Now, experts are sounding the alarm bell over this significant risk. Researchers from Australia’s Flinders University say that as many as 25 percent of chemotherapy and radiotherapy patients develop heart failure as a result of their treatment. Perhaps even more concerningly, most of these patients have little to no knowledge of the risks to their heart health because their doctors failed to inform them about it.
The researchers say that a person’s precise risk of developing heart failure from cancer treatment depends on several factors, including the type of radiotherapy and/or chemotherapy administered as well as known cardiovascular risk factors such as obesity and smoking. They say that better heart monitoring throughout the process could help reduce the impact of this effect.
Complicating matters is the fact that cancer-treatment-related heart problems might not appear right away. In fact, heart failure from cancer therapy might not develop until as long as 20 years after undergoing treatment.
In a sample of patients who had experienced heart muscle damage as a result of cancer treatment, the researchers found that only 11 percent of them had been referred to a cardiologist prior to starting chemotherapy, and only 48 percent were referred to a heart failure clinic at the conclusion of their treatment.
Interestingly, there was an improvement in appropriate heart care for cancer patients following the European Society for Medical Oncology’s publication of Clinical Practice Guidelines. After this information was released, the percentage of people referred to cardiologists before chemotherapy rose from 0 to 23 percent, while the percentage of patients who were given a baseline echocardiogram climbed from 57 to 77 percent.
Unfortunately, none of the chemotherapy patients they interviewed had been informed about their heart health needs. Although more than half of them said they had started eating healthier after their diagnosis, none of them knew exactly what a balanced diet should contain.
This prompted the study’s authors to recommend that cancer patients’ hearts be monitored throughout their treatment given the toxicity of drugs like trastuzumab and anthracyclines. They warned that doctors need to make the effects of these treatments on the heart clear to those with cancer and let them know how they might minimize that risk, such as through diet or exercise.
Those who do develop heart problems during treatment could have their therapy modified to help stem the problem.
There are lots of ways that cancer therapy can cause heart problems. Some chemotherapeutic agents weaken the heart muscle, while newer angiogenesis inhibitors that stop new blood vessels from forming can lead to dramatic rises in blood pressure, blood clots, and heart failure. Some agents can cause a low blood flow to the heart, arrhythmia, inflammation of the sac surrounding the heart, or heart attack. Meanwhile, hormonal therapies can lead to heart attack, blood clots and stroke.
The problem is so common that a new specialty in medicine has emerged to help patients deal with its effects. Cardio-oncology sees oncologists and cardiologists combining their knowledge to help cancer patients protect their heart health while undergoing treatment.
When doctors recommend chemotherapy or radiotherapy, patients need to be warned of all the potential risks up front, including the threat it can pose to heart health, so they can weigh the pros and cons and make an informed decision that gives them the best chance of a long, healthy life.
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