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KEY CONCEPTS
Myocardial dysfunction related to chemotherapy can be classified as type 1 or type 2. Type 1 is typically irreversible and associated with myocyte death. Anthracyclines are the prototype drugs that cause type 1 cardiotoxicity, and this can manifest months to years later. Thus, lifelong cardiac monitoring is recommended. Type 2 myocardial dysfunction is associated with reversible myocyte contractile dysfunction. Trastuzumab is the prototype drug causing type 2 dysfunction, but other targeted agents such as tyrosine kinase inhibitors (TKIs) can also cause type 2 cardiotoxicity. Trastuzumab can be reinitiated after recovery of left ventricular (LV) systolic dysfunction. Myocardial dysfunction is less common with TKIs than with trastuzumab, but LV dysfunction reverses in only about half of these patients.
Cancer can be associated with risks for cardiovascular ischemia beyond traditional risk factors. These risks include hypercoagulability associated with cancer, development of coronary or carotid vascular disease related to radiation therapy, tumor embolization, and arterial ischemia related to chemotherapies (L-asparaginase, cisplatin, 5-fluorouracil, capecitabine, and gemcitabine) and angiogenesis inhibitors (thalidomide and TKIs).
QT prolongation with risk of torsades de pointes is an important consideration in patients with cancer. Many cancer drugs prolong the QT interval, and this can be exacerbated by concomitant use of antiemetics, methadone, antibiotics, antifungal agents, antiviral agents, antiarrhythmic agents, and antipsychotics, and by electrolyte abnormalities. QT prolongation is particularly prominent with vandetanib, nilotinib, vemurafenib, and arsenic.
Pericardial effusions are common in patients with cancer. Two thirds of pericardial effusions are nonmalignant and related to loss of lymphatic drainage or certain drugs or infection or radiation. The 1-year survival rate is 55% in nonmalignant effusions and dismal, 16%, with malignant effusions.
Hypertension is commonly caused by angiogenesis inhibitors. Onset of hypertension is typically in days to weeks and usually returns to baseline after the vascular endothelial growth factor (VEGF) inhibitor is discontinued. It is not yet clear if hypertension can be considered a marker of response to therapy.
Atrial fibrillation is common in patients with cancer, particularly after thoracic surgery. It often requires pharmacotherapy for rate or rhythm control, and anticoagulation must be guided by the risk of bleeding versus the risk of thromboembolism.
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Oncocardiology is a fast-growing medical subspecialty focused on the management of heart diseases in patients with cancer. Although cancer remains a leading cause of morbidity and mortality worldwide, the survival rate of patients with cancer has increased in the last 25 years. In the United States, the 5-year relative survival rate of patients diagnosed with cancer between 1975 and 1977 was 50%. For patients diagnosed between 1999 and 2005, the survival rate increased to 68%. The U.S. National Cancer Institute estimates that at least 13.7 million cancer survivors were alive in the United States in 2012.1 More recent data show a continued decline in cancer-related death over the past three consecutive decades with a 27% decrease in cancer mortality between 1991 and 2016.2
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Although survival from cancer is ...