Mainly employed in emergency departments and outpatient cardiology clinics, this test measures the amount of troponin T in the blood of a person deemed at risk from myocardial infarction.
A regulatory protein involved in the contraction of skeletal and cardiac muscles, troponin T is released into the blood when the myocardium get injured by a heart attack or similar incident.
The amount of troponin T present in the blood corresponds to the injury sustained by the myocardium. Higher levels indicate greater damage to the muscle.
The fifth-generation troponin test features greater sensitivity. Older tests take three to six hours to detect heart attacks, but it only takes one hour.
"Critical diagnoses rely on the biomarker troponin, and over the past 15 years, improvements in the sensitivity of the test have increased our ability to detect heart issues faster," said Dr. Robert Fitzgerald of the University of California San Diego School of Medicine.
One of the new test's features are sex specific cutoffs to compensate for the lower troponin T baselines for women, improving its accuracy for female patients.
Approved for use in the U.S. in January 2017, the new test was adopted by hospitals such as the University of California San Diego Health (UC San Diego Health).
During the hospital's first two months of the new troponin test, cardiologists used it alongside the older version on patients for side-by-side comparisons.
"We saw a good number of cases where the results of the previous version showed normal results but the fifth generation showed abnormal results with some kind of cardiac issue going on," said Dr. Lori Daniels, a cardiologist at UC San Diego Health.
She cited faster decision-making, immediate administration of treatment, and earlier discharge of patients with normal levels of troponin T.
"With sensitive tests like the fifth generation of troponin, we can identify new disease states and why heart cells are dying," said Fitzgerald. (Related: Probiotics for your heart: Eat yogurt twice a week to reduce risk of heart attack in those with high blood pressure by up to 30%.)
The test has spotted heart attack in victims such as Mike Hammer, who entered the UC San Diego Health emergency room feeling inexplicably faint.
"I’m an avid cyclist and walk five to 15 miles a day, so you can imagine my shock when I found out I was facing a heart issue. It came out of the blue," said Hammer.
Hammer was subjected to several tests – but not the troponin test – to determine the problem with his heart.
"We wanted to rule out blockages in his coronary arteries," explained Dr. Daniels.
According to her, the standard blood tests cleared a heart attack. She and her colleagues recommended Hammer get a pacemaker. Despite the pacemaker, new symptoms appeared, forcing Hammer to return.
"A few days after the procedure, I started to feel pressure in my chest and shortness of breath. I was back in the hospital with questions," he related.
At that point, his cardiologists decided to use the troponin test. They drew blood from Hammer and analyzed his troponin T levels. The highest healthy level for men was 22. Hammer registered 41 on the test, which prompted an angiogram.
"His heart was compressing his coronary artery and he was having a heart attack. The new troponin test truly helped us put all the pieces of the puzzle together," said Dr. Daniels.
"It saved my life," agreed Hammer.
Learn more about your all-important heart at Heart.news.