runs out. If an arrhythmia is detected, the cardiology team inform the stroke consultant who will either bring the patient to clinic or write to their GP.
From 2009 until October 2020, 376 patients with a stroke or TIA underwent implantation of a Reveal device. 1 patient had a Reveal DX, 155 patients a Reveal XT and 220 a Reveal Linq.
The pick-up rate of AF on any duration is 41%. The incidence of AF lasting >30 seconds is 30%. The median time to detection is 131 days. Of these 94% have been commenced on anticoagulation to date.
The team have identified that currently there are a number of weeks between the patient being identified as suitable for Reveal LINQ and it being inserted: average 138 days. The majority of this delay is due to waiting time for outpatient Holter monitoring and reporting. They are working on streamlining the referral pathway even more and decreasing the waiting time for Holter monitors in order for the device to be inserted as close to the time of the stroke as possible.
Key learning points
It is important to have a good relationship and communications channels between stroke and cardiology services. As part of the adoption plan they have used MDT meetings and good communication links to support this. This allowed the team to gradually increase the capacity for Reveal device implantation.
A multidisciplinary approach has led to identification of suitable patients that is reflected in the high pick-up rate by the implantable cardiac monitors.
Using education, training and communications to raise awareness of the importance of identifying the cause of ischaemic stroke within the teams as undiagnosed AF is a strong risk factor for recurrent disabling strokes.