Scientists call for controversial heart stem cell trial to be stopped

Clinicians and researchers have petitioned that a clinical trial for a stem-cell based treatment for heart disease be halted, as some of the results on which it was based have been called into question.

Thirty-one papers by Dr Piero Anversa and his teams have been recommended for retraction by two institutions where he was previously employed as a lab director. Harvard Medical School and the Brigham and Women's Hospital, both in Massachusetts, called for the retractions after evidence that the labs falsified or fabricated data was discovered.

Cardiologist Dr Darryl Davis at the University of Ottawa Heart Institute said: 'I think that the trial should be halted, and they should have an external review. The Anversa data comprised part of the rationale for that trial, and I think we have to understand better what these cells actually can do before we subject the patients to the risk of having an invasive procedure.'

The current trial, CONCERT-HF, aims to help patients with heart failure or who are recovering from heart attacks. It is partly based on Dr Anversa and his colleagues' published work that heart stem cells called 'c-kit' cells could be used to re-grow heart muscle. However, when other researchers attempted to repeat the experiments, they found that these cells were not turning into heart muscle, but rather died or fused with other cells. 

The CONCERT-HF trial is risky because it requires an invasive biopsy. Patients' heart and bone marrow cells are harvested and transformed into stem cells that are injected into their hearts. There are four groups in the study: those that receive c-kit cells, bone marrow-derived cells, those that receive both or those that receive a placebo. 

Not everyone agrees that the trial needs to be halted. Dr Denis Buxton, director of the Basic and Early Translational Research program at the National Heart, Lung and Blood Institute (which is collaborating on CONCERT-HF but was not involved with Dr Anversa's lab), said that there was a 'compelling need' for these patients.

'I think the feeling is this trial has the potential to provide such an option,' said Dr Buxton. 'Multiple preclinical studies have demonstrated improvement in cardiac function, and advanced heart failure patients really have no treatment options and have poor survival.' 

A board will review the trial and the information related to the retractions requested to make a recommendation to trial participants.