One in four strokes may be caused by an irregular heart beat known as atrial fibrillation (AF). Having AF means you are five times as likely to have a stroke. Often, AF is diagnosed only after a stroke has occurred. The risk of stroke from AF can be reduced by anticoagulant drugs that make the blood less likely to form the clots that cause strokes. It is possible that more strokes could be prevented if people who had AF but have never been diagnosed and otherwise consider themselves well, were invited to be tested for AF in an organised manner as part of a screening program. However, the UK National Screening Committee has recently said that they are unsure that a screening program would be beneficial. They have asked researchers to collect more evidence. This small study forms part of a larger effort to inform this decision. In this study we intend to find out how common AF is in under 65s and what proportion of young AF patients would benefit from anticoagulation therapy. Additionally, we want to see if we can define patients with a high risk of AF using information contained in routine medical records. We hope the information we gather can help us design a study to find out whether some young people should be screened for AF.
Untreated atrial fibrillation (AF) is associated with a five-fold increase in the risk of stroke. While age is a key determinant of AF, about 20% of AF occurs in people under the age of 65. Younger individuals experiencing stroke will lose more years of healthy life than older individuals, and therefore may benefit more from AF detection. However fewer young patients will have the diagnosis and not all of these will benefit from stroke prevention therapy, so there is still uncertainty about the benefit of screening people under 65 for AF. Additionally, there is value in determining whether information contained in GP medical records could be used to target high risk people in younger age groups in a potential screening programme. We propose two retrospective cohort studies. Cohort (i) will include all AF incident cases at any time and will be used to calculate AF incident rates, calculate the patient's cardiovascular risk at diagnosis (using CHA2DS2-VASc risk score) and examine how this risk varies over time. Cohort (ii) will be random sample of people under 65 years between 2004 and 2016 that will be used to calculate AF incidence rates stratified by cardiovascular risk.
Atrial fibrillation incidence rate; CHA2DS2-VASc score.
Duncan Edwards - Chief Investigator - University of Cambridge
Silvia (Silva) Mendonca - Corresponding Applicant - University of Cambridge
Catherine Saunders - Collaborator - University of Cambridge
Jenny Lund - Collaborator - University of Cambridge
Jonathan Mant - Collaborator - University of Cambridge
Patient Level Index of Multiple Deprivation;Other