Improved diagnostic performance of transluminal attenuation gradient in combination with morphological evaluation of coronary artery stenosis using 320-row computed tomography

Purpose

To assess the utility of transluminal attenuation gradient (TAG) in combination with coronary computed tomography angiography (CTA) for detecting obstructive coronary artery stenosis.

Materials and methods

We retrospectively evaluated coronary CTA data in 35 consecutive patients who underwent invasive coronary angiography (ICA). We compared the diagnostic performance of TAG with that of quantitative coronary angiography, which we used as the reference standard. For the combination of TAG and coronary CTA, we designed a logical conjunction model (CCTA&&TAG) as well as a logical disjunction model (CCTA||TAG), and evaluated their diagnostic accuracies.

Results

Among 130 vessels of 35 patients, 30 lesions (23%) showed significant stenosis on ICA. TAG predicted significant coronary artery stenosis with a sensitivity of 75%, specificity of 63%, positive predictive value of 40%, negative predictive value of 89%, and accuracy of 66%, and had a cutoff value of ? 15.4 HU/10 mm. The respective values for CCTA&&TAG were 73, 98, 88, 90, and 90%; those for CCTA||TAG were 94, 61, 56, 94, and 72%. CCTA&&TAG improved the diagnostic accuracy significantly more than CCTA||TAG.

Conclusion

TAG in conjunction with coronary CTA improves the diagnostic accuracy of coronary CTA.

     

Correlation and predictive value of aortic root calcification markers with coronary artery calcification and obstructive coronary artery disease

Objective

To evaluate the correlation between aortic root calcification (ARC) markers and coronary artery calcification (CAC) derived from coronary artery calcium scoring (CACS) and their ability to predict obstructive coronary artery disease (CAD).

Methods

We retrospectively analyzed 189 patients (47% male, age 60.3 ± 11.1 years) with an intermediate probability of CAD who underwent clinically indicated CACS and coronary CT angiography (CCTA). ARC markers [aortic root calcium score (ARCS) and volume (ARCV)] were calculated and compared to CAC markers: coronary artery calcium score (CACS), volume (CACV), and mass (CACM). CCTA datasets were visually evaluated for significant CAD (stenosis ≥ 50%) and the ability of ARC markers to predict obstructive CAD was assessed.

Results

ARCS (mean 67.7 ± 189.5) and ARCV (mean 67.3 ± 184.7) showed significant differences between patients with and without CAC (109.4 ± 238.6 vs 9.42 ± 31.4, p < 0.0001; 108.5 ± 232.4 vs 9.9 ± 30.5, p < 0.0001). A strong correlation was found for ARCS and ARCV with CACS, CACM, and CACV (all p < 0.0001). In a multivariate analysis, ARCS (OR 1.09, p = 0.033) and ARCV (OR 1.12, p = 0.046) were independent markers for CAC. Using a receiver-operating characteristics analysis, the AUC to detect severe CAC was 0.71 (p < 0.0001) and 0.71 (p < 0.0001) for ARCS and ARCV, respectively. ARCS (0.67, p < 0.0001) and ARCV (0.68, p < 0.0001) showed discriminatory power for predicting obstructive CAD, yielding sensitivities 61 and 78% and specificities of 62 and 80%, respectively.

Conclusion

ARC markers are associated with and independently predict the presence of CAC and obstructive CAD. Further testing is required in patients with severe ARC and significant CAD in order to reliably obtain these markers from thoracic-CT or X-ray for proper risk classification.

     

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.

     

Segmental quantitative myocardial perfusion with PET for the detection of significant coronary artery disease in patients with stable angina

Purpose

The goal of this study is to determine the technical accuracy of segmental perfusion parameters assessed with quantitative cardiac PET imaging in the evaluation of coronary artery disease (CAD) in patients with stable angina.

Methods

A cohort of patients who participated in the EVINCI protocol underwent an evaluation of coronary anatomy by invasive coronary angiography (ICA) and/or coronary computed tomography angiography (CCTA) and PET myocardial perfusion imaging with H₂ ¹⁵O, ¹³NH₃ or ⁸²Rb. PET studies were analyzed by two independent observers blinded to clinical and instrumental data, and classified as positive or negative for significant CAD using only segmental perfusion measurements and cut-off values from literature.

