Importance The diagnostic value is unclear of a 0 coronary artery calcium (CAC) score to rule out obstructive coronary artery disease (CAD) and near-term clinical events across different age groups.

Objective To assess the diagnostic value of a CAC score of 0 for reducing the likelihood of obstructive CAD and to assess the implications of such a CAC score and obstructive CAD across different age groups.

Design, Setting, and Participants This cohort study obtained data from the Western Denmark Heart Registry and had a median follow-up time of 4.3 years. Included patients were aged 18 years or older who underwent computed tomography angiography (CTA) between January 1, 2008, and December 31, 2017, because of symptoms that were suggestive of CAD. Data analysis was performed from April 5 to July 7, 2021.

Exposures Obstructive CAD, which was defined as 50% or more luminal stenosis.

Main Outcomes and Measures Proportion of individuals with obstructive CAD who had a CAC score of 0. Risk-adjusted diagnostic likelihood ratios were used to assess the diagnostic value of a CAC score of 0 for reducing the likelihood of obstructive CAD beyond clinical variables. Risk factors associated with myocardial infarction and death were estimated.

Results A total of 23 759 symptomatic patients, of whom 12 771 (54%) had a CAC score of 0, were included. This cohort had a median (IQR) age of 58 (49-65) years and was primarily composed of women (13 160 [55%]). Overall, the prevalence of obstructive CAD was relatively low across all age groups, ranging from 3% (39 of 1278 patients) in those who were younger than 40 years to 8% (52 of 619) among those who were 70 years or older. In patients with obstructive CAD, 14% (725 of 5043) had a CAC score of 0, and the prevalence varied across age groups from 58% (39 of 68) among those who were younger than 40 years, 34% (192 of 562) among those aged 40 to 49 years, 18% (268 of 1486) among those aged 50 to 59 years, 9% (174 of 1963) among those aged 60 to 69 years, to 5% (52 of 964) among those who were 70 years or older. The added diagnostic value of a CAC score of 0 decreased at a younger age, with a risk factor–adjusted diagnostic likelihood ratio of a CAC score of 0 ranging from 0.68 (approximately 32% lower likelihood of obstructive CAD than expected) in those who were younger than 40 years to 0.18 (approximately 82% lower likelihood than expected) in those who were 70 years or older. The presence of obstructive vs nonobstructive CAD among those with a CAC score of 0 was associated with a multivariable adjusted hazard ratio of 1.51 (95% CI, 0.98-2.33) for myocardial infarction and all-cause death; however, this hazard ratio varied from 1.80 (95% CI, 1.02-3.19) in those who were younger than 60 years to 1.24 (95% CI, 0.64-2.39) in those who were 60 years or older.

Conclusions and Relevance This cohort study found that the diagnostic value of a CAC score of 0 to rule out obstructive CAD beyond clinical variables was dependent on age, with the added diagnostic value being smaller for younger patients. In symptomatic patients who were younger than 60 years, a sizable proportion of obstructive CAD occurred among those without CAC and was associated with an increased risk of myocardial infarction and all-cause death.

重要性 0 冠状动脉钙化 (CAC) 评分在排除不同年龄组的阻塞性冠状动脉疾病 (CAD) 和近期临床事件方面的诊断价值尚不清楚。

目的 评估 CAC 评分为 0 对降低阻塞性 CAD 可能性的诊断价值，并评估这种 CAC 评分和阻塞性 CAD 在不同年龄组中的影响。

设计、设置和参与者 该队列研究从丹麦西部心脏登记处获得数据，中位随访时间为 4.3 年。纳入的患者年龄在 18 岁或以上，在 2008 年 1 月 1 日至 2017 年 12 月 31 日期间接受了计算机断层扫描血管造影 (CTA)，因为症状提示 CAD。数据分析于 2021 年 4 月 5 日至 7 月 7 日进行。

暴露 阻塞性 CAD，定义为 50% 或更多的管腔狭窄。

主要结果和测量 CAC 评分为 0 的阻塞性 CAD 个体的比例。风险调整后的诊断似然比用于评估 CAC 评分为 0 的诊断价值，以降低超出临床变量的阻塞性 CAD 的可能性。估计与心肌梗死和死亡相关的危险因素。

