Study: Excess weight-loss risks harming CRT-D heart failure patients

Ordinarily, of course, losing excess weight is often a good thing. But researchers are warning that some heart failure patients with CRT-D implants (cardiac resynchronization therapy with defibrillation) shouldn't necessarily shed those extra pounds. If they do, the scientists found in a massive study of nearly 1,000 patients, these folks could develop even worse heart failure or die.

That's another potentially difficult wrinkle for CRT-D makers such as Boston Scientific ($BSX), which funded the multi-center Madit-CRT trial. The results, presented at the American College of Cardiology's 62nd Annual Scientific Session in San Francisco, come as CRT-D sales are slumping in general due to regulatory problems and increased concerns about device overuse and safety. Added risks could contribute to usage decline.

Researchers at the University of Rochester Medical Center and elsewhere had expected excess weight loss to be beneficial, unplanned or not. But they were surprised to find the opposite appeared true, Valentina Kutyifa, a postdoctoral research associate there and the study's lead author, said in a statement.

She noted that heart failure patients with CRT-D devices who unexpectedly lost just 5 pounds faced elevated risks of "a serious cardiac event," suggesting that these patients need their doctors to monitor them closely. In particular, the study determined, heart failure patients with left bundle branch block faced double the risk of worsening heart failure or death.

Close to 1,000 patients took part in the study and they were examined a year after CRT-D implantation. Of those patients, 17% lost 4.4 pounds, and they experienced heightened risk of heart failure or death, though patients without major weight loss did not.

Kutyifa cautioned that researchers were not recommending that obese heart failure patients stay that way, because that can cause a litany of health problems in and of itself (sleep apnea and coronary artery disease, among other issues). But the research team noted that the finding also pointed to an "obesity paradox." What does this mean? It is where obese patients who have health problems ranging from heart disease to diabetes appear to be healthier than people who have the proper weight.

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