Cardiac computed tomographic angiography in an outpatient setting: An analysis of clinical outcomes over a 40-month period

Prognostic durability of coronary computed tomography angiography

AIMS

This large prospective cohort study sought to confirm the incremental prognostic value of coronary computed tomographic angiography (CCTA) measured over a prolonged follow-up duration. CCTA has diagnostic and prognostic value but data supporting its long-term prognostic value in a large prospectively recruited cohort with suspected coronary artery disease (CAD) has been limited.

METHODS AND RESULTS

Consecutive patients (without history of myocardial infarction, revascularization, cardiac transplantation, and congenital heart disease) were prospectively enrolled. CCTA was evaluated for CAD severity, total plaque score (TPS), and left ventricular ejection fraction. Patients were followed for major adverse events (MAE) and major adverse cardiac events (MACE).Over a total of 99 months, 8667 consecutive CCTA patients (mean age = 57.1 ± 11.1 years, 52.9% men) were prospectively enrolled and followed for a mean duration of 7.0 ± 2.6 years. At follow-up, there were a total of 723 MAE, 278 MACE, 547 all-cause deaths, 110 cardiac deaths, and 104 non-fatal myocardial infarction. Patients without coronary atherosclerosis at the time of CCTA had a very low annual event rate for both MAE and MACE (0.45%/year and 0.19%/year, respectively). Both MAE and MACE increased with increasing TPS and severity of CAD. In patients with non-obstructive CAD and who were statin-naive, TPS ≥5 had MACE rates >0.75%/year. Patients with high-risk CAD had an annual MAE and MACE rates of 3.52%/year and 2.58%/year, respectively. Adjusted hazard ratio of the severity of CAD based on multivariable analyses indicated that the prognostic values were incremental.

CONCLUSION

CCTA has independent and incremental prognostic value that is durable over time. The absence of coronary atherosclerosis portends an excellent prognosis. Patients with increasing non-obstructive plaque burden have worse prognosis and a TPS threshold ≥5 may identify a population that may benefit from statin therapy.

Long-Term Prognostic Value of Coronary CTA in Orthotopic Heart Transplant Recipients

OBJECTIVE. This study aimed to evaluate the long-term prognostic value of coronary CTA (CCTA) in heart transplant recipients. MATERIALS AND METHODS. The records of 114 patients who had undergone a heart transplant (mean age, 61.7 ± 11.1 [SD] years; 83.3% men) and who underwent CCTA for the surveillance of coronary allograft vasculopathy (CAV) from June 2007 to December 2017 were retrospectively evaluated for the occurrence of major adverse cardiovascular events (MACEs) (cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, coronary revascularization, cardiac arrhythmias, stroke, and retransplant). Patients were classified according to the presence of nonobstructive CAV (lumen reduction < 50%) or obstructive disease (lumen reduction ≥ 50%) and using a coronary segment involvement score (SIS). Differences in MACE rate between groups were compared. RESULTS. Obstructive CAV was observed in 12 heart transplant recipients (10.5%). During a mean follow-up of 67.5 ± 41.4 months the overall rates of MACE were 50% and 14.7% in patients with obstructive and nonobstructive CAV, respectively (p < .05), resulting in an odds ratio for MACE of 6 (95% CI, 1.7-21.2). Comparison of event-free survival showed a hazard ratio (HR) of 5 (95% CI, 1.95-13; p =. 004) for patients with obstructive disease. The presence of four or more stenotic coronary segments (SIS ≥ 4) was associated with a higher rate of events (HR, 3.46; 95% CI, 1.46-8.23). CONCLUSION. In patients who have undergone a heart transplant, CCTA offers a significant long-term prognostic impact on the prediction of MACEs.

Pilot study of the multicentre DISCHARGE Trial: image quality and protocol adherence results of computed tomography and invasive coronary angiography

OBJECTIVE

To implement detailed EU cardiac computed tomography angiography (CCTA) quality criteria in the multicentre DISCHARGE trial (FP72007-2013, EC-GA 603266), we reviewed image quality and adherence to CCTA protocol and to the recommendations of invasive coronary angiography (ICA) in a pilot study.

