Atrial fibrillation is rising sharply in COPD patients, but the riskiest are still missing treatment

One of the largest studies ever conducted in primary care has revealed a quiet but consequential shift in the health of people living with chronic obstructive pulmonary disease. Between 2010 and 2022, new diagnoses of atrial fibrillation, the world’s most common sustained heart rhythm disorder, climbed steadily among COPD patients in the United Kingdom, rising from 13.8 to 19.3 cases per 1000 person-years. That represents a 33 percent increase over just over a decade, and it comes with an unsettling twist: the patients at greatest risk of a devastating stroke remain the least likely to receive the blood thinners that could protect them.

The research, published in eClinicalMedicine, drew on the Clinical Practice Research Datalink Aurum database, an anonymized repository of medical records covering more than 50 million patients registered with over 1800 general practices across England. The investigators linked these primary care records to Hospital Episode Statistics, which capture every admission to publicly funded hospitals in the country, allowing them to track both routine diagnoses and serious exacerbations of lung disease. From this vast data resource, they assembled a cohort of 444,668 adults aged 50 and over with a physician diagnosis of COPD, who together contributed nearly 2.3 million person-years of follow-up. Within this group, 37,645 people, or 8.5 percent, were newly diagnosed with atrial fibrillation during the study window.

The scale of the comorbidity problem is difficult to overstate. COPD affects more than 390 million people worldwide and is the third leading cause of death globally, while atrial fibrillation touches over 52 million lives. Previous meta-analyses have estimated that patients with COPD face roughly twice the risk of developing atrial fibrillation compared with those without the lung disease, and that risk climbs as lung function deteriorates. The new study reinforces this dose-response relationship with unusual granularity. Incidence rates rose consistently with age, were higher in men than women across every age band, and were markedly elevated among patients with more severe COPD, whether severity was measured by forced expiratory volume in one second, breathlessness scores, or recent exacerbations requiring hospitalization. Patients hospitalized for a severe COPD flare in the previous year showed incidence rates above 55 per 1000 person-years by 2022, several times higher than those with well-preserved lung function.

The temporal pattern also tells a story about modern healthcare. After a gradual year-on-year climb, incidence plateaued between 2016 and 2019, then dropped 22 percent in 2020 compared with 2019, a dip the authors attribute to reduced access to primary care during the COVID-19 pandemic. The rebound afterward suggests the underlying trend was never interrupted, merely masked. The researchers note that the rising trajectory mirrors patterns seen in the general UK population, implying that improved detection and better survival among people with atrial fibrillation risk factors, rather than something unique to COPD, may be driving much of the increase. Still, the consistency of the elevation across every marker of COPD severity points to a genuine biological contribution, likely involving chronic inflammation, hypoxia, and the structural cardiac changes that accompany long-standing lung disease.

Why does this matter so much? Because atrial fibrillation in a COPD patient is more dangerous than atrial fibrillation alone. Recent cohort evidence indicates that people with both conditions face approximately 1.6 times the risk of ischemic stroke compared with those who have atrial fibrillation without COPD. Oral anticoagulants are the cornerstone of stroke prevention in atrial fibrillation, and current guidelines recommend that treatment decisions be made independently of COPD status. Yet the real-world evidence on whether this actually happens has been sparse and contradictory, with some studies suggesting higher anticoagulation rates in COPD patients and others suggesting lower or equivalent rates.

The new findings go further than any previous work by tracking prescribing trends over thirteen years. Among the 34,851 patients newly diagnosed with atrial fibrillation during follow-up, 66.3 percent received an oral anticoagulant within a year of diagnosis. The rate of initiation nearly tripled over the study period, from 10.3 prescriptions per 100 person-months in 2010 to 30.1 per 100 person-months in 2022, a 2.9-fold increase. The most dramatic rise occurred among patients aged 90 and older, whose initiation rate was more than nine times higher in 2022 than in 2010, albeit from a very low baseline. This transformation was driven almost entirely by the direct oral anticoagulants, or DOACs, which received European approval for stroke prevention in 2011. Warfarin and other vitamin K antagonists, once the only option, collapsed to a 96 percent lower initiation rate by 2022, while DOAC use surged 64-fold between 2012 and 2022.

