Long-Term Prognosis of Patients With Intramural Course of Coronary Arteries Assessed With CT Angiography

Non-Invasive Assessment of Endothelial Shear Stress in Myocardial Bridges Using Coronary Computed Tomography Angiography

Myocardial bridging (MB) is a segment of coronary arteries with an intramural course, typically spared from atherosclerosis, while the adjacent proximal segment is reported to be atherosclerosis-prone, a phenomenon contributed to local endothelial shear stress (ESS). We aimed to describe the ESS milieu in coronaries with MBs combining coronary computed tomography angiography with computational fluid dynamics and to investigate the association of atherosclerosis presence proximal to MBs with hemorheological characteristics. Patients (n = 36) were identified and 36 arteries with MBs (11 deep and 25 superficial) were analyzed. ESS did not fluctuate 5 mm proximally to MBs vs 5 mm within MBs (0.94 vs 1.06 Pa, p = .56). There was no difference when comparing ESS in the proximal versus mid versus distal MB segments (1.48 vs 1.37 vs 1.9 Pa, p = ns). In arteries with plaques (n = 12), no significant ESS variances were observed around the MB entrance, when analyzing all arteries (p = .81) and irrespective of morphological features of the bridged segment (deep MBs; p = .65, superficial MBs; p = .84). MBs are characterized by homogeneous, atheroprotective ESS, possibly explaining the absence of atherosclerosis within bridged segments. The interplay between ESS and atherosclerosis is potentially not different in arteries with MB compared with arteries without bridges.

Combined Computed Tomography Angiography-Computed Tomography Perfusion in the Identification and Prognostic Assessment of Myocardial Bridging from the CORE320 Study: 5-Year Follow-Up

Our objective is to use computed tomography angiography (CTA) and computed tomography perfusion (CTP) to identify the ischemic significance of myocardial bridging (MB). We also seek to determine the long-term prognostication of MB in the presence or absence of obstructive coronary artery disease (CAD). The CORE320, a prospective, multicenter study including 381 patients with known or suspected CAD clinically referred for invasive coronary angiography who underwent combined (CTA-CTP) and single-photon emission computed tomography before conventional coronary angiography. The incidence of MB was identified in 135 patients (35.4%) with 93.9% identified in the left anterior descending artery. MB were divided as partially encased versus fully encased. There was no difference in ischemia identified between partially encased MB and fully encased MB (37 [40%] vs 25 [35%], p = 0.54]. Ischemia was identified at similar rates in partially versus fully encased MB by single-photon emission computed tomography at (8 [9%] vs 8 [11%], p = 0.57] and CTP (34 [37%] vs 21 [30%], p = 0.33]. There was no difference in the primary outcome of 5-year outcome of combined incidence of myocardial infarction or death. The restricted mean survival time in patients with CTA with <50% stenosis with or without a MB was 4.906 years (95% confidence interval 4.759 to 5.000) and 4.891 years (95% confidence interval 4.718 to 5.000), respectively (p = 0.824). Cardiac computed tomography perfusion imaging can assess both anatomic and functional significance of myocardial bridging with diagnostic accuracy similar to current standard imaging. Furthermore, 5-year cardiovascular events were not different with the presence of MB in both obstructive and non-obstructive CAD.

Challenges in Evaluation and Management of Children with Myocardial Bridging

Myocardial bridging (MB) is a congenital anomaly where a coronary artery branch or group of branches extends inside a tunnel consisting of myocardium. Although it is mostly considered "benign," it is reported that MB may lead to significant cardiac problems and sudden cardiac deaths. While it is a congenital anomaly, its symptoms usually arise at further ages rather than childhood. The literature on MB in children is in the form of case reports or small case series. This is why pediatric cases are assessed in the light of information obtained from adults. This review compiled the literature on MB in adults and children and compared it, as well as discussing questions arising regarding the clinic, diagnosis, and treatment of MB.

Prevalence and characteristics of intramural coronary artery in hypertrophic obstructive cardiomyopathy: a coronary computed tomography and invasive angiography study

Background

The prevalence and morphologic characteristics of intramural coronary artery (ICA) in patients with hypertrophic obstructive cardiomyopathy (HOCM) have yet to be fully illuminated. Our study aimed to investigate the prevalence and morphologic characteristics of ICA in patients with HOCM using coronary computed tomography (CT) angiography and invasive coronary angiography.

Methods

Patients with a diagnosis of HOCM who were admitted for selective myectomy in Fuwai Hospital were prospectively enrolled between September 2015 and June 2019. Both preoperative coronary CT and invasive angiography were scheduled for all participants.

