Article: FDA Clears New Lab Test to Help Rule Out Heart Attack

The Food and Drug Administration (FDA) today cleared for marketing a new laboratory blood test that will significantly increase the ability of doctors to rule out a heart attack when a person shows up at an emergency room with severe chest pains.

The test is the first new blood test for evaluation of heart attacks since the introduction of the blood test for troponin, a protein present in the blood after a heart attack, in 1994.

The test, the Albumin Cobalt Binding (ACB) Test, manufactured by Ischemia Technologies, Inc., of Arvada Colo., works by measuring how much cobalt is bound to the blood protein albumin. Changes in the structure of albumin occur in several illnesses, including heart attacks.

The ACB test is not a stand-alone heart attack test but must be used together with an electrocardiogram (ECG) and a blood test for troponin. A normal ACB test with a normal ECG and normal troponin gives doctors increased confidence that patients can go home because they did not have a heart attack.

An estimated 3 million to 5 million Americans come to emergency rooms each year with symptoms of a heart attack. Only an estimated 22 percent actually have a heart attack. The rest have a variety of other ailments, such as severe indigestion, hiatal hernia, pneumonia, gallstones, and hepatitis.

With the ACB test, a cobalt solution is added to a blood sample. Results are read on a chemistry analyzer. In patients with a normal albumin, more cobalt is bound to the albumin, leaving less free cobalt to be detected by the test. In patients with abnormal albumin, less cobalt is bound to the albumin, leaving more free cobalt to be detected by the test.

FDA cleared the test based on results of a study conducted by the manufacturer of more than 200 patients at high risk of heart attack who had severe chest pain. Sixty three percent of the patients had heart attacks. The ACB test helped to correctly identify the patients who did not have heart attacks.

The study showed that when the ACB test was used together with an ECG and a troponin test, physicians were 70 percent accurate in ruling out heart attack. With an ECG and troponin test alone, physicians were 50 percent accurate in ruling out a heart attack.