MATERIALS AND METHODS

From every clinical centre, imaging datasets of three patients per arm were assessed for adherence to the inclusion/exclusion criteria of the pilot study, predefined standards for the CCTA protocol and ICA recommendations, image quality and non-diagnostic (NDX) rate. These parameters were compared via multinomial regression and ANOVA. If a site did not reach the minimum quality level, additional datasets had to be sent before entering into the final accepted database (FADB).

RESULTS

We analysed 226 cases (150 CCTA/76 ICA). The inclusion/exclusion criteria were not met by 6 of the 226 (2.7%) datasets. The predefined standard was not met by 13 of 76 ICA datasets (17.1%). This percentage decreased between the initial CCTA database and the FADB (multinomial regression, 53 of 70 vs 17 of 75 [76%] vs [23%]). The signal-to-noise ratio and contrast-to-noise ratio of the FADB did not improve significantly (ANOVA, p = 0.20; p = 0.09). The CTA NDX rate was reduced, but not significantly (initial CCTA database 15 of 70 [21.4%]) and FADB 9 of 75 [12%]; p = 0.13).

CONCLUSION

We were able to increase conformity to the inclusion/exclusion criteria and CCTA protocol, improve image quality and decrease the CCTA NDX rate by implementing EU CCTA quality criteria and ICA recommendations.

KEY POINTS

• Failure to meet protocol adherence in cardiac CTA was high in the pilot study (77.6%). • Image quality varies between sites and can be improved by feedback given by the core lab. • Conformance with new EU cardiac CT quality criteria might render cardiac CTA findings more consistent and comparable.

Long-term prognostic value of stress myocardial perfusion imaging and coronary computed tomography angiography: A meta-analysis

BACKGROUND

We conducted a meta-analysis to compare the long-term prognostic value of stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) for adverse cardiovascular events in subjects with suspected or known coronary artery disease.

METHODS AND RESULTS

We searched PubMed, Cochrane, Web of Science, and Scopus database between January 2000 and December 2014 for stress MPI and CCTA studies that followed up ≥ 100 subjects for ≥ 2.5 years and provided the unadjusted and/or adjusted hazard ratio (HR) at Cox regression analysis. Summary risk estimates for abnormal perfusion at MPI or ≥ 50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 21 eligible articles (10 MPI and 11 CCTA) including 25,258 participants (13,484 in MPI and 11,774 in CCTA studies) with suspected or known coronary artery disease. Among the included publications, 8 MPI and 8 CCTA studies reported the HR for the occurrence of hard events (death and nonfatal myocardial infarction). The pooled HR was comparable for MPI and CCTA studies. The HR for the occurrence of a combined endpoint including revascularization as event was reported in 4 MPI and 6 CCTA studies. The pooled HR was higher for CCTA compared to MPI (P < .05) also when only MPI and CCTA studies with limited representation of prior CAD were considered.

CONCLUSIONS

The long-term prognostic value of MPI and CCTA for the occurrence of hard events is similar. However, the association between event-free survival and CCTA is higher than MPI when coronary revascularization is included in the endpoint.

Cardiac magnetic resonance and computed tomography angiography for clinical imaging of stable coronary artery disease. Diagnostic classification and risk stratification

Despite advances in the pharmacologic and interventional treatment of coronary artery disease (CAD), atherosclerosis remains the leading cause of death in Western societies. X-ray coronary angiography has been the modality of choice for diagnosing the presence and extent of CAD. However, this technique is invasive and provides limited information on the composition of atherosclerotic plaque. Coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) have emerged as promising non-invasive techniques for the clinical imaging of CAD. Hereby, CCTA allows for visualization of coronary calcification, lumen narrowing and atherosclerotic plaque composition. In this regard, data from the CONFIRM Registry recently demonstrated that both atherosclerotic plaque burden and lumen narrowing exhibit incremental value for the prediction of future cardiac events. However, due to technical limitations with CCTA, resulting in false positive or negative results in the presence of severe calcification or motion artifacts, this technique cannot entirely replace invasive angiography at the present time. CMR on the other hand, provides accurate assessment of the myocardial function due to its high spatial and temporal resolution and intrinsic blood-to-tissue contrast. Hereby, regional wall motion and perfusion abnormalities, during dobutamine or vasodilator stress, precede the development of ST-segment depression and anginal symptoms enabling the detection of functionally significant CAD. While CT generally offers better spatial resolution, the versatility of CMR can provide information on myocardial function, perfusion, and viability, all without ionizing radiation for the patients. Technical developments with these 2 non-invasive imaging tools and their current implementation in the clinical imaging of CAD will be presented and discussed herein.