Results

Coronary CT angiography detected ICA in 106 (23.3%) out of 455 patients. Dynamic compression of coronary arteries was observed in 87 patients (19.1%) by invasive coronary angiography. We found ICA covered with complete myocardial encasement in 98 patients (92.5%), with deep myocardial bridging (MB) observed most frequently (P=0.005). All patients with dynamic compression of coronary arteries had ICA. Dynamic luminal reduction ≥50% was present in 77 (16.9%) of the study participants. Pearson's correlation analysis revealed that the length and degree of dynamic compression were significantly related with MB length and depth (Pearson's correlation r=0.241, 0.581, 0.316, and 0.209; P=0.014, <0.001, 0.002, and 0.032, respectively).

Conclusions

Patients with HOCM commonly present with ICA and it can be visualized well by coronary CT angiography. Deep or extensive MB is more likely to produce coronary artery dynamic compression. Preoperative identification of this congenital coronary artery variant may be helpful for surgical planning.

Anatomical characteristics of anomalous left coronary artery from the opposite sinus (left-ACAOS) and its clinical relevance: A serial coronary CT angiography study

BACKGROUND

Anomalous left coronary artery from the opposite sinus (left-ACAOS) is a rare congenital heart disease. While "interarterial course" is considered as the malignant anatomic feature for these patients, a number of patients with left-ACAOS, who don't follow the above anatomic pattern, were reported with ischemic symptoms.

PURPOSE

This study aims to evaluate the anatomic characteristics of left-ACAOS and their clinical relevance.

METHODS

The coronary computed tomography angiography (CCTA) data from 44 patients with 46 left-ACAOS vessels were retrospectively included. Patients were divided into 2 groups: those with ischemic symptoms (n = 19) and those without ischemic symptoms (n = 25). Baseline clinical characteristics were recorded and the follow-up was done by telephone. CCTA images were reviewed for anomalous coronary artery, take-off angle and level, ostia morphology and grading, proximal narrowing, anomalous course and atherosclerotic plaques.

RESULTS

The prevalence of left-ACAOS was approximately 0.09% among 48, 719 consecutive patients referred for coronary CTA in our institution. Right sinus of Valsalva (RSV) was the most common origin (36/46, 78.26%). Left-ACAOS arising from right coronary artery (RCA) had narrower proximal segment (P = 0.014) and more prone to atherosclerosis (P = 0.040) than left-ACAOS arising from right sinus of Valsalva (RSV). Proximal narrowing severity (P < 0.001) and degree of maximal coronary stenosis (P = 0.034) of the anomalous left artery was higher in patients with ischemic symptoms than those without. Of note, no MACE was recorded during a mean follow-up of 43.4 ± 26.2 months.

CONCLUSION

Left-ACAOS arising from RCA seems to be more prone to atherosclerosis than other subtypes. Proximal narrowing was more severe in patients with ischemia symptoms, which may contribute to risk stratification and clinical management.

Coronary plaque burden of the left anterior descending artery in patients with or without myocardial bridge: A case-control study based on coronary CT-angiography

BACKGROUND

The clinical significance of myocardial bridging (MB) on the left anterior descending artery (LAD) is debated. We aimed to assess the association between MB and LAD plaque volumes/compositions in a case-control set up.

METHODS

In our retrospective analysis we investigated 50 cases with incidentally recognized LAD MB and 50 matched controls without LAD MB on coronary computed tomography angiography. We quantified plaque volumes proximal to the MB and beneath it in patients with MB and in the corresponding coronary segments in patients without MB.

RESULTS

In total, we have included 100 patients (mean age 60.6 ± 10.8 years, males: 80%). Plaque volume was similar in the LAD segments proximal to the MB in cases vs. controls (150.0 mm³ [IQR: 90.7-194.5 mm³] vs. 132.8 mm³ [IQR: 94.2-184.3 mm³], respectively; p = 0.95) while the plaque volume was smaller beneath LAD MB vs. control segment (16.2 mm³ [IQR: 12.6-25.8 mm³] vs. 21.1 mm³ [IQR: 14.0-42.4 mm³], respectively; p = 0.002). No significant differences were found regarding different plaque components in segments proximal to the MB while fatty plaque and necrotic core volumes were smaller or negligible in coronary segment beneath MB than in controls (0.07 mm³ [IQR: 0.005-0.27 mm³] vs. 12.7 mm³ [IQR: 7.4-24.4 mm³] and 0.00 mm³ [IQR: 0.00-0.04 mm³] vs. 0.06 mm³ [IQR: 0.03-2.8 mm³], respectively (p < 0.001).

CONCLUSION

Comparing patients with MB vs. matched controls without it, MB was not associated with increased plaque volumes in LAD segment proximal to MB and plaque quantity was smaller in the MB segment. Our data are supportive of benign nature of incidentally recognized LAD MB.

