Two Biomarkers Predict Increased Risk for Silent Strokes

Two biomarkers appear to indicate the risk for cerebrovascular and cardiovascular disease and other causes of mild brain damage that present with no symptoms.

High blood levels of the cardiac biomarkers troponin T and N-terminal brain natriuretic peptide (NT-proBNP) can be associated with the risk in the future of damaged brain tissue.

Medical scientists at the Methodist Hospital (Houston, TX, USA) analyzed the association of NT-proBNP and cardiac troponin T measured with a highly sensitive assay (hs-cTnT) from about 1,100 patient volunteers who agreed to have blood drawn. The participants also had two magnetic resonance imaging (MRI) scans 11 years apart as the scientists searched for silent brain infarcts and also white matter lesions (WMLs) caused by chronic inflammation.

The investigators found a strong relationship between high NT-proBNP and the likelihood of brain infarcts and WMLs. Study participants with the highest levels of NT-proBNP had as much as 3.5 times the number of brain infarcts as participants with low NT-proBNP levels, and more WMLs. Those with the highest levels of troponin T had as much as 3.0 times the number of brain infarcts and more WMLs.

The protein troponin T is part of the troponin complex and its presence is often used to diagnose recent heart attacks. NT-proBNP is an inactive peptide fragment left over from the production of brain natriuretic peptide (BNP), a small neuropeptide hormone that has been shown to have value in diagnosing recent and ongoing congestive heart failure. The authors concluded that early measurement of the cardiovascular biomarkers NT-proBNP and hs-cTnT followed by an MRI may also help in early detection of cerebrovascular disease before development of symptoms, at a time when interventions directed by a specialist may be beneficial for the prevention of cognitive decline.

Christie M. Ballantyne, MD, the principal investigator of the study from the Baylor College of Medicine (Houston, TX, USA) said, “The concept of prevention is expanding. It's not good enough to simply do a few tests and try to assess risk for heart attack. What we need to do is assess the risk for heart attack, stroke, heart failure, and also asymptomatic disease so we can start preventive efforts earlier. Waiting to correct problems until after a symptomatic stroke may be too late. The highly sensitive troponin T test we used is not approved for general clinical use in the USA yet, but the NT-proBNP test is just now starting to be used more widely beyond making a diagnosis for heart failure." The study was published online on May 9, 2013, in the journal Stroke.

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