Prognostic Value of Nonobstructive and Obstructive Coronary Artery Disease Detected by Coronary Computed Tomography Angiography to Identify Cardiovascular Events

Background—

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.

Prognostic utility of coronary computed tomographic angiography

Coronary computed tomographic angiography (CCTA) employing CT scanners of 64-detector rows or greater represents a noninvasive method that enables accurate detection and exclusion of anatomically obstructive coronary artery disease (CAD), providing excellent diagnostic information when compared to invasive angiography. There are numerous potential advantages of CCTA beyond simply luminal stenosis assessment including quantification of atherosclerotic plaque volume as well as assessment of plaque composition, extent, location and distribution. In recent years, an array of studies has evaluated the prognostic utility of CCTA findings of CAD for the prediction of major adverse cardiac events, all-cause death and plaque instability. This prognostic information enhances risk stratification and, if properly acted upon, may improve medical therapy and/or behavioral changes that may enhance event-free survival. The goal of the present article is to summarize the current status of the prognostic utility of CCTA findings of CAD.

Napkin-ring sign on coronary CT angiography for the prediction of acute coronary syndrome

OBJECTIVES

The aim of this study was to determine the predictive value of the napkin-ring sign on coronary computed tomography angiography (CTA) for future acute coronary syndrome (ACS) events in patients with coronary artery disease.

BACKGROUND

Recent studies have reported a close association between the napkin-ring sign on coronary CTA and thin-cap fibroatheroma.

METHODS

The subjects of this prospective study were 895 consecutive patients who underwent coronary CTA examination and were followed for >1 year. The primary endpoint was an ACS event (cardiac death, nonfatal myocardial infarction, or unstable angina pectoris). The coronary CTA analysis included the presence of obstructive plaque, positive remodeling (PR), low-attenuation plaque (LAP), and the napkin-ring sign. The napkin-ring sign was defined by the following criteria: 1) the presence of a ring of high attenuation around certain coronary artery plaques; and 2) attenuation of the ring presenting higher than those of the adjacent plaque and no >130 Hounsfield units.

RESULTS

Of the 12,727 segments, 1,174 plaques were observed, including plaques with PR in 130 segments (1.0%), LAP in 107 segments (0.8%), and napkin-ring signs in 45 segments (0.4%). Thirty-six of the 45 plaques with napkin-ring signs (80%) overlapped with those showing either PR or LAP. During the follow-up period (2.3 ± 0.8 years), 24 patients (2.6%) experienced ACS events, and plaques developed in 41% with a napkin-ring sign. Segment-based Cox proportional hazards models analysis showed that PR (p < 0.001), LAP (p = 0.007), and the napkin-ring sign (p < 0.0001) were independent predictive factors for future ACS events. Kaplan-Meier analysis demonstrated that plaques with napkin-ring signs showed a higher risk of ACS events compared with those without a napkin-ring sign.

CONCLUSIONS

The present study demonstrated for the first time that the napkin-ring sign demonstrated on coronary CTA was strongly associated with future ACS events, independent of other high-risk coronary CTA features. Detection of the napkin-ring sign could help identify coronary artery disease patients at high risk of future ACS events.

