Limitations of coronary computed tomographic angiography for delineating the lumen and vessel contours of coronary arteries in patients with stable angina

Sex Differences in Aortic Stenosis: From the Pathophysiology to the Intervention, Current Challenges, and Future Perspectives

Calcific aortic stenosis (AS) is a major cause of morbidity and mortality in high-income countries. AS presents sex-specific features impacting pathophysiology, outcomes, and management strategies. In women, AS often manifests with a high valvular fibrotic burden, small valvular annuli, concentric left ventricular (LV) remodeling/hypertrophy, and, frequently, supernormal LV ejection fraction coupled with diastolic dysfunction. Paradoxical low-flow low-gradient AS epitomizes these traits, posing significant challenges post-aortic valve replacement due to limited positive remodeling and significant risk of patient-prosthesis mismatch. Conversely, men present more commonly with LV dilatation and dysfunction, indicating the phenotype of classical low-flow low-gradient AS, i.e., with decreased LV ejection fraction. However, these distinctions have not been fully incorporated into guidelines for AS management. The only treatment for AS is aortic valve replacement; women are frequently referred late, leading to increased heart damage caused by AS. Therefore, it is important to reassess surgical planning and timing to minimize irreversible cardiac damage in women. The integrity and the consideration of sex differences in the management of AS is critical. Further research, including sufficient representation of women, is needed to investigate these differences and to develop individualized, sex-specific management strategies.

Impact of minimal lumen segmentation uncertainty on patient-specific coronary simulations: A look at FFRCT

We examined the effect of minimal lumen segmentation uncertainty on Fractional Flow Reserve obtained from Coronary Computed Tomography AngiographyFFR CT . A total of 14 patient-specific coronary models with different stenosis locations and degrees of severity were enrolled in this study. The optimal segmented coronary lumens were disturbed using intra± 6 % and inter-operator± 15 % variations on the segmentation threshold.FFR CT was evaluated in each case by 3D-OD CFD simulations. The findings suggest that the sensitivity ofFFR CT to this type of uncertainty increases distally and with the stenosis severity. Cases with moderate or severe distal coronary lesions should undergo either exact and thorough segmentation operations or invasive FFR measurements, particularly if theFFR CT is close to the cutoff (0.80). Therefore, we conclude that it is crucial to consider the lesion's location and degree of severity when evaluatingFFR CT results.

Application of Patient-Specific Computational Fluid Dynamics in Anomalous Aortic Origin of Coronary Artery: A Systematic Review

Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital heart condition with fixed and dynamic stenotic elements, potentially causing ischemia. Invasive coronary angiography under stress is the established method for assessing hemodynamics in AAOCA, yet it is costly, technically intricate, and uncomfortable. Computational fluid dynamics (CFD) simulations offer a noninvasive alternative for patient-specific hemodynamic analysis in AAOCA. This systematic review examines the role of CFD simulations in AAOCA, encompassing patient-specific modeling, noninvasive imaging-based boundary conditions, and flow characteristics. Screening articles using AAOCA and CFD-related terms prior to February 2023 yielded 19 publications, covering 370 patients. Over the past four years, 12 (63%) publications (259 patients) employed dedicated CFD models, whereas 7 (37%) publications (111 patients) used general-purpose CFD models. Dedicated CFD models were validated for fixed stenosis but lacked dynamic component representation. General-purpose CFD models exhibited variability and limitations, with fluid-solid interaction models showing promise. Interest in CFD modeling of AAOCA has surged recently, mainly utilizing dedicated models. However, these models inadequately replicate hemodynamics, necessitating novel CFD approaches to accurately simulate pathophysiological changes in AAOCA under stress conditions.

Novel near-infrared spectroscopy-intravascular ultrasound-based deep-learning methodology for accurate coronary computed tomography plaque quantification and characterization

Aims

Coronary computed tomography angiography (CCTA) is inferior to intravascular imaging in detecting plaque morphology and quantifying plaque burden. We aim to, for the first time, train a deep-learning (DL) methodology for accurate plaque quantification and characterization in CCTA using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS).

