Carnethon MR, Gulati M, Greenland P. Prevalence and cardiovascular disease correlates of low cardiorespiratory fitness in adolescents and adults. JAMA. 2005;294:2981 8. 124. Gupta S, Rohatgi A, Ayers CR, et al. Cardiorespiratory fitness and classification of risk of cardiovascular disease mortality. Circulation. 2011;123:1377 83. 125. Lauer MS. How will exercise capacity gain enough respect? Circu- lation. 2011;123:1364 6. 126. Mark DB, Hlatky MA, Harrell FE Jr, et al. Exercise treadmill score for predicting prognosis in coronary artery disease. Ann Intern Med. 1987; 106:793 800. 127. Mark DB, Shaw L, Harrell FE Jr, et al. Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease. N Engl J Med. 1991;325:849 53. 128. Cheezum MK, Hulten EA, Taylor AJ, et al. Cardiac CT angiography compared with myocardial perfusion stress testing on downstream resource utilization. J Cardiovasc Comput Tomogr. 2011;5:101 9. 129. Min JK, Shaw LJ, Berman DS, et al. Costs and clinical outcomes in individuals without known coronary artery disease undergoing coronary computed tomographic angiography from an analysis of Medicare category III transaction codes. Am J Cardiol. 2008;102: 672 8. 130. Min JK, Kang N, Shaw LJ, et al. Costs and clinical outcomes after coronary multidetector CT angiography in patients without known coronary artery disease: comparison to myocardial perfusion SPECT. Radiology. 2008;249:62 70. 131. Fazel R, Shaw LJ. Radiation exposure from radionuclide myocardial perfusion imaging: concerns and solutions. J Nucl Cardiol. 2011;18: 562 5. 132. Garber AM, Solomon NA. Cost-effectiveness of alternative test strategies for the diagnosis of coronary artery disease. Ann Intern Med. 1999;130:719 28. 133. Kuntz KM, Fleischmann KE, Hunink MG, et al. Cost-effectiveness of diagnostic strategies for patients with chest pain. Ann Intern Med. 1999;130:709 18. 134. Lorenzoni R, Cortigiani L, Magnani M, et al. 