Immediate computed tomography coronary angiography versus delayed outpatient stress testing for detecting coronary artery disease in emergency department patients with chest pain

Noninvasive testing for coronary artery disease (CAD) is warranted for symptomatic patients with intermediate pretest likelihood of CAD. Accomplishing testing in an emergency department (ED) environment is challenging. We compared two strategies of CAD testing in ED patients: immediate computed tomography coronary angiography (CTCA) versus delayed outpatient stress testing. We conducted a historical control cohort study comparing symptomatic ED patients without an acute coronary syndrome who warranted noninvasive CAD testing. Two cohorts (50 patients each) were defined by CAD testing strategy, immediate CTCA versus delayed stress testing. Outcomes were duration of ED stay, detection of CAD, and 3-month rates of readmission, myocardial infarction, (MI) or death. Median duration of stay was 417.5 minutes (interquartile range [IQR] 359.0-581.0) in the CT cohort and 400.0 minutes (IQR 338.0-471.0) in the control cohort (P = 0.53). CAD was detected in 14 CT cohort patients versus 1 in control (P = 0.0004), due to low follow-up in the control cohort (18 of 50, 36%). Obstructive CAD was diagnosed in 6 CT cohort patients versus 1 in control (P = 0.11). During 3 months of follow-up, four patients in each cohort were reevaluated in the ED for chest pain; no patients suffered MI or death. A strategy of immediate CTCA is superior to a delayed stress testing strategy for detecting CAD in ED patients with chest pain and prompting appropriate referrals for further management. Delayed stress testing was primarily ineffective due to low follow-up. Immediate CTCA can be used safely without altering the ED duration of stay.

Coming of age: coronary computed tomography angiography

Technical development has substantially improved diagnostic performance of coronary computed tomography angiography (CCTA). A large number of studies have addressed proof of concept, feasibility, and clinical robustness of this noninvasive diagnostic technique, and most have consistently described the ability of CCTA to reliably rule out significant coronary artery stenosis. Clinical evidence supports the significant role of CCTA in an increasing number of scenarios, including the detection of coronary disease in symptomatic patients who are at intermediate risk and evaluation of coronary revascularization procedures. After initial feasibility testing, the scientific evaluation of CCTA now points toward analyzing prognosis, outcome, and cost-effectiveness of this noninvasive diagnostic tool. In this article, appropriate clinical indications, diagnostic performance, current clinical applications, prognostic value, and cost-effectiveness of CCTA are reviewed.

Prognostic value of cardiac computed tomography angiography: a systematic review and meta-analysis

OBJECTIVES

The purpose of this study was to systematically review and perform a meta-analysis of the ability of cardiac computed tomography angiography (CCTA) to predict future cardiovascular events and death.

BACKGROUND

The diagnostic accuracy of CCTA is well reported. The prognostic value of CCTA has been described in several studies, but many were underpowered. Pooling outcomes increases the power to predict rare events.

METHODS

We searched multiple databases for longitudinal studies of CCTA with at least 3 months follow-up of symptomatic patients with suspected coronary artery disease (CAD) reporting major adverse cardiovascular events (MACE), consisting of death, myocardial infarction (MI), and revascularization. Annualized event rates were pooled using a bivariate mixed-effects binomial regression model to calculate summary likelihood ratios and receiver-operating characteristic curves.

RESULTS

Eighteen studies evaluated 9,592 patients with a median follow-up of 20 months. The pooled annualized event rate for obstructive (any vessel with >50% luminal stenosis) versus normal CCTA was 8.8% versus 0.17% per year for MACE (p < 0.05) and 3.2% versus 0.15% for death or MI (p < 0.05). The pooled negative likelihood ratio for MACE after normal CCTA findings was 0.008 (95% confidence interval [CI]: 0.0004 to 0.17, p < 0.001), the positive likelihood ratio was 1.70 (95% CI: 1.42 to 2.02, p < 0.001), sensitivity was 0.99 (95% CI: 0.93 to 1.00, p < 0.001), and specificity was 0.41 (95% CI: 0.31 to 0.52, p < 0.001). Stratifying by no CAD, nonobstructive CAD (worst stenosis <50%), or obstructive CAD, there were incrementally increasing adverse events.

CONCLUSIONS

Adverse cardiovascular events among patients with normal findings on CCTA are rare. There are incrementally increasing future MACE with increasing CAD by CCTA.

Influence of smoking on the prognostic value of cardiovascular computed tomography coronary angiography

AIMS

Computed tomography coronary angiography (CTA) is an important non-invasive imaging modality increasingly used for the diagnosis and prognosis of coronary artery disease (CAD). The purpose of the current study was to determine the influence of smoking status on the prognostic value of CTA in patients with suspected or known CAD.

