Survey of observer variation in transesophageal echocardiography: comparison of anesthesiology and cardiology literature

Current review of acute type A aortic dissection in Malaysia

Acute type A aortic dissection (ATAAD) still poses significant challenges and management dilemmas for cardiovascular surgeons worldwide. Despite the continuous improvement in diagnosis and management strategies for ATAAD, clinical outcomes remain poor and the optimal therapy is still debatable especially those with malperfusion syndrome (MPS). This review is based on the current literature and includes the results from the Aortic Registry of National Heart Institute of Malaysia (NHIM) database. It covers different aspects of ATAAD and concentrates on the outcome of surgical repair. The diagnosis is often delayed leading to variable outcomes. High index of suspicion and urgent treatment is required to tackle this dynamic disease which include the variation in presentation and clinical course. Different surgical techniques and perfusion strategies have been described to save patients. Complex techniques such as total arch replacement (TAR) with frozen elephant trunk and valve sparing root surgery may provide long-term benefit in selected patients, but require significant surgical expertise and experience.

Non-contrast CT-based radiomic signature for screening thoracic aortic dissections: a multicenter study

OBJECTIVE

To develop a non-contrast CT-based radiomic signature to effectively screen for thoracic aortic dissections (ADs).

METHODS

We retrospectively enrolled 378 patients who underwent non-contrast chest CT scans along with CT angiography or MRI from 4 medical centers. The training and validation sets were from 3 centers, while the external test set was from a 4th center. Radiomic features were extracted from non-contrast CT images. The radiomic signature was created on the basis of selected features by a logistic regression algorithm. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve, accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were conducted to assess the predictive ability of radiomic signature.

RESULTS

The radiomic signature demonstrated AUCs of 0.91 (95% confidence interval [CI], 0.86-0.95) in the training set, 0.92 (95% CI, 0.86-0.98) in the validation set, and 0.90 (95% CI, 0.82-0.98) in the external test set. The predicted diagnosis was in good agreement with the probability of thoracic AD. In the external test group, the diagnostic accuracy, sensitivity, specificity, PPV, and NPV were 90.5%, 85.7%, 91.7%, 70.6%, and 96.5%, respectively.

CONCLUSIONS

A radiomic signature based on non-contrast CT images can effectively predict thoracic ADs. This method may serve as a potential screening tool for thoracic ADs.

KEY POINTS

• The non-contrast CT-based radiomic signature can effectively predict the thoracic aortic dissections. • This radiomic signature shows better predictive performance compared to the current clinical model. • This prediction method may be a potential tool for screening thoracic aortic dissections.

Acute type A aortic dissection - a review

Acute type A aortic dissection (ATAAD) is still one of the most challenging diseases that cardiac surgeons encounter. This review is based on the current literature and includes the results from the Nordic Consortium for Acute Type-A Aortic Dissection (NORCAAD) database. It covers different aspects of ATAAD and concentrates on the outcome of surgical repair. The diagnosis is occasionally delayed, and ATAAD is usually lethal if prompt repair is not performed. The dynamic nature of the disease, the variation in presentation and clinical course, and the urgency of treatment require significant attentiveness. Many surgical techniques and perfusion strategies of varying complexity have been described, ranging from simple interposition graft to total arch replacement with frozen elephant trunk and valve-sparing root reconstruction. Although more complex techniques may provide long-term benefit in selected patients, they require significant surgical expertise and experience. Short-term survival is first priority so an expedited operation that fits in with the surgeon's level of expertise is in most cases appropriate.

Quantification of chronic aortic regurgitation by vector flow mapping: a novel echocardiographic method

AIMS

Quantification of aortic regurgitation (AR) using echocardiography is challenging. A newly established echocardiographic method, vector flow mapping (VFM), can directly measure blood flow volume (FV) regardless of rheological characteristics. We intended to assess the accuracy of VFM in the quantification of chronic AR.

METHODS AND RESULTS

Twenty-one patients with chronic AR, along with 21 healthy volunteers selected as controls, underwent conventional echocardiography and estimation of aortic blood flow using quantitative Doppler and VFM. The regurgitation ratio (RegR), derived as the quotient of backward and forward aortic FV in the ascending aorta measured by VFM, increased with AR severity: 1.1 +/- 1.5% (normal), 11.4 +/- 3.8% (mild AR), 31.2 +/- 8.0% (moderate AR), and 59.3 +/- 4.7% (severe AR). In a linear regression model, RegR closely correlated with the VC width (r = 0.932) and regurgitation fraction and effective regurgitant orifice measured by the quantitative Doppler method (r = 0.929 and 0.891, respectively). The intra- and interobserver variability of RegR was 4.2 and 6.7%, respectively. There was no difference between RegR measured in the apical five-chamber view and in that in apical three-chamber view using the paired t-test (P = 0.751).

CONCLUSION

RegR measured by VFM, a new Doppler method allowing quantitative analysis of FV in spite of the presence of turbulent flow, is a highly reproducible parameter with good accuracy for AR quantification.

Intraobserver variability in grading severity of repeated identical cases of mitral regurgitation

BACKGROUND

In clinical practice, mitral regurgitation (MR) is often assessed from the visual impression of the color Doppler image. It is recognized that repeated scanning can give different images and that different observers may grade the same images differently. In this study, we focus on a more intrinsic source of variability-intraobserver variability in grading of identical images, presented more than once at the same sitting. Furthermore, we look for evidence that observer grading is influenced by the severity of the immediately preceding case viewed.

METHODS

Anonymous, 4-chamber color Doppler 2-dimensional video clips of MR were obtained from 60 unselected patients with MR. Six clips were identified by 2 observers as of contentious severity (either between mild and moderate or between moderate and severe). A 72-clip sequence was constructed from the 54 "uncontentious" selected cases of MR intermingled with 3 presentations of each of the 6 "contentious" images. Each contentious image was shown once without a designed order, once preceded by 3 clips of less severe MR, and once preceded by 3 clips of more severe MR.

RESULTS

Only 1 (8%) of 12 observers gave consistent gradings for the triply presented images. More than 90% (11/12) of the observers reported a different grading of the same clip of MR in at least 1 of the 6 cases. The MR severity was changed in 51.4% of the triplets of identical images shown. Of 12 reporters, 5 (42%) showed classification variability between severe and nonsevere grades in at least 1 of the 6 cases. The direction of change showed no sign of consistency between observers (P = .375).

CONCLUSION

Even a skilled observer cannot be relied upon to give an identical grading to an identical simple video clip of MR, when re-presented surreptitiously within a few minutes. Interobserver variability cannot therefore simply be blamed on differential levels of skill. Because, even under these ideal and dramatically simplified conditions, visual assessment is so variable, the future emphasis of echocardiographic MR grading may lie in integrating qualitative analysis with simple quantification methods.