by Dianne Armitage
Anyone who has had breast cancer is probably all too familiar with the one-in-eight mantra, concerning the likelihood of developing the disease during our lifetime. As survivors, it is of the utmost importance that we also realize nearly twice as many women in the United States die of heart disease, stroke and other cardiovascular diseases as from all forms of cancer, including breast cancer.
Since the side effects of some forms of chemotherapy and radiation may include an increased risk of heart disease, especially weakening of the heart muscle (cardiomyopathy), what better month than February, when our thoughts turn to hearts, flowers and, by all means don’t forget the chocolates, to explore both our risks and some of the possible preventatives we can put into play.
Diligence during treatment
Because certain chemotherapy drugs can damage the heart, before beginning any treatment, you will want to thoroughly discuss this topic with your doctors so you know your risks.
The drugs most commonly associated with potential heart problems are the anthracyclines (which include Daunorubicin, Doxorubicin, Epirubicin, Idarubicin, Mitoxantrone, and Valrubicin), but other drugs may cause heart damage, too. This complication occurs in about 1 in 10 people who receive these drugs and usually involves damage to the heart muscles.
Certain types of chemotherapy also increase the risk of heart attack, especially during infusion. Some newer anti-cancer treatments, such as Trastuzumab (Herceptin) may cause heart damage as well, although the effect is often temporary and reversible. Fortunately, heart disease associated with chemotherapy is relatively rare.
For women undergoing radiation therapy, if the area of your body receiving radiation includes your heart, you have an increased risk of cardiomyopathy, coronary artery disease and heart attack. The combination of radiation and chemotherapy can further increase your risk of heart damage. (Read more about recent studies on radiation in Breast Cancer Breakthroughs.) This is an important topic you will want to thoroughly discuss with your doctor so steps can be taken to reduce these risks as much as possible.
Whenever a doctor is considering using a chemotherapy drug that could potentially cause heart damage, they should definitely check your heart function to make sure there are no major problems. Your heart function should also be checked during treatment to ensure that no unhealthy changes have occurred.
Tests such as an electrocardiogram (EKG), an echocardiogram, or a MUGA scan are done to check for any changes in heart function. An electrocardiogram records the heart's electrical impulses, while an echocardiogram is an ultrasound of the heart. With a MUGA scan, you are given a radioactive substance that a special scanner traces through your heart to tell how well your heart is pumping. If problems develop, the chemotherapy drug will be stopped to prevent further permanent damage.
If the heart is damaged by chemotherapy, it may not be able to pump blood through the body as well as it did before treatment. This can lead to fluid build-up and other problems known as congestive heart failure.
Would you recognize the symptoms? Any of the following are reason to contact your doctor:
- Puffiness or swelling in the hands and feet (fluid retention)
- Shortness of breath that gets worse with exercise or lying flat
- Dizziness
- Erratic heartbeat
- Dry cough
Hope may be on the horizon
Is there any way to prevent this problem? One cardiologist and his cancer doctor colleague in Minnesota believe they may have have found a solution. Cardiologist Dr. Steven Heifetz has partnered with Dr. Barbara Bowers, an oncologist at Fairview Southdale Breast Center, in an effort to find a way to prevent the heart damage caused by chemotherapy.
Heifetz found a handful of studies that reported success using a beta blocker called Carvedilol. Beta blockers slow down the heart and lower blood pressure. Carvedilol, in particular, has antioxidant properties, and as Heifetz points out, heart damage caused by chemotherapy drugs is often due to oxidation.
Since those results were preliminary, Heifetz knew that it wasn't wise to read too much into them, but he also felt there was little risk in trying Carvedilol on patients during their chemotherapy treatments. The drug's side effects are minimal and it's an affordable, generic medication (a six-month supply runs about $20.00).
Together, Bowers and Heifetz, both University of Minnesota physicians, created an onco-cardiology clinic, where Bowers treats the patients' cancer and Heifetz's team tracks their heart function.
Since they began working together more than three years ago, none of their more than 50 patients has shown any signs of cardiac damage. Dr. Bowers says typically by this point, a small percentage of her patients would have already developed heart failure. She is cautiously optimistic, but says she will feel more confident in their findings when the patients are five or 10 years out and still show no signs of heart damage.
Harvard University recently announced that it will open a new cardio-oncology program to address the heart-related side effects of cancer therapies. A program of that scale will be able to generate more meaningful data on the effectiveness of drugs like Carvedilol.
On another front, Dr. Julie Taguchi, an Oncologist at Sansum Clinic in Santa Barbara feels that Coenzyme Q10 (CoQ10) may also afford some protection for women undergoing chemotherapies that compromise heart function. It is believed that CoQ10 helps to maintain a healthy cardiovascular system, and there is evidence of CoQ10 deficiency in heart failure. Recently, CoQ10 plasma concentrations have been demonstrated as an independent predictor of mortality in chronic heart failure, with a deficiency being detrimental to the long-term prognosis.
It’s your body, treat it well
Regardless of whether or not you have been exposed to drugs during treatment that can compromise your heart, simply living and aging are also factors. There is much you can do to keep your heart healthier. The American Heart Association has very clear guidelines about some of the ways this can be accomplished:
And now for some good (tasting) news
We’ve touched on many ways in which you can protect your heart, but we’d be remiss if we didn’t mention chocolate. It is February, after all, so we know you will be looking for a heart-healthy Valentine. Right? Right!
You’re going to love this. Chocolate is derived from plants, which means it contains many of the health benefits of dark vegetables. These benefits are from flavonoids (let’s hear it for Vitamin P), which act as antioxidants. Among other things, antioxidants protect the body from free radicals, which can cause damage that leads to heart disease.
Dark chocolate contains nearly eight times the number of flavonoids found in strawberries (let’s hear it for dark chocolate-dipped strawberries)! Flavonoids help relax blood pressure and balance certain hormones in the body. Dark chocolate has also been shown to reduce LDL cholesterol (the bad cholesterol) by up to 10 percent.
But that’s not all. Dark chocolate stimulates endorphin production, which has been shown to produce a feeling of pleasure. It also contains serotonin, which many believe acts as an anti-depressant.
Not all chocolate is created equal. Dark chocolate contains a lot more cocoa than other forms of chocolate, and this doesn’t mean you can select varieties with nougat, caramel or other fillings. They only add sugar and fat that erases any benefit you derive from the chocolate. And, unfortunately, milk chocolate has not been shown to have any of the health benefits associated with the darker, flavanoid-rich variety. Luckily, chocolate companies have now learned to make dark chocolate that maintains flavonoid levels at 95% and are adding those to their production lines.
Looking for a heart healthy exercise? How about putting on your walking shoes and hightailing it to the nearest candy store to purchase a small portion of quality dark chocolate? This seems like the perfect personal Valentine gift – and you can savor the flavor on the walk home!