Several large, recent studies have demonstrated the impact of coronary CTA on prognosis, although the follow-up time has been relatively short.1,2 Only 1 study has evaluated the longer term follow-up of cardiovascular events among patients referred for coronary CTA.3 Because patients referred forBackground-The contribution of plaque extent to predict cardiovascular events among patients with nonobstructive and obstructive coronary artery disease (CAD) is not well defined. Our objective was to evaluate the prognostic value of plaque extent detected by coronary computed tomography angiography. Methods and Results-All consecutive patients without prior CAD referred for coronary computed tomography angiography to evaluate for CAD were included. Examination findings were classified as normal, nonobstructive (<50% stenosis), or obstructive (≥50%). Based on the number of segments with disease, extent of CAD was classified as nonextensive (≤4 segments) or extensive (>4 segments). The cohort included 3242 patients followed for the primary outcome of cardiovascular death or myocardial infarction for a median of 3.6 (2.1-5.0) years. In a multivariable analysis, the presence of extensive nonobstructive CAD (hazard ratio, 3.1; 95% confidence interval, 1.5-6.4), nonextensive obstructive (hazard ratio, 3.0; 95% confidence interval, 1.3-6.9), and extensive obstructive CAD (hazard ratio, 3.9; 95% confidence interval, 2.2-7.2) were associated with an increased rate of events, whereas nonextensive, nonobstructive CAD was not. The addition of plaque extent to a model that included clinical probability as well as the presence and severity of CAD improved risk prediction. Conclusions-Among patients with nonobstructive CAD, those with extensive plaque experienced a higher rate of cardiovascular death or myocardial infarction, comparable with those who have nonextensive disease. Even among patients with obstructive CAD, greater extent of nonobstructive plaque was associated with higher event rate. Our findings suggest that regardless of whether obstructive or nonobstructive disease is present, the extent of plaque detected by coronary computed tomography angiography enhances risk assessment. (Circ Cardiovasc Imaging. 2014;7:282-291.)

Background— Coronary computed tomographic angiography (CCTA) is an accurate test for the identification of coronary artery disease (CAD), yet the impact of CCTA results on subsequent medical therapy and risk factors has not been widely reported. Methods and Results— We identified consecutive patients aged >18 years without prior CAD who underwent CCTA from 2004 to 2011 and had complete data on medications before and after CCTA. CCTA results were categorized as no CAD, <50% stenosis, and ≥50% stenosis. Based on the number of involved segments, extent of disease was categorized as nonextensive (≤4 segments) or extensive CAD (>4 segments). Electronic medical records and patient interviews were reviewed blinded to CCTA findings to assess initiation of aspirin and intensification of lipid-lowering therapies. Survival analysis was performed to evaluate intensification of lipid therapy as a predictor of cardiovascular death or nonfatal myocardial infarction. Among 2839 patients with mean follow-up of 3.6 years, the odds of physician intensification of lipid-lowering therapy significantly increased for those with nonobstructive CAD (odds ratio, 3.6; 95% confidence interval, 2.9–4.9; P <0.001) and obstructive CAD (odds ratio, 5.6; 95% confidence interval, 4.3–7.3; P <0.001). Low-density lipoprotein cholesterol levels declined significantly in association with intensification of lipid-lowering therapy after CCTA in all patient subgroups. In a hypothesis-generating analysis, among patients with nonobstructive but extensive CAD, statin use after CCTA was associated with a reduction in cardiovascular death or myocardial infarction (hazards ratio, 0.18; 95% confidence interval, 0.05–0.66; P =0.01). Conclusions— Abnormal CCTA findings are associated with downstream intensification in statin and aspirin therapy. In particular, CCTA may lead to increased use of prognostically beneficial therapies in patients identified as having extensive, nonobstructive CAD.

Objective To evaluate the prognostic value and test characteristics of coronary artery calcium (CAC) score for the identification of obstructive coronary artery disease (CAD) in comparison with coronary computed tomography angiography (CCTA) among symptomatic patients. Methods Retrospective cohort study at two large hospitals, including all symptomatic patients without prior CAD who underwent both CCTA and CAC. Accuracy of CAC for the identification of ≥50% and ≥70% stenosis by CCTA was evaluated. Prognostic value of CAC and CCTA were compared for prediction of major adverse cardiovascular events (MACE, defined as non-fatal myocardial infarction, cardiovascular death, late coronary revascularization (>90 days), and unstable angina requiring hospitalization). Results Among 1145 included patients, the mean age was 55 ± 12 years and median follow up 2.4 (IQR: 1.5–3.5) years. Overall, 406 (35%) CCTA were normal, 454 (40%) had <50% stenosis, and 285 (25%) had ≥50% stenosis. The prevalence of ≥70% stenosis was 16%. Among 483 (42%) patients with CAC zero, 395 (82%) had normal CCTA, 81 (17%) <50% stenosis, and 7 (1.5%) ≥ 50% stenosis. 2 (0.4%) patients had ≥70% stenosis. For diagnosis of ≥50% stenosis, CAC had a sensitivity of 98% and specificity of 55%. The negative predictive value (NPV) for CAC was 99% for ≥50% stenosis and 99.6% for ≥70% stenosis by CCTA. There were no adverse events among the 7 patients with zero calcium and ≥50% CAD. For prediction of MACE, the c-statistic for clinical risk factors of 0.62 increased to 0.73 (p < 0.001) with CAC versus 0.77 (p = 0.02) with CCTA. Conclusion Among symptomatic patients with CAC zero, a 1–2% prevalence of potentially obstructive CAD occurs, although this finding was not associated with future coronary revascularization or adverse prognosis within 2 years.