Associations of myocardial bridging with adverse cardiac events: a meta-analysis of published observational cohort studies involving 4,556 individuals

Background

Data derived from small series have demonstrated an association of myocardial bridge (MB) with adverse cardiac events, while MB has been traditionally considered as a benign condition. Hence, the precise clinical implications of MB on prognosis remains inconsistent. Our purpose is to perform a meta-analysis to assess the clinical implications of MB on prognosis.

Methods

We performed an extensive search of PubMed and reference lists of relevant articles. Studies which compared prognosis between subjects with and without MB were identified from 1960 to 31 March 2018. Studies selection was limited to human data and restricted to English language.

Results

Six eligible studies were included in current meta-analysis. Of 4,556 subjects, 1,389 (30.5%) presented MB. MB was associated with an increased risk of adverse cardiac events [odds ratio (OR), 1.71; 95% confidence interval (CI): 1.29 to 2.26; P=0.0002], non-fatal myocardial infarction (OR: 3.17; 95% CI: 1.21 to 8.31; P=0.02), and angina requiring hospitalization (OR: 2.31; 95% CI: 1.55 to 3.45; P<0.0001), respectively, compared with subjects without MB.

Conclusions

This meta-analysis of currently available observational cohort studies suggests that MB has an association with adverse cardiac events. Further prospective multicenter studies with large sample size are needed to confirm current findings. Moreover, studies refining the impact of different types of MB on cardiac events, myocardial ischemia, and symptoms requiring therapy, may provide more insights to this issue.

Effect of Intramural Course of Coronary Arteries Assessed by Computed Tomography Angiography in Patients With Hypertrophic Cardiomyopathy

This study evaluated the prevalence, anatomical pattern, and prognostic implications of an intramural course of the coronary arteries in patients with hypertrophic cardiomyopathy (HC). The study population consisted of 92 patients with HC and 100 patients without HC. The presence of an intramural course of the coronary arteries was evaluated by coronary computed tomography angiography (CTA), and its length and depth were measured. During follow-up, the occurrence of unstable angina requiring hospitalization, myocardial infarction, and all-cause mortality was evaluated. An intramural course of the coronary arteries was more common in patients with HC than patients without HC (62% vs 25%, p <0.001). In the patients with an intramural coronary artery course, those with HC had a longer course (29.1 ± 15.3 mm vs 23.0 ± 13.0 mm; p = 0.037) with deeper penetration into the left ventricular myocardium (2.8 ± 1.2 mm vs 2.1 ± 0.8 mm; p = 0.007) and more involvement of multiple coronary arteries (38% vs 4%; p <0.001). During follow-up (mean 5.5 ± 3.5 years), cardiac events occurred in 17 of 57 patients (29.8%) with an intramural course and 11 of 35 (31.4%) without an intramural course (p = 0.87). On Kaplan-Meier survival analysis, there was no difference in cumulative event rate between HC patients with or without an intramural course (p = 0.89, log rank test). In conclusion, patients with HC have a high rate of an intramural course of the coronary arteries on CTA. The number of involved arteries and the length and depth of the intramural course differ between patients with and without HC, but apparently have no association with worse clinical outcomes.

Optimized protocol of multiple post-processing techniques improves diagnostic accuracy of multidetector computed tomography in assessment of small bowel obstruction compared with conventional axial and coronal reformations

BACKGROUND

Axial and coronal reformations have been a widely used image post-processing protocol for the ordinary multidetector computed tomography (MDCT) examination of patients with small bowel obstruction (SBO) or other abdominal diseases. The diagnostic accuracy of MDCT for assessing SBO is expected to be further improved through the use of multiple post-processing techniques.

AIM

To systemically evaluate the diagnostic accuracy and efficiency of an optimized protocol using multiple post-processing techniques for MDCT assessment of SBO and secondary bowel ischemia.

METHODS

This retrospective cross-sectional study included 106 patients with clinically suspected SBO. Two readers applied three protocols to image post-processing and interpretation of patients’ MDCT volume data. We compared the three protocols based on time spent, number of images, diagnostic self-confidence, agreement, detection rate, and accuracy of detection of SBO and secondary bowel ischemia.

RESULTS

Protocol 2 resulted in more time spent and number of images than protocols 1 and 3 (P < 0.01), but the results of the two readers using the same protocol were not different (P > 0.05). Using protocol 3, both readers added multiple post-processing techniques at frequencies of 29.2% and 34.9%, respectively, for obstruction cause, and 32.1% and 30.2%, respectively, for secondary bowel ischemia. Protocols 2 and 3 had higher total detection rates of obstruction cause and secondary bowel ischemia than protocol 1 (P < 0.01), but no difference was detected between protocols 2 and 3 (P > 0.05). The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of protocols 2 and 3 were superior to those of protocol 1 for evaluating obstruction cause and secondary bowel ischemia.

CONCLUSION

Our optimized protocol of multiple post-processing techniques can both guarantee efficiency and improve diagnostic accuracy of MDCT for assessing SBO and secondary bowel ischemia.