The practice of medicine continues to be challenged by the rapid evolution of technology. That’s especially difficult when physicians lack strong evidence or must make decisions amid conflicting findings.
Two articles in this issue highlight this discord. Our cover story addresses what might appear to be a cruel twist of fate. As more patients survive cancers, subtle injuries to the heart and elsewhere resulting from lifesaving radiation therapy and chemotherapy manifest into cardiovascular diseases many years after treatment. In another story, we look at digoxin, which has been used to treat heart failure for decades.
Next to cancer, cardiovascular disease ranks as the leading killer for survivors of childhood cancers and breast cancer. Together, those patients add up to about 3 million people in the U.S. That is just two patient populations. There are many more types of cancer, and many more established and newly developed drugs on the market.
Our article focuses on anthracyclines, but cardio-oncologists emphasize that newer drugs may prove cardiotoxic as well. Their pathways may be similar to anthracyclines, which cause cardiomyocyte cell death that can lead to cardiomyopathy and heart failure. But just as many types of cancer drugs attack cancer cells in different ways, so might they interact with the cardiovascular system differently.
Cardio-oncologists have been raising awareness of this growing patient population. But without clinical trials to inform guidelines, they can’t say with certainty when, how or how often they should monitor patients.
Digoxin, on the other hand, has the advantage of being tested in a large, randomized clinical trial and the Digitalis Investigation Group (DIG) data still provide a resource for studies. The original results pertain to a different era in patient care, some physicians argue, and options now exist that may be superior.
Digoxin’s challengers offer data from studies where patients were not randomized to receive digoxin or placebo. This puts practitioners in a bind. Do they go with evidence from DIG, which may be out of step with contemporary practice, or do they choose current evidence that doesn’t meet the standards of a randomized trial?
How do you reconcile these issues? Please let us know.