TY - JOUR
T1 - Coronary artery calcium improves risk classification in younger populations
AU - Paixao, Andre R M
AU - Ayers, Colby R.
AU - El Sabbagh, Abdallah
AU - Sanghavi, Monika
AU - Berry, Jarett D
AU - Rohatgi, Anand K
AU - Kumbhani, Dharam J
AU - McGuire, Darren K
AU - Das, Sandeep R
AU - de Lemos, James A
AU - Khera, Amit
N1 - Funding Information:
DHS participants were prospectively followed for fatal and nonfatal cardiovascular outcomes, and events were ascertained through December 31, 2010 (13) . Fatal events were tracked using the National Death Index (14) . Participants were contacted annually and assessed for interval nonfatal cardiovascular events. In addition, participants were tracked for hospital admissions using the Dallas Fort Worth Hospital Council Data Initiative database (DFWHC ERF Information Quality Services Center Regional Data [2000 to 2011]; Dallas-Fort Worth Hospital Council Education and Research Foundation, Information and Quality Services Center, Irving, Texas). This includes hospital admission data for 70 of 72 hospitals in the Dallas Fort Worth metroplex. Using these data sources, >90% of participants were followed for nonfatal events. Primary records were requested for all suspected cardiovascular events, and these events were separately adjudicated by 2 cardiologists blinded to CAC assessment and all study variables (13) . The outcome for the primary analysis was defined as the time–to–first event of the composite of CHD-related death, nonfatal MI, or percutaneous or surgical coronary revascularization. All revascularization events (coronary artery bypass graft surgery and percutaneous revascularization) occurring within the first 3 months following CAC scanning were excluded from the analyses to minimize the possibility that the CAC test result influenced the revascularization event. Secondary analyses were performed for the composite outcome of hard CHD (CHD-related death and MI).
Publisher Copyright:
© 2015 American College of Cardiology Foundation.
PY - 2015/11
Y1 - 2015/11
N2 - Objectives This study sought to assess the effect of coronary artery calcium (CAC) on coronary heart disease (CHD) risk prediction in a younger population. Background CAC measured by computed tomography improves CHD risk classification in older adults, but the effectiveness of CAC in younger populations has not been fully assessed. Methods In the DHS (Dallas Heart Study), a multiethnic probability-based population sample, traditional CHD risk factors and CAC were measured in participants without baseline cardiovascular disease or diabetes. Incident CHD - defined as CHD death, myocardial infarction, or coronary revascularization - was assessed over a median follow-up of 9.2 years. Predicted CHD risk was assessed with a Weibull model inclusive of traditional risk factors before and after the addition of CAC as ln(CAC + 1). Participants were divided into 3 10-year risk categories, <6%, 6% to <20%, and ≥20%, and the net reclassification improvement (NRI) was calculated. We also performed a random-effects meta-analysis of NRI from previous studies inclusive of older individuals. Results The analysis comprised 2,084 participants; mean age was 44.4 ± 9.0 years. CAC was independently associated with incident CHD (hazard ratio per SD: 1.90, 95% confidence interval [CI] 1.51 to 2.38; p < 0.001). The addition of CAC to the traditional risk factor model resulted in significant improvement in the C-statistic (delta = 0.03; p = 0.003). Among participants with CHD events, the addition of CAC resulted in net correct upward reclassification of 21%, and among those without CHD, a net correct downward reclassification of 0.5% (NRI: 0.216, p = 0.012). Results remained significant when the outcome was restricted to CHD death and myocardial infarction and when individuals with diabetes were included. The NRI observed in this study was similar to the pooled estimate from previous studies (0.200, 95% CI: 0.140 to 0.258) and the addition of our study to the meta-analysis did not result in significant heterogeneity (I2 = 0%). Conclusions CAC scoring also improves CHD risk classification in younger adults.
AB - Objectives This study sought to assess the effect of coronary artery calcium (CAC) on coronary heart disease (CHD) risk prediction in a younger population. Background CAC measured by computed tomography improves CHD risk classification in older adults, but the effectiveness of CAC in younger populations has not been fully assessed. Methods In the DHS (Dallas Heart Study), a multiethnic probability-based population sample, traditional CHD risk factors and CAC were measured in participants without baseline cardiovascular disease or diabetes. Incident CHD - defined as CHD death, myocardial infarction, or coronary revascularization - was assessed over a median follow-up of 9.2 years. Predicted CHD risk was assessed with a Weibull model inclusive of traditional risk factors before and after the addition of CAC as ln(CAC + 1). Participants were divided into 3 10-year risk categories, <6%, 6% to <20%, and ≥20%, and the net reclassification improvement (NRI) was calculated. We also performed a random-effects meta-analysis of NRI from previous studies inclusive of older individuals. Results The analysis comprised 2,084 participants; mean age was 44.4 ± 9.0 years. CAC was independently associated with incident CHD (hazard ratio per SD: 1.90, 95% confidence interval [CI] 1.51 to 2.38; p < 0.001). The addition of CAC to the traditional risk factor model resulted in significant improvement in the C-statistic (delta = 0.03; p = 0.003). Among participants with CHD events, the addition of CAC resulted in net correct upward reclassification of 21%, and among those without CHD, a net correct downward reclassification of 0.5% (NRI: 0.216, p = 0.012). Results remained significant when the outcome was restricted to CHD death and myocardial infarction and when individuals with diabetes were included. The NRI observed in this study was similar to the pooled estimate from previous studies (0.200, 95% CI: 0.140 to 0.258) and the addition of our study to the meta-analysis did not result in significant heterogeneity (I2 = 0%). Conclusions CAC scoring also improves CHD risk classification in younger adults.
KW - calcium score
KW - coronary heart disease
KW - net reclassification
KW - risk prediction
KW - risk stratification
UR - http://www.scopus.com/inward/record.url?scp=84946752875&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84946752875&partnerID=8YFLogxK
U2 - 10.1016/j.jcmg.2015.06.015
DO - 10.1016/j.jcmg.2015.06.015
M3 - Article
C2 - 26476504
AN - SCOPUS:84946752875
SN - 1936-878X
VL - 8
SP - 1285
EP - 1293
JO - JACC: Cardiovascular Imaging
JF - JACC: Cardiovascular Imaging
IS - 11
ER -