Photo courtesy of CDC
Doctor and patient
ORLANDO—Results of a retrospective study showed that survivors of lymphoma or breast cancer had a significantly greater risk of congestive heart failure (CHF) than patients who did not have cancer.
This increased risk was observed as early as a year after cancer diagnosis but was still present 20 years after diagnosis.
Overall, 1 in 10 cancer patients had CHF at the 20-year mark.
“The majority of patients do not develop heart failure, but our research helps us recognize the factors associated with it and the importance of appropriate heart care following cancer treatment,” said Carolyn Larsen, MD, of the Mayo Clinic in Rochester, Minnesota.
“Our research suggests that periodic cardiac imaging to monitor for heart damage may be needed for some cancer patients, even if they have no signs of heart damage initially after chemotherapy. Additionally, it emphasizes that working to live a heart-healthy lifestyle is important for cancer patients and survivors to reduce the overall risk of heart disease.”
Dr Larsen and her colleagues presented this research as a poster (abstract 1105-066) at the American College of Cardiology’s 67th Annual Scientific Session & Expo (ACC.18).
Patients
Using data from the Rochester Epidemiology Project, the researchers retrospectively tracked CHF cases in 900 cancer patients and 1550 non-cancer patients. Patients were treated in Olmsted County in Minnesota from 1985 to 2010.
For both patient groups, the median age at baseline was about 53, a little more than 90% of each group was white, and nearly 80% of each group was female.
Six to 7% of patients had diabetes, and about 30% of each group had hypertension. Thirty-eight percent of each group had hyperlipidemia, and 31% were obese.
Five percent of cancer patients and 2% of controls had coronary artery disease (P<0.001). This was the only significant difference in baseline characteristics.
Cancer patients had been diagnosed with non-Hodgkin lymphoma (28%), Hodgkin lymphoma (9%), or breast cancer (64%). Forty-seven percent had received radiation, including right chest (21%), left chest (23%), and mediastinal (4%).
Eighty-four percent of patients had received anthracycline therapy. The median doxorubicin isotoxic dose was 240 mg/m2.
At baseline, 12% of cancer patients were on beta-blockers, 8% were on angiotensin converting enzyme inhibitors, 4% were on angiotensin receptor blockers, and 11% were on statins.
Results
Cancer patients were more than 3 times as likely as controls to develop CHF. The hazard ratio (HR) was 3.6 (P<0.01) in an analysis adjusted for age, gender, diabetes, hypertension, coronary artery disease, dyslipidemia, and obesity at baseline.
The increased CHF risk among cancer patients was evident after the first year from cancer diagnosis and persisted at 20 years of follow-up.
“The risk of heart failure doesn’t go away after a couple of years,” Dr Larsen said. “It’s a long-term issue that patients need to discuss with their doctors and use as motivation to stay heart healthy.”
The incidence of CHF—in cancer patients and controls, respectively—was as follows:
- 1 year—1.5% vs 0.1%
- 5 years—3.1% vs 0.9%
- 10 years—5.0% vs 2%
- 20 years—10.1% vs 5.8%.
A multivariable analysis in the cancer patients revealed a few independent risk factors for CHF, including:
- Doxorubicin isotoxic dose ≥ 300 mg/m2 (HR=2.34, P=0.003)
- Age at diagnosis (HR=3.06 for age ≥ 80 vs 60-69, P=0.01)
- Coronary artery disease at diagnosis (HR=2.27, P=0.04)
- Diabetes mellitus at diagnosis (HR=2.39, P<0.01).
Dr Larsen said additional research is needed to determine why diabetes carries a greater risk than other traditional risk factors, such as high blood pressure, in this group.
Mitigating risk
These findings raise important questions about what the appropriate surveillance should be for heart problems post-cancer treatment, Dr Larsen said. She believes more frequent cardiac imaging may be warranted in some patients to detect signs of CHF earlier.
“It’s an area that needs to be better defined,” Dr Larsen said. “An echocardiogram is usually done 6 to 12 months after cancer treatment with an anthracycline, but how often should it be done after that? We need to be more vigilant in making sure we try to prevent or control heart issues post-cancer care, especially in light of the growing appreciation of the connection between some cancer treatments and heart disease.”
Dr Larsen also noted that patients themselves can play a role in decreasing their risk of CHF, even if they are starting at a disadvantage.
A heart-healthy lifestyle—maintaining a normal body weight, regular exercise, and controlling other risk factors such as high blood pressure, diabetes, and high cholesterol—can help lower the risk of heart disease and CHF.
“If patients know they have received a drug treatment that might increase their risk of heart failure, it’s even more important to take care of the aspects of their life that they can control to reduce their risk as much as possible and to work with their medical care team to detect issues as early as possible,” Dr Larsen said.