Photo Ulf Sirborn

Johan Engdahl

Anknuten till Forskning

We do atrial fibrillation screening and stroke prevention!

Om mig

I hold a position as senior consultant, Department of Cardiology at Danderyds University Hospital and as adjunct lecturer at the Department of Clinical Sciences, Karolinska Institutet at the same hospital. 

My research activities started in the field of cardiac arrest and resuscitation and is now mainly devoted to aspects of atrial fibrillation, such as stroke prevention and atrial fibrillation detection.


Our research group is dedicated to improve stroke prevention among patients with atrial fibrillation, partly by studying ECG screening and alternative ways of detecting patients with atrial fibrillation. We reported the first population-based atrial fibrillation screening study to date, the STROKESTOP  study. The study program of STROKESTOP Pilot, STROKESTOP 1 and STROKESTOP 2 is one of the most ambitious atrial fibrillation screening programs to date, with the primary endpoint of STROKESTOP 2 still to be reported in 2024. 

In an attempt to fill the knowledge gap on the benefit of atrial fibrillation screening post ischemic stroke or TIA, we launched the AF SPICE study in 2022. AF SPICE is a multicentre, randomised diagnostic trial comparing standard and extended ECG screening following ischemic stroke or TIA, currently with 22 sites recruiting patients and 900 patients randomised in october 2023. Patient inclusion will be run 2022-2025 followed by a register-based follow-up until 2028.

Many different factors have been used as enrichment for finding the optimal population. In particular, low yield in ECG screening and low participation in the invited population has been barriers.  To find new strategies for participant enrichment, increased participation and increases screening yield, the project CONSIDERING-AF is planned. This project is a collaboration between Pfizer/Bristol Myers Squibb, Karolinska Institutet, Region Halland and Halmstad University. In Region Halland, highly detailed phenotyping of the population, including health care and sociodemographic data, are available. Using this detailed phenotyping, individuals aged at least 65 years with increased risk of incident /undetected AF according to a risk prediction model will be randomized to a digital screening procedure in which the participant will self-apply the ECG device or control without intervention. An equal screening procedure will be undertaken in a population aged at least 65 years without any enrichment. In total, 3000 individuals will be randomized and the study is scheduled to commence in late 2022.  

The concept of atrial cardiomyopathy as the substrate for AF has recently been proposed. The cardiomyopathy results in excessive supraventricular activity such as ectopics or runs of supraventricular tachycardia, as well as AF.  Further, the cardiomyopathy affects blood biomarkers for inflammation and myocardial damage.  Much is still not known on the natural course and expressions of atrial cardiomyopathy. 

In the trial ESA AF, patients with signs of   atrial cardiomyopathy expressed as excessive supraventricular ectopics or supraventricular runs on Holter ECG will be phenotyped with blood biomarkers and for cardiac structure and heart rhythm in order to investigate signs of atrial cardiomyopathy and presence of silent or undiagnosed atrial fibrillation.