According to a study presented today at EuroEcho-Imaging 2016.1, heart damage caused by chemotherapy is worse in patients suffering from diabetes. The study explored different cancer types and the impact they had on cardiovascular health in order to identify patients at a higher risk.
The researchers conducted their study using the Hospital Garcia de Orta’s surveillance program, operated by Cardiology, Oncology and Hematology departments.
The program is used to assess and monitor patients who are undergoing anthracycline-based chemotherapy. Clinical and ECG tests are conducted on the patients before, during and after chemotherapy even if they do not present any adverse symptoms.
These tests are conducted in order to minimize risk of heart disease and prevent heart attacks, by detecting any abnormal cardiovascular markers.
Cardiovascular disease is more significant in diabetes patients because diabetes patients suffer from high blood glucose levels due to decreased insulin production. This high levels of blood glucose can damage arteries, increase blood pressure, leading to medical complications such as heart disease and stroke.
Lead author Dr Ana Catarina Gomes, a cardiologist in training at the Hospital Garcia de Orta in Almada, Portugal, said regarding the findings, “Cardiotoxicity induced by chemotherapy with anthracyclines is being increasingly reported, mainly because a smaller proportion of patients now die from cancer. In the coming years this cardiotoxicity looks set to increase the burden of heart failure in cancer survivors.”
Dr Gomes and her team explored possible risk factors that could bring on such symptoms in patients who had undergone chemotherapy using anthracycline drugs. These drugs are commonly used in chemotherapy treatments to fight cancerous tumors.
The researchers recruited 83 patients, all of whom were already registered in the surveillance program. Out of these 83, 54 had breast cancer, 20 suffered from lymphoma, and 9 patients were diagnosed with gastric cancer.
Each patient’s demographic data and cardiovascular risk factors were collected. The cardiovascular risk factors included hypertension, diabetes mellitus, dyslipidaemia, and whether they smoked or not. Moreover, patients’ previous cardiovascular and non-cardiovascular diseases were also recorded and cumulative dose and type of anthracyclines they received as part of their chemotherapy.
Meanwhile, the ECG tests recorded data on heart chamber dimensions, systolic and diastolic functionality, ejection fraction (the amount of blood pumped in each heart contraction) and global longitudinal strain (for detecting subtle changes in left ventricle’s systolic function), before, during, and after the end of chemotherapy for each patient.
Using the changes in this ECG data from baseline to follow up, the scientists assessed the patient’s susceptibility for each cardiovascular risk factor while also weighing in the different types of cancer a patient had.
A total of 39 patients were treated with the drug doxorubicin while 44 patients received dose of epirubicin, all the cumulative doses were within safe ranges. Patients were 52 years old on average, minimum age was 39 and maximum age was 65 years.
78% of the participants were female. Approximately 31% of the patients suffered from hypertension, 16% had dyslipidemia (high cholesterol, high triglycerides or both), 7% had diabetes, and 16% were smokers.
Overall, the results showed that global longitudinal strain and left ventricular ejection fraction decreased continuously with time and both these functions had significantly reduced after chemotherapy compared to baseline.
Hypertensive patients showed a trend toward greater reductions in ejection fraction. Patients suffering from diabetes had an even significant decrease in global longitudinal strain during chemotherapy treatment, despite the baseline levels being similar to non-diabetics.
Whereas breast cancer patients had less severe cardiotoxic symptoms opposed to patients with lymphoma cancer or gastric cancer. After the first chemotherapy cycle had been completed, breast cancer patients had a slightly less decrease in ejection fraction and an improved diastolic function while in the middle of treatment they had better systolic function.
These difference in cardiovascular functions, before and during chemotherapy were irrespective of the cumulative dose of anthracyclines and was close in all cancer types.
According to Dr Gomes, global longitudinal strain reduction is an early predictor of heart disease. She further said that this decrease was more significant in patients suffering from diabetes. She believed that the toxic and hazardous nature of cancers themselves can have a drastic impact on cardiovascular health, and the level of impact could differ depending on the cancer type.
Cancer patients can minimize cardiovascular risk factors by changing their lifestyle, the most obvious being quitting smoking, exercising, eating a healthy diet, free of sugars and saturated fats. Certain medications could be needed as well to effectively cut down heart disease risk.
But, Dr Gomes added, that the treatment of cancer should be the first priority and should not be put on hold in fear of developing certain heart diseases. Delaying cancer treatment can further aggravate the cancer.
Cancer is one of those diseases in which early detection, diagnosis and treatment are crucial for positive outcomes. Cancer caught at an early stage minimizes the risk of excess tumor growth and minimizes the risk of cancer spreading to other organs of the body.
If the cancer spreads and affects other vital organs or if the tumor has become too big, treatment can become difficult and a person’s chances of survival become lower. Most cancer can also be diagnosed later due to an unrelated medical emergency.