The cancer and arrhythmia conundrum
Managing overlapping cardiovascular and oncologic concerns requires a nuanced approach to patient care
A growing body of evidence is revealing important nuances for managing cancer and an arrhythmia when they coexist.
Paari Dominic, MBBS, MPH, will address the research and its implications during Saturday’s “Arrhythmia Research Summit: The Latest Advances in Atrial Fibrillation.” He said it’s clear that AFib is becoming more common in cancer patients, but the reasons behind it are complex.
“One (reason) is the fact that cancer patients survive longer now. Because of newer cancer therapies that are more effective, we see patients far after their cancer was diagnosed and treated,” he said. “Now you’re seeing the effects of the cancer and the cancer treatment many years later, and we’re seeing that cardiac arrhythmias are one of the effects of that cancer treatment.
“The other factor is that many of the newer cancer drugs like chemotherapeutic agents are causing a lot more cardiac arrhythmias.”
Dominic, who is director of electrophysiology and medical director of the electrophysiology lab at University of Iowa Health Care in Iowa City, Iowa, said ibrutinib, for example, entered the market several years ago and has been effective in treating multiple types of cancer, such as chronic lymphocytic leukemia. The downside, he said, is that the medication is also known to cause AFib.
Likewise, radiation therapy has been identified as an independent risk factor for developing AFib, particularly in patients undergoing thoracic or chest-area radiation.
But whether the arrhythmia is caused by medications, radiation therapy or cancer surgery, Dominic said, his research has led him to look at the common genetic and protein-based links between cancer and AFib.
“Regardless of which is diagnosed first, both conditions share common phenomena, which include comorbidities, (and) gene mutations and protein disturbances that are common to both of these disease processes,” he said. “In some patients, (the common factor) causes cancer first and then causes AFib, while in others it causes AFib first and then cancer.”
No matter which comes first, treatment for the AFib is going to be similar. But he cautioned that there are nuances that cardiologists need to know.
“For example, when patients develop AFib, we put them on blood thinners, which are necessary to prevent stroke in AFib patients. But in a cancer patient with AFib, you have to be careful starting them on blood thinners because some of these cancers can bleed from the blood thinner and cause significant damage to these patients,” he said. “So, what we’re talking about is just how to tailor the regular treatment that you give AFib patients, based on their cancer treatment and their cancer history, and just how to make some modifications in those treatments.”
Bringing to light the links between cancer and arrhythmias is fundamental for future treatment of both conditions, Dominic said.
“Awareness of these two conditions existing together was not there for a very long time, and that awareness is very slowly unfolding,” he said. “But I think they are very linked diseases that we don’t always see that way. And in the future, this might be a very important area that we need to focus on.”
