Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas.
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas.
JACC Cardiovasc Imaging. 2015 Nov;8(11):1285-93. doi: 10.1016/j.jcmg.2015.06.015. Epub 2015 Oct 14.
This study sought to assess the effect of coronary artery calcium (CAC) on coronary heart disease (CHD) risk prediction in a younger population.
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.
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.
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 (I(2) = 0%).
CAC scoring also improves CHD risk classification in younger adults.
本研究旨在评估冠状动脉钙（CAC）对年轻人群冠心病（CHD）风险预测的影响。
通过计算机断层扫描测量 CAC 可改善老年人的 CHD 风险分类，但 CAC 在年轻人群中的有效性尚未得到充分评估。
在 DHS（达拉斯心脏研究）中，我们对一个多民族基于概率的人群样本进行了研究，在没有基线心血管疾病或糖尿病的参与者中测量了传统的 CHD 危险因素和 CAC。通过中位数为 9.2 年的随访，评估了 CHD 事件（定义为 CHD 死亡、心肌梗死或冠状动脉血运重建）的发生情况。使用 Weibull 模型评估包括传统危险因素在内的预测 CHD 风险，在加入 CAC 后表示为 ln（CAC+1）。将参与者分为 3 个 10 年风险类别，<6%、6%~<20%和≥20%，并计算净重新分类改善（NRI）。我们还对包括老年人在内的先前研究的 NRI 进行了随机效应荟萃分析。
该分析共纳入 2084 名参与者，平均年龄为 44.4±9.0 岁。CAC 与 CHD 事件独立相关（每标准差的风险比：1.90，95%置信区间[CI]：1.51 至 2.38；p<0.001）。在传统危险因素模型中加入 CAC 可显著提高 C 统计量（差值=0.03；p=0.003）。在发生 CHD 事件的参与者中，加入 CAC 可使正确的向上重新分类增加 21%，而在没有 CHD 的参与者中，正确的向下重新分类减少 0.5%（NRI：0.216，p=0.012）。当将结局限制为 CHD 死亡和心肌梗死时，以及当纳入糖尿病患者时，结果仍然显著。本研究观察到的 NRI 与先前研究的汇总估计值相似（0.200，95%CI：0.140 至 0.258），将本研究纳入荟萃分析并未导致显著异质性（I²=0%）。
CAC 评分也可改善年轻成年人的 CHD 风险分类。
