Chicago ? Two new studies find shortfalls in the Food and Drug Administration’s approval process for heart devices such as pacemakers and stents.

Safety targets often weren’t clearly spelled out in the research submitted by device makers and important patient information was missing, according to one study conducted by researchers from the FDA and Boston’s Beth Israel Deaconess Medical Center.

A separate analysis by researchers at the University of California, San Francisco, found heart devices frequently got the FDA’s blessing based on research done outside the United States in small groups of patients. Many device studies lacked standards most scientists expect: randomization and a clear goal.

Dr. Jeffrey Shuren, the FDA’s acting device center director, said the agency is taking a close look at its device program and making changes. It wants manufacturers to adhere to tougher research guidelines that will be out in 2010, Shuren said.

The FDA, the nation’s chief watchdog on device safety, approves products ranging from wrinkle fillers to artificial knees. Heart devices fall into a category of high-risk devices that require the toughest review before they can be marketed. They include implantable defibrillators, valves and stents, which are tiny mesh-metal tubes used to prop open arteries.

The new studies, published in separate medical journals, cap a year of scrutiny and criticism for the FDA’s medical devices division. In August, the head of that division resigned, months after scientists under his leadership alleged they were pressured to approve certain products. The year began with congressional investigators saying the FDA should take immediate steps to make sure the riskiest devices are approved through the most stringent process.

The new studies didn’t examine the safety of the approved devices, and didn’t look for differences in the approval process for items that were later recalled.