结果 共纳入 23 759 例有症状患者，其中 12 771 例（54%）的 CAC 评分为 0。该队列的中位 (IQR) 年龄为 58 (49-65) 岁，主要由女性组成 (13160 [55%])。总体而言，所有年龄组的阻塞性 CAD 患病率都相对较低，从 40 岁以下人群中的 3%（1278 名患者中的 39 名）到 70 岁或以上人群中的 8%（619 名中的 52 名）不等。在阻塞性 CAD 患者中，14%（5043 名中的 725 名）的 CAC 评分为 0，并且不同年龄组的患病率在 40 岁以下的患者中为 58%（68 名中的 39 名），34%（562 名中的 192 名） ) 在 40 至 49 岁的人中，18% (268 of 1486) 在 50 至 59 岁的人中，9% (1963 年的 174 人) 在 60 至 69 岁的人中，5% (52 of 964) 在70岁或以上。CAC 评分为 0 的附加诊断价值在年轻时降低，在那些患有 CAC 评分为 0 的患者中，风险因素调整后的诊断似然比范围为 0.68（阻塞性 CAD 的可能性比预期低约 32%）。在 70 岁或以上的人群中，年龄小于 40 岁至 0.18（比预期的可能性低约 82%）。在 CAC 评分为 0 的患者中，阻塞性与非阻塞性 CAD 的存在与心肌梗死和全因死亡的多变量调整风险比为 1.51（95% CI，0.98-2.33）相关；然而，该风险比从 60 岁以下的 1.80 (95% CI, 1.02-3.19) 到 60 岁或以上的 1.24 (95% CI, 0.64-2.39) 不等。CAC 评分为 0 的风险因素调整诊断似然比从 40 岁以下患者的 0.68（阻塞性 CAD 的可能性比预期低约 32%）到 0.18（比预期的可能性低约 82%） 70岁或以上的人。在 CAC 评分为 0 的患者中，阻塞性与非阻塞性 CAD 的存在与心肌梗死和全因死亡的多变量调整风险比为 1.51（95% CI，0.98-2.33）相关；然而，该风险比从 60 岁以下的 1.80 (95% CI, 1.02-3.19) 到 60 岁或以上的 1.24 (95% CI, 0.64-2.39) 不等。CAC 评分为 0 的风险因素调整诊断似然比从 40 岁以下患者的 0.68（阻塞性 CAD 的可能性比预期低约 32%）到 0.18（比预期的可能性低约 82%） 70岁或以上的人。在 CAC 评分为 0 的患者中，阻塞性与非阻塞性 CAD 的存在与心肌梗死和全因死亡的多变量调整风险比为 1.51（95% CI，0.98-2.33）相关；然而，该风险比从 60 岁以下的 1.80 (95% CI, 1.02-3.19) 到 60 岁或以上的 1.24 (95% CI, 0.64-2.39) 不等。在 70 岁或以上的人中，18 岁（比预期的可能性低约 82%）。在 CAC 评分为 0 的患者中，阻塞性与非阻塞性 CAD 的存在与心肌梗死和全因死亡的多变量调整风险比为 1.51（95% CI，0.98-2.33）相关；然而，该风险比从 60 岁以下的 1.80 (95% CI, 1.02-3.19) 到 60 岁或以上的 1.24 (95% CI, 0.64-2.39) 不等。在 70 岁或以上的人中，18 岁（比预期的可能性低约 82%）。在 CAC 评分为 0 的患者中，阻塞性与非阻塞性 CAD 的存在与心肌梗死和全因死亡的多变量调整风险比为 1.51（95% CI，0.98-2.33）相关；然而，该风险比从 60 岁以下的 1.80 (95% CI, 1.02-3.19) 到 60 岁或以上的 1.24 (95% CI, 0.64-2.39) 不等。

结论和相关性 本队列研究发现，CAC 评分为 0 以排除临床变量以外的阻塞性 CAD 的诊断价值取决于年龄，对于年轻患者，附加的诊断价值较小。在 60 岁以下有症状的患者中，相当大比例的阻塞性 CAD 发生在没有 CAC 的患者中，并且与心肌梗塞和全因死亡的风险增加有关。