METHODS AND RESULTS

In 1207 patients (57% male, age 57 ± 12 years) referred for CTA, the presence of significant CAD (≥ 50% stenosis) was determined. During follow-up (FU) the following events were recorded: all cause mortality, and non-fatal infarction. The prognostic value of CTA in smokers and non-smokers was compared using an interaction term in the Cox proportional hazard regression analysis. Significant CAD was observed in 327 patients (27%), and 273 patients (23%) were smokers. During a median FU time of 2.2 years, an event occurred in 50 patients. After correction for baseline characteristics including smoking in a multivariate model, significant CAD remained an independent predictor of events. Furthermore, a significant interaction (P < 0.05) was observed between significant CAD and smoking. The annualized event rate in smokers with significant CAD was 8.78% compared with 0.99% in smokers without significant CAD (P < 0.001). In non-smokers with significant CAD the annualized event rate was 2.07% compared with 1.01% in non-smokers without significant CAD (P= 0.058).

CONCLUSION

The prognostic value of CTA was significantly influenced by smoking status. The event rates in patients with significant CAD were approximately four-fold higher in smokers compared with non-smokers. These findings suggest that smoking cessation needs to be aggressively pursued, especially in smokers with significant CAD.

The consequences of applying NICE chest pain guidelines to an acute medical population: a role for cardiac computed tomography

BACKGROUND

Cardiac computed tomography (CCT) is a well-validated investigation for the non-invasive assessment of coronary artery disease (CAD). The National Institute for Clinical Excellence (NICE) have recently released guidelines incorporating CCT into the diagnostic algorithm for chest pain of recent onset.

AIM

To assess the frequency of eligibility for CCT in medical admissions with suspected cardiac chest pain using criteria defined by NICE.

DESIGN

A retrospective, observational study, set in a teaching hospital acute medical unit.

METHODS

A total of 198 consecutive patients admitted over a 4-month period with suspected cardiac chest pain (57% male; mean age 63.5 years) were assessed for eligibility for CCT based on NICE guideline criteria.

RESULTS

Of the 198 patients admitted, 65 (33%) patients were excluded by a raised troponin I or ischaemic ECG changes; 100 (51%) patients were excluded by pain categorized as non-anginal and 171 (86%) patients were excluded by a modified Diamond Forrester score outside the range 10-29%. Applying NICE criteria to this population ultimately resulted in 2 (1%) patients recommended for CCT, 12 (6%) for functional cardiac testing and 17 (9%) for invasive angiography.

CONCLUSION

Applying current NICE guidelines for chest pain of recent onset to medical admissions results in a lesser uptake of CCT than functional testing and invasive angiography. If the NICE guidelines are revised to include patients with an intermediate pre-test probability of CAD, CCT may have a greater role.

Noninvasive anatomical coronary artery imaging versus myocardial perfusion imaging: which confers superior diagnostic and prognostic information?

Myocardial perfusion imaging (MPI) has been a valuable diagnostic and prognosticating tool for decades, but recently it has been challenged by the growing evidence about either comparable or superior diagnostic and prognostic value of computed tomography (CT)-based anatomical imaging modalities. Although there are some studies suggesting synergy and potential for combined use of these modalities to better diagnose coronary artery disease (CAD), it is important to evaluate these approaches separately, given cost and other restraints. This review compares the noninvasive anatomical imaging modalities of coronary artery calcium scoring and coronary CT angiography to the functional assessment modality of MPI in the diagnosis and prognostication of significant CAD in symptomatic patients. A large number of studies investigating this subject are analyzed with a critical look on the evidence, underlying the strengths and limitations. Although the overall findings of the presented studies are favoring the use of CT-based anatomical imaging modalities over MPI in the diagnosis and prognosticating of CAD, the lack of a high number of large- scale, multicenter randomized controlled studies limits the generalizability of this early evidence. Further studies comparing the short- and long-term clinical outcomes and cost-effectiveness of these tests are required to determine their optimal role in the management of symptomatic patients with suspected CAD.

