Assessing Your Heart Attack and Stroke Risk

by Simeon Margolis, M.D., Ph.D.

The search for new ways to predict the likelihood that a person will have or die from a heart attack or stroke in the near future has become something of a cottage industry in biomedical research.

These efforts seem to have escalated into a wild scramble in the last decade, ever since the blood test for C-reactive protein (CRP) has been promoted as an almost magical "marker" or predictor of these dire events.

The barrage of scientific papers produced from this search for new markers has advanced many an academic career. Less desirable for consumers has been the need to pay for tests they may not really need.

A recent report from the Framingham Heart Study examined 10 such biomarker tests - 9 blood tests and one urine test - in more than 3,000 participants. Among the blood tests included were CRP, homocysteine, B-type natriuretic peptide, fibrinogen, and plasminogen-activator inhibitor. The urine test measured the ratio of albumin to creatinine. The participants were then followed for about seven years.

As you might expect, the presence of multiple markers was associated with a significant increase in a participant's risk of heart attack and stroke, and especially a greater risk of death during the follow-up period. B-type natriuretic peptide and the urinary albumin-to-creatinine ratio were the most effective individual markers to predict both the risk of cardiovascular events and death. Surprisingly, CRP predicted the risk of death, but not of cardiovascular events.

The most important finding from this study was that testing for these markers added "only moderately" to the information provided by the standard risk-factor tests - high LDL cholesterol, high blood pressure, cigarette smoking, low HDL cholesterol, diabetes, family history, and age - used to assess a person's risk of cardiovascular events.

These findings support the recommendation by most doctors that these markers be measured, if at all, only in those people who, after undergoing the standard risk-factor tests, are at intermediate risk for a heart attack or stroke. Some of the biomarker tests will continue to be widely used because most Americans fall into the intermediate-risk category.

Nonetheless, I think it is a good idea to ask your doctor why you have been told to obtain one or more of these tests, or to refrain from asking for these tests yourself unless your doctor believes your level of risk warrants them.