heart damage from chemo: test helps with risks

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reduced heart function is a side effect of cancer treatment that may be prevented by early intervention.

by dave yasvinski

published feb 03, 2021

last updated feb 20, 2025

3 minute read

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3 minute read

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test can predict heart damage from chemo before it's too late

many people who undergo chemotherapy end up experiencing cardiotoxicity. getty

researchers are ringing in heart month with a new, more sensitive test that can closely monitor the vital organ in cancer patients undergoing painful chemotherapy.

the study, published in the journal of the american college of cardiology, points out that one in 20 high-risk patients face the added threat of developing heart failure after waging war with cancer. the research compared heart function in patients before and after they were subjected to anthracycline-based chemotherapy — an effective cancer treatment that can lead to a form of heart damage called cardiotoxicity.

“we hoped our study would show a better way to care for cancer patients, who are already fighting one disease and should not have to worry about the future risk of heart failure too,” said dr. dinesh thavendiranathan, the lead of the cardiotoxicity prevention program at the ted rogers centre for heart research in toronto and an expert in cardiotoxicity.

the 307 participants in the study, 90 per cent of whom had been diagnosed with breast cancer, were split into two groups and observed throughout their cancer treatment. the first group received standard care, which entails using echocardiography to determine left ventricular ejection fraction (lvef) — a measure of how much blood the ventricle pumps out with each contraction. the second group received the same test in addition a new imaging method that measures global longitudinal strain (gls) to determine if there are any deformities in the heart muscle itself.

“lvef is the traditional imaging method, but we already know measuring gls allows for a better identification of heart damage,” thavendiranathan said. “what we didn’t know is if we can reduce the risk of cardiotoxicity by intervening once this early heart damage is detected.”

while the trial did not achieve its primary purpose — there was no measurable difference in heart function between patients in the lvef or lvef plus gls groups following treatment — simply using gls to continually monitor patients led to a smaller reduction in heart function compared to traditional techniques. it also dropped the risk of cardiotoxicity and helped identify heart damage earlier and in twice as many patients.

“the purpose of a sensitive method like gls is to pick up the presence of disease and treat it early,” said thavendiranathan. “this means more patients will be treated, and if we start heart medications when a change is identified, we can prevent significant worsening of heart function.”

that alone will be welcome news to patients already staring down one daunting disease. “when i was diagnosed, i was scared for my life,” said sindhu johnson, one of the trial’s cancer patients who was randomly assigned to the group that received gls monitoring. “i was willing to undertake any treatment, but i understood my survival may come at a price. and that price included cardiotoxicity.”

that bill never came due for johnson as a change in her gls measurement during the trial alerted doctors that her treatment was beginning to damage her heart. the early detection gave thavendiranathan the time needed to initiate cardio-protective therapy and improve his patient’s heart function through medication before any lasting damage could occur. johnson did not suffer cardiotoxicity and her heart was functioning normally by the trial’s end.

“our findings suggest we should consider changing how we follow patients during cancer therapy and add gls to routine heart surveillance,” said thavendiranathan.

the recommendation will be heartening news for millions of patients who might be spared a second crisis not long after surviving the first. “this trial gave me hope and i’m thankful to say i’m now doing well and the cancer treatment worked,” sindhu said. “dr. thavendiranathan is an excellent physician and researcher and i’m very thankful to him.”

dave yasvinski is a writer with healthing.ca

if you or someone you care about is living with heart disease and stroke, connecting with a support network can help to not only learn ways to better manage their health, but also share experiences with others. some canadian resources include social and peer support at the heart and stroke foundation.