Cardio-oncology or Onco-cardiology? Take your Pick

Oct 15, 2018

Either one is fine – the point is to make sure the practice stays a step ahead of the next new drug class causing the problem.

The introduction to an article I read recently sums up a new reality: “Current oncologic treatments have brought a strong reduction in mortality in cancer patients. However, the cancer-therapy related cardiovascular complications, in particular chemotherapy and radiation therapy-induced cardiotoxicities, are a major cause of morbidity mortality in people living with or surviving cancer.”1 Some of the culprits-anthracyclines, HER2-targeted therapy for breast cancer, and tyrosine kinase inhibitors-have been around a while.1 A more recent addition to the chemotherapy armamentarium for cancer-the immune checkpoint inhibitors (ICIs)-deserve extra attention from the cardiology community.2 These agents are undergoing an extensive marketing push through television advertising.

The ICIs amplify T-cell mediated immune responses against cancer cells.2 Clinical trials have demonstrated positive results against advanced melanoma, non-small cell lung cancer, renal cell carcinoma, head and neck cancer, urothelial cancer, and Hodgkin disease.2 That said, the cardiovascular complications can be severe. Eighteen cases of myocarditis occurred among 20 594 individuals treated with ICIs; incidence was higher in patients receiving 2 ICIs simultaneously.2 The even more worrisome statistic is that 50% of the patients with myocarditis died.2  Myasthenia gravis accompanied myocarditis in some of these patients.2

The continuum of cardiac danger does not end there. Pericarditis, with or without myocarditis, is also a complication of ICI therapy.2 The pericardial inflammation has led to tamponade physiology. Left ventricular fibrosis and failure have been described as has Takotsubo syndrome.2 Arrhythmias were common with ICI treatment including atrial fibrillation, ventricular tachycardia or fibrillation, and heart block. A database for cardiovascular complications reported with ICIs suggests that toxic effects on the heart seem to be increasing.2

Investigation into the mechanism underlying these cardiovascular toxicities is ongoing but there is still little evidence-based guidance for monitoring and managing such patients. Should cardiovascular disease be treated in a cancer survivor as it is in patients with chronic diseases such as diabetes and hypertension?1 Not always. Even though the interdisciplinary area of cardio-oncology has continued to grow more sophisticated over the past 20 years,1 the chemotherapies and their collateral damage have as well. We need to match pace with our vigilance.

References:

1. Han X, Zhou Y, Liu W. Precision cardio-oncology: understanding the cardiotoxicity of cancer therapy.  NPJ Precis Oncol. 2017;1:31. doi: 10.1038/s41698-017-0034-x. eCollection 2017
2. Lyon AR, Yousaf N, Battisti NML, Moslehi J, Larkin J. Immune checkpoint inhibitors and cardiovascular toxicity. Lancet Oncol. 2018;19:PE447-E458.