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Two Biomarkers Predict Increased Risk for “Silent” Strokes

Two biomarkers widely being investigated as predictors of heart and vascular disease appear to indicate risk for “silent” strokes and other causes of mild brain damage that present no symptoms, report researchers from The Methodist Hospital and several other institutions in an upcoming issue of Stroke (now online).

The researchers found high blood levels of troponin T and NT-proBNP were associated with as much as 3 and 3.5 times the amount of damaged brain tissue, respectively. The findings are part of the large-scale Atherosclerosis Risk in Communities (ARIC) study, funded by the National Heart, Lung, and Blood Institute.

“The concept of prevention is expanding,” said principal investigator Christie Ballantyne, M.D., director of the Center for Cardiovascular Disease Prevention at The Methodist Hospital. “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.”

One possible outcome is that patients determined to be in high-risk groups could be started on anti-stroke medications sooner.

In another ARIC paper published two months ago in Stroke, Ballantyne and coauthors reported a strong association between blood levels of troponin T and NT-proBNP and more severe instances of stroke, called symptomatic stroke. The current study looked at the two biomarkers and “subclinical,” asymptomatic events in the brain that are usually caused by a lack of blood flow.

“Taken together, these two papers show the biomarkers are effective at identifying people who are likely to have mild brain disease and stroke well before damage is done,” said Ballantyne, who also is a Baylor College of Medicine professor. “This hopefully will give doctors more time to help patients take corrective steps to protect their brains.”

For the subclinical brain disease study, researchers gleaned data from about 1,100 patient volunteers who agreed to have blood drawn and two MRI scans eleven years apart to look for silent brain infarcts and also white matter lesions (WMLs) caused by chronic inflammation.

Statistical analysis showed a strong relationship between high NTproBNP 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 natiuretic peptide (BNP), a small neuropeptide hormone that has been shown to have value in diagnosing recent and ongoing congestive heart failure.

“The highly sensitive troponin T test we used is not approved for general clinical use in the US yet, but the NT-proBNP test is just now starting to be used more widely beyond making a diagnosis for heart failure,” Ballantyne said.

The Center for Cardiovascular Disease Prevention is part of the Methodist DeBakey Heart & Vascular Center.

Also contributing to this study were Razvan Dadu, Salim Virani, Vijay Nambi, and Ron Hoogeveen (Baylor College of Medicine and Methodist Center for Cardiovascular Disease Prevention), Myriam Fornage and Eric Boerwinkle (University of Texas Health Sciences Center at Houston), Alvaro Alonso (University of Minnesota School of Public Health), Rebecca Gottesman (Johns Hopkins School of Medicine), and Thomas Mosley (University of Mississippi Medical Center). It was funded with grants from NHLBI and NIH, while Roche Applied Science helped fund the development of diagnostic technology.

Stroke is published by the American Heart Association and American Stroke Association.

Source: Cardiovascular Biomarkers and Subclinical Brain Disease in the Atherosclerosis Risk in Communities Study.

Source: Troponin T, N-terminal pro-B-type natriuretic peptide, and incidence of stroke: the atherosclerosis risk in communities study.

Source: The Methodist Hospital System

Clinical Advantages of Critical Diagnostics’ Cardiac Biomarker ST2 Featured In YouTube Video

Critical Diagnostics, makers of the Presage® ST2 Assay, recently announced that a six-minute videotape by Antoni Bayes-Genis, MD PhD., head of Cardiology Service at Hospital Germans Trias i Pujol, in Barcelona Spain discussing results of a study just completed on the use of biomarkers over conventional clinical assessments for risk stratification of heart failure patients has been posted on YouTube for immediate viewing.

The study followed 876 heart failure patients with a mean age of 70.3 years for a period of 40 months. During this follow up period, 311 patients died. Researchers compared 11 clinical variables, including age, sex, ischemic etiology of heart failure, left ventricular ejection fraction, New York Heart Association functional class, diabetes, renal function, beta blocker treatment, ace inhibitor treatment, sodium and hemoglobin biomarkers, which are routinely used to stratify heart failure risk against three biomarkers: NT-proBNP from Roche (OTC: RHHBY), high-sensitivity troponin T and Critical Diagnostics’ ST2.

The results from this recent study highlights the enduring clinical utility of ST2 despite being combined with the established and widely accepted cardiac biomarkers, like NTpro BNP, in medical practice. “The best results were obtained for ST2 and high-sensitivity troponin T,” notes Dr. Bayes-Genis, the primary investigator of the study. “Whenever we added NT-proBNP to these other two biomarkers, net reclassification improvement was reduced.”

Check out the video below.

“We are seeing strong adoption of ST2 by leading cardiologists who understand many of the limitations of utilizing natriuretic peptide markers like BNP and NT-proBNP in their practice,” states David Geliebter, CEO of Critical Diagnostics. “Natriuretic peptide markers certainly have their role in diagnosing heart failure, but fall short in guiding treatment of diseased patients. In study after study, ST2 has consistently demonstrated improved accuracy of patient prognosis over natriuretic peptide markers alone.

“Two of the biggest criticisms we hear about natriuretic peptide markers are that their levels don’t change or change too slowly, so their value as a serial marker for guiding treatment is questionable and, furthermore, that results are often skewed by other influencers such as age, gender, body mass index, atrial fibrillation, history of heart failure, anemia and impaired renal failure. By comparison, ST2 levels change rapidly in response to changes in the patient’s condition—sometimes within hours—thus helping physicians make informed decisions on an appropriate course of action to take and, if needed, to quickly adjust care, such as titrating medication. Moreover, unlike natriuretic peptide markers, ST2 levels are not adversely affected by the above-mentioned confounding factors.”

“Heart failure has become a growing public epidemic, with increasing incidence and prevalence,” Dr. Bayes-Genis stresses. “As a result, there is a need to understand risk factors and risk stratifiers, to better identify the patients that are going to have a better or a worse outcome. We now have a new generation of biomarkers, high-sensitivity troponin T and ST2, which are easily measurable in our routine practice, which provide additional information to stratify the prognosis of patients with heart failure.”

Source: Critical Diagnostics

A Simpler Way to Predict Heart Failure

The most widely used models for predicting heart failure rely on a complex combination of lifestyle, demographic, and cardiovascular risk factor information. But recently Vijay Nambi, M.D., Ph.D., and Christie Ballantyne, M.D., of The Methodist Hospital Center for Cardiovascular Disease Prevention and the Baylor College of Medicine presented new data that show two biomarkers can improve heart failure risk prediction as part of a simpler model. Their presentation was part of the American Heart Association’s Scientific Sessions 2012 in Los Angeles.

A Simpler Way to Predict Heart Failure

The most widely used models for predicting heart failure rely on a complex combination of lifestyle, demographic, and cardiovascular risk factor information.

New PLATO analysis evaluates the influence of high-sensitivity troponin biomarker status in NSTE-ACS patients managed with revascularization or medical management

AstraZeneca (NYSE: AZN) today announced results from a post-hoc analysis of a sub-group of the PLATO study. This new analysis evaluated outcomes in 9,946 patients with non–ST-elevation acute coronary syndrome (NSTE-ACS) managed with or without in-hospital revascularization in relation to measurements at randomization of high-sensitivity troponin-T (hs-TnT), a biomarker test that may be a more sensitive indicator of ongoing heart muscle damage than previously available troponin tests.