BackgroundUnlike most noninvasive imaging modalities, coronary computed tomography angiography can characterize subtypes of atherosclerotic plaque.ObjectivesThe purpose of this study was to investigate the prognostic implications of adverse coronary plaque characteristics in patients with suspected coronary artery disease.MethodsIn this SCOT-HEART (Scottish COmputed Tomography of the HEART Trial) post hoc analysis, the presence of adverse plaque (positive remodeling or low attenuation plaque), obstructive disease, and coronary artery calcification within 15 coronary segments was assessed on coronary computed tomography angiography of 1,769 patients who were followed-up for 5 years.ResultsAmong study participants (mean age 58 ± 10 years; 56% male), 608 (34%) patients had 1 or more adverse plaque features. Coronary heart disease death or nonfatal myocardial infarction was 3 times more frequent in patients with adverse plaque (n = 25 of 608 [4.1%] vs. n = 16 of 1,161 [1.4%]; p < 0.001; hazard ratio [HR]: 3.01; 95% confidence interval (CI): 1.61 to 5.63; p = 0.001) and was twice as frequent in those with obstructive disease (n = 22 of 452 [4.9%] vs. n = 16 of 671 [2.4%]; p = 0.024; HR: 1.99; 95% CI: 1.05 to 3.79; p = 0.036). Patients with both obstructive disease and adverse plaque had the highest event rate, with a 10-fold increase in coronary heart disease death or nonfatal myocardial infarction compared with patients with normal coronary arteries (HR: 11.50; 95% CI: 3.39 to 39.04; p < 0.001). However, these associations were not independent of coronary artery calcium score, a surrogate measure of coronary plaque burden.ConclusionsAdverse coronary plaque characteristics and overall calcified plaque burden confer an increased risk of coronary heart disease death or nonfatal myocardial infarction. (Scottish COmputed Tomography of the HEART Trial [SCOT-HEART]; NCT01149590)

Background: The future risk of myocardial infarction is commonly assessed using cardiovascular risk scores, coronary artery calcium score, or coronary artery stenosis severity. We assessed whether noncalcified low-attenuation plaque burden on coronary CT angiography (CCTA) might be a better predictor of the future risk of myocardial infarction. Methods: In a post hoc analysis of a multicenter randomized controlled trial of CCTA in patients with stable chest pain, we investigated the association between the future risk of fatal or nonfatal myocardial infarction and low-attenuation plaque burden (% plaque to vessel volume), cardiovascular risk score, coronary artery calcium score or obstructive coronary artery stenoses. Results: In 1769 patients (56% male; 58±10 years) followed up for a median 4.7 (interquartile interval, 4.0–5.7) years, low-attenuation plaque burden correlated weakly with cardiovascular risk score ( r =0.34; P <0.001), strongly with coronary artery calcium score ( r =0.62; P <0.001), and very strongly with the severity of luminal coronary stenosis (area stenosis, r =0.83; P <0.001). Low-attenuation plaque burden (7.5% [4.8–9.2] versus 4.1% [0–6.8]; P <0.001), coronary artery calcium score (336 [62–1064] versus 19 [0–217] Agatston units; P <0.001), and the presence of obstructive coronary artery disease (54% versus 25%; P <0.001) were all higher in the 41 patients who had fatal or nonfatal myocardial infarction. Low-attenuation plaque burden was the strongest predictor of myocardial infarction (adjusted hazard ratio, 1.60 (95% CI, 1.10–2.34) per doubling; P =0.014), irrespective of cardiovascular risk score, coronary artery calcium score, or coronary artery area stenosis. Patients with low-attenuation plaque burden greater than 4% were nearly 5 times more likely to have subsequent myocardial infarction (hazard ratio, 4.65; 95% CI, 2.06–10.5; P <0.001). Conclusions: In patients presenting with stable chest pain, low-attenuation plaque burden is the strongest predictor of fatal or nonfatal myocardial infarction. These findings challenge the current perception of the supremacy of current classical risk predictors for myocardial infarction, including stenosis severity. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01149590.

Purpose of ReviewCost-effective care pathways are integral to delivering sustainable healthcare programmes. Due to the overestimation of coronary artery disease using traditional risk tables, non-invasive testing has been utilised to improve risk stratification and initiate appropriate management to reduce the dependence on invasive investigations. In line with recent technological improvements, cardiac CT is a modality that offers a detailed anatomical assessment of coronary artery disease comparable to invasive coronary angiography.Recent FindingsThe recent publication of the National Institute for Health and Care Excellences (NICE) Clinical Guideline 95 update assesses the performance and cost utility of different non-invasive imaging strategies in patients presenting with suspected anginal chest pain. The low cost and high sensitivity of cardiac CT makes it the non-invasive test of choice in the evaluation of stable angina. This has now been ratified in national guidelines with NICE recommending cardiac CT as the first-line investigation for all patients presenting with chest pain due to suspected coronary artery disease. Additionally, randomised controlled trials have demonstrated that cardiac CT improves diagnostic certainty when incorporated into chest pain pathways.SummaryNICE recommend cardiac CT as the first-line test for the evaluation of stable coronary artery disease in chest pain pathways.