The fine-grained prescribing data reveal how completely the therapeutic landscape has changed. Apixaban emerged as the dominant agent, peaking at 208.1 prescriptions per 1000 person-months in 2021 and accounting for 61.6 percent of all oral anticoagulants started between 2020 and 2022. Edoxaban, introduced in 2016, overtook rivaroxaban by 2020 and then jumped from 49.4 to 95.4 prescriptions per 1000 person-months between 2021 and 2022. Rivaroxaban, an early favorite, peaked in 2016 and declined steadily thereafter. Dabigatran, the first DOAC approved, never gained significant traction. Notably, these patterns closely match prescribing trends reported in atrial fibrillation patients generally, suggesting that the presence of COPD did not materially alter which drug clinicians chose, only, in some cases, whether they prescribed one at all.

And that is where the treatment gap emerges. Despite the overall tripling of anticoagulation, several high-risk groups were persistently less likely to receive treatment. Patients aged 90 and older had the lowest initiation rates of any age group throughout the study, even though stroke risk climbs steeply with age and guidelines recommend anticoagulation for most patients with atrial fibrillation over 75. Non-White patients were prescribed anticoagulants less often than White patients, echoing documented disparities in atrial fibrillation care more broadly. Most strikingly, people with the most severe COPD, identified by low percent-predicted lung function, severe breathlessness, or recent hospitalization for an exacerbation, consistently received fewer prescriptions than those with milder disease, a pattern that held across all years, ages, and sexes. Patients with chronic kidney disease, liver disease, a history of bleeding, cancer, or dementia were also less likely to be treated.

The authors caution that these patterns may not reflect inappropriate care alone. Contraindications, frailty, polypharmacy, and patient preferences all legitimately shape prescribing decisions, and clinicians may reasonably hesitate before adding a blood thinner to a regimen already burdened by multiple respiratory medications. Yet the concern about physician hesitancy is hard to dismiss, because evidence on the safety and efficacy of anticoagulants specifically in patients with coexisting COPD and atrial fibrillation remains thin. Without dedicated trials or robust observational outcome data in this population, uncertainty itself becomes a barrier to treatment, and the patients facing the highest thromboembolic risk are left in a zone of clinical ambiguity.

The study has limitations worth noting. The database does not capture prescriptions issued by specialists or during hospitalizations, which may lead to modest underestimation of prescribing rates, though the central role of general practitioners in the UK system likely mitigates this. Restricting the cohort to adults over 50 reduced but did not eliminate the possibility of misclassifying some asthma patients as having COPD. The ethnicity-stratified analyses aggregated small numbers of non-White patients into a single category, limiting insight into specific minority subgroups, and the cohort included only individuals with COPD, so comparisons with the general population are indirect. Even so, the sheer size of the cohort, the representativeness of the data, and the consistency of results across sensitivity analyses using multiple imputation lend considerable weight to the conclusions. The message for clinicians and health systems is clear: as atrial fibrillation becomes increasingly common among people with COPD, stroke prevention must keep pace, and the oldest, sickest, and most ethnically marginalized patients, precisely those at greatest risk, should not be left behind. Integrated care pathways and routine bidirectional screening for both conditions, identified as research priorities by the American Thoracic Society, may offer a route forward, but the first step is recognizing that a growing treatment gap exists at all.

Subject of Research: Temporal trends in atrial fibrillation incidence and oral anticoagulant prescribing among adults with COPD in UK primary care

Article Title: Trends in the incidence of atrial fibrillation and the prescription of oral anticoagulants in adults with chronic obstructive pulmonary disease in UK primary care (2010–2022): a cohort study

Article References: Trends in the incidence of atrial fibrillation and the prescription of oral anticoagulants in adults with chronic obstructive pulmonary disease in UK primary care (2010–2022): a cohort study. (n.d.). https://doi.org/10.1016/j.eclinm.2026.104245

Image Credits: AI Generated

DOI: 10.1016/j.eclinm.2026.104245

Keywords: atrial fibrillation, COPD, oral anticoagulants, DOACs, stroke prevention, UK primary care, CPRD, cohort study, health disparities, warfarin, apixaban, epidemiology