Heart Risks Found Without Lab Testing

06/04/08 Diagnosis

A new study shows that methods using non-laboratory-based risk factors can predict cardiovascular events, such as heart attack, stroke and angina as accurately as more costly laboratory-based tests.

These findings, if definitively proven, could have important implications for poorer countries where laboratory testing is hard to come by.

Researchers at Brigham and Women’s Hospital in Boston conducted a follow-up study on a population originally studied in the early 1970s. Of the original 14,407 participants, 6,186 people who did not report a history of heart problems including heart attack, stroke, angina, or cancer in the ‘70s were involved.

The lab-based method, which required blood tests, looked at age, systolic blood pressure, (the blood pressure when the heart contracts typically written as the first number in the reading), smoking status, total cholesterol, reported diabetes status, and current treatment, if any, for high blood pressure.

The non-lab method substituted body mass index (BMI) for cholesterol screening. BMI is the number calculated from a person’s weight and height used to screen for weight categories that may lead to health problems.

Of the 6,186 study participants, there were 1,529 first-time cardiovascular events and 578 deaths due to cardiovascular disease. Both the lab and non-lab method calculated a number called the c-statistic to assess cardiovascular risk prediction. The c-statistics determined by lab and non-lab methods were the same for men and women. In addition, the non-lab method classified people at the same rate as the lab method, indicating accuracy.

Study authors pointed out that the cost to developing nations to perform cholesterol tests on people at risk for developing cardiovascular disease could use more than 10 percent of the nation’s health care budget.

“The 10 percent figure refers to India and is hypothetical," says Thomas A. Gaziano, M.D., MSc, assistant professor, Harvard Medical School and the study’s lead author. “It assumes everyone would be tested and the current level of funding.”

Non-lab tests, study authors say, are effective at collecting the appropriate information to determine risk quickly in a non-invasive way. Using lab methods would require significant expenditures for a test that  may not be more effective than gathering other diagnostic or prognostic information. 

Mari S. Gold is has written for The New York Times, American Profile, Relish Magazine, TravelSmart, Indianapolis Monthly, and numerous e-zines. An avid cook and foodie, she contributes restaurant reviews to Zagat Guides and The Vermont News Guide, and is working on a young adult novel with a food theme. Married with grown children and two cats, she divides her time between New York City where she is director of communications for a major health care organization, and Dorset, Vermont.