Myocardial perfusion imaging with first-pass computed tomographic imaging: Measurement of coronary flow reserve in an animal model of regional hyperemia

BACKGROUND

The accurate assessment of myocardial blood flow (MBF) is a potential adjunct to the anatomy of CT coronary angiography.

PURPOSE

To compare semi-quantitative parameters from first-pass CT (FP CT) imaging with absolute measures of MBF in an animal model of altered MBF.

METHODS

A pig model of intracoronary adenosine (n = 8) was used during FP CT. This produces a zone with hyperemic MBF and a control zone within a slice. A subset of these animals also underwent LAD occlusion with imaging. Fluorescent microspheres (Mcsp) were injected into the left atrium to determine absolute MBF concurrent with CT imaging. Pigs were placed in a 64-slice (Philips) CT with acquisition performed during IC adenosine and occlusion. A 40% dilution of Iopamidol 370 (1 mL/kg) was injected IV at 5 mL/second. CT acquisition was ECG gated over 40 cardiac phases with the following parameters: 180 degrees axial mode (pitch = 0), field of view = 250 mmsq, 512 x 512 matrix, slice thickness = 2.5 mm x 10 slices, temporal resolution = 330 ms, 120 kV, 495 ma. Mcsp were injected immediately following CT imaging. The heart was sectioned into 2.5 mm slices to match the CT images and segmented. Time attenuation curves (TAC) were generated from CT in intervention and control zones based on Mcsp values. Mcsp coronary flow reserve (CFR) = hyperemic/control MBF, and CT CFR was derived from intervention/control area under curve from baseline corrected TIC.

RESULTS

MBF control = .65 +/- .28, MBF adenosine = 2.6 +/- .7 mL/min/g (P < .0001). CFR = 4.1 +/- 1.1, CT CFR = 4.3 +/- 1.4 (P = NS). There was a significant (r = .94, P < .0001) correlation between CFR and CT CFR.

CONCLUSIONS

CT first-pass myocardial perfusion imaging is feasible using a simple semi-quantitative analysis which provides reasonable estimates of MBF.

Diabetes: prognostic value of CT coronary angiography--comparison with a nondiabetic population

PURPOSE

To evaluate the prognostic value of multidetector computed tomographic (CT) coronary angiography in a diabetic population known to have or suspected of having coronary artery disease (CAD) compared with that in nondiabetic individuals.

MATERIALS AND METHODS

Institutional review board approval and patient informed consent were obtained. Three hundred thirteen patients with type 2 diabetes mellitus (DM) and 303 patients without DM underwent unenhanced 64-detector row CT, at which a calcium score was obtained, followed by CT angiography. Multidetector CT coronary angiograms were retrospectively classified as normal, showing nonobstructive CAD (<or=50% luminal narrowing), or showing obstructive CAD (>50% luminal narrowing). During follow-up after CT angiography, major events (cardiac death, nonfatal myocardial infarction, and unstable angina requiring hospitalization) and total events (major events plus coronary revascularizations) were recorded for each patient. Cox proportional hazards analysis and Kaplan-Meier analysis were used to compare survival rates.

RESULTS

In the group of 313 patients with DM, there were 213 men, and the mean age was 62 years +/- 11 (standard deviation). In the group of 303 patients without DM, there were 203 men, and the mean age was 63 years +/- 11. The mean number of diseased segments (5.6 vs 4.4, P = .001) and the rate of obstructive CAD (51% vs 37%, P < .001) were higher in patients with DM. Patients were followed up for a mean of 20 months +/- 5.4 (range, 6-44 months). At multivariate analysis, DM (P < .001) and evidence of obstructive CAD (P < .001) were independent predictors of outcome. Obstructive CAD remained a significant multivariate predictor for both patients with DM and patients without DM. In both patients with DM and patients without DM with absence of disease, the event rate was 0%. The event rate increased to 36% in patients without DM but with obstructive CAD and was highest (47%) in patients with DM and obstructive CAD.

CONCLUSION

In both patients with DM and patients without DM, multidetector CT coronary angiography provides incremental prognostic information over baseline clinical variables, and the absence of atherosclerosis at CT coronary angiography is associated with an excellent prognosis. Multidetector CT coronary angiography might be a clinically useful tool for improving risk stratification in both patients with DM and patients without DM.