Methods and results

Seventy patients were prospectively recruited who underwent CCTA and NIRS-IVUS imaging. Corresponding cross sections were matched using an in-house developed software, and the estimations of NIRS-IVUS for the lumen, vessel wall borders, and plaque composition were used to train a convolutional neural network in 138 vessels. The performance was evaluated in 48 vessels and compared against the estimations of NIRS-IVUS and the conventional CCTA expert analysis. Sixty-four patients (186 vessels, 22 012 matched cross sections) were included. Deep-learning methodology provided estimations that were closer to NIRS-IVUS compared with the conventional approach for the total atheroma volume (ΔDL-NIRS-IVUS: -37.8 ± 89.0 vs. ΔConv-NIRS-IVUS: 243.3 ± 183.7 mm3, variance ratio: 4.262, P < 0.001) and percentage atheroma volume (-3.34 ± 5.77 vs. 17.20 ± 7.20%, variance ratio: 1.578, P < 0.001). The DL methodology detected lesions more accurately than the conventional approach (Area under the curve (AUC): 0.77 vs. 0.67, P < 0.001) and quantified minimum lumen area (ΔDL-NIRS-IVUS: -0.35 ± 1.81 vs. ΔConv-NIRS-IVUS: 1.37 ± 2.32 mm2, variance ratio: 1.634, P < 0.001), maximum plaque burden (4.33 ± 11.83% vs. 5.77 ± 16.58%, variance ratio: 2.071, P = 0.004), and calcific burden (-51.2 ± 115.1 vs. -54.3 ± 144.4, variance ratio: 2.308, P < 0.001) more accurately than conventional approach. The DL methodology was able to segment a vessel on CCTA in 0.3 s.

Conclusions

The DL methodology developed for CCTA analysis from co-registered NIRS-IVUS and CCTA data enables rapid and accurate assessment of lesion morphology and is superior to expert analysts (Clinicaltrials.gov: NCT03556644).

Pill or pump? Nitroglycerin 0.5 mg tablet vs 0.8 mg spray: Effect on proximal vessel diameters at Coronary CT Angiography (CCTA)

INTRODUCTION

The administration of sublingual Nitroglycerin (NTG) prior to CT coronary angiography (CCTA) can be perfomed using pump spray or tablets. Choice of method seems to be based on local preference, rather than published guidelines. This retrospective analysis tested whether proximal coronary diameters differed dependent on the sublingual administration of 0.5 mg Nitroglycerin (NTG) tablets or 0.8 mg NTG spray.

METHODS

287 ECG-gated CCTA studies with optimal image quality and Agatston scores<400 were included in this retrospective analysis. 143 of the patients were dosed with NTG tablets at a dose of 0.5 mg prior to CCTA. 144 patients received 2 puffs of 0.4 mg NTG spray for a total dose of 8 mg. All were scanned on a second-generation Dual Source CT. Diameters of proximal segments of Left Main (LM), Right (RCA), Left Anterior (LAD) and circumflex (CX) coronary arteries were measured using semi-automatic electronic callipers by two blinded readers. Results were summarised as the mean of maximum and minimum diameters. Sex-specific analysis of diameters was carried out using repeated-measures ANOVA for each vessel. Agreement between readers was examined with Bland-Altman analysis and intra-class-correlation coefficient (ICC).

RESULTS

No significant differences in coronary diameters were found except in the RCA for women and LM for men. In both cases, diameters were smaller in the spray group (11 and 9%, respectively). Reader agreement was excellent, with ICC>0.96 for all vessels, and no significant bias, except in CX (0.03 mm).

CONCLUSIONS

We found no evidence for the systematic superiority of either administration method in proximal coronary vessels.

IMPLICATIONS FOR PRACTICE

Choosing between tablet or spray NTG prior to CCTA can be guided by practical, economical and hygienic considerations alone.

Identification of vulnerable non-culprit lesions by coronary computed tomography angiography in patients with chronic coronary syndrome and diabetes mellitus

Background

Among patients with diabetes mellitus (DM) and chronic coronary syndrome (CCS), non-culprit lesions (NCLs) are responsible for a substantial number of future major adverse cardiovascular events (MACEs). Thus, we aimed to establish the natural history relationship between adverse plaque characteristics (APCs) of NCLs non-invasively identified by coronary computed tomography angiography (CCTA) and subsequent MACEs in these patients.

Methods

Between January 2016 and January 2019, 523 patients with DM and CCS were included in the present study after CCTA and successful percutaneous coronary intervention (PCI). All patients were followed up for MACEs (the composite of cardiac death, myocardial infarction, and unplanned coronary revascularization) until January 2022, and the independent clinical event committee classified MACEs as indeterminate, culprit lesion (CL), and NCL-related. The primary outcome was MACEs arising from untreated NCLs during the follow-up. The association between plaque characteristics detected by CCTA and primary outcomes was determined by Marginal Cox proportional hazard regression.

