A study conducted in Denmark has shown that patients with breast cancer may be at an increased risk of developing the heart condition atrial fibrillation (AF).
“This study was the first to show that women with recent breast cancer had an increased risk of developing AF,” said lead investigator Maria D’Souza from the cardiology department Herlev and Gentofte Hospital in Hellerup.
D’Souza and colleagues suggest that the reason this patient group may be more prone to AF is that breast cancer induces inflammation, a well-known risk factor for the condition.
The findings have recently been published in the journal HeartRhythm, the official journal of the Heart Rhythm Society and the Cardiac Electrophysiology Society.
In a retrospective analysis of nationwide registries in Denmark, the researchers found that women with breast cancer were at an increased risk of developing AF within three years following their diagnosis, compared with female counterparts of the same age in the general population.
D’Souza says that modern treatment regimens ensure that about 80% of breast cancer patients become long-term survivors. However, long-term complications arising from both the cancer and associated treatments can threaten survival.
In particular, an increased incidence of heart disease, especially ischemic heart disease and heart failure have been observed in this patient group.
The team therefore hypothesized that women with breast cancer may be more susceptible to developing AF as a result of inflammation.
After identifying breast cancer patients diagnosed between 1998 and 2015 and matching 74,155 female patients with 222,465 age- and sex-matched controls form the general population, the researchers used cumulative incidence curves and multivariate Cox regression models to estimate the long-term incidence of AF.
They found that breast cancer was associated with a greater risk of AF, in a manner that was dependent on current age and the time since diagnosis.
Patients younger than 60 were at more than twice the risk in the first six months following their diagnosis and an 80% greater risk between six months to three years following diagnosis.
Those older than 60 were at a similar risk to the general population during the first six months but were at a 14% greater risk during the six month- to three-year time frame.
Our findings should encourage doctors to focus on the risk of AF in patients with recent breast cancer in order to diagnose and treat as early as possible, and researchers to search for increased risk of AF looking at the cancer itself, treatment, genetic predisposition, and shared life style risk factors.
Maria D’Souza, Lead Investigator
“Ultimately, earlier treatment may result in better stroke prevention.”