Acorn Cardiovascular Inc., a med-tech start-up in New Brighton, thinks it has developed a heart device that will be a novel way to improve the quality of life for people suffering from heart failure. But the high-profile consumer advocacy group Public Citizen expressed "deep concern" this week about whether the company's experimental device has been sufficiently reviewed by federal regulators.

"We are extremely concerned that the [Food and Drug Administration] may approve a device that a study has failed to demonstrate is safe or effective,'' said Dr. Peter Lurie, deputy director of Public Citizen's Health Research Group.

In an effort that has been closely watched in the medical-technology community, Acorn has been trying for the past four years to win FDA approval for its CorCap cardiac support device. The mesh device supports the heart, which often swells to three times its normal size as heart failure progresses.

Two advisory panels for the FDA have recommended against approval of the Acorn device after reviewing the company's application and holding public hearings. The agency itself has rejected the company's application three times. Acorn has even taken its case to a dispute resolution panel, a highly unusual move in the device world, which also voted against approval of its device.

Normally, a company in this situation would have abandoned the rather-expensive effort, especially a start-up like Acorn, which has no other products on the market.

But Acorn has been encouraged along the way by Dr. Daniel Schultz, a surgeon who is head of the FDA's device division, and the company subsequently reached an agreement with the agency to conduct a second, albeit smaller, clinical trial involving 50 patients. If that study is successful, the device could be approved by the agency without being first reviewed by an advisory committee and without a public hearing, according to Public Citizen.

In a Nov. 12 letter to Schultz, Public Citizen said the design of the new study "is so poor that it is unlikely to provide reliable data that would contradict the negative findings of the data so far submitted to the FDA." The number of patients enrolled in the study is too small, and they will not be followed for a sufficient amount of time, Lurie said.

But Acorn President Steve Anderson says the Public Citizen letter contains factual errors and quotes advisory panel members out of context. "The confirmatory trial referenced by Public Citizen was designed in close collaboration with FDA and included input from representatives of the advisory panels,'' he said, noting the company's initial clinical trial was one of the largest of its kind in FDA history.

FDA spokesman Scott McFarland said that the agency could not confirm that it had received a letter and, if it did, would respond directly to Public Citizen.

Washington-based Public Citizen has criticized Schultz in the past for overruling an advisory panel's recommendation in 2005 against approval of a pacemaker-like device to treat depression made by Houston-based Cyberonics Inc.

Janet Moore • 612-673-7752