Blood test could help predict risk of death, heart problems

A new study out of Europe has found that a simple blood test targeting a molecule found in gut bacteria may be able to predict serious risk of heart problems and even death in patients who show up in the emergency room with chest pains.

The researchers involved in a study published this week in the European Heart Journal have found that measuring levels of a molecule known as trimethylamine N-oxide (TMAO), which is produced by gut bacteria from “components of red meat, eggs, and dairy products in blood,” could give emergency-room doctors a “quick and reliable” way of assessing the risk of major heart troubles or death in patients.

The study, led by Thomas Luscher, a professor of Cardiology at the University of Heart Centre in Zurich, Switzerland, showed that TMAO levels could predict risk not only in the short-term (the first 30 days after a visit to the hospital), but also risk of death in the longer term – up to seven years later.

Higher TMAO levels have already been shown to predict the risk of thrombosis (blood clots) in heart disease patients, but the new findings suggest they are a marker for predicting serious heart problems or death in healthy people who go to hospitals with possible heart problems such as angina or heart attack for the first time.

Researchers examined TMAO levels in the blood of 530 patients at a U.S. hospital, as well as more than 1,600 patients who had coronary angiography within five days of being admitted to one of four university hospitals in Switzerland.

Researchers followed up with the patients for several years, looking at whether a patient had developed blood vessel problems, heart attack, stroke or had undergone a procedure known as revascularisation. If the patient had died, they examined cause of death.

“We found that Cleveland patients with higher TMAO levels were more likely to experience major adverse cardiovascular event at 30 days, six months and seven years after their hospital admittance,” Luscher said in a statement announcing the study.

Luscher added that adjusting for age, smoke, diabetes and other risk factors, the findings showed that those with higher TMAO levels were six times more likely to die, suffer a heart attack or stroke at 30 days and at six months, and nearly twice as likely to die with seven years.

The findings suggest that patients may be able to reduce their risk by trying to reduce TMAO levels in two possible ways: changing their diet or developing new drugs that prevent TMAO from being produced in the body.

“TMAO offers a better understanding of the clinical impact that our daily diet has on the cardiovascular system, specifically in patients presenting with acute coronary syndrome,” co-author Dr. Slayman Obeid said in the statement. “This opens the way for new preventive measures, such as encouraging patients to switch from a diet rich in red meat, dairy products and eggs to a Mediterranean diet rich in green leafy vegetables and fibre.”

The researchers noted that TMAO testing is “quick and easy” to perform in a laboratory, and would only cost US$50-55 in a U.S. hospital.