A major medical journal has published a notice of concern about data included in a paper that found benefits for an experimental stem-cell therapy in a small number of heart failure patients. The concerns were raised during an internal investigation at Brigham and Womens Hospital and Harvard Medical School that has already led to the retraction of another paper led by the same prominent and controversial cardiologist.

In an expression of concern posted online Thursday night and first reported by the blog Retraction Watch, editors of the British medical journal The Lancet said Harvard had notified them of an ongoing investigation that has raised questions about the integrity of certain data used in two figures in a 2011 paper overseen by Dr. Piero Anversa at the Brigham.

A notice of concern is issued when a journal learns of potential problems with a paper but is awaiting more information before deciding whether to correct or retract the study.

It alerts our readers to the fact the investigation is going on, a journal spokesperson said Friday.

The Harvard and Brigham investigation has already revealed compromised data in a 2012 paper in the journal Circulation, which described rapid turnover of cells in the heart and was also overseen by Anversa. That paper was retracted Tuesday.

Both papers examined the regenerative capacity of the heart, in an effort to harness cardiac stem cells to repair damaged or diseased heart muscle.

This notice of concern, coupled with the recent retraction, is extremely troubling because of the large number of clinical trials inspired by reports from this group, the many desperate patients potentially affected, and the large amount of federal and private money that has been diverted from other areas of promising research to pursue these ideas, Dr. Jonathan Epstein, a professor of cardiovascular research at the University of Pennsylvania Perelman School of Medicine, wrote in an e-mail.

Neither of the journals has been specific about who is at fault or what the nature of the problems are.

The focus of this investigation is on two supplemental figures published online, The Lancet said. As far as we are aware, the investigation is confined to the work completed at BWH.

Anversa has not responded to e-mail or voicemail messages.

More here:

Harvard investigation leads to expression of concern on Brigham-led stem cell research