MedicalResearch.com Interview with:
Lori Daniels, MD, MAS, FACC
Professor of Medicine
Director, Coronary Care Unit
UCSD Division of Cardiology
Sulpizio Cardiovascular Center
La Jolla, CA
Medical Research: What is the background for this study?
Dr. Daniels: A large number of individuals who are at risk for developing cardiovascular disease (CVD) may not be identified as “at risk” by traditional screening methods. Blood-based biomarkers provide a possible way, in conjunction with traditional risk factor screening, to assess risk in individuals. Two such biomarkers which are gaining widespread attention are NT-proBNP and cardiac troponin T (TnT). NT-proBNP is secreted by cardiac muscle cells in response to stretch, while TnT is consider a marker of cardiac cellular damage. Previous studies have shown that each of these markers is associated with long-term risk of cardiovascular outcomes in the general population. Race and ethnicity have been shown to affect the levels of these markers, and whether these markers are equally predictive of future cardiovascular risk in various ethnic groups has not been well studied.
The Multi-Ethnic Study of Atherosclerosis (MESA) is an NIH-funded, multicenter, prospective, population-based study of white, black, Hispanic, and Chinese individuals without clinical CVD at baseline. Participants had blood drawn at a baseline study visit in 2000-2002, and again several years later, in 2004-2005. They have been followed for the development of CVD since then.
The purpose of this study was to learn whether NT-proBNP (single and serial measures) and TnT are predictive of incident cardiovascular disease in a diverse cohort of 5592 participants from the MESA. We also wanted to learn whether the addition of these biomarkers to established CVD risk prediction scores, including the 2013 American College of Cardiology (ACC)/American Heart Association (AHA) Pooled Cohort Risk Equation and the Framingham Risk Score, could improve performance of the risk score.
Medical Research: What are the main findings?
Dr. Daniels: The main findings are that higher NT-proBNP and TnT levels were associated with an increased risk of coronary heart disease (CHD) and CVD events, above and beyond traditional risk factors.
NT-proBNP improved risk prediction and classification compared to the Framingham Risk Score and the Pooled Cohort Risk Equation. Change in NT-proBNP was independently associated with events. None of the observed associations varied by ethnicity.
Medical Research: What should clinicians and patients take away from your report?
Dr. Daniels: NT-proBNP and TnT are robust prognostic markers across various ethnicities. However, the relatively low prevalence of detectable TnT limits its clinical applicability for risk prediction in populations similar to this one. It is probably premature to change clinical practice based upon this study; whether these markers can meaningfully improve upon current methods of risk stratification for primary CVD prevention is not yet clear.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Daniels: The present study used a contemporary TnT assay, which was detectable in 1.5% of MESA participants at baseline. Highly sensitive cardiac troponin assays are now available (though not yet FDA-approved) which can detect troponin in the majority of apparently healthy individuals. Future studies evaluating highly sensitive cardiac troponin in MESA participants will be able to better inform us about the correlates and predictive value of cardiac troponin among various ethnic groups