Atrial fibrillation is associated with significant increases in the risk of all-cause mortality, cardiovascular diseases and renal disease in addition to its pivotal contribution to stroke, a new meta-analysis confirms.
According to the authors the findings suggest AF could be acting as a marker for shared underlying risk factors for cardiovascular disease.
The analysis published in The BMJ was based on 104 cohort studies with a total of 9.6 million participants, of whom almost 600,000 had AF.
It revealed that the risk of stroke was 2.3-fold higher for people with AF compared to people without AF.
More surprisingly, however, the researchers found that heart failure was five times more common in people with AF.
Overall, the presence of AF was associated with a 46%, 61%, 64%, 88% and a 96% increased risk in all-cause mortality, ischaemic heart disease, chronic kidney disease, sudden cardiac death and major cardiovascular events, respectively.
The researchers noted that the associations between AF and cardiovascular outcomes were broadly consistent across subgroups and sensitivity analyses.
For example, they were unaffected by age, the presence of coronary artery disease, absolute cardiovascular risk scores or a history of prior stroke.
They said the enormous scale of the meta-analysis helped to address previous uncertainties about the non-stroke risks of AF.
“Our assessment of the consistency of relative risk estimates across demographic and clinical subgroups is an important expansion on previous studies, many of which have limited their analysis to a single patient subgroup, such as those with ischaemic heart disease and congestive heart failure,” they wrote.
However more work was needed to determine the extent to which AF was a cause of related non-stroke mortality and morbidity.
“It seems likely that AF could be acting as a marker for shared underlying risk factors for cardiovascular disease,” the research team wrote in the BMJ.
“These include hypertension, which is diagnosed in up to 90% of patients with AF, as well as obesity, diabetes and obstructive sleep apnoea.”
The authors suggested that while the focus of recent research had been on novel oral anticoagulants to reduce stroke, a more comprehensive approach to cardiovascular risk reduction might be needed.
The fact that medications for rate and rhythm control in AF had been shown to have little or no effect of non-stroke outcomes strongly suggested that other mechanisms were likely to be involved, they added.