Patients with a history of cancer are 2 times more likely of developing atrial fibrillation (AFib), the most common heart rhythm disorder, compared with the general population.

Comparatively, patients with prostate cancer had the highest burden of AFib, followed by those with colon, lung, and breast cancers. Whereas previous studies have shown that individuals with cancer are at a greater risk for developing AFib at the time of cancer diagnosis, prior to any treatment and after therapy is initiated, researchers noted that this is the first study to examine AFib’s association with specific cancer types.

Researchers examined data from the National Inpatient Sample, analyzing the records of more than 143 million adult patients who visited a hospital in the United States between 2012 and 2015. From these data, researchers found that 14.5 million individuals (10%) were found to have some form of AFib. They then examined medical records for these patients to determine how often AFib and cancer coexisted and to determine whether people with certain cancer types were more likely to have AFib.

After adjusting for known cardiovascular risk factors, such as hypertension or diabetes, researchers found that the odds of having AFib with any cancer was more than twice what would be expected, with prostate cancer ranking the highest in association with AFib, followed by breast, lung, and colon cancers, and non-Hodgkin lymphoma. Death rates were also more likely among patients with AFib who had prostate cancer compared with those without AFib.

"When we looked at everyone with some form of AFib, those with certain types of cancer were more likely to have heart rhythm abnormalities, and this trend persisted even after accounting for other cardiovascular risk factors and disease,” said study lead author Muhammad Khan, MD, a resident at St. Mary Medical Center in Langhorne, Pennsylvania, in a press release.

Researchers found a 2.3-fold increased chance of having AFib with all cancers studied. Furthermore, there was a greater than 50% increased risk of AFib in patients with prostate, colon, or lung cancers.

The findings suggest that other factors may be contributing to AFib in patients with these cancers, according to the study authors. For example, such cancers may be associated with higher mortality due to circulating pro-coagulants and greater systematic inflammation; however, this relationship has yet to be studied.

"Based on our findings, certain patients should be considered at higher risk of AFib and may benefit from cardiac evaluation and appropriate treatments, whether it be with medication or ablative techniques, to help improve the survival rates in the long-term,” Khan said.

Khan suggested that the mean age of prostate cancer diagnosis and AFib is around the same, so there may be a correlation due to the similar age of onset. “Given the older age of onset, these patients tend to have more comorbidities that may contribute to them developing AFib," Khan said in the press release.

Researchers were unable to distinguish whether AFib cases new, chronic, or paroxysmal, nor were they able to track which cancer treatment patients received. Many lifesaving cancer treatments, including certain chemotherapies and targeted drugs, are known to cause heart damage.

Further studies are needed to clarify what is behind the development of AFib in patients with cancer, according to the authors. Additionally, research is needed to investigate which inflammatory markers may have a greater association with the development of AFib and to better understand how to treat AFib more effectively and possibly prevent its onset in patients with cancer.

Reference
  1. Certain Cancers Come with Higher Risk of Serious Heart Rhythm Disorder [news release]. American College of Cardiology website. Published March 18, 2020. https://www.acc.org/about-acc/press-releases/2020/03/18/08/45/certain-cancers-come-with-higher-risk-of-serious-heart-rhythm-disorder. Accessed March 20, 2020.