Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a major global public health problem. It is associated with a five-fold increase in risk of stroke.

There are three types of AF—paroxysmal, persistent, or permanent. In paroxysmal AF, episodes come and go, and usually stop without any treatment.

Persistent AF episodes can last for periods of more than 7 days and are treated with medication or a medical procedure called cardioversion.

In permanent AF, the irregular heartbeat is present all the time and cardioversion has failed to restore a normal heart rhythm.

All patients with AF, including paroxysmal AF, are at an increased risk of stroke. UK guidelines recommend anticoagulant treatment, such as the blood-thinning drug warfarin, for patients with all types of AF in order to reduce the risk of stroke. Within 1.5 years, over a fifth of patients with paroxysmal AF progress to permanent AF.

A study, carried out by the University of Birmingham’s Institute of Applied Health Research and published in Heart, has discovered that patients with paroxysmal AF are significantly less likely to receive anticoagulants for stroke prevention than patients with persistent or permanent AF.

Lead author Andrea Isaew, a research nurse at the University of Birmingham, said: “Prior to our study, there had been no research into the treatment of paroxysmal AF in a UK primary care setting.”

“We felt there was vital need for this research, especially given the fact that AF has become one of the most important public health problems and a significant cause of increasing health-care costs in western countries over the last few decades.”

Corresponding author Dr. Nicola Adderley, also of the University of Birmingham, said: “Our team of researchers analyzed the records of 14 million patients from 648 GP surgeries from across the country, looking specifically at records covering a 15-year period between 2000 and 2015.”

“We found that patients with paroxysmal AF were consistently less likely to be prescribed anticoagulants than those with persistent or permanent AF.”

“Although the proportion of AF patients prescribed anticoagulants increased considerably, in 2015 fewer paroxysmal AF patients were prescribed anticoagulants—a treatment gap of 13%.”

“While the anticoagulant treatment gap has narrowed over the years, from 15% in 2000 to 13% in 2015, over the same period a diagnosis of paroxysmal AF became three times more common.

“This means that the number of paroxysmal AF patients missing out on anticoagulants is greater now than 16 years ago.”

“Underuse of anticoagulants in patients with paroxysmal AF is likely to result in preventable strokes among this group, leading to greater levels of avoidable death and disability.”

“Although the gap is narrowing, we need to remind ourselves that all patients with AF are at increased risk of stroke. Paroxysmal AF patients should be given the same priority for stroke prevention as other AF patients.”

The paper was presented at the South West Regional Conference of the Society for Academic Primary Care at the University of Oxford, as well as the National Institute for Health Research’s Clinical Research Network West Midlands’ Primary Care Research Nurse Away Day in Birmingham to encourage clinicians to review treatment of both new and established paroxysmal AF patients.

Andrea Isaew concluded: “The question remains as to whether the difference in treatment between patients with paroxysmal AF and patients with other AF is the result of lower levels of treatment initiation by clinicians or whether patients with paroxysmal AF are more likely to stop their treatment. We need to continue to explore this area of research.”