The study -- which was funded by Sutent's maker, Pfizer -- looked at 48 patients in a "real-world" setting who were taking the drug for either advanced kidney cancer or a gastrointestinal stromal tumor (GIST).
Fifteen percent of the patients experienced heart conditions such as symptomatic left ventricular dysfunction or heart failure while taking Sutent. The problems began between 22 days and 435 days after beginning therapy, although most started within the first three months of treatment.
The 15 percent incidence of heart trouble shown in this setting is almost double that seen in clinical trials, which had found that up to 8 percent of patients had experienced heart failure.
Heart failure involves a decline in the heart's ability to pump blood.
In this study, individuals with a history of heart failure, coronary artery disease or low body-mass index were at an even higher risk if they took Sutent, the researchers noted.
Three of five patients followed long term continued to have heart problems even after they stopped taking the drug.
Two recent studies, one published in January in the New England Journal of Medicine and another in December in The Lancet, also found that use of Sutent can boost patients' blood pressure and add to their risk of heart failure.
At the time of the release of The Lancet paper, Pfizer released a statement agreeing that these heart risks do exist. However, the company added that the cardiovascular events "were medically manageable in most patients and underscore the importance of having a collaborative team of health-care professionals working together to appropriately manage patients who have limited available options" in treating their cancer.
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