MELBOURNE – Specialist cardio-oncology clinics may be needed to address the long-term cardiac care of cancer patients treated with cardiotoxic chemotherapy regimens such as anthracyclines and trastuzumab, presenters told the World Congress of Cardiology 2014.
Dr. Puja K. Mehta, codirector of the cardio-oncology program at the Barbra Streisand Women’s Heart Center, presented poster data showing that 12% of women who attended the clinic over a 7-month period had a previous diagnosis of cancer, nearly half of which were cases of breast cancer.
Dr. Puja K. Mehta
The study of 892 patients seen at the center found that 92% of all breast cancer survivors had at least one cardiac risk factor – 55% had hypertension, 64% had hyperlipidemia, 14% had diabetes, 18% coronary artery disease, and 23% ischemic heart disease.
There is growing awareness of the long-term sequelae of cardiotoxic chemotherapy regimens but the challenge was how to take a preventive approach to the problem, Dr. Mehta said at the meeting sponsored by the World Heart Federation.
"People who have had a history of breast cancer ... often they’re only seeing oncologists to follow up on breast cancer recurrence so they are getting yearly mammograms and those things, but what they’ve missed is a little bit of hypertension that’s been there for years and then you get the accelerated atherosclerosis," Dr. Mehta said in an interview with Cardiology News.
The study’s authors suggest that cardio-oncology clinics could play an important role in implementing lifestyle modification and preventive interventions to reduce the risk of cardiac sequelae in cancer survivors.
In another presentation, American Heart Association President Mariell Jessup, Medical Director of the Penn Heart and Vascular Center, said early-onset cardiotoxicity occurs in a relatively small percent of patients – around 1%-2% – within the first year after chemotherapy treatment.
However late-onset cardiotoxicity was far more insidious as it affected a wide range of patients and the signs may not manifest until long after chemotherapy.
"We used to be taught that it came within the first year or so, and so when someone showed up 10 years or 15 years from treatment we discounted the fact that it was cardiotoxicity from anthracycline," Dr. Jessup told Cardiology News.
Dr. Mariell Jessup
Dr. Jessup said an estimated 20%-30% of patients who had been treated with anthracyclines would likely show some kind of cardiac problems, but the addition of trastuzumab to breast cancer chemotherapy further increased the risk.
"They can present with heart failure ... but if they have radiotherapy on top of chemotherapy they are more susceptible to proximal coronary disease," she said.
"Then we’re seeing a group of patients that end up at cardiac transplant because of their heart failure, and they have very fragile bone marrows so they don’t tolerate immunosuppression as well, and they tend to be very anemic."
Dr. Jessup told the conference that more research was critical to understand the mechanisms of anthracycline cardiotoxicity, and to identify predictive markers of cardiac damage, but she stressed clinician awareness was also fundamental.
"We need to educate clinicians about not only the importance of these chemotherapeutic agents to the survival of patients following their cancer but how to be particularly attuned to the possibility that exposure many years before can lead to cardiac toxicity."
A member of the audience raised the question about treating patients with angiotensin-converting enzyme inhibitors at the same time as their chemotherapy to reduce the cardiac impact of the chemotherapy.
Dr. Jessup said while there were some intriguing data emerging about the concurrent use of ACE inhibitors and beta-blockers in patients treated with anthracyclines, there still remained questions about when the drugs should be used as they may not be well tolerated during chemotherapy.
Dr. Jessup had no disclosures. Dr. Mehta declared grant/research support from Gilead, and a coauthor declared grant/research support from Gilead and consultancies and honoraria from a range of organizations.