Coronary computed tomography angiography (CCTA) has a high accuracy for detection of obstructive coronary artery disease (CAD). Several studies also showed a good predictive value for subsequent cardiac events. However, the follow-up period of these studies was limited to ∼2 years and long-term follow-up data on prognosis out to 5 years are very limited. This study is based on 1584 patients with suspected CAD undergoing CCTA between December 2003 and November 2006. Among other CCTA parameters, the total plaque score defined as number of abnormal segments (having either a non-obstructive plaque or a stenosis) and the most severe stenosis were recorded. The primary endpoint was a composite of death and non-fatal myocardial infarction. Revascularization procedures later than 90 days after the CT study were assessed as secondary endpoints. During a median follow-up of 5.6 years (IQR: 5.1–6.3 years) 61 patients suffered death or myocardial infarction and 52 underwent late revascularization. The severity of CAD and the total plaque score were the best predictors of death and non-fatal myocardial infarction, both significantly improving prediction over standard clinical risk scores (multivariate c-index 0.60 and 0.66, respectively, P = 0.002 and 5 segments). Both parameters also improved prediction of need for subsequent revascularization (c-index 0.72 and 0.63, respectively, P < 0.0001 and P = 0.0013, respectively). Data from CCTA predict both death and myocardial infarction as well as need for subsequent revascularizations out to 5 years. CCTA imaging may be a valuable tool in the assessment of long-term prognosis in patients with suspected CAD.
1 March 2016 in Journal of Cardiovascular Computed Tomography
Background—: Several studies have demonstrated a high accuracy of coronary computed tomography angiography (CCTA) for detection of obstructive coronary artery disease (CAD), whereas some studies have also shown a good prediction of cardiac events. However, it remains to be proven whether CCTA is better predictive of events than conventional risk scores or calcium scoring. Therefore, we compared CCTA with calcium scoring and clinical risk scores for the ability to predict cardiac events. Methods and Results—: Patients (n=2223) with suspected CAD undergoing CCTA were followed up for a median of 28 months. The end point was the occurrence of cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, and coronary revascularization later than 90 days after CCTA). Patients with obstructive CAD had a significantly higher event rate (2.9% per year; 95% confidence interval, 2.1 to 4.0) than those without obstructive CAD, having an event rate 0.3% per year (95% confidence interval, 0.1 to 0.5; hazard ratio, 13.5; 95% confidence interval, 6.7 to 27.2; P <0.001). CCTA had significant incremental predictive value when compared with calcium scoring, both with scores assessing the degree of stenosis ( P <0.001) and with scores assessing the number of diseased coronary segments ( P =0.027). Conclusions—: In patients with suspected CAD, CCTA not only detects coronary stenosis but also improves prediction of cardiac events over and above conventional risk scores and calcium scoring. This may result in a reclassification of cardiovascular risk in a substantial proportion of patients.
OBJECTIVE: Diabetic patients have a high prevalence of coronary artery disease (CAD), but timely diagnosis of CAD remains challenging. We assessed the ability of coronary computed tomography angiography (CCTA) to detect CAD in diabetic patients and to predict subsequent cardiac events. RESEARCH DESIGN AND METHODS: We analyzed 140 diabetic patients without known CAD undergoing CCTA; 1,782 patients without diabetes were used as a control group. Besides calcium scoring and the degree of the most severe stenosis, the atherosclerotic burden score counting the number of segments having either a nonstenotic plaque or a stenosis was recorded. The primary end point was a composite of hard cardiac events defined as all-cause death, nonfatal myocardial infarction, or unstable angina requiring hospitalization. RESULTS: During a mean follow-up of 33 months, there were seven events in the diabetic group and 24 events in the control group. The best predictor in diabetic patients was the atherosclerotic burden score: the annual event rate ranged from 0.5% for patients with 9 lesions, resulting in a hazard ratio (HR) of 1.3 (95% CI 1.1–1.7) for each additional lesion (P = 0.005). For comparison, in nondiabetic patients the annual event rate ranged from 0.3 to 2.2%, respectively, resulting in an HR of 1.2 (95% CI 1.1–1.3, P < 0.001). The atherosclerotic burden score improved the prognostic value of conventional risk factors significantly (P < 0.001). CONCLUSIONS: In diabetic patients without known CAD, CCTA can identify a patient group at particularly high risk for subsequent hard cardiac events.