AF risk elevated in certain cancers

The risk of atrial fibrillation (AF) appears to be elevated among patients with a history of cancer, particularly those with prostate cancer, according to a study presented at ACC.20.

“We found 2.3-fold increased odds of having AF with all cancers studied,” noted study lead author Dr Muhammad Khan from the St. Mary Medical Center in Langhorne, Pennsylvania, US. “There was a greater than 50 percent increased risk of AF in prostate, colon, and lung cancer patients. Of these three, those with prostate cancer had the highest risk of AF.”

The study population comprised 143,211,398 adults who presented at a hospital in the US between 2012 and 2015, as listed in the National Inpatient Sample database. AF was documented in 10.12 percent of patients.

After adjusting for cardiovascular (CV) and AF risk factors (eg, hypertension, diabetes, coronary artery disease, cardiomyopathy, valvular disorder, and thyrotoxicosis), patients with a history of any cancer had a more than twofold risk of AF (2.35-fold) compared with the general population. [ACC.20, abstract 20-A-15029-ACC]

The risk of AF was highest among patients with a history of prostate cancer (1.63-fold), followed by cancer of the lung (1.6-fold), colon (1.53-fold), thorax (1.44-fold), or breast (1.43-fold). The risk of AF was also elevated among patients with a history of non-Hodgkin’s lymphoma (1.44-fold) or leukaemia (1.34-fold). However, there was no significant association between AF and thyroid cancer.

Among patients with prostate cancer, mortality risk was significantly increased among those who also had AF compared with those without AF (3.28 percent vs 2.31 percent). Patients with AF and colon cancer or non-Hodgkin’s lymphoma also had elevated mortality rates compared with those without AF (2.46 percent vs 2.2 percent [colon cancer] and 1.64 percent vs 1.61 percent [non-Hodgkin’s lymphoma]; p<0.001 for all).

According to Khan, the results suggest that AF may be linked to factors specific to certain cancers. “For example, these cancers may be associated with higher mortality due to circulating pro-coagulants and greater systemic inflammation,” he said, noting that this hypothesis, as well as other potential mechanisms behind the cancer–AF association, needs further research.

Regarding the association between AF and prostate cancer specifically, the similar age of onset may play a role. “The mean age of prostate cancer diagnosis and AF is around the same – generally 66 years – so there may be a correlation between the two. Given the older age of onset, these patients tend to have more comorbidities that may contribute to them developing AF,” Khan pointed out.

“Based on our findings, certain patients should be considered at higher risk of AF 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 and co-authors noted that the study did not account for type of AF (new, chronic, or paroxysmal) or cancer treatments, some of which are known to have CV adverse effects.