Results

On a per-patient basis, the overall inter-observer agreement on PET results was 90 % (kappa?=?0.79), indicating substantial agreement. On a per-vessel basis, the inter-observer agreement on PET results was 88 % (kappa?=?0.74) in the RCA territory, 94 % (kappa?=?0.84) in the LAD territory and 94 % (kappa?=?0.85) in the LCX territory.Segmental PET measurements correctly identified 85 % of the patients, resulting in a global sensitivity of 86 %, a specificity of 84 %, a positive predictive value (PPV) of 69 % and a negative predictive value (NPV) of 93 %.In vessel-based analyses, quantitative perfusion parameters had a sensitivity, specificity, PPV and NPV of 92 %, 82 %, 42 % and 99 %, respectively, for the detection of significant coronary stenoses in all major coronary arteries.

Conclusions

The assessment of absolute myocardial perfusion parameters measured at a segment level lead to reliable and accurate identification of patients with significant coronary stenosis at ICA and/or CCTA.

     

Relationship between diverse patient body size- and image acquisition-related factors,and quantitative and qualitative image quality in coronary computed tomography angiography: a multicenter observational study

Purpose

We investigated the effects of patient- and image acquisition-related factors on the image quality in coronary CT angiography (CCTA).

Materials and methods

We enrolled 1197 patients (728 men; 65 ± 12 years). All underwent CCTA under the routine scan protocol in 23 participating hospitals. The subjective image quality (3-point Likert scale: excellent, good, and poor) and the attenuation of the left and right coronary artery (LCA, RCA) were recorded; the effects of patient and image acquisition-related factors on vascular attenuation were then compared.

Results

The mean LCA attenuation was 515.2 ± 65.8 (excellent), 401.4 ± 63.4 (good), and 319.5 ± 47.6 HU (poor). The corresponding RCA attenuation was 496.6 ± 67.6, 390.5 ± 58.5, and 308.5 ± 50.7 HU, respectively. Univariate analysis revealed significant associations between sufficient coronary attenuation (> 400 HU) and the age, gender, body surface area (BSA), number of detectors, contrast synchronization, scan mode, and the fractional contrast dose. Multivariate analysis revealed that the bolus tracking method, prospective electrocardiogram gating, and fractional contrast dose were significantly associated with sufficient coronary enhancement.

Conclusion

BSA and fractional contrast dose are the most important patient- and image acquisition-related factors for sufficient coronary attenuation in CCTA.

     

Prognostic value of coronary atherosclerosis progression evaluated by coronary CT angiography in patients with stable angina

Objectives

To investigate the progression of coronary atherosclerosis burden by coronary CT angiography (CCTA) and to demonstrate its association with the incidence of major adverse cardiac events (MACE).

Methods

We retrospectively studied patients with stable angina who had undergone repeat CCTA due to recurrent or worsening symptoms. Lipid-rich, fibrous, calcified and total plaque burden as well as coronary diameter stenosis were quantitatively analysed. The incidence of MACE during follow-up was determined.

Results

The final cohort consisted of 268 patients (mean age 52.9 ± 9.8 years, 71 % male) with a mean follow-up period of 4.6 ± 0.9 years. Patients with lipid-rich, fibrous, calcified and total plaque burden (%) progression, as well as coronary diameter stenosis (%) progression had a significantly higher incidence of MACE than those without (all p < 0.05). The progression of lipid-rich plaque (HR = 1.601, p = 0.021), total plaque burden (HR = 2.979, p = 0.043) and coronary diameter stenosis (HR = 4.327, p <0.001) were independent predictors of MACE (all p < 0.05).

Conclusions

Patients presenting with recurrent or worsening symptoms associated with coronary artery disease who have coronary atherosclerosis progression on CCTA are at an increased risk of future MACE.

Key Points

? Repeat CCTA can provide information regarding the progression of coronary atherosclerosis. ? Coronary atherosclerosis progression at CCTA is independently associated with MACE. ? CCTA findings could serve as incremental predictors of MACE.