Results

Overall, 1,248 NCLs of the 523 patients were analyzed and followed up for a median of 47 months. The cumulative rates of indeterminate, CL, and NCL-related MACEs were 2.3%, 14.5%, and 20.5%, respectively. On multivariate analysis, NCLs associated with recurrent MACEs were more likely to be characterized by a plaque burden >70% [hazard ratio (HR), 4.35, 95% confidence interval (CI): 2.92-6.44], a low-density non-calcified plaque (LDNCP) volume >30 mm³ (HR: 3.40, 95% CI: 2.07-5.56), a minimal luminal area (MLA) <4 mm² (HR: 2.30, 95% CI: 1.57-3.36), or a combination of three APCs (HR: 13.69, 95% CI: 9.34-20.12, p < 0.0001) than those not associated with recurrent MACEs. Sensitivity analysis regarding all indeterminate MACEs as NCL-related ones demonstrated similar results.

Conclusions

In DM patients who presented with CCS and underwent PCI, half of the MACEs occurring during the follow-up were attributable to recurrence at the site of NCLs. NCLs responsible for unanticipated MACEs were frequently characterized by a large plaque burden and LDNCP volume, a small MLA, or a combination of these APCs, as determined by CCTA.

Modification of the HEART pathway by adding coronary computed tomography angiography for patients suspected of acute coronary syndrome in the emergency department

The HEART (history, ECG, age, risk factors, troponin) pathway (HP) was developed for identifying low-risk patients for early discharge among patients presenting with chest pain to the emergency department (ED). We investigated whether adding coronary computed tomography angiography (CCTA) results to selected patients could improve the diagnostic accuracy of the HP. Patients suspected of acute coronary syndrome who had undergone CCTA were included. The HP was modified by adding CCTA results of stenosis of any major epicardial coronary arteries to patients either with 0-3 points and a positive troponin test or with 4-6 points. All patients were reclassified into low and increased risk groups. We then compared the accuracy of the modified HP, the HP, and the HEART score. The primary outcome was the 30-day major adverse cardiac events (MACE). Of the total 1239 patients included, MACE occurred in 206 (16.6%) patients. Adding the CCTA results increased the proportion of patients with low risk (68.7%) compared with the HP (40.0%) and the HEART score (47.4%). Using the modified HP, 50.4% of patients with intermediate-risk by the HEART score could be discharged from the ED and had no MACE. Incorporation of CCTA results improved the accuracy rate for the prediction of MACE compared with the HP and the HEART score (net reclassification improvements were 34.5 and 39.6%, respectively). Using the CCTA after the HP in selected patients could be a better strategy to discharge more patients early and safely.

Value of Transverse Groove on the Earlobe and Hair Growth on the Ear to Predict the Risk for Coronary Artery Disease and Its Severity among Iranian Population, in Tehran City

Background:

The use of phenotypic parameters along with other noninvasive diagnostic modality can lead to early diagnosis of coronary artery disease (CAD) and prevent its life-threatening outcome. Recently, the application of head and face components for assessing the risk for CAD much attention has been paid. The present study aimed to assess the relationship between ear characteristics (transverse groove on the earlobe and hair growth on the ear) and the risk for CAD and its severity among Iranian patients.

Materials and Methods:

In this cross-sectional study, the study population consisted of 105 consecutive patients with suspected CAD undergoing coronary angiography. The severity of CAD was determined by the number of disease vessels as well as the presence of left main lesions assessed by coronary angiography. All patients were examined to evaluate the appearance of ear regarding the presence of transverse groove on the earlobe and hair growth on the ear.

Results:

Comparing cardiovascular parameters across the groups with and without transverse groove on the earlobe showed a higher rate of CAD as well as the higher number of involved coronary arteries than in the groups without transverse groove on the earlobe. Similarly, the presence of CAD and its higher severity were more revealed in patients with hair growth on the ear as compared to the group without this phenotype. According to multivariable logistic regression analysis and with the presence of baseline parameters, the presence of transverse groove on the earlobe and hair growth on the ear increased the risk for CAD by 2.4 and 4.4 fold, respectively.

Conclusion:

Along with classic cardiovascular risk factors, the role of growing hair on the ear and transverse groove on the ear to predict high risk for CAD should be considered.

Clinical utility of coronary computed tomography angiography in patients diagnosed with high-grade stenosis of the coronary arteries

OBJECTIVES

We purposed to evaluate the reliability of coronary computed tomography angiography (CCTA) in patients with a CCTA finding of high-grade stenosis.

PATIENTS AND METHODS

Between May 2015 and March 2017, patients who underwent invasive coronary angiography (ICA) because of detection of high-grade stenosis by CCTA ( ≥ 70% stenosis of epicardial arteries or ≥ 50% of the left main coronary artery; Coronary Artery Disease Reporting and Data System grade 4 or 5) were selected for this study from our prospective registry cohort.

