According to the American Heart Association, the number of deaths attributed to cardiovascular disease has declined 30.6% from 1998 to 2008. However, cardiovascular disease accounted for 32.8% of deaths in 2008, or 1 out of every 3 deaths in the United States.1
Risk factors, such as blood pressure and cholesterol levels, as well as other cardiovascular biomarker levels, can aid in determining those who are at risk for cardiac events. Unfortunately, these risk factors are not foolproof in predicting all cardiac events. Despite awareness and management of risk factors, it has been estimated that 43% of coronary events would still occur, and 40% to 50% of sudden cardiac deaths (SCD) occur before risk factors are able to predict cardiac events.2,3
Those who die suddenly with no so sign of cardiac disease often have silent cardiac target organ damage (cTOD). The presence of silent cTOD has been shown to increase the risk of cardiac events. Patients with silent ischemia, for example, are known to have a 21-fold increase in risk of a coronary event.4 It has also been shown that cTODs such as left ventricular hypertrophy (LVH), left ventricular systolic dysfunction (LVSD), left ventricular diastolic dysfunction (LVDD), and left atrial enlargement (LAE) each independently predict cardiovascular events. 5,6,7,8
Nadir et al. hypothesized that identification of silent cTOD would aid in the prevention of cardiovascular events, including SCDs.9 To identify cTOD present, The Nadir group evaluated several known cardiac biomarkers including: B-type natriuretic peptide (BNP), high-sensitivity cardiac troponin T (hs-cTnT), microalbuminuria, the estimated glomerular filtration rate, and uric acid The individuals were also screened using transthoracic echocardiography, stress echocardiography, and/or myocardial perfusion imaging.
Of the 300 asymptomatic individuals recruited for the study, 34% had evidence of a cTOD. Out of all biomarkers analyzed, BNP levels were significantly higher in those with cTOD compared with those without. BNP levels were also higher in those who had more than one form of cTOD compared with those who had a single form of cTOD. Hs-cTnT also performed well, but BNP levels had the highest correlation to imaging data.
To date, the gold standard diagnostic tool for cardiovascular disease is imaging studies, such as echocardiography. It is not standard practice to investigate healthy individuals for possible cTOD and would be costly and time consuming to perform imaging on these individuals. Biomarkers like BNP could be used as a primary screening tool with follow-up image studies performed, if necessary. The eventual hope is to reduce the mortality of cardiovascular diseases and prevent silent cTOD from leading to more serious and potentially life-threatening cardiac events.
1. Roger, V.L. (2012) ‘AHA statistical update: Heart disease and stroke statistics-2012 update. A report from the american heart association‘, Circulation, 125 (2012), (pp. e2-e220)
2. Chiuve, S.E., et al., (2006) ‘Healthy lifestyle factors in the primary prevention of coronary heart disease among men: Benefits among users and nonusers of lipid-lowering and antihypertensive medications‘ Circulation, 114 (2006), (pp. 160-167)
3.De Vreede-Swagemakers, J.J., et al. (1997) ‘Out-of-hospital cardiac arrest in the 1990s: A population-based study in the Maastricht area on incidence, characteristics and survival‘, Journal of the American College of Cardiology, 30 (1997), (pp. 1500-1505)
4. Rutter, M.K., et al. (2002) ‘Significance of silent ischemia and microalbuminuria in predicting coronary events in asymptomatic patients with type 2 diabetes‘, Journal of the American College of Cardiology, 40 (2002), (pp. 56-61)
5. Tsang, T.S., et al. (2003) ‘Prediction of risk for first age-related cardiovascular events in an elderly population: The incremental value of echocardiography‘, Journal of the American College of Cardiology, 42 (2003), (pp. 1199-1205)
6. Gosse, P., (2005) ‘Left ventricular hypertrophy—the problem and possible solutions‘,The Journal of International Medical Research, 33 (Suppl 1) (2005), (pp. 3A-11A)
7. Benjamin, E.J., et al. (1995) ‘Left atrial size and the risk of stroke and death‘ The Framingham Heart Study Circulation, 92 (4), (pp. 835-41)
8. Redfield, M.M., et al. (2003) ‘Burden of systolic and diastolic ventricular dysfunction in the community: Appreciating the scope of the heart failure epidemic‘, JAMA, 289 (2003), (pp. 194-202)
9. Nadir, M.A., et al., (2012) ‘Improving the primary prevention of cardiovascular events by using biomarkers to identify individuals with silent heart disease‘, Journal of American College of Cardiology, 60 (11), (pp. 960-968)