A large UK study has linked abnormal heart rhythm to cognitive decline, which is the latest in a growing body of evidence suggesting that there is a significant correlation between common heart conditions and the risk of dementia.
University College London (UCL) researchers looked at 4.3 million individuals on the UK’s primary electronic health record to identify 233,833 people with the common heart condition atrial fibrillation (AF) and 233,747 without it.
Through this, and taking obvious comorbidities and risk factors into account, the researchers still found a 45% increased likelihood in developing mild cognitive impairment (MCI) in the cohort with new diagnoses of the heart condition who were without medical treatment for it.
“Our study showed that AF was associated with a 45% increase in the risk of MCI, and that cardiovascular risk factors and multi-comorbidity appear to associate with this outcome,” said senior author Dr Rui Providencia, professor at the Institute of Health informatics Research at UCL.
This follows a 2019 South Korean study that also found a strong link between the two conditions.
MCI is early-stage cognitive decline, which can at times be reversed but can also be an early warning sign of a dementia-associated disease.
AF is the most common type of treated arrhythmia and can be characterized by a heart that beats too slowly, too fast, or simply irregularly. Its root cause is irregular coordination in the upper chambers (atria) of the heart, which impacts how blood flows to the lower chambers (ventricles).
According to the Centers for Disease Control and Prevention, around 12.1 million Americans are expected to suffer from this condition by 2030. While case numbers increase with age, more women develop AF largely because they, as a whole, live longer. In 2019, AF was mentioned on 183,321 death certificates and was the underlying cause of death in 26,535 of those cases.
“Progression from MCI to dementia appears to be, at least partially, mediated by cardiovascular risk factors and the presence of multiple comorbidities,” Providencia said.
While many factors such as sex and other conditions like depression can impact the risk of MCI, these factors didn’t change the link the researchers found between AF and MCI.
However, one factor that seemed to play a large role in mediating risk was medication. The researchers found that for the individuals with AF that were treated with digoxin, oral anticoagulant treatment and amiodarone treatment had no greater risk of MCI than the cohort without AF.
The researchers add that these findings highlight the importance of getting AF diagnosed and treated, and a confirmatory clinical trial could look deeper into this link.
The study was published in the journal JACC: Heart Failure.
Source: University College London via Scimex