RESULTS

Among 646 eligible patients, only 263 (41%) patients were correctly diagnosed with significant coronary artery disease on ICA as same as CCTA findings. The per-vessel analysis revealed that 620 (68%) of 916 affected vessels had confirmed concordant significant stenosis between the CCTA and ICA results. The concordance rate was 49% among the segments with identified plaques in the per-segment analysis. Revascularization of the target vessel identified with severe stenosis by CCTA was performed in 228 (35%) patients. A logistic regression analysis revealed that smoking [odds ratio (OR): 1.59, 95% confidence interval (CI): 1.04-2.42, P = 0.03], taller height (OR: 1.02, 95% CI: 1.00-1.05, P = 0.016), and presence of typical symptoms of angina (OR: 1.86, 95% CI: 1.34-2.59, P < 0.001) were found to increase the probability of diagnostic concordance. A greater calcified segment involvement score (OR: 0.88, 95% CI: 0.82-0.94, P < 0.001) was associated with a lower diagnostic concordance.

CONCLUSION

The diagnostic discordance between CCTA and ICA was frequently observed in patients who were diagnosed with a CCTA finding of high-grade stenosis.

Clinical Implications of Moderate Coronary Stenosis on Coronary Computed Tomography Angiography in Patients with Stable Angina

PURPOSE

The present study investigated the diagnostic accuracy and clinical implications of moderate stenosis (50-69%, Coronary Artery Disease Reporting and Data System, grade 3) on coronary computed tomography angiography (CCTA), compared with invasive coronary angiography (ICA).

MATERIALS AND METHODS

Two hundred and seventy-six patients who underwent ICA due to moderate stenosis alone on CCTA were selected from our prospective registry cohort.

RESULTS

Diagnostic concordance between CCTA and ICA was found in only 50 (18%) patients. Among the 396 vessels and 508 segments with moderate stenosis, diagnostic concordance was found in 132 vessels (33%) and 127 segments (25%). Segments with calcified plaque had lower diagnostic concordance than those with mixed or non-calcified plaque (22% vs. 28% vs. 27%, respectively, p=0.001). While calcified plaque burden did not have an influence on severe stenosis (≥70%) on ICA, higher burden of non-calcified plaque was correlated with a greater incidence of ICA-based severe stenosis, which was more frequent in patients with ≥3 segments of non-calcified plaque (75%) than those without non-calcified plaque (22%, p<0.001). Typical angina and mixed or non-calcified plaque were correlated with a higher incidence of under-diagnosis, while the use of next-generation computed tomography scanners reduced the incidence of under-diagnosis. Increased body weight, left circumflex artery involvement, and calcified plaque were independent factors that increased the risk of over-diagnosis of CCTA.

CONCLUSION

The diagnosis of moderate stenosis by CCTA may be limited in estimating the exact degree of ICA-based anatomical stenosis. Unlike calcific burden, non-calcific burden was positively correlated with the presence of severe stenosis on ICA.

Coronary Computed Tomographic Angiography Does Not Accurately Predict the Need of Coronary Revascularization in Patients with Stable Angina

PURPOSE

To evaluate the ability of coronary computed tomographic angiography (CCTA) to predict the need of coronary revascularization in symptomatic patients with stable angina who were referred to a cardiac catheterization laboratory for coronary revascularization.

MATERIALS AND METHODS

Pre-angiography CCTA findings were analyzed in 1846 consecutive symptomatic patients with stable angina, who were referred to a cardiac catheterization laboratory at six hospitals and were potential candidates for coronary revascularization between July 2011 and December 2013. The number of patients requiring revascularization was determined based on the severity of coronary stenosis as assessed by CCTA. This was compared to the actual number of revascularization procedures performed in the cardiac catheterization laboratory.

RESULTS

Based on CCTA findings, coronary revascularization was indicated in 877 (48%) and not indicated in 969 (52%) patients. Of the 877 patients indicated for revascularization by CCTA, only 600 (68%) underwent the procedure, whereas 285 (29%) of the 969 patients not indicated for revascularization, as assessed by CCTA, underwent the procedure. When the coronary arteries were divided into 15 segments using the American Heart Association coronary tree model, the sensitivity, specificity, positive predictive value, and negative predictive value of CCTA for therapeutic decision making on a per-segment analysis were 42%, 96%, 40%, and 96%, respectively.

CONCLUSION

CCTA-based assessment of coronary stenosis severity does not sufficiently differentiate between coronary segments requiring revascularization versus those not requiring revascularization. Conventional coronary angiography should be considered to determine the need of revascularization in symptomatic patients with stable angina.