     

Low Contrast Dose Catheter-Directed CT Angiography (CCTA)

Purpose

Catheter-directed computed tomography angiography (CCTA) has been shown to reduce the contrast volumes required in conventional CTA, thus minimizing the risk of contrast-induced nephropathy (CIN).

Materials and Methods

A retrospective analysis was performed on cases where CCTA was used to assess access vessels prior to transfemoral aortic valve implantation (TAVI, n = 53), abdominal aortic aneurysm assessment for endovascular aneurysm repair (EVAR, n = 11), and peripheral vascular disease (PVD, n = 24).

Results

We show that CCTA can image vasculature with adequate diagnostic detail to allow assessment of lower extremity disease, anatomic suitability for EVAR, as well as potential contraindications to TAVI. Average contrast volumes for pre-TAVI, pre-EVAR, and PVD cases were 7, 11, and 28 mL, respectively.

Conclusion

This study validates the use of CCTA in obtaining diagnostic images of the abdominal and pelvic vessels and in imaging lower extremity vasculature.

     

Using coronary CT angiography for guiding invasive coronary angiography: potential role to reduce intraprocedural radiation exposure

Objectives

We investigated the potential reduction of patient exposure during invasive coronary angiography (ICA) if the procedure had only been directed to the vessel with at least one ≥ 50% stenosis as described in the CT report.

Methods

Dose reports of 61 patients referred to ICA because of at least one ≥ 50% stenosis on coronary CT angiography (CCTA) were included. Dose–area product (DAP) was documented separately for left (LCA) and right coronary arteries (RCA) by summing up the single DAP for each angiographic projection. The study population was subdivided as follows: coronary intervention of LCA (group 1) or RCA (group 2) only, or of both vessels (group 3), or further bypass grafting (group 4), or no further intervention (group 5).

Results

57.4% of the study population could have benefitted from reduced exposure if catheterization had been directly guided to the vessel of interest as described on CCTA. Mean relative DAP reductions were as follows: group 1 (n = 18), 11.2%; group 2 (n = 2), 40.3%; group 3 (n = 10), 0%; group 4 (n = 3), 0%; group 5 (n = 28), 28.8%.

Conclusions

Directing ICA to the vessel with stenosis as described on CCTA would reduce intraprocedural patient exposure substantially, especially for patients with single-vessel stenosis.

Key points

? Patients with CAD can benefit from decreased radiation exposure during coronary angiography. ? ICA should be directed solely to significant stenoses as described on CCTA. ? Severely calcified plaques remain a limitation of CCTA leading to unnecessary ICA referrals.

     

<Emphasis Type="Bold">Discrepancies between coronary CT angiography and invasive coronary angiography with focus on culprit lesions which cause future cardiac events</Emphasis>

Objectives

To evaluate the clinical significance of discrepant lesions between coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) in a longitudinal study.

Methods

In 220 patients with suspected coronary artery disease (CAD) who underwent both 256-row CCTA and ICA, the obstructive CAD (≥ 50% stenosis) on CCTA was compared with that on ICA as the reference standard. We analysed the causes of the discrepancy between CCTA and ICA. During a 40-month follow-up period, major adverse cardiac events (MACE) were assessed.

Results

Discordance between CCTA and ICA was observed in 121 of the 3166 coronary artery segments (3.8%). Common causes were calcification (45.9%) and positive remodelling (PR) (29.6%) in 83 false positive lesions, and noise (40.0%) and motion artefact (37.8%) in 38 false negative lesions. MACE occurred in seven lesions among the discrepant lesions; six among the 29 PR lesions (20.7%) and one among the 53 calcified lesions (1.9%). With respect to the prediction power of MACE in an intermediate stenosis, the CCTA-related value including PR was higher than the ICA-related value.

Conclusions

PR was a frequent cause of MACE among the false positive lesions on CCTA. Therefore, the presence of PR on CCTA may suggest clinical significance, although it can be missed by ICA.

Key Points

? Compared to ICA, PR in CCTA may be cause of false positive lesion. ? CCTA-related value including PR shows higher prediction power of MACE than ICA-related value. ? PR reflects atherosclerotic burden that can be related to cardiac events. ? PR in CCTA should be observed carefully, even if it is false positive.

