Prognostic value of coronary electron-beam computed tomography for coronary heart disease events in asymptomatic populations

The predictive ability of electron-beam computed tomography (EBCT) for coro nary heart disease outcomes, particularly hard coronary outcomes (myocardia l infarction or death), has been questioned in asymptomatic populations. Ou r objective was to synthesize data on the use of EBCT for determining cardi ovascular prognosis in asymptomatic populations. Studies were identified us ing standard systematic review methods. The outcome of interest was relativ e risk for myocardial infarction or sudden death, and combined events inclu ding revascularization, Nine articles met the inclusion criteria, of which 5 were of independent studies. Using meta-analytic techniques to synthesize prognostic data, there was an increased risk (summary risk ratio 8.7, 95% confidence interval 2.7 to 28.1) of a combined outcome of nonfatal myocardi al infarction or death or revascularization if the calcium score was above a median score. Similarly, there was an increased risk for hard events: myo cardial infarction or death (summary risk ratio 4.2, 95% confidence interva l 1.6 to 11.3). However, there was significant heterogeneity in the studies ' quality and patient populations. Although EBCT appears to predict combine d and hard coronary outcomes similarly in high risk, asymptomatic populatio ns, these results should be interpreted with caution. Further study is need ed on the incremental value of EBCT over conventional risk prediction befor e this test is used in screening asymptomatic populations, (C) 2000 by Exce rpta Medica, Inc.