Incremental Prognostic Value of Coronary CT Angiography in Patients With Suspected Coronary Artery Disease

Background—

Multidetector CT coronary angiography (MDCTCA) is capable of detecting coronary artery disease (CAD) with a high diagnostic accuracy. In particular, this technique is credited with having a negative predictive value close to 100%. However, data about the prognostic value of MDCTCA are currently lacking. We sought to determine the prognostic value of MDCTCA in patients with suspected but undocumented CAD and, in particular, the incremental prognostic value as compared with clinical risk and calcium scoring.

Methods and Results—

A total of 441 patients (age, 59.7±11.6 years) with suspected CAD underwent MDCTCA to evaluate the presence and severity of the disease. Patients were followed up as to the occurrence of hard cardiac events (cardiac death, nonfatal myocardial infarction, and unstable angina requiring hospitalization). Coronary lesions were detected in 297 (67.3%) patients. During a mean follow-up of 31.9±14.8 months, 44 hard cardiac events occurred in 40 patients. CT calcium scoring showed a statistically significant incremental prognostic value as compared to a baseline clinical risk model ( P =0.018), whereas MDCTCA provided an additional incremental prognostic value as compared with a baseline clinical risk model plus calcium scoring if considering both nonobstructive versus obstructive CAD ( P =0.016) or, better, plaque composition (calcified versus noncalcified and/or mixed plaques, P =0.0001). During follow-up, an excellent prognosis was noted in patients with normal coronary arteries, with an annualized incidence rate of 0.88% if compared with those with mild CAD (3.89%) and with patients with significant coronary disease (8.09%). The presence of noncalcified or mixed plaques, regardless of lesion severity, was found to be the strongest predictor of events ( P <0.0001) as a potential marker of plaque vulnerability.

Conclusions—

MDCTCA provides independent and incremental prognostic information as compared to baseline clinical risk factors and calcium scoring in patients with suspected CAD.

Prognostic value of absence or presence of coronary artery disease determined by 64-slice computed tomography coronary angiography a systematic review and meta-analysis

To determine via a meta-analysis the prognostic value of 64-slice computed tomography angiography (CTA) by quantifying risk of major adverse cardiac events (MACE) in different patient groups classified according to CT angiographic findings. A systematic literature search and meta-analyses was conducted on 10 studies examining stable, symptomatic and intermediate risk patients by 64-slice CTA. Patients were followed up for a mean of 21 month. Patient groups with CT-angiographic non-obstructive (stenosis <50% of luminal narrowing) or obstructive (stenosis ≥50% of luminal narrowing) CAD were compared to those having normal angiography without CAD. MACE (cardiac death, non-fatal myocardial infarction and revascularization) numbers were used to calculate odds ratios (OR) with 95% confidence interval (CI) in each group. Ten studies including 5,675 patients were eligible for meta-analysis. The cumulative MACE rate over 21 months were 0.5% in patients with normal CTA, 3.5% in non-obstructive CAD and 16% in obstructive CAD. Compared to normal CTA, non-obstructive CAD was associated with significant increased risk of MACE with OR=6.68 (3.01-14.82 CI 95%), P=0.0001. Obstructive CAD was associated with further significant increased risk of MACE with OR=41.19 (22.56-75.18, CI 95%), P=0.0001. The studies were homogenous, P-value >0.05 for heterogeneity. 64-slice CTA is able to differentiate low-risk from high-risk patients with suspected or known CAD. Absence of CAD predicts excellent prognosis, while obstructive CAD is associated with markedly increased risk of MACE.