     

Coronary flow reserve and relative flow reserve measured by N-13 ammonia PET for characterization of coronary artery disease

Objective

We evaluated the relationships between coronary flow reserve (CFR) and relative flow reserve (RFR) measured by N-13 ammonia positron emission tomography (PET) for characterization of epicardial coronary artery disease (CAD).

Methods

Sixty-nine consecutive stable angina patients underwent N-13 ammonia PET, coronary computed tomography angiography (CCTA), and if necessary, invasive coronary angiography (CAG) within 2 weeks. Myocardial blood flow (MBF), CFR, RFR, and coronary vascular resistance of the reference arterial territory (CVR_ref) were measured by N-13 ammonia PET. The presence of significant stenosis (SS) and diffuse atherosclerosis (DA) was evaluated on CCTA and CAG. Functional parameters measured by PET were compared among arteries with and without SS and DA.

Results

Arteries with SS and those with DA showed significantly lower stress MBF, as compared to those without. RFR was significantly lower in arteries with SS as compared to those without, while CFR was not. CFR was significantly lower in arteries with DA as compared to those without, while RFR was not. Among arteries without SS, CFR was significantly lower in those with DA as compared to those without. However, among arteries with SS, CFR was similar between those with and without DA. In contrast, RFR was significantly lower in arteries with SS, regardless of the presence of DA. CFR and RFR showed a weak positive correlation (r = 0.269) with discordance in 24 cases (35%). Among the arteries with CFR-RFR discordance, the prevalence of DA was significantly higher in those with low CFR but preserved RFR, as compared to those with preserved CFR but low RFR (75 vs 25%, p = 0.028). CVR_ref was significantly higher in arteries with DA, implicating a correlation of DA with underlying microvascular disease.

Conclusions

CFR and RFR measured by myocardial perfusion PET could provide a comprehensive information for characterization of epicardial CAD.

     

Comprehensive morphologic and functional imaging of heart transplant patients: first experience with dynamic perfusion CT

Objectives

We aimed to assess the diagnostic performance of a combined protocol with coronary computed tomography angiography (CCTA) and stress CT perfusion imaging (CTP) in heart transplant patients for comprehensive morphological and functional imaging.

Methods

In this prospective study, 13 patients undergoing routine follow-up 8±6 years after heart transplantation underwent CCTA and dynamic adenosine stress CTP using a third-generation dual-source CT scanner, cardiac magnetic resonance (MR) adenosine stress perfusion imaging at 1.5 T, and catheter coronary angiography. In CCTA stenoses >50% luminal diameter narrowing were noted. Myocardial perfusion deficits were documented in CTP and MR. Quantitative myocardial blood flow (MBF) was calculated with CTP. Left ventricular ejection fraction was determined on cardiac MR cine images. Radiation doses of CT were determined.

Results

One of the 13 patients had to be excluded because of severe motion artifacts. CCTA identified three patients with stenosis >50%, which were confirmed with catheter coronary angiography. CTP showed four patients with stress-induced myocardial hypoperfusion, which were confirmed by MR stress perfusion imaging. Quantitative analysis of global MBF showed lower mean values as compared to known reference values (MBF under stress 125.5 ± 34.5 ml/100 ml/min). Average left ventricular ejection fraction was preserved (56 ± 5%).

Conclusions

In heart transplant patients, a comprehensive CT protocol for the assessment of morphology and function including CCTA and CTP showed good concordance to results from MR perfusion imaging and catheter coronary angiography.

Key Points

? Stress CT perfusion imaging enables the detection of myocardial ischemia ? CT myocardial perfusion imaging can be combined with coronary computed tomography angiography ? Combining perfusion and coronary CT imaging is accurate in heart transplant patients ? CT myocardial perfusion imaging can be performed at a reasonable radiation dose

     

Quantitative coronary CT angiography: absolute lumen sizing rather than %stenosis predicts hemodynamically relevant stenosis

Objective

To identify the most accurate quantitative coronary stenosis parameter by CTA for prediction of functional significant coronary stenosis resulting in coronary revascularization.

