The U.S. Food and Drug Administration does not believe there is sufficient evidence of symptom improvement to approve a new heart failure drug manufactured by the company Novartis AG.

"We recommend that serelaxin not be approved at this time because there is insufficient evidence to support the proposed indication to "improve the symptoms of acute heart failure through reduction of the rate of worsening of heart failure," the reviewers said, Reuters reported. "We did not identify any significant safety concerns precluding approval."

Acute heart failure is considered a medical emergency and occurs when the heart has trouble pumping blood around the body, Reuters reported. About five million people live with acute heart failure in the U.S. alone. One million are hospitalized for heart failure episodes every year and 22 percent of those patients die.

Novartis filed for drug approval after only one study; which suggested the medication could alleviate shortness of breath when taken along with other standard treatments and slows the progression of heart failure. The study showed the Novartis drug reduced instances of death by 37 percent when the results were compared with a control group.

The FDA said they usually require two separate trials to be conducted before a drug can be approved. They also said the drug failed to treat symptoms such as "cough, choking, fatigue and anxiety," Reuters reported.

"Therefore, the current evidence does not support a broad claim related to the symptoms of acute heart failure," the researchers said, Reuters reported. "[The trail results] do not provide persuasive evidence of an effect on dyspnea".

The review was posted on the FDAs website Tuesday; in the near future outside advisors will hold a meeting and make their own recommendations on the drug's approval.  The FDA will not be required  to follow this panel's advice, but will take it into serious consideration.