Responsible use of computed tomography in the evaluation of coronary artery disease and chest pain

Many options are available to clinicians for the noninvasive evaluation of the cardiovascular system and patient concerns about chest discomfort. Cardiac computed tomography (CT) is a rapidly advancing field of noninvasive imaging. Computed tomography incorporates coronary artery calcium scoring, coronary angiography, ventricular functional analysis, and information about noncardiac thoracic anatomy. We searched the PubMed database and Google from inception to September 2009 for resources on the accuracy, risk, and predictive capacity of coronary artery calcium scoring and CT coronary angiography and have reviewed them herein. Cardiac CT provides diagnostic information comparable to echocardiography, nuclear myocardial perfusion imaging, positron emission tomography, and magnetic resonance imaging. A cardiac CT study can be completed in minutes. In patients with a nondiagnostic stress test result, cardiac CT can preclude the need for invasive angiography. Prognostic information portends excellent outcomes in patients with normal study results. Use of cardiac CT can reduce health care costs and length of emergency department stays for patients with chest pain. Cardiac CT examination provides clinically relevant information at a radiation dose similar to well-established technologies, such as nuclear myocardial perfusion imaging. Advances in technique can reduce radiation dose by 90%. With appropriate patient selection, cardiac CT can accurately diagnose heart disease, markedly decrease health care costs, and reliably predict clinical outcomes.

Computed tomography of the coronary arteries in diagnosis

IMPORTANCE OF THE FIELD

Cardiac computed tomography (CT) has recently emerged as a non-invasive alternative to catheter angiography for the assessment of coronary artery disease. Rapid technological advances have rendered coronary CT angiography to a robust, accurate and fast imaging modality to assess coronary artery disease in selected patients. The list of further indications in which cardiac CT is an appropriate test remains a topic of discussion.

AREAS COVERED IN THIS REVIEW

This review discusses the main literature available on the use of cardiac CT in the indications considered appropriate in the 2006 Appropriateness Criteria by the American College of Radiology with special emphasis on the temporal trends in the utilization of cardiac CT in clinical practice and in the opinion of the experts, and provides an outlook on how cardiac CT might evolve in the future.

WHAT THE READER WILL GAIN

The reader will gain insight into the strengths and shortcomings of CT of the coronary arteries in coronary artery diagnosis and will learn why cardiac CT is appropriate in some indications but not in others.

TAKE HOME MESSAGE

Recent research in cardiac CT has substantially improved the evaluation of the coronary arteries with CT, and the list of indications cardiac CT is appropriate for might expand further in the coming years.

The value of multi-slice-computed tomography coronary angiography for risk stratification

Multi-slice-computed tomography coronary angiography (CTA) provides direct non-invasive anatomic assessment of the coronary arteries allowing for early identification of coronary artery disease (CAD). This information is useful for diagnosis of CAD, particularly the rule out of CAD. In addition, early identification of CAD with CTA may also be useful for risk stratification. The purpose of this review is to provide an overview of the current literature on the prognostic value of CTA and to discuss how the prognostic information obtained with CTA can be used to further integrate the technique into clinical practice. Non-invasive anatomic assessment of plaque burden, location, composition, and remodeling using CTA may provide prognostically relevant information. This information has been shown to be incremental to the Framingham risk score, coronary artery calcium scoring, and myocardial perfusion imaging. Characterization of atherosclerosis non-invasively has the potential to provide important prognostic information enabling a more patient-tailored approach to disease management.Future studies assessing outcome after CTA-based risk adjustments are needed to further understand the value of detailed non-invasive anatomic imaging.

Measuring progression of coronary atherosclerosis with computed tomography: searching for clarity among shades of gray

Computed tomography (CT) allows visualization of both calcified and noncalcified atherosclerotic plaque in the entire coronary tree. When assessing an individual patient's risk of cardiac events, direct visualization of coronary plaque has substantial advantages over assessment of surrogate markers or risk factors. Ideally, practitioners would be able to follow progression or regression of coronary disease via quantitative measurements of plaque volume and composition in individual patients. Once this is possible, CT could be used to: (1) make more informed decisions about whether and how aggressively to treat patients at risk for coronary artery disease, and (2) to follow the effects of treatment in patients with known coronary artery disease. At this point in time, coronary calcium scoring is more reproducible than CT angiography for quantifying plaque and also has a much larger body of evidence supporting its ability to predict cardiac events. In this paper we will review the current techniques for quantifying calcified and noncalcified coronary atherosclerosis with cardiac CT, the strengths and limitations of each approach and the data supporting the ability to quantify and follow progression or regression of plaque.