Methods

160 consecutive patients were prospectively examined with CTA. Proximal coronary stenosis was quantified by minimal lumen area (MLA) and minimal lumen diameter (MLD), %area and %diameter stenosis. Lesion length (LL) was measured. The reference standard was invasive coronary angiography (ICA) (>70 % stenosis, FFR <0.8).

Results

210 coronary segments were included (59 % positive). MLA of ≤1.8 mm² was identified as the optimal cut-off (c?=?0.97, p?<?0.001; 95 % CI 0.94–0.99) (sensitivity 90.9 %, specificity 89.3 %) for prediction of functional-relevant stenosis (for MLA >2.1 mm² sensitivity was 100 %). The optimal cut-off for MLD was 1.2 mm (c?=?0.92; p?<?0.001; 95 % CI 0.88–95) (sensitivity 90.9, specificity 85.2) while %area and %diameter stenosis were less accurate (c?=?0.89; 95 % CI 0.84–93, c?=?0.87; 95 % CI 0.82–92, respectively, with thresholds at 73 % and 61 % stenosis). Accuracy for LL was c?=?0.74 (95 % CI 0.67–81), and for LL/MLA and LL/MLD ratio c?=?0.90 and c?=?0.84.

Conclusions

MLA ≤1.8 mm² and MLD ≤1.2 mm are the most accurate cut-offs for prediction of haemodynamically significant stenosis by ICA, with a higher accuracy than relative % stenosis.

Key Points

? Quantitative coronary CT-angiography is accurate for prediction of functional relevant stenosis. ? Absolute lumen area and diameter rather than %stenosis predict functional relevance. ? Lumen area <1.8 mm ² and diameter <1.2 mm are the most accurate cut-offs. ? Quantitative parameters are helpful for decision-making in terms of patient management.

     

Iterative image reconstruction algorithms in coronary CT angiography improve the detection of lipid-core plaque – a comparison with histology

Objectives

To evaluate whether iterative reconstruction algorithms improve the diagnostic accuracy of coronary CT angiography (CCTA) for detection of lipid-core plaque (LCP) compared to histology.

Methods and materials

CCTA and histological data were acquired from three ex vivo hearts. CCTA images were reconstructed using filtered back projection (FBP), adaptive-statistical (ASIR) and model-based (MBIR) iterative algorithms. Vessel cross-sections were co-registered between FBP/ASIR/MBIR and histology. Plaque area <60 HU was semiautomatically quantified in CCTA. LCP was defined by histology as fibroatheroma with a large lipid/necrotic core. Area under the curve (AUC) was derived from logistic regression analysis as a measure of diagnostic accuracy.

Results

Overall, 173 CCTA triplets (FBP/ASIR/MBIR) were co-registered with histology. LCP was present in 26 cross-sections. Average measured plaque area <60 HU was significantly larger in LCP compared to non-LCP cross-sections (mm²: 5.78?±?2.29 vs. 3.39?±?1.68 FBP; 5.92?±?1.87 vs. 3.43?±?1.62 ASIR; 6.40?±?1.55 vs. 3.49?±?1.50 MBIR; all p?<?0.0001). AUC for detecting LCP was 0.803/0.850/0.903 for FBP/ASIR/MBIR and was significantly higher for MBIR compared to FBP (p?=?0.01). MBIR increased sensitivity for detection of LCP by CCTA.

Conclusion

Plaque area <60 HU in CCTA was associated with LCP in histology regardless of the reconstruction algorithm. However, MBIR demonstrated higher accuracy for detecting LCP, which may improve vulnerable plaque detection by CCTA.

Key Points

? A low attenuation plaque area is associated with the presence of lipid-core plaque ? MBIR leads to higher diagnostic accuracy for detecting lipid-core plaque ? The benefit of MBIR is mainly due to increased sensitivity at high specificities ? Semiautomated CCTA assessment can detect vulnerable plaques non-invasively

     

Coronary computed tomography angiography using 128-slice dual-source computed tomography in patients with severe calcification

Purpose

To compare coronary computed tomography angiography (CTA) and coronary angiography (CAG) with regard to luminal graphic definition of calcified segments using 128-slice dual-source computed tomography (DSCT), specifically for patients with an Agatston score >400.

