In early April of 2020, Lori Chen felt a lump in her breast while she was in the shower. The Toronto-based pharmacist was 36 years old and had a two-and-a-half-year-old son, and it was early in the pandemic, when much of the world was in lockdown.
She cried for days.
Lori decided to focus on her family and the things that were within her control. She started chemotherapy, underwent a mastectomy and began to feel that her life would soon return to some semblance of normal.
That was until an echocardiogram in October 2020 revealed that she was in imminent danger of heart failure.
Lori, who had no symptoms of heart disease, says this new diagnosis was even scarier than discovering she had breast cancer.
"When I thought of heart failure, I pictured my grandmother who had swollen ankles and trouble walking up stairs," she says. "I didn't have anything like that. I was in shock."
Lori had always known that her cancer treatment could affect her heart, but now she was facing the reality of that risk.
A toll on the heart
Cancer treatment–related cardiotoxicity is damage to the cardiovascular system caused by otherwise life-saving approaches to combat the disease.
"Surgery, radiation therapy, chemotherapy, targeted therapy, immunotherapy — all of these are related to some form of cardiovascular toxicity," says Dr. Dinesh Thavendiranathan, an international expert in the field of cardio-oncology and part of the team that cared for Lori at UHN's Peter Munk Cardiac Centre, home to the largest cardiotoxicity clinical program in Canada.
Treatment aside, many cancer patients are also at a higher risk of developing cardiovascular disease due to shared risk factors, such as smoking, obesity and inflammation, he says. Cardiotoxicity can manifest as high blood pressure, valve problems, inflammation and damaged blood vessels.
If left untreated, it can lead to heart failure. But the outcomes are good when patients are identified early, Dr. Thavendiranathan says.
The research he led has helped his team develop screening strategies, including new biomarkers, 3-D echocardiography, myocardial strain imaging and cardiac MRI methods.
"We have screening strategies. We have solutions," Dr. Thavendiranathan says. "We have cardiologists with expertise in this. And we know that cardiotoxicity can be treated."
Early detection and quick diagnosis
Awareness, on the part of both doctors and patients, is crucial because symptoms of heart damage, from severe fatigue and shortness of breath to heart palpitations, are also side effects of cancer treatment that can easily be missed.
And there are also patients such as Lori, who are asymptomatic. Fortunately, she was being closely monitored and her failing heart function was discovered during an echocardiogram.
Lori's oncologist immediately referred her to Dr. Thavendiranathan.
"Surveillance, early detection and long-term follow-up with cancer patients allows us to pick up subtle changes to the heart so that we can intervene," Dr. Thavendiranathan says.
In the past, when cancer patients were diagnosed with heart damage, their cancer therapies would simply be stopped.
"There's nothing more devastating than that," he says. "As a cardio-oncologist, it's about understanding both the oncology and the cardiology components and providing a balanced consultation, so that you're not just saying 'stop the cancer therapy.'"
Passionate care and treatment
Dr. Thavendiranathan and his team started Lori on cardiac therapy, introducing medications to reduce the strain on her heart.
"We were able to continue the heart medications while she received the rest of her cancer treatment, so there was no interruption to her treatment at all," he says. "Her heart function improved and she recovered nicely."
Dr. Thavendiranathan also supported Lori with relaxation techniques and an exercise plan.
"The exercise piece is important because during cancer therapy, patients often feel as though they have no control over anything," he says. "The one thing they can control that can improve their cardiovascular outcomes is exercise."
While most cancer centres might have a single cardiologist on staff, the Peter Munk Cardiac Centre is unique in that it's a non-cancer centre with five cardiologists dedicated to cardio-oncology patients. The centre trains more cardiologists, cardiovascular surgeons and vascular surgeons than any other hospital in Canada.
Specialized cardiac care continues long after a patient's cancer treatment has ended. In Lori's case, that included monitoring throughout a post-cancer pregnancy.
Pregnancy complications
Before her breast cancer diagnosis, Lori had been trying to get pregnant. She was able to freeze some of her eggs before starting chemotherapy, but her IVF treatment was unsuccessful.
Lori had almost resigned herself to the fact that she would have only one child when she discovered she was pregnant in July 2022. Although she was excited, Lori worried that her heart might not be able to handle it.
"If a patient develops cardiotoxicity and then becomes pregnant, her risk of developing heart failure is about one in three," Dr. Thavendiranathan says. "We instituted a surveillance program, which included conducting an echocardiogram each trimester."
Fortunately, Lori's heart function remained stable and her son, Theodore, was delivered safely in March 2023.
"Throughout my pregnancy I didn't feel as though I could celebrate until the baby was actually born," she says. "It was an amazing moment of 'he's here!' I had been focused on this goal for so long and it was just super exciting."
Successful outcomes
Lori credits the entire team at the Peter Munk Cardiac Centre for getting her through every anxious moment, from diagnosis to delivery room.
"It's human nature to jump to the worst-case scenario when you get a diagnosis like cancer or heart failure," she says. "It's helpful to feel that you're not all alone trying to figure it out, knowing that you have people who are experts in their field, who are compassionate, who pay attention, who don't rush you. I felt incredibly supported."
Normally, Lori would have continued taking heart medications for the rest of her life. But, last summer, Dr. Thavendiranathan approached her about joining a clinical trial to determine whether patients like her could withdraw their heart-failure therapy once they'd recovered their heart function.
"I wanted to help, so I chose to participate," she says.
In addition to being a clinician, Dr. Thavendiranathan is at the forefront of much of the research conducted in the Ted Rogers Cardiotoxicity Prevention Research Program at UHN's Peter Munk Cardiac Centre and Ted Rogers Centre for Heart Research.
Its research is largely funded by donors who are as inspired by the possibility of innovation and medical breakthroughs as Dr. Thavendiranathan himself. He and his team recently identified three biomarkers linked to heart dysfunction in the blood of breast cancer patients that could help in the future development of targeted therapies.
Data collected from patients at the Peter Munk Cardiac Centre over the last decade also shows the lasting impact of its specialized care.
"It's encouraging to see that with careful surveillance and treatment, we can prevent the development of future heart failure so that when patients have completed their cancer therapy, they can lead a wholesome life," Dr. Thavendiranathan says.
People shouldn't have to live every day thinking about their cancer because they've been left with cardiovascular disease, he says.
"To have been able to prevent the worst outcomes of Lori's heart failure so that she can continue on with her work, take care of her children and have a good quality of life — that's tremendously satisfying."
