Cancer drugs wrapped in a fatty layer cause less heart damage than naked ones do, research in pigs finds. But the drugs, called anthracyclines, still harm the heart.
Patients treated with anthracyclines are 15 times as likely to experience heart failure — often years after treatment — and eight times as likely to die from it as people who have not received the drugs, says Mariann Gyöngyösi, a cardiologist at the Medical University of Vienna. She presented the researchin Vienna December 5 at EuroEcho-Imaging, the annual meeting of the European Association of Cardiovascular Imaging.
Doctors in Europe and Canada can give the anthracycline drug doxorubicin to patients in a form wrapped in a fatty layer designed to protect healthy tissue. This form of doxorubicin, called Myocet, is still experimental in the United States.
To determine whether Myocet is less damaging to the heart than standard doxorubicin, Gyöngyösi and colleagues gave pigs three doses of one form of the drug. About three months later, the researchers performed cardiac MRIs on the pigs and examined enzymes in the pigs’ blood that signal heart damage.
Compared with pigs that received naked doxorubicin, pigs given Myocet had less impairment in the ability of the two main chambers of the heart to pump blood. But all animals had evidence of myocardial fibrosis, a condition in which heart tissue becomes stiff and cannot contract properly.
Additionally, damage-related enzymes were high in all pigs’ blood, further indicating that both drugs harm the heart.