Materials and methods

Of 1148 consecutive patients who underwent coronary CTA using a 128-slice DSCT, 132 subjects had severe calcification with an Agatston score >400. Thirty-nine of the 132 patients who had undergone CAG within 3 months before or after coronary CTA were included. We investigated the distribution of calcification, and we visually evaluated significant stenosis in the calcified and all segments. Results were compared with CAG.

Results

The target group in this study had a very high mean Agatston score of 1771 ± 1724. Results for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 247 calcified vs all 325 segments were as follows: sensitivity 93.2 vs 92.2%, specificity 83.9 vs 87.5%, PPV 70.8 vs 69.6%, and NPV 96.7 vs 97.3%, respectively.

Conclusion

128-slice DSCT has potential for evaluation of calcified segments in the lumen, even in patients whose Agatston score exceeds 400.

     

Diagnostic accuracy of coronary CT angiography using 3<Superscript>rd</Superscript>-generation dual-source CT and automated tube voltage selection: Clinical application in a non-obese and obese patient population

Purpose

To investigate diagnostic accuracy of 3^rd-generation dual-source CT (DSCT) coronary angiography in obese and non-obese patients.

Methods

We retrospectively analyzed 76 patients who underwent coronary CT angiography (CCTA) and invasive coronary angiography. Prospectively ECG-triggered acquisition was performed with automated tube voltage selection (ATVS). Patients were dichotomized based on body mass index in groups A (<30 kg/m², n?=?37) and B (≥30 kg/m², n?=?39) and based on tube voltage in groups C (<120 kV, n?=?46) and D (120 kV, n?=?30). Coronary arteries were assessed for significant stenoses (≥50 % luminal narrowing) and diagnostic accuracy was calculated.

Results

Per-patient overall sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were 96.9 %, 95.5 %, 93.9 %, 97.7 % and 96.1 %, respectively. Sensitivity and NPV were lower in groups B and D compared to groups A and C, but no statistically significant differences were observed (group A vs. B: sensitivity, 100.0 % vs. 93.3 %, p?=?0.9493; NPV, 100 % vs. 95.5 %, p?=?0.9812; group C vs. D: sensitivity, 100.0 % vs. 92.3 %, p?=?0.8462; NPV, 100.0 % vs. 94.1 %, p?=?0.8285).

Conclusion

CCTA using 3^rd-generation DSCT and (ATVS) provides high diagnostic accuracy in both non-obese and obese patients.

Key Points

? Coronary CTA provides high diagnostic accuracy in non-obese and obese patients. ? Diagnostic accuracy between obese and non-obese patients showed no significant difference.? <120 kV studies were performed in 44 % of obese patients. ? Current radiation dose-saving approaches can be applied independent of body habitus.

     

Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study

Purpose

Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA.

Methods

Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images.

Results

In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%–49%, 50%–69%, 70%–99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896–3.189, P < 0.001].

Conclusion

Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA.

     

Image quality and radiation dose of coronary CT angiography performed with whole-heart coverage CT scanner with intra-cycle motion correction algorithm in patients with atrial fibrillation

Objectives

To evaluate image quality, coronary evaluability and radiation exposure of coronary CT angiography (CCTA) performed with whole-heart coverage cardiac-CT in patients with atrial fibrillation (AF).

Materials and methods

We prospectively enrolled 164 patients with AF who underwent a clinically indicated CCTA with a 16-cm z-axis coverage scanner. In all patients CCTA was performed using prospective ECG-triggering with targeted RR interval. We evaluated image quality, coronary evaluability and effective dose (ED). Patients were divided in two subgroups based on heart rate (HR) during imaging. Group 1: 64 patients with low HR (<75 bpm), group 2: 100 patients with high HR (≥75 bpm). Written informed consent was obtained from all patients and the institutional ethics committee approved the study protocol.

Results

In a segment-based analysis, coronary evaluability was 98.4 % (2,577/2,620 segments) in the whole population, without significant differences between groups (1,013/1,024 (98.9 %) and 1,565/1,596 (98.1 %), for groups 1 and 2, respectively, p=0.15). Mean ED was similar in both groups (3.8±1.9 mSv and 3.9±2.1 mSv in groups 1 and 2, respectively, p=0.75)

Conclusions

The whole-heart-coverage scanner could evaluate coronary arteries with high image quality and without increase in radiation exposure in AF patients, even in the high HR group.

