Coronary computed tomography angiography---a promising imaging modality in diagnosing coronary artery disease

Diagnostic value of scoring model of treadmill exercise test combined with dynamic electrocardiogram for latent coronary heart disease

OBJECTIVE

To investigate the diagnostic value of scoring model of treadmill exercise test (TET) combined with dynamic electrocardiogram (DECG) for latent coronary heart disease (LCHD).

MATERIALS AND METHODS

Using coronary angiography, the diagnostic values of TET and DECG alone or combination for LCHD of 200 eligible patients were compared. The effects of different clinical features and DECG indices on the positive detection rate of TET combined with DECG were compared. Multivariate logistic regression analysis was performed for factors influencing diagnostic accuracy, and nomogram prediction model was established using screened independent risk factors.

RESULTS

Serial and parallel combinations of TET and DECG had superior sensitivity, specificity, positive and negative predictive values and accuracy than those of single detection. Patients with an age > 65 years, smoking, hypertension, diabetes mellitus, hyperlipidemia, family history of CHD and positive DECG indicators had higher positive detection rate, as independent risk factors for accuracy. The diagnostic accuracy of TET combined with DECG predicted by the nomogram model was 82.9%. The actual concordance index (C-index) for model evaluation was 0.817, the C-index after internal validation was 0.811, and the C-index after external validation was 0.802, indicating a good concordance of the model.

CONCLUSIONS

TET combined with DECG has high diagnostic accuracy for LCHD, and the scoring model constructed by DECG indicators can prominently improve the accuracy of combined diagnosis. Therefore, TET combined with DECG is significantly better than TET or DECG alone, which is of great diagnostic value for LCHD.

The diagnostic performance of coronary artery angiography with 64-MSCT and post 64-MSCT: systematic review and meta-analysis

PURPOSE

To comprehensively investigate the diagnostic performance of coronary artery angiography with 64-MDCT and post 64-MDCT.

MATERIALS AND METHODS

PubMed was searched for all published studies that evaluated coronary arteries with 64-MDCT and post 64-MDCT. The clinical diagnostic role was evaluated by applying the likelihood ratios (LRs) to calculate the post-test probability based on Bayes' theorem.

RESULTS

91 studies that met our inclusion criteria were ultimately included in the analysis. The pooled positive and negative LRs at patient level were 8.91 (95% CI, 7.53, 10.54) and 0.02 (CI, 0.01, 0.03), respectively. For studies that did not claim that non-evaluable segments were included, the pooled positive and negative LRs were 11.16 (CI, 8.90, 14.00) and 0.01 (CI, 0.01, 0.03), respectively. For studies including uninterruptable results, the diagnostic performance decreased, with the pooled positive LR 7.40 (CI, 6.00, 9.13) and negative LR 0.02 (CI, 0.01, 0.03). The areas under the summary ROC curve were 0.98 (CI, 0.97 to 0.99) for 64-MDCT and 0.96 (CI, 0.94 to 0.98) for post 64-MDCT, respectively. For references explicitly stating that the non-assessable segments were included during analysis, a post-test probability of negative results >95% and a positive post-test probability <95% could be obtained for patients with a pre-test probability of <73% for coronary artery disease (CAD). On the other hand, when the pre-test probability of CAD was >73%, the diagnostic role was reversed, with a positive post-test probability of CAD >95% and a negative post-test probability of CAD <95%.

CONCLUSION

The diagnostic performance of post 64-MDCT does not increase as compared with 64-MDCT. CTA, overall, is a test of exclusion for patients with a pre-test probability of CAD<73%, while for patients with a pre-test probability of CAD>73%, CTA is a test used to confirm the presence of CAD.

A systematic review of the clinical effectiveness of 64-slice or higher computed tomography angiography as an alternative to invasive coronary angiography in the investigation of suspected coronary artery disease

Background

This systematic review summarized recent evidence pertaining to the clinical effectiveness of 64-slice or higher computed tomography angiography (CTA) in patients with suspected coronary artery disease (CAD). If CTA proves to be a successful diagnostic performance measure, it could prevent the use of invasive diagnostic procedures in some patients. This would provide multiple health and cost benefits, particularly for under resourced areas where invasive coronary angiography is not always available.

Methods

A systematic method of literature searching and selection was employed with searches limited to December 2006 to March 2009. Included studies were quality assessed using National Health and Medical Research Council (NHMRC) diagnostic levels of evidence and a modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Individual and pooled diagnostic performance measures were calculated using standard meta-analytic techniques at the patient, vessel and segment level. A positive result was defined as greater than or equal to 50% stenosis.

Results

Twenty-eight studies were included in the systematic review examining 3,674 patients. The primary meta-analysis at the patient-level indicated a sensitivity of 98.2% and specificity of 81.6%. The median (range) positive predictive value (PPV) was 90.5% (76%-100%) and negative predictive value (NPV) 99.0% (83%-100%). In all vessels, the pooled sensitivity was 94.9%, specificity 89.5%, and median (range) PPV 75.0% (53%-95%) and NPV 99.0% (93%-100%). At the individual artery level, overall diagnostic accuracy appeared to be slightly higher in the left main coronary artery and slightly lower in the left anterior descending and circumflex artery. In all segments, the sensitivity was 91.3%, specificity 94.0% and median (range) PPV 69.0% (44%-86%) and NPV 99.0% (98%-100%).

Conclusions

The high sensitivity indicates that CTA can effectively identify the majority of patients with significant coronary artery stenosis. The high NPV at the patient, vessel and segment level establishes CTA as an effective non-invasive alternative to invasive coronary angiography (ICA) for the exclusion of stenosis.

Usefulness of multidetector-row computed tomography in diagnosis of anomalous origin of left coronary artery arising from the pulmonary artery

Anomalous origin of the left coronary artery arising from the pulmonary artery (ALCAPA) is a rare congenital heart defect that affects approximately 1 in 300,000 live births and accounts for 0.5% of all congenital heart disease. Without surgical intervention, most patients with this anomaly die in infancy. The diagnosis of ALCAPA syndrome is sometimes difficult, especially in children, because it often presents with atypical symptoms and signs. Echocardiography can yield some findings that are highly indicative of this syndrome. Cardiac catheterization usually establishes the diagnosis, but it is invasive and painful. Multidetector-row computed tomography (MDCT) is a valuable alternative tool to confirm the diagnosis of ALCAPA syndrome. In this report, we describe a 24-year-old woman with a dilated right coronary artery detected by transthoracic echocardiography, showing an interventricular abnormal flow over the diastolic phase of the cardiac cycle and the left main coronary artery not merging with the ascending aorta. The diagnosis of ALCAPA syndrome was confirmed by MDCT.

Applying preoperative multidetector computed tomography to bilateral coronary artery fistulas

Coronary artery fistula arising from both the right coronary artery and the circumflex coronary artery is rare. A 28-year-old woman with non-insulin-dependent diabetes mellitus and end-stage renal disease who was on regular hemodialysis complained of recent progressive exertional dyspnea. Congestive heart failure was diagnosed during work-up for simultaneous kidney and pancreas transplantation. Bilateral coronary fistulas draining into the coronary sinus were found by coronary angiography and further characterized by multidetector computed tomography followed by 3D reconstruction preoperatively. The operation was performed smoothly without heart arrest.