Key points

? Last-generation CT scanner improves coronary artery assessment in AF patients. ? The new CT scanner enables low radiation exposure in AF patients. ? Diagnostic ICA maybe avoided in AF patients with suspected CAD. ? Whole-heart coverage CT scanner enables low radiation exposure in AF patients.

     

Usefulness of paclitaxel-releasing high-pressure balloon associated with cutting balloon angioplasty for treatment of outflow stenoses of failing hemodialysis arteriovenous shunts

Aim

To evaluate the technical and clinical success, primary patency (PP) and complications of angioplasty performed with paclitaxel-coated balloon (PCBs) associated with cutting balloon and for the treatment of the outflow stenoses of failing hemodialysis arteriovenous shunt.

Material and methods

From September 2014 to September 2015, 50 patients with 66 stenoses were registered. Vascular accesses were autogenous (n = 20) and prosthetic (n = 30). Stenosis were documented during follow-up with routine echo-color Doppler, clinical evaluation and in the remaining incidentally during fistulography. Angioplasty was performed with cutting balloon and afterward with PCB. The mean follow-up time was 8 months (range 6–15 months). Technical success, clinical success, primary patency and complications were registered.

Results

Technical success was 100 %. Clinical success was 94.7 %. Primary patency rate was 87.7 %; in five patients, a significant re-stenosis (≥50 %) was registered. A residual asymptomatic stenosis (<30 %) was registered in four cases (7 %). No major complications were registered.

Conclusions

A short-term patency benefit may be obtained including PCB in angioplasty treatment of failing hemodialysis arteriovenous shunts.

     

Diagnostic performance of noninvasive fractional flow reserve derived from coronary computed tomography angiography in ischemia-causing coronary stenosis: a meta-analysis

Purpose

Fractional flow reserve based on coronary computed tomographic angiography (CCTA; FFR_CT) can evaluate functional severity in coronary artery disease (CAD). This study investigated the diagnostic value of FFR_CT for determining CAD severity.

Materials and methods

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until June 16, 2016 using the following search terms: fractional flow reserve, coronary computed tomography angiography, myocardial ischemia. Randomized controlled trials, two-arm prospective studies, and retrospective studies were included in the analysis.

Results

Twenty-one studies were included with a total of 2216 subjects and 2798 vessels. FFR_CT, sensitivity per-vessel and per-patient were ≥82% and specificity was ≥73% for diagnosis of ischemia. FFR_CT had better diagnostic accuracy and discrimination than CCTA.

Conclusion

This study indicates that FFR_CT may be a good tool for screening and diagnosing of myocardial ischemia in patients with CAD.

     

Right and left ventricular uptake with Rb-82 PET myocardial perfusion imaging: Markers of left main or 3 vessel disease

Background

Relative myocardial perfusion imaging may underestimate severity of coronary disease (CAD), particularly in cases of balanced ischemia. Can quantification of peak left (LV) and right (RV) ventricular Rb-82 uptake measurements identify patients with left main or 3 vessel disease?

Methods

Patients (N = 169) who underwent Rb-82 PET MPI and coronary angiography were categorized as having no significant coronary stenosis (n = 60), 1 or 2 vessel disease (n = 81), or left main disease/3 vessel disease (n = 28), based on angiography. Maximal LV and RV ventricular myocardial Rb-82 uptake was measured during stress and rest.

Results

Failure to augment LV uptake by ≥ 8500 Bq/cc at stress, predicted left main or 3 vessel disease with a sensitivity of 93% and specificity of 61% (area under curve = 0.83). A ≥10% increase in RV: LV uptake ratios with stress over rest was 93% specific (area under curve = 0.74) for left main or 3 vessel disease. These indices incrementally predicted left main or 3 vessel disease compared to models including age, gender, cardiac risk factors, and summed stress and difference scores.

Conclusion

Quantifying maximal rest and stress LV and RV uptake with PET myocardial perfusion imaging may independently and incrementally identify patients with left main or 3 vessel disease.